Australian Medicinal Plants
Australian Medicinal Plants
Australian Medicinal Plants
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I.E.Cocka,b*
a
Biomolecular and Physical Sciences, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan,
b
Genomics Research Centre, Gold Coast Campus, Griffith University, Parklands Drive, Southport,
Dedication
Abstract
1.2.1. Terpenes
Components
5. Toxicity, Crossreactivity And The Safe Use Of Medicinal And Aromatic Plants
6. Conclusion
References
Glossary
List of Tables
Figure 1: The structure of isoprene, the basic unit of terpenes and terpenoids
of Eucalyptus leaves
essential oils
Figure 13: Leptospermum scoparium entire plant and close up of foliage and flowers
Figure 21: Acacia aulocarpa tree, Acacia aulocarpa foliage and flowers,
Acacia complanta foliage, and Acacia complanta with open seed pods
Figure 23: Scaevola spinescens (a) whole plant and (b) foliage and berries
Figure 35: Adasonia gregorii tree (cultivated) in summer with full leaf growth
Melia azedarach
Figure 37: Melia azedarach whole tree and leaves and flowers
Biography of Dr Ian Cock
Dr Ian Cock obtained his PhD for studies in reproductive biology/immunology into “Early
Pregnancy Factor (EPF)” and very early pregnancy detection from Griffith University,
Brisbane, Australia in 1994. Following his PhD studies, Dr Cock undertook postdoctoral
studies into cytochrome’s P450 and multiple drug interactions in the Department of
Biochemistry and in the Department of Physiology and Pharmacology, both at the University
has taught and developed a number of courses across three campuses of Griffith University
since this time. His teaching broadly encompasses biochemistry, biological chemistry, cell
biology, immunology, plant biology and biotechnology. Specific areas of expertise and
interest include metabolism and its regulation, phytochemistry and natural product discovery,
redox biochemistry and redox control systems, protein structure/function, enzymology,
Dr Cock currently also leads a research team in the Department of Biomedical and
Biophysical Sciences at Griffith University. The Griffith University research team is involved
in bioactivity and phytochemical studies into a variety of plant species of both Australian and
international origin. The current research interests of this team involve bioactivity, structural
and mechanistic studies into the medicinal potential of Aloe vera, South Asian and South
Syzygiums, Petalostigmas and Xanthorrhoea johnsonii (grass trees). This range of projects
Cock is also a member of the editorial boards of four scientific journals, including being the
Affiliations
Plants contain a myriad of natural compounds which exhibit important bioactive properties. These
compounds may provide alternatives to current medications and afford a significant avenue for new
drug discovery. As a result of geographic isolation, Australia is home to a large variety of unique and
distinct flora not found elsewhere in the world. Due to the harsh conditions seen in many parts of
Australia, plants have developed unique survival methods and phytochemicals specific to the
environmental conditions they inhabit and may hold the key to the treatment of many diseases and
medical conditions. Herbal medicines have played an important role in the health, culture and
traditions of Australian Aboriginal people prior to the arrival of Europeans. Much of our
understanding of the medicinal potential of Australian native plants is from accounts of Aboriginal
disappearing as the Aboriginal culture merges into main stream society and the passing of oral
traditions between each generation diminishes. Given the diverse nature of the flora present and the
diminishing traditional knowledge, Australian plants remain relatively unstudied and it is surprising
Much of our understanding of Australian medicinal plants is fragmented. With the exception of
Lassak and McCarthy’s book “Australian Medicinal Plants” and various early colonial texts (such as
the 1889 work “The Useful Plants of Australia” by Maiden) which describe Aboriginal and early
and government reports. Whilst readily available to scientific researchers in this field, much of this
information is difficult to obtain for interested lay persons. Furthermore, the Lassak and McCarthy
and the Maiden texts deal almost exclusively with our understanding of Australian
knowledge of Australian medicinal and aromatic plants. The ethnoparmacologies of various groups,
from Aborigines, to early colonial settlers, to later migrant ethnopharmacologies are explored and
tabulated as quick reference sources. Knowledge of Australian medicinal plants phytochemistry and
mechanisms of action are also summarised, particularly where relating to the aromatic Australian
plants (eg. Eucalypts, Melaleukas, Leptospermums etc). This volume also provides an introduction to
current scientific studies into Australian medicinal plants (with specific examples) and some of the
techniques used in the hopes of stimulating interest and further studies in this field.
I.E.Cocka,b*
a
Biomolecular and Physical Sciences, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan,
b
Genomics Research Centre, Gold Coast Campus, Griffith University, Parklands Drive, Southport,
Plants have a long history of being used for a wide variety of purposes including food, clothing,
shelter, tools, weapons and as therapeutic agents. Before the advances of modern medicine,
civilizations confronted with illness and disease discovered a wealth of useful therapeutic agents
from within the plant and fungi kingdoms. Knowledge of these medicinal preparations and of their
toxic potential was passed down through generations by oral tradition and sometimes recorded in
herbal literature. The earliest records outlining mans usage of plant medications are more than 6000
years old. Sumerian clay tablets (4000 BC) detail 1000 medicinal plants and plant remedies (Afzal and
Armstrong, 2002; Levetin and McMahon, 2003). The Pun-tsao, a Chinese record of thousands of
herbal cures dates to 2500 BC. The Hippocratic Corpus (a collection of medical texts of herbal
remedies) by Greek physician Hippocrates was recorded in the late fifth century BC and the Roman
writings De Materia Medica by Dioscorides, document more than 600 plant species with medicinal
value (Levetin and McMahon, 2003). These records have more value than merely as an
Many developing cultures (particularly Asian and African) have assimilated herbal medicine into
their primary modality of health care (Farnsworth et al., 1985) and herbal medications remain an
important component of their medicinal systems. By documenting and practicing traditional
medicine these cultures have accumulated comprehensive ethnobotanical data and improved their
skills over time. Today, Ayuvedic medicine is still commonly practiced within India with an estimated
85% of Indians still using crude plant formulations for the treatment of various diseases and ailments
(Kamboj, 2000).
understanding of plant based remedies. Table 1 lists some commonly used allopathic drugs derived
from plants. The listed drugs have widespread medicinal uses including as analgesics, central
agents, cardiac drugs, cholesterol lowering agents, anti-diabetic agents, as well as psychoactives.
This is merely a sampling of current plant derived pharmaceuticals and serves only to illustrate the
importance of herbal derived medicines and semi-synthetic drugs derived from purified
phytochemicals to allopathic medicine. Indeed, it has been estimated that approximately 25% of all
prescription drugs currently in use are originally derived from plants (Hostettmann and Hamburger,
1993; Newman et al., 2000; Walsh, 2003). Furthermore, approximately 75% of new anticancer drugs
marketed between 1981 and 2006 are derived from plant compounds (Newman et al., 2000).
As a result of geographic isolation, Australia is home to a large variety of unique and distinct flora
not found elsewhere in the world. Due to the harsh conditions seen in many parts of Australia,
plants have developed unique survival methods specific to the environmental conditions they
inhabit. Australian Aborigines had developed a good understanding of the botany in their local areas
and have used a variety of plant medicines to help maintain their health for approximately 40, 000
years (Barr et al., 1993; Lassak and McCarthy, 2006). However, traditional Australian Aboriginal
knowledge of plants as therapeutics is disappearing as the Aboriginal culture merges into main
stream society and the passing of oral traditions between each generation diminishes (Lassak and
McCarthy, 2006). Given the diverse nature of the flora present and the diminishing traditional
knowledge, Australian native plants remain relatively unstudied and it is surprising more research is
not being undertaken. There is a very real need to document the traditional usage of Australian
This volume aims to document and summarise the current understanding of Australian aromatic and
medicinal plants and to stimulate further research in this field. Before undertaking a description of
the usage of Australian native plants, it is necessary to understand the classes of phytochemicals
present in plants and the divergent evolution that has resulted in Australia’s high degree of endemic
species. Many of these species live in extremely harsh environments, making them candidates for
scientific examination.
Plants have evolved to synthesise an extremely diverse range of chemical compounds known as
secondary metabolites. These secondary metabolites have no apparent role in primary plant growth
or development processes, are often unique to plants from a single species and increase during
times of high stress such as drought, fire and bacterial infection (Taiz and Zeiger, 2006). Many of
these compounds exhibit anti-microbial, anti-oxidant, cytotoxic and other medicinally useful
properties (Taiz and Zeiger, 2006). These activities can be attributed to the presence of a variety of
phytochemical constituents, which can be divided into three main chemically distinct groups:
properties common to the three major classes overlap (eg. a phenolic compound may contain
nitrogen, making it both a phenolic compound and an alkaloid). Proanthocyanidins are examples of
tannins (phenolic compounds) which contain nitrogen and are found in Australian Acacia species.
Similarly, terpenes present within the essential oils from a variety of Australian plant species (eg.
Eucalyptus and Melaleuca species) may be considered both terpenes and phenolics as they structure
1.2.1. Terpenes
Terpenes or terpenoids are formed by the union of five carbon elements (isoprene units) (Figure 1)
H3C
H3C CH3
Figure 1: The structure of isoprene, the basic unit of terpenes and terpenoids.
The union of two isoprene units forms a monoterpene. Examples of well known monoterpenes
include limonene (lemon oil) (Figure 2a) and menthol (peppermint oil) (Figure 2b) which provide
defence against potential predators and are sometimes used as food flavouring agents (Taiz and
Zeiger, 2006). Monoterpenes can undergo further modification to form sesquiterpenes (15 carbon
units), diterpenes (20 carbon units) and polyterpenes (many carbon units).
Terpenes are toxins which act as feeding deterrents to many plant feeding insects and mammals and
are relatively insoluble in water (Taiz and Zeiger, 2006). Pyrethroids for example, are a class of
terpenes which exhibit toxicity as well as insecticidal and anti-microbial activities. They occur in the
leaves and flowers of Chrysanthemum species (Taiz and Zeiger, 2006). They are often used as a
component of insecticides due to their low persistence in the environment and negligible toxicity to
mammals (Taiz and Zeiger, 2006). Recent research has shown that some terpenes are only produced
and emitted from the plant after insect feeding has begun (Taiz and Zeiger, 2006). These substances
may have no effect on the insects that stimulated their production, but increase resistance to future
attack, or they may attract predatory and parasitic insects which in turn kill the plant feeding insects
Many Australian plants contain mixtures of terpenes known as essential oils. In particular, the
essential oils of members of the family Myrtaceae (Eucalypts, Melaleucas, Leptospermums and
Callistemons) are known to be particularly rich in terpenes. These plants, their medicinal uses and
their phytochemistry will be described separately in more detail in later sections of this volume. The
terpene containing essential oils of these plants add a characteristic odour and flavour to plant
foliage and some therefore may be used as food flavouring agents. Some essential oils possess a
broad spectrum of anti-microbial activities and may be used to fight against pathogens (Deininger,
Phenolic compounds are secondary metabolites that contain a phenol group (Figure 3).
OH
isoflavones, flavonols, anthocyanins, coumarins, chalcones and phytoelaxins (Figure 4). In plants,
phenolic compounds act as a defence mechanism against herbivores and pathogens, attract
pollinators, absorb UV radiation, minimise oxidative stress and reduce the growth of nearby
(e) Coumarins.
The function of phenolic compounds varies greatly. Flavones and flavonols (Figure 4a and 4c) are
present in the leaves of all green plants and protect them from UV damage by absorbing light in the
shorter wavelengths (Taiz and Zeiger, 2006). Anthocyanins (Figure 4d) are pH dependent coloured
flavonoids which attract pollinators (Taiz and Zeiger, 2006) whilst isoflavones/isoflavonoids (Figure
4b) exhibit strong antimicrobial activity (Taiz and Zeiger, 2006). Isoflavones and isoflavonoids have
also been identified for use in the treatment of a wide range of health conditions such as
Tannins may act as general toxins that reduce growth and survival of many herbivores when added
to their diet (Taiz and Zeiger, 2006). Tannins inhibit the growth of many fungi, yeast, bacteria and
viruses and have also been suggested as anti-carcinogens (Scalbert, 1991). Tannic acid and propyl
gallate inhibit food borne, aquatic and off-flavour-producing micro-organisms (Scalbert, 1991). In
contrast, foods containing tannins (eg. tea tannins) are regularly consumed by humans and have
been shown to promote health rather than hinder it (de Mejia et al., 2009).
Phytoalexins are antibiotics produced by plants when under stress. They exhibit strong antimicrobial
activity and are generally undetectable before initial infection. They are synthesized very rapidly
after microbial attack and accumulate around the site of infection (Taiz and Zeiger, 2006).
Phytoalexins from different plant families can be produced as different secondary metabolites eg.
Capsidiol (from pepper and tobacco; Figure 5a) is a sesquiterpene whilst resveratrol (from grape
skin; Figure 5b) is an isoflavonoid. Because of its structural resemblance to estrogen, resveratrol
exhibits agonistic and antagonistic activities towards the estrogen receptor and it has been
suggested that resveratrol could reduce localized estrogen production in breast cancer cells (Wang
et al., 2006). Resveratrol also displays chemo-preventive activity by inhibiting, delaying or reducing
The interaction of several flavonoids with ATP-binding cassette (ABC) transporters such as P-
glycoprotein (Di Pietro et al., 2002), multi drug resistance associated protein 1 (Leslie et al., 2001),
and Breast Cancer Resistance Protein (BCRP) (Zhang et al., 2004) (which are believed to limit the
intracellular accumulation of cytotoxic agents in cancer cells when over expressed) have been
reported. These same flavonoids have been shown to modulate breast cancer resistance protein
BCRP on a transcriptional level in Caco-2 and MCF-7 cells (Ebert et al., 2007). The flavonoid, acacetin-
Many Australian plants are known to contain high levels of phenolic compounds. These plants, their
medicinal uses, and their phytochemistry will be described in more detail in later sections of this
volume.
removing free radical intermediates or inhibiting other oxidation reactions by becoming oxidized
themselves. Free radicals or Reactive Oxygen Species (ROS) are highly reactive compounds that
damage cells and are created by both the external environment (eg. smoking, UV radiation and
stress) and the internal environment (eg. purine metabolism or adrenaline synthesis) (Herna´ndez et
al., 2008).
In order to minimize oxidative stress-related trauma, ROS homeostasis in plants is tightly regulated.
It has been suggested that phenolic compounds such as flavonoids, coumarins, phenolic acids,
tannins, and phenolic diterpenes act as antioxidants through two mechanisms (Herna´ndez et al.,
2008): by protecting plants from oxidative stress by scavenging free radicals such as ROS, and by
Through these mechanisms, antioxidants protect cells against oxidative stress related damage,
thereby maintaining the redox homeostasis of biological fluids and preventing disease (Rice-Evans et
al., 1996; Rice-Evans, 2001; Miniati, 2007; Hsu and Yen, 2008). Antioxidants have been found to play
an important role in the reduction of atherosclerosis, inflammatory injury, cancer (Hertog et al.,
1996; Lambert et al., 2005), cardiovascular disease (Geleijnse et al., 2002) and neurological
degenerative disorders such as Alzheimer’s and Parkinson’s disease (Youdim et al., 2002). They are
also linked with anti-diabetic bioactivities (Matsui et al., 2002) and have been associated with the
reduction of obesity (Tsuda et al., 2003). In addition, flavonoids are inhibitory to a variety of human
pathogens including bacteria, fungus and viruses (Bylka et al., 2002). Studies have shown that many
dietary phenolic constituents derived from plants are more effective antioxidants in vitro than
standards used for determining antioxidant activity such as vitamin C or vitamin E (Wu et al., 2008).
Several Australian plants have been identified as having particularly high levels of phenolic
antioxidants (Netzel et al, 2007; Netzel et al, 2006). These are described in more detail in section
2.1.4.
Nitrogen containing compounds (alkaloids) are secondary metabolites which are biosynthesized
from common amino acids. The basic structure of a phenolic alkaloid is shown in Figure 6. Alkaloids
are of considerable interest due to their unique properties and include many subclasses such as
cyanogenic glycosides.
N
OH
Morphine (Figure 7a), the first medically useful alkaloid identified, was isolated from Papaver
somniferum (opium poppy) in 1805 (Fessenden and Fessenden, 1982). Other major alkaloids include
cocaine (Figure 7b), nicotine (Figure 7c) and caffeine (Figure 7d).
Figure 7: Structures of (a) morphine, (b) cocaine, (c) nicotine and (d) caffeine.
Alkaloids are found in approximately 20% of vascular plant species and are thought to be effective
defences against browsing animals. Pyrrolizidine alkaloid (isolated from Heliotropium subulatum
extracts) shows antimicrobial activity against both fungal and bacterial species (Craig, 1998).
Biologically active carbazole alkaloids (from Murraya koenigii) display mosquitocidal and anti-
microbial activities as well as exhibiting topoisomerase I and II inhibition activities (Ramsewak et al.,
1999). Although these compounds are lethal when administered in high doses, they have
pharmacological uses as medicines, stimulants or sedatives at lower doses. Another medically useful
alkaloid, digoxin, is produced within the leaves of the plant genus Digitalis. This cardiac glycoside is
used as an antiarrhythmic agent to control heart conditions such as atrial fibrillation, atrial flutter
Many Australian plants contain bioactive alkaloids. The bark of Australian Acacia species (family
Fabacea, subfamily Mimosoideae) in particular has been shown to contain high levels of nitrogenous
tannins. For example, Acacia mearnsii (Black Wattle) bark contains 20-40% tannins by weight, of
which up to 70% are proanthocyanidins (Tindale and Roux, 1969). The phytochemistry and known
medicinal bioactivities of these and other plants is discussed separately in more detail in later
Australian flora is unique, with many species not occurring naturally in any other part of the world.
Prior to the mid-Jurassic period (about 170 million years ago) Australia was part of a super continent
called Gondwana which contained most of today’s southern hemisphere land masses as well as India
and Arabia (which are today in the northern hemisphere) (Meert, 2003; Cattermole, 2000). Free
movement of living organisms was possible throughout Gondwana and biodiversity patterns were
uniform throughout the supercontinent. Indeed, the Jurassic flora of Australia is thought to be very
similar to other regions of Gondwana (Adam, 1992). During the late Jurassic period East Gondwana
(Australia, Antarctica, India and Madagascar) split from West Gondwana (Africa and South America)
(Meert, 2003). Approximately 120 million years ago India and Madagascar split from East Gondwana
and began to move north. Australia split from Antarctica more than 40 million years ago effectively
isolating it from the rest of the world. This isolation allowed Australia’s flora to evolve separately
The Greening of Gondwana (White, 1998) provides an in depth study of the evolution of Australian
plants from the time of the supercontinent to present day. During the Cretaceous period, Australia
experienced warm, moist conditions and rainforests were prevalent across much of the continent.
Later, in the Tertiary period, Australia became drier and there was an increase in flora evolution and
many new species arose to adapt to the environmental conditions. Eucalypts and Acacias are
thought to have evolved during this time in response to the dry conditions and nutrient deficient
soils. Approximately 15 million years ago as Australia and South East Asia moved closer together, an
invasion of plant taxa from the north occurred, accounting for the taxonomic similarities between
South East Asian and Australian northern tropical rainforest plants. Apart from this invasion,
Australia’s isolation has resulted in a high degree of endemism. Many of Australia’s plants are
already known to have medicinal properties and some have been used by Australian Aborigines for
over 40 000 years. Whilst the world looks towards South American rainforests for new wonder
drugs, the possibility exists that the unique plants that have evolved in the harsh Australian
conditions may also hold the key to the treatment of many diseases and medical conditions.
The usage of Australian plants for the treatment of illness and injury falls into four main categories:
2.1.1. Indigenous Australian (Aboriginal) Ethnopharmacology.
Prior to European settlement in Australia, the Aboriginal people used a variety of plant medicines to
help maintain their health (Barr et al., 1993; Lassak and McCarthy, 2006). It has been suggested that
Aborigines needed relatively little medication prior to the arrival of European settlers due to their
generally good health (Lassak and McCarthy, 2006). Some of the commonly used Aboriginal
medicinal plants are outlined in Table 2. This is not a complete listing. Many of the early reports
insufficiently or incorrectly described the taxonomy of the medicinal plants. Furthermore, many
plants had different uses for different Aboriginal groups in different regions of Australia. Where
plant identity or usage is in doubt, listings were omitted. Plants used by European or later settlers
and Australian native plants used exclusively in other parts of the world are dealt with elsewhere in
this volume.
Aborigines treated their occasional bouts of diarrhoea and dysentery with astringents such as
Eucalyptus astringents. Fever was treated with a wide variety of plants, dependent on what was
locally available. Toothache was relatively common due to a tough, fibrous diet, particularly amongst
the elderly, and was treated by a wide variety of plant medications. Sore and infected eyes were
some of the major problems faced by Australian Aborigines. Arguably the major health threat faced
by Aborigines was bacterial infection (Roth, 1903). The commonness of this complaint is reflected in
the number of plants Aborigines used as antiseptics. Much of the information about the
antimicrobial activities of Australian plants is anecdotal although research into the antiseptic nature
of Australian plants is receiving recent attention (Cock, 2008; Palombo and Semple, 2001; Setzer et
al., 2000). However, still only a few of the Aboriginal medicinal plants have undergone rigorous
scientific investigation to confirm their antimicrobial activities. One study (Palombo and Semple,
2001) examined a panel of plant extracts commonly used by Australian Aboriginals and found
approximately 20% of the samples tested were able to inhibit bacterial growth. This group has also
demonstrated the antiviral activity of the same panel of Australian plants (Semple et al., 1998).
There are many other Australian plants, some used by Australian Aborigines, that have not been
With the arrival of European settlers, infectious diseases (eg. measles, mumps, chicken pox and
venereal diseases) were introduced and caused major health problems in a population with no prior
exposure (Lassak and McCarthy, 2006). The Aborigines actively sought and developed plant
medications in an attempt to combat these introduced illnesses. See for example, the relatively large
number of plant medications used to treat venereal diseases by the Aborigines (Table 2), all of which
Table 2: Botanical names of plant species used by Australian Aborigines and their traditional
medicinal uses.
Amaryllidaceae
(1979)
Apiaceae
Apocynaceae
Tabernaemontana orientalis sap, fruit antiseptic, skin sores Webb (1959), Roth (1903)
Araceae
Asclepiadaceae
Asteraceae
Centipeda cunninghamii whole plant cold, skin infections Zola and Gott (1992),
Centipeda minima whole plant sore eyes, colds Reid and Betts (1979)
Centipedia thespidioides whole plant colds, sore throat, sore Webb (1969)
eyes
Pseudognaphalium
luteoalbum whole plant general illness Palmer (1883)
headache
cold, respiratory
Pterocaulon sphacelatum aerial portions of plant infections, Latz (1995), Barr et al. (1993),
Araucariaceae
Boraginaceae
bite
Burseraceae
Cabombaceae
Caesalpiniaceae
Senna pleurocarpa leaves, seed pods laxative Lassak and McCarthy (2006)
Campanulaceae
Isotoma petraea whole plant respiratory complaints Barr et al. (1993), Smith (1991)
Capparidaceae
insect bites/stings
Cleome viscosa whole plant colds, rheumatism, pain Reid and Betts (1979)
Casuarinaceae
dysentery, mouthwash
Chenopodiaceae
Convolvulaceae
Evolvulus alsinoides stems, roots, leaves pain, dysentery, fever Johnson and Cleland (1943),
Maiden (1889)
Merremia tridenta whole plant sores, antiseptic Roth (1903)
Cucurbitaceae
Mukia maderaspatana whole plant skin sores, pain relief Latz (1995), Low (1990)
Silberbauer (1971)
Cycadaceae
Cyperaceae
Dennstaedtiaceae
Pteridium esculentum stems, leaves insect bites, rheumatism Hegnauer (1962), Webb (1948)
Eucryphiaceae
Euphorbiaceae
Beyeria lechenaultii aerial portions of plant fever, general illness Webb (1969)
tuberculosis
Breynia stipitata leaves sore eyes Webb (1959)
Euphorbia alsiniflora whole plant dysentery, fever Lassak and McCarthy (2006)
Euphorbia atoto flowers, sap sore throat Reid and Betts (1979)
Euphorbia australis whole plant skin sores, antiseptic Latz (1995), Reid and Betts (1979)
Euphorbia coghlanii sap skin sores, skin cancer Reid and Betts (1979)
Euphorbia drummondii whole plant skin sores, genital sores, Latz (1995), Reid and Betts (1979)
intestinal worms,
dysentery, Maiden (1889)
colic warts
Excoecaria parvifolia bark pain, general illness Lassak and McCarthy (2006)
chicken pox
Fabaceae
Crotalaria eremaea aerial portions of plant general illness Barr et al. (1993), Goddard and
Kalotas (1988)
Crotalaria cunninghamii bark, leaves headache, sore eyes Reid and Betts (1979)
Flagellariaceae
Goodeniaceae
Scaevola spinescens stem, leaves skin sores, boils, pain Lassak and McCarthy (2006),
(1939)
Scaevola taccada fruit, leaf tinea, skin sores Lassak and McCarthy (2006),
Webb (1959)
Gyrostemonaceae
Codonocarpus cotinifolius stem, leaves skin sores, pain relief, Barr et al. (1993), Smith (1991)
respiratory complaints
Haemodoraceae
Hernandiaceae
rheumatism
Lamiaceae
Ajuga australis whole plant skin sores, boils Lassak and McCarthy (2006),
Basilicum polystachyon aerial portions of plant fever Lassak and McCarthy (2006),
Prostanthera striatifloria aerial portions of plant respiratory infection, Latz (1995), Barr et al. (1993),
Mentha diemenica whole plant menstrual disorders, Hager (1930), Maiden (1889)
insecticide
general internal
Plectranthus congestus leaves complaints Roth (1903)
Prunella vulgaris leaves cuts, antiseptic, fever Gildemeister and Hoffmann (1961)
Ewart (1930)
Lauraceae
Litsea glutinosa bark, leaf skin sores, scabies, pain Webb (1969), Webb (1959)
infections, antiseptic
Lecythidaceae
Barringtonia calyptrata leaves fever, pain Webb (1969)
Roth (1903)
Liliaceae
Lobeliaceae
Loranthaceae
Amyema maidenii whole plant genital inflammation Cleland and Johnston (1939)
Malvaceae
Menispermaceae
Mimosaceae
Acacia beauverdiana ash from burnt wood pain Reid and Betts (1979)
Woolls (1867)
Acacia kempeana bark, leaves chest infection, cold, Latz (1995), Barr et al. (1993),
Acacia monticola roots, twigs colds, coughs Reid and Betts (1979)
Acacia tetragonophylla stem, leaves cough, wound treatment, Reid and Betts (1979)
dysentery
Acacia transluscens leaves, twigs skin sores, headache Reid and Betts (1979)
Moraceae
Myoporaceae
Eremophilia alternifolia stem, leaves general illness, pain Palombo and Semple (2001)
Eremophilia duttonii stem, leaves respiratory infection, Palombo and Semple (2001)
(1983)
toothache
Eremophilia freelingii stem, leaves cough, pain fever, cuts Palombo and Semple (2001)
Eremophilia latrobei stem, leaves respiratory infection, Palombo and Semple (2001)
(1983)
Eremophilia longifolia stem, leaves respiratory infection, eye Latz (1995), Barr et al. (1993),
(1889)
respiratory infection,
Eremophilia sturtii stem, leaves cough, Palombo and Semple (2001)
Myrtaceae
Lauterer (1895)
Asteromyrtus symphyocarpa leaves liniment, headache, pain, Lassak and McCarthy (2006),
Eucalyptus camaldulensis bark (gum), leaves diarrhoea Campbell (1973), Maiden (1922)
Eucalyptus haemastoma bark (gum) dysentery, cuts, wounds, Lassak and McCarthy (2006),
antiseptic
Eucalyptus papuana bark colds, sore eyes Reid and Betts (1979)
Eucalyptus racemosa bark (gum) dysentery, cuts, wounds, Lassak and McCarthy (2006),
astringent (1895)
Eucalyptus sclerophylla bark (gum) dysentery, cuts, wounds, Lassak and McCarthy (2006),
antiseptic
Eucalyptus signata bark (gum) dysentery, cuts, wounds, Lassak and McCarthy (2006),
antiseptic
diarrhoea, fever,
Eucalyptus tetrodonta bark, wood, leaves headache, Webb (1969)
influenza
Eucalyptus terminalis bark (gum) diarrhoea, chest pains Reid and Betts (1979)
tooth ache
headaches, colds,
Melaleuca quinquenervia leaves coughs, Lassak and McCarthy (2006),
Myristicaceae
Orchidaceae
Papilionaceae
Pittosporaceae
Poaceae
respiratory infections,
Cymbopogon ambiguus leaves pain, Latz (1993), Barr et al. (1993),
wash
Cymbopogon obtectus aerial portions of plant respiratory infections Barr et al. (1993), Smith (1991)
Proteaceae
Grevillea pyramidalis bark skin sores, antiseptic Reid and Betts (1979)
Hakea suberea bark skin and mouth sores Barr et al. (1993), Smith (1991)
Persoonia falcata bark, leaves sore throats, colds, sore Webb (1969), Webb (1959)
eyes
Ranunculaceae
Rhamnaceae
Ventilago viminalis bark, root toothache, rheumatism Reid and Betts (1979)
Rhizophoraceae
Rosaceae
Rubiaceae
Timonius timon wood, bark sore eyes, colds, fever Webb (1969)
Rutaceae
Maiden (1889)
diseases, malaise
Sapindaceae
Scrophulariaceae
Scoparia dulcis whole plant malaria, fever, stomach Webb (1969), Maiden (1889)
Stemodia grossa leaves colds, headache, pain Reid and Betts (1979)
Smilacaceae
Solanaceae
Solanum lasiophyllum roots poultice for swelling Reid and Betts (1979)
Sterculiaceae
Thymelaeaceae
(1897)
Tiliaceae
diarrhoea, dysentery,
Grewia retusifolia fruit, root, leaves boils, Lassak and McCarthy (2006),
Urticaceae
Verbenaceae
Verbena officinalis whole plant fever, rheumatism, pain, Maiden (1889), Woolls (1867)
venereal diseases
Vitaceae
Zingiberaceae
European settlers arriving in Australia bought with them a tradition of herbal drug usage from their
countries of origin. In particular, aromatic and bitter tasting remedies were highly reputed by early
European settlers (Lassak and McCarthy, 2006). Many European remedies of the time were based on
plant preparations. When European settlers arrived in Australia, they actively sought out Australian
plants with similar aromatic and/or bitter taste characteristics to the plants from their homelands
(Maiden, 1889). The search for plants with these characteristics was fortuitous as the bitter taste
and ‘sharp’ aroma of some plants is often due to the presence of nitrogenous containing alkaloids.
Many studies have demonstrated the medicinal value of alkaloids when used in small doses (Jansen
et al., 2006; Sener et al., 2003; Citoglu et al., 1998; Yui et al., 1998). However, these same alkaloids
can be toxic in larger doses (Jansen et al., 2006; Dweck, 2001; Hall et al., 2001; Weniger et al., 1998;
Nanayakkara et al., 1988). Hence caution is necessary when using alkaloid containing plant
preparations.
Unlike indigenous ethnomedicinal usage, settler plant usage is well documented (Bailey, 1909; Roth,
1903; Maiden, 1889; Woolls, 1867; Bailey, 1883; Bailey 1881). Such literature is invaluable as it
indicates plants that early European settlers deemed medicinally important and point to plants that
should be investigated as possible sources of phytomedicines. Surprisingly, few of these plants have
been thoroughly scientifically investigated to date. The known plants used by settlers are
summarised in Table 3. This by no means is a complete listing. Where plant identity or usage is in
doubt, listings were omitted. Plants used exclusively by overseas populations and not by immigrants
Table 3: Botanical names of plant species used by Australian settlers/immigrants and their medicinal
uses.
Apocynaceae
Alstonia constricta bark tonic fever, malaria Webb (1948), Maiden (1889)
Asclepiadaceae
Asteraceae
Chinese immigrants)
Brassicaceae
Burseraceae
Canarium muelleri resin cuts, skin sores, ulcers Bailey (1909)
Caesalpiniaceae
Chenopodiaceae
Atriplex nummularia whole plant scurvy, blood diseases Lassak and McCarthy (2006)
Monimiaceae
Atherosperma
moschatum bark laxative, tonic, diuretic Lassak and McCarthy (2006),
Maiden (1889)
Euphorbiaceae
Euphorbia alsiniflora whole plant dysentery, fever Lassak and McCarthy (2006)
wounds (Chinese
Omalanthus populifolius leaves settlers) Webb (1948)
Gentianaceae
Lamiaceae
Myrtaceae
Eucalyptus gummifera bark antiseptic Maiden (1907)
Eucalyptus terminalis bark (gum) diarrhoea, chest pains Reid and Betts (1979)
neuralgia, rheumatism,
toothache, earache
headaches, colds,
Melaleuca quinquenervia leaves coughs, Lassak and McCarthy (2006)
Portulacaceae
Portulaca oleracea whole plant blood cleanser Lassak and McCarthy (2006)
Proteaceae
Ranunculaceae
Clematis microphylla aerial portions of plant sores, gastric disorders Clarke (1987)
Rosaceae
Rubiaceae
Rutaceae
Smilacaceae
blood purifier
Winteraceae
There is considerable overlap between the plants used by early European settlers and Aborigines.
For example, many plants of the family Myrtaceae (especially Eucalypts and Melaleucas) were used
by both groups, especially as antiseptic agents and to treat colds and coughs. It is not clear how
much the early European settlers learnt from Aborigines. In fact, some early reports indicate that the
new settlers were largely unwilling to try Aboriginal treatments (Lassak and McCarthy, 2006). The
language barrier also prevented communication of plant medications between the Aboriginal and
settler populations. Even when settlers did learn of medicinal plants from Aborigines, they were not
always effective as the method of preparation and usage of plant medicines is also important to
their effect. Lassak and McCarthy (2006) describes a case where an early settler, having heard of
Aborigine usage of Planchonia careya bark as an antiseptic, prepared the medication by shredding
the hard outer bark into water and making an infusion. Instead, the Aborigines used to prepare an
infusion from only the inner bark. The settler’s preparation proved of little use, possibly due to these
preparation differences.
Later migration to Australia by people from diverse regions has also bought a wealth of further
knowledge of plant medicinal use. All world populations have developed their own plant based
medical systems. In particular, Asian emigration bought a far wider understanding of the therapeutic
potential of plants. Plant medicinal use in India (eg. Ayurveda) and traditional Chinese medicinal
plant use are particularly well documented (Patwardhan et al, 2005; Khan and Balick, 2001) and will
not be dealt with here. Similarly, African (Iwu, 1993), Middle Eastern (Ghazanfar, 1994), North
American (Moerman, 1998) and South American (Roth and Lindorf, 2002) populations have well
established phytomedicinal systems. Immigrants from these regions have bought with them their
own systems of medicinal plant use, all of which have added to our understanding of Australian
Many Australian plant species are widely distributed around the world, occurring both naturally and
as introduced species. Some species occur naturally in South East Asia and India and as far away as
Africa and the Middle East. Other species have been introduced into a variety of locations as
commercially useful species (eg. Eucalypt introduction into Portugal and North America) and in some
cases are considered invasive (Santos, 1997). There is often overlap between plant usage in Australia
and in overseas populations. For example, Euphorbia atoto was used by Australian Aborigines as well
as by Indian and Arabian healers as a herbal medicine (Reid and Betts, 1979; Bailey, 1883). However,
there are no records of the therapeutic use of some plants in Australia which have been used
medicinally in other parts of the world. Table 4 summarises the use of Australian native plants in
overseas populations. This is by no means a complete listing. Where plant identity or usage is in
Table 4: Botanical names of plant species used by overseas populations and their medicinal uses.
Adiantaceae
astringent, chest
Adiantum aethiopicum whole plant infections Hager (1930), Maiden (1889)
(Europe)
Amaranthaceae
Deeringia
amaranthoides leaves measles (Indonesia) Webb (1948)
Anacardiaceae
Semecarpus
australiensis juice, nut rheumatism, warts, Maiden (1889)
asthma (India)
Apocynaceae
(India)
narcotic, purgative,
Cerbera manghas nuts, bark, leaves laxative Maiden (1889)
(Java)
Araceae
Eclipta prostrata roots liver complaints (India), Hurst (1942), Bailey (1909)
Asteraceae
Ageratum conyzoides whole plant wounds (Nigeria) Adesogan and Okunade (1979)
Wedelia calendulaceae whole plant tonic (Sri Lanka) Webb (1948), Bailey (1909)
Boraginaceae
Trichodesma
zeylanicum whole plant diuretic, snake bite (India) Bailey (1881)
Caesalpiniaceae
Cynometra ramiflora root, leaves purgative, leprosy, Webb (1948), Maiden (1889)
scabies (India)
Capparidaceae
Vietnam)
Casuarinaceae
(China)
Commelinaceae
Convolvulaceae
Cucurbitaceae
Cyperaceae
(India)
Euphorbiaceae
Mallotus philippensis seed pods skin complaints, leprosy Webb (1948), Bailey (1883)
Fabaceae
coughs, (India),
Abrus precatorius roots, leaves, seeds ophthalmic Maiden (1889)
(India, Brazil)
Caesalpinia bonduc seeds, leaves, roots tonic (India), astringent Maiden (1889)
(Vietnam)
herpes, rheumatism,
ulcers (India)
Hydrophyllaceae
Lauraceae
Cassytha filiformis whole plant ulcers, sore eyes (India) Maiden (1889)
Lecythidaceae
laxative (India)
Barringtonia racemosa root, bark, seeds laxative, ulcers, skin Maiden (1889)
diseases (India)
Lythraceae
(1881)
(India)
Meliaceae
Melia azedarach fruit, root, bark leprosy, malaria (India) Webb (1948), Maiden (1908)
purgative (USA)
Nyctaginaceae
Boerhavia diffusa root, whole plant expectorant, asthma, Hegnauer (1969), Webb (1948)
diuretic (India)
Nelumbonaceae
Olacaceae
Orchidaceae
Pacific islands)
Plumbaginaceae
Africa)
Polygonaceae
Portulacaceae
Rhamnaceae
Rubiaceae
Morinda citrifolia leaves, bark, roots antiseptic, ulcers (India) Webb (1948), Maiden (1889)
Sapindaceae
Scrophulariaceae
Scoparia dulcis whole plant malaria, fever Webb (1969), Maiden (1889)
Simaroubaceae
tonic, dyspepsia,
Ailanthus triphysa bark dysentery Hegnauer (1973), Bailey (1909)
(China)
Thymelaeaceae
Verbenaceae
Clerodendrum inerme leaves, bark wounds (New Guinea), Webb (1959), Webb (1948)
fever (Guam)
Violaceae
Hybanthus
enneaspermus roots urinary disorders (India) Bailey (1881)
Vitaceae
2.1.4. Plants Not Currently Used Medicinally But Containing Bioactive Components
Many plants for which no medicinal use has been previously reported may be considered potential
therapeutic agents due to their chemical compositions. Recent studies have reported a variety of
Australian native plants to be high in antioxidants (Netzel et al., 2007; Netzel et al., 2006). In
particular, Davidsonia pruriens (Davidson plum) (Figure 8a), Eugenia carissoides (Cedar Bay cherry),
Kunzea pomifera, Citrus microcitrus (finger lime) (also known as Microcitrus australasica),
Pleiogynium timorense (Burdekin plum), Podocarpus elatus (Illawarra plum) (Figure 8b), Rubus
moluccanus (Molucca raspberry), two Szyzygium species (Szyzygium australe (bush cherry) and
ferdinandiana (Kakadu plum) (Figure 8c) were found to be good sources of ascorbic acid and other
antioxidants. Indeed, Terminalia ferdinandiana was reported as having ascorbic acid levels per gram
of fruit more than 900 times higher than blueberries. All of these plants are also reported to have
high levels of phenolic compounds and anthocyanins (Netzel et al., 2007; Netzel et al., 2006).
Figure 8: (a) Davidsonia pruriens (Davidson plum), (b) Podocarpus elatus (Illawarra plum), Terminalia
ferdinandiana (Kakadu plum). Photos (b) and (c) were accessed from Wikipedia Commons on 21
January 2011 and are adapted and reproduced here with the relevant permissions
(http://en.wikipedia.org/wiki/Terminalia_ferdinandiana ;
Australia in 2009.
Antioxidants have been associated with the prevention of cancer (Lambert et al., 2005; Hertog et al.,
1996), cardiovascular disease (Geleijnse et al., 2002) and neurological degenerative disorders
(Youdim et al., 2002). They are also linked with anti-diabetic bioactivities (Matsui et al., 2002) and
have been associated with the reduction of obesity (Tsuda et al., 2003). Antioxidants can directly
scavenge free radicals, protecting cells against oxidative stress related damage to proteins, lipids and
nucleic acids (Rice-Evans, 2001; Rice-Evans et al., 1996). Therefore, the Australian plants identified
by the Netzel studies (Netzel et al., 2007; Netzel et al., 2006) have potential for the treatment of a
variety of diseases and disorders and their potential bioactivities warrant further investigation.
Indeed, preliminary studies have demonstrated the broad spectrum antiseptic potential of
Similarly, plants rich in flavonoids have a wide range of potential medicinal uses. Numerous
medicinal plants contain levels of flavonoids found to be useful in treating disorders of the
peripheral circulation (Mills and Bone, 2000) and that are anti-inflammatory (Mills and Bone, 2000),
antispasmodic (Robbers and Tyler, 2000) and anti-allergic (Mills and Bone, 2000). Flavonoids also are
inhibitory towards a variety of human pathogens including bacteria, fungus and viruses (Bylka et al.,
2004). Therefore, plants found to possess high flavanoid levels may prove useful in combating these
diseases/medical conditions. Plants containing high levels of other chemical agents (eg. alkaloids and
Although scientific investigation into the usage of Australian medicinal plants is still in its infancy,
some plants have already proved useful. In particular, the Eucalypts and Melaleucas have proved
valuable medicinally and commercially. This volume will attempt to summarise the current state of
research in this field and point to possible future research directions. To provide a background, a
selection of Australian plants that have already proved to be useful medicinal/therapeutic products
will be examined. This is not a complete examination of all noteworthy plants but will give an
indication of the potential for discovery of new commercially important medicinal products. To
begin, the essential oil producing plants which currently form the bulk of the commercialisation of
Australian medicinal plants will be discussed. Examples of plants used for the commercial production
of essential oils include the Eucalypts, Melaleucas, Leptospermums and Backhousia citriodora.
Perhaps no other plant personifies Australia to the same degree as do the Eucalyptus species (Figure
9). Eucalyptus is a diverse genus of trees in the family Myrtaceae. Of the more than 700 species that
comprise this genus, most are endemic to Australia. A smaller number are also native to New
Guinea, Indonesia and the Philippines. Eucalypts can be found in almost every region of the
Australian continent. They have also been widely introduced into drier subtropical and tropical
regions in areas as diverse as Africa, the Middle East, India, USA and South America. In many of
these areas these trees are considered invasive (Santos, 1997) whilst in other areas they are prized
Figure 9: (a) Eucalyptus forrest with Eucalyptus major in the centre, (b) Eucalyptus major leaves, (c)
Eucalyptus major flowers, (d) Eucalyptus fruit (gum nut) from unverified species and (e) Eucalyptus
Eucalypts are valued for their wood and some are also valuable sources of proteins, tannins, gum
and dyes, although their most valuable product is the Eucalyptus oil that is readily distilled from their
leaves (Sartorelli, 2007; Trivedi and Hotchandani, 2004). Essential oils from some Eucalyptus species
(eg. Eucalyptus pulverulenta) comprise up to 90% cineole (Brophy et al., 1985; Foley and Lassak,
2004). The structure of cineole is shown in Figure 10. Essential oils from other plants containing
cineole (eg. Heteropyxis natalensis Harv) have previously been demonstrated to have good
antimicrobial properties (Gundidza et al., 1993). Eucalyptus oil is used extensively in cleaning and
deodorising products as well as in cough drops and decongestants (Sartorelli, 2007). Eucalyptus oil
also has insect pest repellent properties and is a component in many commercial pesticides (Fradin
Figure 10: Chemical structure of 1,8-cineole, the major oil component of Eucalyptus leaves.
Australian Eucalyptus species also had a role as traditional bush medicines for Australian Aborigines.
Several species have been reported to be used to prepare antiseptic washes (Lassak and McCarthy,
2006; Harborne and Baxter, 1995). The resinous exudate from the trunk of Eucalyptus maculata was
also taken internally to cure bladder infections (Lassak and McCarthy, 2006). Oils from several
Eucalyptus species have been used for the treatment of upper respiratory tract infections, colds,
influenza, sinus congestion (Harborne and Baxter, 1995) and pulmonary infections (Low et al., 1974).
Recent studies have confirmed the antimicrobial activity of oils from many Eucalyptus species (Cock,
Melaleuca (family Myrtaceae) is a diverse genus of trees and shrubs, most of which are endemic to
Australia (Page and Olds, 2004). Figure 11 shows Melaleuca quinquenervia (paper bark) trees as well
as bark, leaves and flowers. A few Melaleuca species are also indigenous to Papua New Guinea and
Indonesia and some species are found in coastal regions of South East Asia. Many species have
papery bark that easily peels from the trunk (Figure 11b) which early Aborigines had many uses for,
including medicinal uses (eg. stemming blood flow from wounds) (Lassak and McCarthy, 2006).
Other parts of the plant, particularly the leaves, were also used by indigenous Australians as
medicines, especially in the treatment of coughs and colds and as antiseptic agents (Lassak and
McCarthy, 2006; Maiden, 1889). European settlers also have a long history of Melaleuca medicinal
use (Lassak and McCarthy, 2006). In fact, it is reported that the early English explorer Captain Cook
and his party used the leaves of Melaleuca alternifolia as early as 1770 (Cook, 1777) to make a tea
and referred to this plant as “Tea Tree”, a name that is still used to this day. With the advent of
European settlement in Australia, Melaleuca alternifolia became a valued bush medicine. However,
it wasn’t until after World War 1 that scientific study demonstrated the medicinal potential of this
plant. Studies in the 1920’s (Penfold and Grant, 1925a, b) showed Tea Tree leaf oil to be
approximately 12 times stronger as an antiseptic agent than carbolic acid (the standard at the time).
Figure 11: Melaleuca quinquenervia (a) group of trees, (b) close up of the “paper” bark, (c)
unopened flowers and (d) flowers and foliage. Pictures were taken at various times throughout 2010
Like the Eucalypts previously described, many Melaleuca species are valued for their oils which are
also rich in 1, 8-cineole (Figure 10) as well as a variety of other terpenes and sesquiterpenes. The
structures of some of the major terpenes present in Melaleucas are shown in Figure 12. Melaleuca
essential oils have well known antiseptic properties and are valued commercially as antibacterial
agents. Recent interest in Australian bush foods has also seen Melaleuca oils used in the food and
flavouring industries and there is scope for commercial development in this area. Melaleuca oils as
natural food additives not only provide a pleasing flavour but also inhibit microbial food spoilage.
Figure 12: Chemical structures of (a) terpinolene, (b) terpinene-4-ol, (c) α-pinene and (d) β-pinene,
Leptospermum (family Myrtaceae) is a genus of more than 80 species that are widely distributed in
Australia, with a few species also native to New Zealand and Malaysia (Thompson, 1983). The
antiseptic properties of several Leptospermum species are well known (Lassak and McCarthy, 2006).
Particularly well studied are the antimicrobial properties of Leptospermum scoparium (Manuka)
(Figure 13), a species endemic to eastern Australia (Brophy et al., 1991) and New Zealand (Wardle,
1991). This species has been traditionally used medicinally for many ailments. The leaf vapour was
used for colds and coughs, the gum exudates for scalds and burns, aqueous bark and seed extracts
for infections and inflammation and the leaves for urinary complaints (Brooker et al., 1987). Honey
derived from L. scoparium is also known as a good antibacterial agent (Weston et al., 2000; Allen et
al., 1991). The medicinal properties of other Leptospermum species are less well studied although
some are also known to have been used by Australian Aborigines as antiseptic agents (Lassak and
McCarthy, 2006). Reports have demonstrated the antibacterial and antifungal activity of
Leptospermum petersonii (lemon scented tea tree) (Davis and Ward, 2003; Lis-Balchin et al., 1996)
Figure 13: Leptospermum scoparium (a) entire plant and (b) close up of foliage and flowers. Photos
January 2010 and are adapted and reproduced here with the relevant permissions.
Research into the medicinal value of other Leptospermum species is less extensive and much still
needs to be done to identify their antimicrobial potential. Many plants of this genus are known to
contain a mixture of terpenes including 1, 8-cineole and terpinen-4-ol (Figure 14) (Porter and
Wilkins, 1999; Carr, 1998). Both 1, 8-cineole and terpinen-4-ol are thought to have antimicrobial
Leptospermum leaves.
Eremophila is a large, diverse genus of plants with more than 210 species which mainly inhabit arid
and semi-arid areas in the central regions of mainland Australia, preferring relatively poor soils and
dry conditions (Page and Olds, 2004). They are commonly referred to by a variety of names including
poverty plant, emu bush, fuchsia bush, terpentine bush and tar bush. Figure 15 shows Eremophila
whole plants, leaves and flowers. Eremophilas were widely used by Australian Aborigines in a
number of roles including as adhesives and sealants as well as being used as medicinal agents
(Richmond, 1993). As well as using Eremophila decoctions and extracts as liniments (Richmond and
Ghisalberti, 1994), Aborigines used them as antiseptic agents to treat cuts, open sores, sore throats
maculata flower, (d) Eremophila nivea whole plant, (e) Eremophila glabra foliage and (f) Eremophila
glabra flower. Pictures were taken at Nielsen’s Native Nursery, Brisbane, Australia in January 2011
by Dr Ian Cock.
Perhaps one of the most promising genus’ of the medicinal Australian plants, Eremophila species
have received much recent attention as potential therapeutic agents. Recent studies (Pennachio et
al., 2005; Pennachio et al., 1996; Pennachio et al., 1995), describe the cardioactive effects of
Eremophila extracts. Studies have also shown various Eremophila species to have antiseptic
properties, particularly towards Gram-positive bacteria (Pennachio et al., 2005; Palombo and
Semple, 2001), thus confirming the validity of traditional Aboriginal medicinal usage. Much is still to
be learnt about the active constituents and the mechanisms of action of Eremophilas, although at
least one of the active components is known. Pennachio et al. (1996) isolated a phenylethanoid
glycoside called verbascoside (Figure 16a) which they showed to significantly increase heart rate and
contractile force in isolated rat hearts. Eremophilas are also known to produce the cyanogenic
glycoside prunasin (Figure 16b) and the sesquiterpenes 10, 11-dehydromyoporone (Figure 16c) and
10, 11-dehydromyodesmone (Figure 16d) (Blackburne et al., 1972) and various alkaloids (Aplin and
Cannon, 1971), any of which may potentially be responsible for the antiseptic nature of Eremophila
species.
Figure 16: Chemical structures of (a) verbascoside, (b) prunasin, (c) 10, 11-dehydromyoporone and
Backhousia citriodora (lemon myrtle) is an Australian plant, native to subtropical areas of eastern
Australia. Figure 17 shows Backhousia citriodora whole plants, leaves and flowers. The leaves of this
plant are widely used as a bush food and as a component of toiletries and cosmetics (Hegarty et al.,
2001). Studies in this laboratory (Cock, 2008) and elsewhere (Wilkinson et al., 2003; Ryan et al.,
2000) have demonstrated the antibacterial activity of B. citriodora leaves. Interestingly, no definitive
ethnobotanical reports of Australian Aboriginal medicinal use of B. citriodora were found in the
literature, although the leaves are known to have been used in cooking. Most of the studies of B.
citriodora antibacterial potential focus on the essential oil of the leaves (Wilkinson et al., 2003; Ryan
et al., 2000). In most plants of this species, more than 90% of the oil is citral (Figure 18), a mixture of
neral (α-citral) and geranial (β-citral) (Opdyke, 1976). Both neral and geranial have previously been
reported to have potent antibacterial activity against a variety of bacteria (Wilkinson et al., 2003;
Figure 17: Backhousia citriodora (a) whole plant and (b) foliage and flowers. Photos were taken in
Figure 18: Chemical structures of (a) neral (α-citral) and (b) geraniol (β-citral), the major oil
The genus Callistemon (family Myrtaceae) consists of 34 species endemic to Australia. Some species
have also been introduced to other areas such as USA (Gilman, 1999) and Africa (Nel et al., 2004;
Macdonald et al., 2003) where they are considered invasive species. They are closely related to
Melaleucas and have similar leaf and flower morphology (Wrigley and Fagg, 1993; Elliot and Jones,
1982). Callistemons are commonly referred to as ‘bottlebrushes’ due to the appearance of their
flowers. Figure 19 shows Callistemon citrinus whole plants, leaves and flowers. They occur naturally
Figure 19: (a) Callistemon citrinus tree, (b) Callistemon citrinus foliage and unopened flowers, (c)
Callistemon citrinus flower. Photos (a) and (c) were accessed from Wikipedia Commons
(http://en.wikipedia.org/wiki/Callistemon_citrinus ; http://en.wikipedia.org/wiki/Callistemon ) on 17
January 2011 and are adapted and reproduced here with the relevant permissions. Photo (b) was
Callistemon flowers were used as a food source by Australian Aborigines. The flowers were sucked
for their nectar or used to make sweet drinks (Nash, 2000). Callistemon species also had roles as
traditional bush medicines for Australian Aborigines (Jirovetz et al., 1997). The leaves were used to
cure respiratory tract infections. Callistemon rigidus leaves have also been used to cure coughing,
bronchitis and respiratory tract infections in Cameroon, China and various other parts of Asia
(Jirovetz et al., 1997). Unfortunately, most of our understanding of the medicinal potential of
Callistemon species is anecdotal with few species being properly studied by rigorous scientific
investigation. Recent reports have confirmed the antibacterial activity of a Callistemon rigidus
(Sanjai and Charu, 2006; Saxena and Gomber, 2006). These preliminary studies have confirmed the
need for further investigation. It has been postulated that terpenes in the leaves may be responsible
Figure 20: Chemical structures of (a) 1, 8-cineole (b) pinene and (c) terpinene-4-ol, components of
Callistemon leaves.
Callistemons have been shown to contain some of the same components found in other Australian
plants with demonstrated antimicrobial activities (Figure 20). 1, 8-cineole (Figure 20a) is a major
constituent of Callistemon leaves (Ming et al., 1998; Misra et al., 1997) and has been shown in other
plants (Eucalypts, Melaleucas, Leptospermums) to kill bacteria and fungi. Likewise, Callistemon
leaves also contain the terpenes pinene (Figure 20b) and terpinene-4-ol (Figure 20c) (Change-Ming
et al., 1998; Misra et al., 1997), either of which may also be responsible for the antiseptic properties
of Callistemon species.
The Acacia genus (family Fabaceae, subfamily Mimoaceae) consists of over 1200 species, more than
700 of which are indigenous to Australia (Ali, 1998). Other species are spread throughout tropical to
warm temperate regions of Africa, India and the Americas. Figure 21 shows an Acacia aulocarpa tree
(Figure 21a) and flowers (Figure 21b), as well as Acacia complanta foliage (Figure 21c) and seed pods
(Figure 21d). Acacias have also been introduced into other countries for ornamental and economic
purposes. Most Acacia species produce quality wood and some are also valuable sources of proteins,
tannins, gum, perfumes, paint, ink and flavouring agents (Arias et al., 2004; Seigler, 2003). For
Australian Aborigines, Acacia seed formed an important part of their diet, providing an easily
obtainable, high energy food (Hegarty and Hegarty, 2001; Latz, 1995) that could easily be ground to
a flour, mixed with water and eaten either raw or cooked to produce a type of unleavened bread.
Other parts of some Acacia species are also eaten. Several species exude a sugary gum from wounds
to the stem and branches (Arias et al., 2004; Hegarty and Hegarty, 2001) whilst others are hosts for
edible grubs often referred to as witchetty grubs by non-Aboriginal Australians (Kalotas and
Goddard, 1985).
Figure 21: (a) Acacia aulocarpa tree, (b) Acacia aulocarpa foliage and flowers, (c) Acacia complanta
foliage, (d) Acacia complanta with open seed pods. Pictures were taken at various times throughout
Australian Acacia species also had roles as traditional bush medicines for Australian Aborigines.
Several species have been reported to be used to prepare antimicrobial washes and lotions (Lassak
and McCarthy, 2006). A. nilotica was traditionally used by Aborigines for ailments such as diarrhoea
and was reported to have antihyperglycemic (Ahhtar and Kahn, 1985), antimicrobial (Abd-El-Nabi,
1992) molluscicidal (Hussein, 1984), antihypertensive and antiplatelet aggregatory activities (Shah et
al., 1997). Unfortunately most of our understanding of the medicinal potential of Australian Acacia
species is anecdotal with few species being properly studied. One South American Acacia species (A.
aroma) has been shown to demonstrate antibacterial activity against both Gram-positive and Gram-
negative bacteria (Arias et al., 2004). Amongst the Australian Acacia species studied, A. kempeana,
trineura and A. olliquinervia (Ali, 1998) have been reported to have to have antibacterial activity. A
potent cyclooxygenase-1 inhibition by extracts of A. ancistrocarpa has also been reported (Li et al.,
2003).
Much is still to be learnt about the active components and mechanisms of action of Acacias,
although they are known to contain a number of biochemicals of medicinal interest including
alkaloids, cyanogenic glycosides, cyclitols, diterpenes, phytosterols, saponins, and tannins (Seigler,
2003). The alkaloid β-Phenethylamine (Figure 22a) and related amines have been reported in a
prominens, and A. suaveolens (Fitzgerald, 1964; White, 1944a, b). 2-methyl-1, 2, 3, 4-tetrahydro-β-
carboline (Figure 22b) has also been reported for some species (Poupat, et al., 1976). Maslin et al.
(1987) report that 96% of Australian Acacias contain the cyanogenic cyanides prunasin (Figure 22c)
and sambunigrin (Figure 22d). Acacias are known to contain a number of terpenes such as the
diterpenes labd-13-en-3β, 8α, 15-triol (Figure 22e) and 3β, 8α-dihydroxylabd-13-en-15-oic acid
(Figure 22f) (Forster et al., 1985). Many species also contain phytosterols and saponins including α-
spinasterol (Figure 22g) (Mahato, 1989). Common flavonoids in Acacia species include the flavan-3-
ols catechin (Figure 22h), epicatechin and epigallocatechin (Tindale and Roux, 1969). Acacia bark
contains high levels of tannins. A. mearnsii (Black Wattle) bark has been reported to contain 20-40%
tannins by weight, of which up to 70% are proanthocyanidins (Figure 22i) (Tindale and Roux, 1969).
Figure 22: Chemical structures of (a) β-Phenethylamine, (b) 2-methyl-1, 2, 3, 4-tetrahydro-β-
carboline, (c) prunasin, (d) sambunigrin, (e) labd-13-en-3β, 8α, 15-triol, (f) 3β, 8α-dihydroxylabd-13-
en-15-oic acid, (g) α-spinasterol, (h) catechin and (i) and proanthocyanidin from Acacias.
Scaevola spinescens (family Goodeniaceae) (commonly known as currant bush, maroon bush and
fanflower) (Figure 23) was used by Australian Aborigines as a medical plant to treat a variety of
conditions (Lassak and MacCarthy, 2006; Ghisalberti, 2004; Leyland, 2002). An infusion of the roots
was used to treat stomach pain and urinary disorders. A decoction of crushed stem was used to treat
boils, rashes and skin disorders. The whole plant was burnt and the fumes inhaled to treat colds.
Leaves and twigs were steamed and sores treated by exposure to this steam.
Figure 23: Scaevola spinescens (a) whole plant and (b) foliage and berries. Photos were taken and
copyrighted by Jeanie Cargo and are reproduced here with the photographer’s permission.
Despite its range of traditional medicinal uses, the phytochemistry and therapeutic potential of S.
spinescens has not been extensively studied. A study by Semple et al. (1998) examined 40 different
Australian plants for antiviral bioactivities (Semple et al., 1998). The study found that S. spinescens
leaf extracts were capable of inhibiting greater than 25% of human cytomegalovirus (CMV) late
antigen production. More recently, studies have detected antiviral bioactivity of S. spinescens
methanolic extract against MS2 bacteriophage (Cock and Kalt, 2010a). These studies demonstrate
the antiviral potential of S. spinescens and provide support for the traditional Aboriginal use of S.
S. spinescens also had uses in the treatment of various cancers. This ethnopharmacological
knowledge was traditionally passed on by word of mouth instead of by written record and
unfortunately much of our understanding of Aboriginal medicinal usage has been lost as Aboriginal
society has merged into mainstream Australian society. Accounts exist of aqueous extracts of S.
spinescens root bark being used to cure cancer (as reviewed in Ghisalberti, 2004), although their
efficacy has yet to be verified in controlled laboratory studies. Annecdotal accounts have also
credited S. spinescens with anticancer activity (Bushfoods, 2010) although these also have yet to be
Whilst individual bioactive compounds are yet to be identified, S. spinescens has been reported to
contain high yields of a number of taraxerene type pentacyclic triterpenoids (Kerr et al., 1996). In
particular, high levels of 14-taraxerene-3,28-diol (1; myricadiol) (Figure 24) were isolated from S.
spinescens in the Kerr et al. study. Similar pentacyclic triterpenoids isolated from Alchornea latifolia
have been linked with cytotoxic activity towards Hep-G2 and A-431 human cancer cell lines and are
potent inhibitors of topoisomerase II (Setzer et al., 2000). Taraxerene triterpenoids from Laggera
pterodonta have also been shown to have antiviral activity against herpes viruses (Kuljanabhagavad
et al., 2009). Studies have also demonstrated the antibacterial activity of pentacyclic triterpenoids
from a variety of other plants (Ahmad et al., 2008; Shai et al., 2008; Djoukeng et al., 2005).
CH3
CH3 CH3
H
CH3 CH3
OH
CH3 H
H
OH H
CH3
Figure 24: Chemical structure of the pentacyclic triterpenoid 14-taraxerene-3, 28-diol (1; myricadiol)
from S. spinescens.
Pittosporum phylliraeoides (family Pittosporaceae) (figure 25), commonly known as ‘cattle bush’ or
‘gumbi gumbi’ is a native Australian plant that was used by Aborigines for a variety of purposes
including improving circulation, as a birth control measure and as an anti-cancer agent. It has been
proposed that P. phylliraeoides contains haemolytic saponins that hydrolyse to form the triterpenoid
compounds phyllyrigenin (Figure 26a) and barrigenol (figure 26b) (Lassak and McCarthy, 2006;
Chopra et al, 1965; Knight and White, 1961). It has also been suggested that as well as saponins,
polyphenols and phytoestrogens are also present within P. phylliraeoides (Lassak and McCarthy,
2006) and these may also be responsible for the therapeutic potential of this plant.
Figure 25: Pittosporum phylliraeoides (a) foliage and (b) fruit. Pictures were taken in Brisbane,
Figure 26: Chemical structures of (a) phyllyrigenin and (b) barrigenol from Pittosporum
phylliraeoides.
scopolamine within its leaves. Scopolamine (Figure 28) is an anticholinergic agent capable of
blocking the neurotransmitter acetylcholine in the central and the peripheral nervous systems. In
minute doses (~330μg); scopolamine has been used for the treatment of nausea, motion sickness,
Figure 27: Duboisia myoporoides (a) foliage and fruit and (b) bark. Photographs were accessed from
The genus Planchonella (family Sapotaceae) consists of approximately 100 species, 18 species of
which are native to Australia. Nomenclature within this genus can be somewhat confused with many
species often included in the genus Pouteria (eg Planchonella queenslandica (Figure 29a) and
Pouteria queenslandica are the same species). Planchonella thyrsoidea has been shown to contain
pyrrolizidine alkaloids (Figure 30a) which have toxic properties (Culvenor, 1967). Triterpene acids
have also been shown to be present in the leaves of Planchonella duclitan and have shown
cytotoxicity toward human colorectal carcinoma cell line HT29 and human breast carcinoma cell line
MCF-7 (Lee et al., 2005). Studies into Planchonella vitiensis have documented the presence of α-
Spinasterol (Figure 30b) within the heartwood (Cambie et al., 1997). Anecdotal evidence also
indicates the presence of alkaloids in Planchonella pohlmanniana (yellow box) and an infusion of
twigs and leaves were used by north Queensland Aborigines as a poultice for boils. The species
Figure 30: Structure of (a) pyrrolizidine alkaloid and (b) α-Spinasterol, secondary metabolites present
The genus Petalostigma (family Picrodendraceae) consists of seven species, two of which have been
investigated for medicinal properties (Kalt and Cock, 2011). These two species, Petalostigma
pubescens (commonly known as ‘quinine tree’) and Petalostigma triloculare, differ slightly in terms
of leaf and fruit shape and size but otherwise have similar morphology. Although the common name
suggests quinine is present within the fruit or leaves, there is no scientific evidence to support this.
However, an infusion of bark or fruit in water is known to have been used by Aborigines to relieve
sore eyes, and as an antiseptic (Lassak and McCarthy, 2006). Fruit was also held in the mouth to
relieve toothache (Lassak and McCarthy, 2006). Studies within my laboratory have demonstrated the
toxicity and broad spectrum antiseptic properties of the leaves and fruit (Kalt and Cock, 2011) and
antiviral bioactivities (Kalt and Cock, in preparation) of both plants. Further work is needed to
Figure 31: Petalostigma pubescens (a) whole plant, (b) foliage and immature fruit and (c) ripe fruit.
Pictures were taken in January 2011 in Toohey Forrest, Australia by Dr Ian Cock.
Active constituents are not fully characterised but the fruit contains a definite bitter substance,
possibly an alkaloid (Lassak and McCarthy, 2006). Investigation into the chemical composition of
(Figure 32c), pubescenone (Figure 32d), and ent-cleistanthane diterpene sonderianol (Figure 32c)
Figure 32: Structure of the five tricyclic diterpenes present within Petalostigma pubescens
significantly more research into the phytochemical composition of Australian plants with therapeutic
potential is required:
• To isolate bioactive compounds for direct use as drugs. Examples of medicines derived from
tubocurarine, taxol, vinblastine and vincristine. These compounds have come into use
Australian plant extracts and essential oils may ultimately also provide a wealth of new
therapeutic agents.
synthesis of patentable compounds of higher activity and lower toxicity. Such a protocol has
quinidine, emetine (and other narcotic analgesics), taxotere, teniposide, verapamil, and
the normal physiology of the human body. Previous international studies have used natural
investigate the synaptic mechanism in the lateral geniculate of the brain (Bishop et al.,
1958). Other known phytochemicals used for similar investigations include atropine
the South American plant Chondrodendron tomentosum), strychnine (an alkaloid isolated
from Strychnos ignatii), veratrine and veratridine (neurotoxic steroidal alkaloids derived
from plants of the family Liliaceae), mescaline (a psychedelic alkaloid derived from peyote
• Finally these studies enable us to use the whole plant or part of it as an herbal remedy eg.
cranberry, echinacea, feverfew, garlic, ginkgo biloba, St. John’s wort (Fabricant et al., 2001).
With regard to Australian plants, herbal remedies currently used mainly relate to the
Leptospermums).
plant derived medicines and the search for pharmacologically unique principles from existing
ethnopharmaceutical remedies. Many Australian plants have not been previously examined for their
New phytopharmaceutical discovery requires the identification of medicinally useful plants, the
isolation of compounds from those plants, and bioactivity testing. It is also essential that any
steps:
(UV/VIS, IR, MS, NMR), physical (X-ray crystallography) and chemical techniques
Australia has a large quantity of unique plants, many of which have either not been scientifically
investigated as medicinal sources, or have only received preliminary examination. Considering the
number of Australian plants which have not yet been studied, thought needs to be given to the
1. Ethnopharmacology.
With the wide choice of plants yet to be studied, often a good starting point is to begin with plants
previously used by traditional healers. Australian Aborigines had a good understanding of the botany
in their local areas and used a variety of plant medicines to help maintain their health (Barr et al.,
1993; Lassak and McCarthy, 2006). Unfortunately, most Aboriginal knowledge of plant usage was
not documented, instead being passed from one generation to the next entirely orally. As Aboriginal
society has been increasingly assimilated into non-Aboriginal society, much of the cultural identity
and traditional knowledge has been lost. Only a handful of individuals remain with extensive
knowledge of traditional medicines and then, not in all regions. For example, many Northern
Territory Aborigines still live traditional lives and ethnopharmaceutical knowledge is still available
(Lassak and McCarthy, 2006). However, in other areas of Australia where Aborigines have either left
their traditional lands and/or abandoned their traditional lifestyles, much of this traditional
knowledge has already been lost. Efforts need to be made to safeguard the remaining knowledge.
Aborigines lived as separate populations in widely varied geographical areas of Australia with
ethnopharmacologies, dependent on the plants available and the requirements of the local
populations. For example, indigenous populations living in the hot, humid conditions of Northern
Queensland would be faced with conditions ideal for bacterial growth. Scratches and skin abrasions
could readily become sceptic if left untreated. It is not surprising that Northern Queensland
Aborigines sought ways of treating these infections. In fact, in an early report of Australian plant use
(Roth, 1903), nearly a quarter of the knowledge of antiseptic plants was obtained from Northern
Queensland Aborigines. Other Aborigine populations from other regions of Australia were faced with
different environmental stresses and had different plant species available. For example, Aborigines
from the coastal regions of Northern New South Wales and Southern Queensland used Crinum
pedunculatum (Figure 33) to treat marine stings whilst Aborigines from central Australia had no such
knowledge of this plant, nor its potential use. It is unlikely, with such varied knowledge across the
indigenous populations, that we will ever be able to determine the full extent of medicinal
Figure 33: Crinum pedunculatum (a) whole plant and (b) flower. Pictures were taken in January 2011
2. Field observations
The researchers own field observations are often valuable in selecting a plant species for testing.
Plants which grow despite environmental stresses, such as plants in tropical rainforests where there
are an abundance of insects, fungi and bacteria, may have adapted to produce molecules with
bioactivities to protect themselves. Ficus coronata (a native fig) for example, is a tree that usually
grows in coastal rainforest areas of Queensland, Northern Territory and northern New South Wales
(Page and Olds, 2004). Growing in these hot, humid conditions (which provide an ideal environment
for bacterial and fungal growth) would on its own make further examination of F. coronata
warranted. This, coupled to the ethnopharmacological knowledge that north Queensland Aborigines
used the sap from this plant as an antiseptic (Lassak and McCarthy, 2006), makes this plant an ideal
Early studies into the antiseptic properties of Eucalyptus leaves also originated through field
observations. A team of Japanese researchers noticed that collected leaves of Eucalyptus gunnii
have an almost total absence of microbes not only inside the leaf, but also on their surface (Egawa et
al, 1977). These researchers examined Eucalyptus gunnii leaves and the leaves of other Eucalyptus
species for antiseptic agents. Not only did they isolate three antifungal agents (gallic acid and two
phenolic compounds) from Eucalyptus gunnii leaves but they also isolated antifungal agents from
In my own laboratory, studies based on field observations have yielded interesting results into the
medicinal potential of Xanthorrhoea johnsonii (Figure 34). X. johnsonii are long lived with some
plants being estimated at more than 550 years of age (Boorsboom, 2005; Stanley et al., 1989; Bulow-
Olsen et al., 1982). However, X. johnsonii are also extremely slow growing with the growth rates
estimated as low as 0.88 cm/year (Bulow-Olsen et al., 1982; Lamont and Downes, 1979). Due to its
slow growth rate, it was thought likely that X. johnsonii may have developed chemical protective
mechanisms to deter foraging animals which could potentially threaten their survival. The number of
animals that use X. johnsonii as a food source is low and even when animals use X. johnsonii as a
food, the leaves are generally not ingested. Indeed, in the only reports we found of grazing animals
foraging on Xanthorrhoea johnsonii leaves, cattle eating the leaves were said to become
uncoordinated and lose condition, become dehydrated, and in severe cases die following ingestion
(McKenzie, 1997; Everist, 1978; Hall, 1956; Hurst, 1942). Studies undertaken in my laboratory
identified an interesting bioactivity for X. johnsonii leaf extracts (Cock and Kalt, 2010b). The leaves
were found to have an apparent anaesthetic effect, similar to the effects previously described for
arrow poison) from Chondrodendron tomentosum (Bisset, 1989; Bisset, 1992a; Bisset, 1992b)
Figure 34: Xanthorrhoea johnsonii (a) plants, (b) close-up of flowers, (c) close-up of seeds and (d) a
single plant with a flower spear. Pictures were taken at various times throughout 2010 in Toohey
3. Taxonomic considerations
Many Australia plants are related to plants from other regions of the world that are know to produce
much of the African continent (Page and Olds, 2004). The fruits and seeds of this plant contain
tartaric acid and are used by African populations as a remedy for dysentery (Watt and Breyer-
Brandwijk, 1962) and as an antiseptic agent (Hussain and Deeni, 1991). A related Adansonia species,
Adansonia gregorii (Figure 35), is native to far north Western Australia (Page and Olds, 2004). No
reports of any similar bioactivities were found for this plant in the literature, neither was any
has shown antibacterial activity for Adansonia gregorii flowers towards a limited panel of bacteria
Cock).
Azadirachta indica (commonly known as Neem tree) is another example of a plant of international
origin with well characterised bioactivities and phytochemistry. A. indica (a member of family
Meliaceae) is native to tropical and semi-tropical regions of Southern Asia. Products made from
Neem claim a wide variety of therapeutic properties including anthelmintic, antifungal, antidiabetic,
antibacterial, antiviral, anti-fertility, and sedative properties, and are commonly prescribed for skin
diseases such as chicken pox and acne in India (Nahak and Sahu, 2010; Vishnukanta, 2008). Indeed,
the wide range of ailments that are claimed to be treatable by A. indica products has resulted in it
being commonly described as "Divine Tree," "Heal All," "Nature's Drugstore," "Village Pharmacy"
and "Panacea for all diseases". Azadirachtin (a triterpene limonoid) (Figure 36a) has been isolated
and characterised from A. indica seeds. Azadirachtin has been shown to exhibit toxicity to some
insects yet low toxicity to mammals and anti-fertility activity in mice (Mandal and Dhaliwal, 2007;
Figure 36: The structure of (a) azadirachtin, a triterpene limonoid from Azadirachta indica and (b)
Melia azedarach var. australasica (family Meliaceae) (Figure 37) is a species closely related to A.
indica. M. azedarach has a wide distribution, occurring naturally in Australia, India, China, parts of
South East Asia and the Pacific Islands. Recent studies have shown that extracts from A. indica and
M. azedarach have similar toxicities towards the cabbage moth Plutella xylostella (Charleston et al.,
2006). Whilst the phytochemistry of M. azedarach has not yet been extensively examined, a recent
study has isolated two limonoid isomers (12-hydroxiamoorastatin (Figure 36b) and meliartenin
(Figure 36c)) from M. azedarach. Both these limonoids were found to have similar ED50 values
towards P. xylostella as azadirachtin isolated from A. indica. Further work is necessary to determine
Figure 37: Melia azedarach (a) whole tree and (b) leaves and flowers. Photographs were accessed
4. Random selection
Random selection should not be overlooked when choosing plants for biotesting. Given the number
of Australian plants that have not yet been investigated, the possibility exists that random testing
could well result in exciting new discoveries. Indeed, recent antimicrobial studies within my
laboratory revealed a wealth of previously unreported antibacterial activities from a wide variety of
Many new diseases and medical conditions that early Australians were not exposed to or did not
know about are now a part of our everyday lives. HIV, Alzheimer’s disease, Parkinson’s disease,
multiple sclerosis and many cancers were not major health concerns for Aborigines nor early
European settlers. Whilst neither modern medicine nor Australian ethnopharmacology has provided
Once a researcher has selected plant material for testing, a relatively simple assay is required to
determine whether that plant has therapeutic (or toxic) actions. Even when a plant preparation is
found to have desirable effects, these effects need to be further localised in specific extracts and
individual fractions. Medicinal plant preparations may contain hundreds of different constituents.
Therefore, even when a plant preparation with a desired bioactivity is found, only a fraction of the
compounds in that preparation may be useful. It is essential that the researcher has relatively simple
and rapid tests available to enable the screening of high sample numbers. These tests should also be
sensitive enough to detect activities in the low concentrations that some substances may be in plant
preparations. The targets for biological testing can be divided into six broad groupings:
1. Lower organisms (eg. Bacteria, fungi, viruses). Testing for antibacterial or antifungal activity is
relatively simple. A crude plant extract or a purified component can be placed in contact with the
microorganism (eg. by disc/plate hole diffusion assays or broth growth inhibition assays) and the
inhibition of microbe growth or death is observed. Antiviral activity is easily determined using the
plaque reduction assay (Cock and Kalt, 2010a; Gentry and Aswell, 1975). With the development of
new antibiotic resistant strains of bacteria and fungi, the development of new antimicrobial agents
is of high priority.
2. Invertebrates (eg. insects, crustaceans, molluscs). Some plants have insecticidal and/or repellent
properties. These plants have potential roles in the prevention of tropical parasitic diseases (eg.
Malaria, Ross River and Dengue fevers). Other plants may act as molluscicides and be useful for
controlling molluscs. Medicinally, these plants would have potential uses in controlling diseases
that spread using a mollusc host for all/part of their lifecycle (eg. Bilharzia, a disease that affects
large numbers of people in developing countries). These plants would also have applications as
pesticides.
Invertebrate assays are also useful in toxicity screening assays. Whilst many laboratories use cell
culture assays (which are expensive and have inherent difficulties) or whole animal assays (which
have ethical constraints as well as being time consuming and expensive), invertebrate bioassays may
provide a convenient, rapid detection alternative. The Artemia nauplii (brine shrimp) bioassay
developed by Meyer et al (1982) has been routinely used in my laboratory and by other researchers
in this field (Setzer et al., 2000). This assay is an efficient, inexpensive and relatively rapid way to
detect toxic compounds, requiring only low amounts of sample (<20 mg). This test correlates well
with cytotoxic activity of some human tumours and therefore has the potential to detect new
3. Cell cultures. Cell culture assays are of particular importance in cancer research where it is
important to find molecules that are cytotoxic to tumour cells or inhibit their growth but not to
normal cultured cells. Many substances have proved cytotoxic to isolated cancer cells (Jansen et
al., 2006; Dweck, 2001; Hall et al., 2001; Weniger et al., 1998; Nanayakkara et al., 1988).
Unfortunately, most of these are also toxic to normal cells. Potential anticancer therapeutics need
to be tested against both tumour and normal cell lines to evaluate their usefulness as
chemotherapeutic agents.
4. Isolated organs. Pharmacological testing often utilises isolated animal organs. Perfused frog heart
has been used (El Bardai et al., 2003; Hotta et al., 1994) to study cardiac glycosides. Similarly,
perfused liver, guinea pig heart, chicken veins etc. have been routinely used for pharmacological
5. Whole animal bioassays. The testing of potential therapeutic agents on live animals is still an
important step in the development of new therapeutic agents as they give a true indication of the
drug’s affect on a whole organism. Whilst a drug may have a desired effect in one or more of the
other assays, they may still have limited potential due to unforeseen factors. Whilst an isolated
plant compound may prove cytotoxic in cell culture assays, they may be of limited use as a
chemotherapeutic agent due to other problems (eg. they may not reach/be transported to the
target tissue). Whole animal tests are invaluable, even if only as a final step in the testing of a
potential new medicinal agent. However, where practical, other testing protocols should be
utilised before resorting to whole animal testing. Not only are there ethical concerns, but whole
animal testing can be expensive (high animal numbers are needed to get statistically significant
results), require specialised animal facilities and expertise and require long assay times.
6. Isolated subcellular systems (eg. enzyme or receptor bioassays). When the causes of a disease are
known it is possible to make direct use of the receptors and/or enzymes known to be implicated in
this condition. For example, when testing anti-cancer drugs, inhibitors of topoisomerases I and II
and protein kinase C as well as substances that affect tubulin polymerisation are potential targets.
Likewise, testing substances for the ability to inhibit cyclooxygenase or lipooxygenase enzymes
(involved in inflammation) would aid in the discovery of novel anti-inflammatory drugs. Tests of
this type are usually very sensitive and very specific so allow screening of large numbers of
5. Toxicity, Crossreactivity And The Safe Use Of Medicinal And Aromatic Plants
Whilst many users are turning to plant based medicines due to their perception of being safer than
allopathic drugs, it is important to realise that dangers are also inherent with natural medicines.
Indeed, it has often been stated that medicines are toxins taken at low doses. Even when a particular
phytochemical within a plant preparation has a medicinally desirable effect, it may also be toxic at
higher doses. An example is the cardiac glycoside digoxin which is present in plants of the genus
Digitalis. Digoxin is an antiarrhythmic agent which is used to control heart atrial fibrillation, atrial
flutter and sometimes heart failure (van Veldhuisen and de Boer, 2009). It is a very useful drug in
therapeutic doses. However, at higher doses, it may cause excessive slowing of the rate of heart
beat (bradycardia) or even block contraction and may be life threatening (The Digitalis Research
Group, 1997). The perception of the safety of plant preparations may result in the user taking higher
doses than would otherwise be achieved with pure, allopathic medicines, without thought of
Many individuals who use plant based medicines self-diagnose their conditions and will prescribe
plant preparations for themselves. An incorrect diagnosis may be dangerous, particularly as plant
medicines often contain multiple bioactive compounds. It is therefore possible that an inappropriate
or even dangerous remedy is prescribed. It is also noteworthy that many drugs actually have
enhanced effects in the presence of other drugs. Similarly, the functioning of some drugs may be
blocked or decreased in the presence of other drugs (including phytochemicals). For example, St
Johns wort is a perennial herb indigenous to Europe which is often used to treat depression (Gupta
and Möller, 2003) as well as a variety of other conditions. It has been well established that
administration of St Johns wort will counteract the effects of warfarin in some patients (Henderson
et al., 2002). Warfarin is a anticoagulant that is often prescribed for preventing thrombosis and
embolism. Therefore the counteracting effect of St Johns wort in patients prescribed warfarin could
potentially have fatal results. Furthermore, a phytochemical that has a desirable effect on a target
tissue may in fact also have an undesirable effect in other tissues (eg. liver or kidney). It is important
to realise that there has been limited scientific studies into the safety and effectiveness of most
plant based remedies. It is necessary to understand the mechanism of action and cross reactivity of
any drug before using multiple drugs or preparations in conjunction. This is routinely undertaken
before allopathic drugs are released to the market, yet no such requirement exists for natural
therapeutics.
Unlike allopathic medicines, many natural medicines are not effectively regulated. This means that
different plant based medicinal preparations will contain different types and quantities of
phytochemicals. Whilst some herbal preparations do contain standardised quantities of one (or even
several phytochemicals) other chemicals within the preparation are often not standardised. For
example, commercially available Aloe vera juices often note levels of several important
phytochemicals (eg. Aloe emodin, barbaloin) without fully detailing the levels of other components.
This is also true of Australian plant based essential oil medications. Eucalyptus oil products may
provide the levels of 1, 8-cineol, but will rarely detail the levels of other phytochemicals. Likewise,
the recent interest in Terminalia ferdinandia due to its high levels of vitamin C has resulted in the
However, T. ferdinandia fruit also contains a number of other phytochemicals which may impact on
the usage and efficacy of this fruit, yet these are rarely measured and reported.
Care also needs to be exercised in specialised cases (eg. in pregnant women). In an effort to avoid
drugs, pregnant women often use natural therapeutics as they believe them to be harmless. During
pregnancy, the maternal bloodstream is shared with the foetal bloodstream. Thus toxic chemicals
ingested by the mother will be shared with the foetus. As the foetus generally will not have
developed the same tolerances as the mother, acute toxicity may develop in the foetus without
being evident in the mother. Furthermore, some chemicals including phytochemicals, may be
mutagenic. These chemicals would be likely to have more profound effects in a developing foetus
than to the mother. Many women quite sensibly quit smoking and drinking alcohol during pregnancy
for this very reason, without considering the effects of the natural therapeutics they are also taking.
Similarly, toxic phytochemicals may also be present in the breast milk of women taking plant
pregnancy. Children, elderly people, immunocompromised individuals, and those suffering severe
allergies to specific drugs are other examples of people who should exercise caution with natural
6. Conclusion
Plants have been the basis of traditional medicines throughout the world for thousands of years and
continue to provide us with new remedies to existing and emerging diseases and medical conditions.
Traditionally, plant based medicines have been used as crude formulations such as infusions,
tinctures and extracts, essential oils, powders, poultices and other herbal preparations. These same
plant medicines now serve as the basis for the discovery of new drugs. Active compounds have been
isolated from medicinal plants, beginning with the isolation of the narcotic analgesic morphine from
the opium poppy in the early 1800’s (Kinghorn, 2001), through the early discoveries of drugs such as
codeine, quinine, cocaine and digitoxin (many of which are still widely used). Plants continue to
provide us with new drugs for both existing and new medical conditions and are vital to drug
discovery (Verpoorte, 1998). Higher plants are well known producers of an enormous variety of
chemically complex, biologically active compounds (Gentry, 1993; McChesney, 1993). Indeed,
approximately 25 % of all prescription drugs currently in use were originally derived from plants
(Walsh, 2003; Hostettmann and Hamburger, 1993; Newman et al., 2000). 75 % of these drugs were
discovered by an examination of traditional medicines (Walsh, 2003; Newman et al., 2000; Harvey,
1993). Furthermore, plant derived drugs and their semi-synthetic analogues comprise nearly 75 % of
all new anticancer drugs marketed between 1981 and 2006 (Newman and Cragg, 2007). Yet despite
the importance of plant derived medications, only approximately 10 % of the estimated 250,000
species worldwide have been screened for one or more bioactivities (Walsh, 2003; Hostettmann and
world (particularly Ayurvedic medicinal plants from India, Chinese traditional medicinal plants and
African ethnobotanicals), Australian plants remain relatively unstudied. Given the unique nature of
many Australian plants and the diverse, and often harsh conditions in which they grow, it is
surprising that more research is not undertaken in this field. In fact most research into medicinal
plants involves an examination of plant species from other regions of the world. Even amongst
research into international plants. For example, the number of publications relating to Aloe vera
medicinal properties greatly exceeds publications of Eucalypts medicinal properties, even amongst
Australian researchers. Presumably this is due to the wealth of knowledge already available about
international plants, providing a starting point for more advanced studies. Likewise, the
documentation of medicinal plants in other cultures may make species selection a simpler process.
However, Australia’s harsh climatic conditions are likely to have resulted in Australian plants
that Australian plants may produce unique phytochemicals that may result in new therapeutic
agents and may provide the starting point for the development of novel drugs. There are quite a
number of promising plants, some of which have been described in this volume, for which rigorous
scientific studies are required. It is hoped that this text may help to stimulate interest in Australian
medicinal plants and may provide a starting point for further studies in this field.
Glossary
Alkaloid: a bitter tasting nitrogenous phytochemical found in some plants. Certain alkaloids
(eg quinine and scopolamine) are medicinally useful in low doses. However, in higher
Allopathic: a medicinal system which aims to treat illness with remedies that induce effects
differing from and counteracting those produced by the disease itself. Western
Anthocyanidin: a class of antioxidant flavonoid which also act as common plant pigments.
Antibacterial: a medicine or agent that prevents the growth of, or kills bacteria.
acetylcholine.
Antifungal: a medicine or agent that prevents the growth of, or kills fungi.
effects of inflammation.
Antimalarial: a medicine or agent that prevents or counteracts malaria.
Antimicrobial: a medicine or agent that prevents the growth of, or kills microbes.
molecules.
microorganisms.
Antithelmintic: a medication that causes the expulsion of parasitic worms from the body by
Antiviral: a medicine or agent that prevents the reproduction or spread of virus. Antiviral
medicines may directly destroy the bacteria, or block one or more steps in their
replicatory cycle.
Aromatic chemical: a compound containing a six membered carbon ring structure with
conjugated double bonds. This structure allows electrons to freely cycle between
Astringent: a substance that constricts tissues, blocking secretion of fluids such as mucus.
Atherosclerosis: the build up of waxy plaque on the inner surface of blood vessels.
Ayurvedic medicine: a philosophy and healing system developed in India over thousands of
and lifestyle intervention. Ayurveda focuses on prevention rather than curative action.
Bioassay: any technique used to compare the biological activity of a substance on a test
Chalcone: an aromatic ketone that as well as being a secondary metabolite in its own right, is
Cardiac glycosides: steroidal glycosides which exert effects on the heart in small amounts
(eg digitonin). However, in higher doses, cardiac glycosides are often toxic.
Cathartic: purgative.
conception.
Coumarin: a bicyclic aromatic compound found in many plants which give them
Cyclitol: a cycloalkane having at least three hydroxyl groups attached at different carbon
Diabetes: a group of medical conditions characterised by high blood glucose levels, either as
Dysentery: disease characterised by severe diarrhoea, often containing mucus and/or blood.
Eczema: an acute or chronic inflammation of the skin, characterised by redness, itching and
flow.
Emphysema: an enlargement of the air vesicles within the lung, resulting in decreased
respiratory function.
Endemic: native to a particular location and not found naturally occurring elsewhere.
Essential oil: a volatile oil obtained by steam distillation plant materials. Common essential
oils include those from Australian native plants of the Eucalyptus and Melaleuca
genuses.
Ethnopharmacology: the use of traditional medicines by specific ethnic and cultural groups.
Expectorant: a medicine which promotes the secretion of bronchial mucus, resulting in the
Flavonoid: a large class of plant secondary metabolites which have antioxidant effects and
limit oxidative damage. Flavonoids are often also responsible for the colour of plants.
Free radical: an atom (usually an oxygen atom) or group of atoms with at least one unpaired
electron. Free radicals are extremely chemically reactive and in order to stabilise
themselves, they remove electrons from nearby molecules thereby oxidising those
molecules. Free radicals have been implicated in many degenerative diseases and
cancer.
supercontinents (the other being Laurasia) formed from the split of the land mass
Panagea. Gondwana later split to form Australia, Africa, South America, Antarctica,
gonorrhoeae.
Hemolytic: causing the breaking open of red blood cells and the release of haemoglobin.
Hydatid: a cyst filled with fluid which forms as a consequence of a infestation of tapeworm
larvae.
Hydrolysis: the addition of a water molecule to a compound resulting in the splitting of that
Infusion: a solution obtained by the steeping or soaking of plant material in water (eg tea).
Invasive: an invasive species is capable of invading a habitat that it does not naturally occur
Kino: the gum exudates obtained from various plants and trees (especially Eucalypts) in
Laurasia: The name of the northern most of the two precursor supercontinents (the other
being Gondwana) formed from the split of the land mass Panagea. Laurasia later split
Leprosy: or Hansen’s disease, is a chronic disease of the skin and nerves, caused by the
convulsions.
Narcotic: a drug that relieves pain and produces numbness and stupor.
oxidising agent. Oxidation reactions may produce free radicals which can cause
Oxidative stress: disturbances in the normal redox state of cells may result in an imbalance
between the production of reactive oxygen species (ROS) and the biological systems
ability to detoxify the reactive species or to repair the damage induced by ROS.
tremor.
Pangaea: an early supercontinent which contained all or nearly all of the current land masses.
Pangaea split during the Triassic era to produce the southern supercontinent
Phenolic compound: secondary metabolites which contain one or more phenol group
Phytochemical: any chemical compound derived from plants which has biological activity,
infection.
of more than one phenol moiety per molecule. Examples include flavonoids and
Poultice: a soft, moist mass applied topically to a sore, aching, inflamed or lesioned part of
Proanthocyanidin: a class of flavanols found in many plants. They are reputed to have
Proteolytic: a substance which hydrolyses proteins into peptides and/or amino acids by
Pruritus: severe itching sensation resulting from an irritation of the sensory nerve endings. It
has many possible causes including allergy, infection, lymphoma and diabetes.
Psychoactive: a drug or substance that acts primarily on the central nervous system, altering
Quinones: a class of organic compounds derived from aromatic compounds which have two
carbonyl groups in the same six membered ring. Quinones are usually yellow/red
Reactive oxygen species (ROS): highly reactive oxygen containing compounds resulting
from incomplete cellular reduction processes. ROS induce oxidative stress and
damage to cellular components and have been linked with aging and a variety of
Reduction: a type of chemical reaction in which electrons are added to an atom or ion.
Rubefacient: a medicinal agent for topical application which increases blood flow and
Scabies: a contagious skin infection caused by the parasitic mite Sarcoptes scabieri. It is
reaction.
vitamin C. Symptoms include weakness, nausea, spongy gums, loose and bleeding
metabolites are often involved in plant defence mechanisms and their production is
Steam distillation: a type of distillation used for isolating the volatile compounds from
botanical material to produce essential oils. Material is boiled in water (or has steam
passed through it) and the steam is condensed to recover the volatile compounds.
Steroid: a class of organic compound consisting of seventeen carbon atoms arranged in four
fused rings, usually with additional functional groups attached. Many have important
physiological functions.
Styptic: an astringent agent which stops bleeding by constricting blood vessels and other
tissues.
pallidum.
Tannin: a diverse class of astringent polyphenolic compounds of plant origin. They often
triterpenes of six and tetraterpenes (also called carotenoids) consist of eight isoprene
units. Polyterpenes consist of long chains of many isoprene units. Terpenes are often
Thrombosis: the formation of a blood clot in a vein or artery, causing loss of circulation.
Ethnopharmacology, 37, 77–79. [This study reports on the antibacterial activity of Acacia
nilotica fruit aqueous extracts against a range of bacterial species, thus validating north
African ethnopharmacologies].
Adam P, (1992), Australian rainforests. Clarendon Press, Oxford, UK. [A review of the
development of rainforest plants in Australia and divergent evolution from other species
Adesogan EK, Okunade AL, (1979), A new flavone from Ageratum conyzoides.
Phytochemistry, 18, 1863-1864. [This study reports on the isolation and structural
identification of a novel flavones from Ageratum conyzoides. The study also describes the
Afzal M, Armstrong D, (Ed), (2002), Oxidative stress Biomarkers and Antioxidant Protocols.
Methods in Molecular Biology, 186, 293-299. [This report provides a historical context for
[This study reports on the isolation and structural identification of 6 antibacterial pentacyclic
triterpenes from Myricaria elegans methanolic extracts. Antibacterial activity was screened
against 6 bacterial species and the structure of antibacterial components was examined with a
Akhtar MS, Khan QM, (1985), Studies on the effect of Acacia arabica fruits (kikar) and
Caralluma edulis roots (Chung) on blood glucose levels in normal and alloxan-diabetic
rabbits. Pakistan Journal of Agricultural Science, 22, 252–259. [This study reports on the
anti-diabetic effect of Acacia arabica fruits and Caralluma edulis roots on blood glucose
Ali M, (1998), Antimicrobial metabolites from Australian Acacia. PhD thesis, University of
Allen KL, Molan PC, Reid, GM, (1991), A survey of the antibacterial activity of some New
Zealand honeys. Journal of Pharmacy and Pharmacology, 43, 817-822. [This study reports
Pygeum africanum extract for the treatment of patients with benign prostatic hyperplasia. The
Aplin TEH, Cannon JR, (1971), Distribution of alkaloids in some Western Australian plants.
Economic Botany, 25, 366-380. [This study reports on the chemistry, particularly relating to
Arias ME, Gomez JD, Cudmani NM, Vattuone MA, Isla MI, 2004, Antibacterial activity of
ethanolic and aqueous extracts of Acacia aroma Gill. Ex Hook et Arn. Life Sciences, 75, 191-
202. [This study reports on the antibacterial activity of Acacia aroma ethanolic and aqueous
ethnopharmacological usage].
Brisbane, Australia. [An early review of plants of the Queensland region, particularly those
Bailey FM, (1883), The Queensland Flora. Government Printer, Brisbane Australia. [An
early review of plants of the Queensland region, particularly those used by either Aborigines
or by early European settlers as medicines. This is particularly interesting in a historical
context].
Bailey FM, (1881), Proceedings of the Linnean Society of N.S.W., 5, 1. [An early review of
Australian plants, particularly those used by either Aborigines or by early European settlers
Darwin. [A review of the plants traditionally used as medicines in the Northern Territory of
Australia. This report is a good starting point for understanding Northern Territory regional
Aboriginal ethnopharmacology].
Bishop PO, Field G, Hennessy BL, Smith JR, (1958), Action of D-lyserginic acid
study reports on the mechanism of action of D-lyserginic acid. It serves to illustrate the
Bisset NG, (1989), Arrow and dart poisons. Journal of Ethnopharmacology, 1989: 25: 1–41.
[A review of plant toxins (particularly curare) used in hunting. The chemistry and bioactivity
is explained].
Bisset NG, (1992a), Curare. In: Alkaloids: Chemical and Biological Perspectives, 8, Pelletier
WS (Ed), Springer, Berlin, 3–150. [A review of plant toxins, particularly curare, examining
Bisset NG, (1992b), War and hunting poisons of the New World. Part 1. Notes on the early
Blackburne ID, Park RJ, Sutherland MD, (1972), Terpenoid chemistry XX. Myoporone and
Australian Journal of Chemistry, 25, 1787-1796. [This study reports on the chemical
Bonney N, (1994), Native Plant. In Bonney, N., Miles, A. (Eds.), Uses of Southern South
New Zealand. [A review of the plants of New Zealand with medicinal uses/potential. This is
Leptospermum scoparium].
Brophy JJ, Goldsack RJ, Bean AR, Forster PI, Lepschi BJ, (1991), Leaf essential oils of the
its allies. Flavor and Fragrance Journal, 14, 98-104. [A review of the essential oils and the
emphasis is on species from eastern Australia, this review is also valuable in understanding
Brophy JJ, Lassak EV, Toia RF, (1985), The steam volatile leaf oil of Eucalyptus
pulverulenta. Planta Medica, 2, 170-171. [This study examines the chemistry of the essential
Bulow-Olsen A, Just J, Liddle MJ, (1982), Growth and flowering history of Xanthorrhoea
johnsonii Lee (Liliaceae) in Toohey Forest Queensland, Botanical Journal Linnean Society,
84, 195–207. [This is a useful publication for understanding the biology of Xanthorrhoea
johnsonii. The emphasis is on the Toohey Forrest region of Brisbane, although the biological
by a marketer of teas of this plant. The site contains testimonies of cancer patients who use
the plant].
Cambie RC, Ser NA, Kokubun T, (1997), Heartwood constituents of Planchonella vitiensis.
Biochemical Systematics and Ecology, 25, 7, 677-678. [This study examines and
Carr A, (1998), Therapeutic properties of New Zealand and Australian tea trees
(Leptospermum and Melaleuca). New Zealand Pharmacy, 18, 2. [This publication reviews
the therapeutic properties of Leptospermum and Melaleuca species from Australia and New
Cattermole PJ, (2000), Building Planet Earth: Five Billion Years of Earth History.
Charleston DS, Kfir R, Dicke M, Vet LEM, (2006), Impact of botanical extracts derived from
Melia azedarach and Azadirachta indica on populations of Plutella xylostella and its natural
enemies: A field test of laboratory findings. Biological Control, 39,105–114. [This study
reports on insecticidal activity of Melia azedarach and Azadirachta indica extracts against
cabbage moths].
Chopra CS, White DE, Melrose GJH, (1965), Triterpene compounds-VIII: The constitution
of phillyrigenin. Tetraherdron, 21, 2585-2592. [An early study into the phytochemical
haemanthidine. Phytotherapy Research, 12, 2005–2006. [This study reports on the anti-
clusiana].
Clarke PA, (1987), Aboriginal uses of plants as medicines, narcotics and poisons in southern
South Australia. Journal of the Anthropological Society of South Australia, 25, 3-23. [An
Flinders Ranges. Transactions of the Royal Society of South Australia, 63, 172-179. [An
account of Aboriginal medicinal plants which explains the names used by Aborigines and
relates them to the taxonomic classification of the time. This publication is interesting in a
historical context].
Cock IE, (2008), Antibacterial activity of selected Australian native plant extracts, The
Cock IE, Kalt FR, (2010a), A Modified MS2 Bacteriophage Plaque Reduction Assay for the
study reports on the development of an antiviral bioactivity assay. The antiviral activity of the
Cock IE, Kalt FR, (2010b), Toxicity evaluation of Xanthorrhoea johnsonii leaf methanolic
extract using the Artemia franciscana bioassay, Pharmacognosy Magazine, 6, 23, 166-171.
[This study reports on the toxicity of the Australian native plant Xanthorrhoea johnsonii.
Cock IE, Mohanty S, (2011), Evaluation of the antibacterial activity and toxicity of
Terminalia ferdinandia fruit extracts, Pharmacognosy Journal, 3, 20, 72-79. [This study
reports on the antibacterial activity and toxicity of the Australian native plant Terminalia
London, UK. [The journal of Captain James Cook, published in 1777, chronicling his voyage
Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L.
on Aedes aegypti (L.) (Diptera : Culicidae). Bioresource Technology, 99, 8, 3066-3070. [This
study reports on the lavicidal and insect deterrant activity of Melia azedarach fruit and leaf
antibacterial dosing of mice and men. Journal of Clinical Infectious Diseases, 26, 1-12. [This
Cribb AB, Cribb JW, (1981), Wild medicine in Australia. Collins Publications, Sydney,
Pharmaceutical Sciences, 57, 7, 1075-1272. [An early study examining the activity of
pyrrolizidine alkaloids. This is interesting not only for the bioactivity studies, but also for
historical context].
Davis C, Ward W, (2003), Control of Chalkbrood disease with natural products. Rural
examines the antimicrobial effects of natural products against the fungus which causes
Chalkbroods disease in bees. This study was useful for its identification of Leptospermum
Deininger R, (1984), Neves aus der Terpenf or schung. Excerpta phytotherapeutika. Lectures
of the Medical Congress, Firma Klosterfrau, Berlin, Germany. [This study examines the
Delaquis PJ, Stanich K, Girard B, Mazza G, (2002), Antimicrobial activity of individual and
mixed fractions of dill, cilantro, coriander and eucalyptus essential oils. International Journal
of Food Microbiology, 74, 101-109. [This study examines the antimicrobial activity of
Cancer, inflammation and behavior. Brain Behavior and Immunity, 23, 6, 721-731. [This
publication is a good starting point for understanding the anticancer properties of tea].
Di Pietro A, Conseil G, Pérez-Victoria GM, Dayan G, Baubichon-Cortay H, Trompier D,
Steinfels E, Jault JM, de Wet H, Maitrejean M, Comte G, Boumendjel AA, Mariotte AM,
ABC transporters, Journal of Cellular and Molecular Life Sciences, 59, 307 - 322. [This
study examines the interactions between flavonoids and protein components in cancer.
examined].
Dweck AC, (1997), The past, present and future of botanicals – a scientific overview. Plenary
comprehensive examination of medicinal natural products and their potential for new drug
discovery].
Dweck PM, (2001), Medicinal Natural Products: A Biosynthetic Approach. 2nd ed, Wiley,
biosynthesis].
Ebert B, Seidel A, Lampen A, (2007), Phytochemicals Induce Breast Cancer Resistance
Toxicological Sciences, 96, 2, 227 - 236. [This study examines the treatment of breast cancer
Eucalyptus species. Experientia, 33, 889-890. [This study examines the antifungal substances
found in Eucalyptus leaves. It serves to illustrate how field observations can lead to species
calcium channel blocker. British Journal of Pharmacology, 140, 1211-1216. [This study
utilizes perfused frog heart to examine the effects of cardiac glycosides from Marrubium
Elliot WR, Jones D, (1982), The Encyclopedia of Australian plants, Vol 2. Lothian
Poisonous Plants on Livestock (Eds Keeler RF, Van Kampen KR, Lynn LJ), Academic Press,
London, 93–100. [This report examines the toxic effects of Xanthorrhoea johnsonii in cattle].
Ewert AJ, (1930), Flora of Victoria. Melbourne University Press, Melbourne, Australia. [An
early examination of the plants of south east Australia. This publication is interesting in a
historical context].
Fabricant DS, (2001), The Value of Plants Used in Traditional Medicine for Drug Discovery.
Farnsworth NR, Akerele O, Bingel AS, Soejarto DD, Guo Z, (1985), Medicinal plants in
therapy. Bulletin of the World Health Organisation, 63, 965–981. [A review of the
Felton GW, Donato KK, Broadway RM, Duffet SS, (1992), Impact of oxidized plant
exigua. Journal of Insect Physiology, 38, 277 - 285. [An examination of the antioxidant
Boston, MA, USA. [This is an organic chemistry text, explaining structural elements,
Fitzgerald JS, (1964), Alkaloids of the Australian Leguminosae. III. The occurrence of
Fradin MS, Day JF, (2002), Comparitive eficiacy of insect repellants against mosquito bites.
non-wood products from plantations. Publication no. 04/154, Rural Industries and
Eucalyptus leaves].
Furey ML, Drevets WC, (2006), Antidepressant efficacy of the antimuscarinic drug
Psychiatry, 63, 10, 1121-1129. [This study reports on the anticholinergic/anaesthetic activity
association of tea flavonoid intake with incident myocardial infarction: the Rotterdam study.
American Journal of Clinical Nutrition, 75, 880-886. [An examination of the cardioprotective
Gentry AH, (1993), Tropical forest biodiversity and the potential for new medicinal plants. In
Human Medicinal Agents From Plants. Balandrin MF, Kinghorn AD (Eds), American
Chemical Society, Washington DC, USA, 13-24. [A review of the medicinal potential of
Gentry GA, Aswell JF, (1975), Inhibition of herpes simplex virus replication by araT.
Virology, 65, 1, 294-296. [This study describes a method of determining antiviral activity by
Ghazanfar SA, (1994), Handbook of Arabian medicinal plants. CRC Press, Boca Raton,
Florida, USA. [A comprehensive review of the plants used in traditional Arabian medicinal
systems].
review of plants of the genus Goodeniaceae. This is useful in understanding the biology,
Germany. [This report provides a historical context for medicinal plant usage internationally].
Gilman EF, (1999), Calistemon rigidus, Fact sheet FPS-93. Environmental Horticulture
Department, Institute of Food and Agricultural Sciences, University of Florida, USA. [This
publication examines the invasive nature of introduced Calistemon rigidus in the USA].
Gott B, (1992), SAUSE Database, South Australian Plants used by Aborigines. Department
Grace MH, Jin YH, Wilson GR, Coates RM, (2006), Structures, biogenetic relationships, and
traditional medicinal uses use the fruit, this study examines the chemistry of the heartwood].
Gupta RK, Möller HJ, (2003), St. John’s wort. An option for the primary care treatment of
depressive patients?, European Archives of Psychiatry and Clinical Neuroscience, 253, 140-
148. [An examination of the potential of St. John’s wort in psychiatry patients suffering from
depression].
Gundidza M, Deans SG, Kennedy A, Mavin S, Waten-nam PG, Gray A, (1993), The
essential oil from Hetropyxis natalensis Harv: Its antimicrobial activities and
phytoconstituents. Journal of the Science of Food and Agriculture, 63, 361-364. [This study
reports on the chemical characterization and antimicrobial bioactivity of essential oil from
Hetropyxis natalensis. The study emphasizes the value of the oil in relation to the retardation
Hager’s Handbuch der Pharmazeutischen Praxis. (1930), Springer Verlag, Berlin, Germany.
[This report provides a historical context for medicinal plant usage internationally].
Agricultural Science, 13, 1–10. [This study reports on the poisoning of cattle by
compounds from plants. Taylor and Francis, London, UK. [A very useful publication for
publication on the traditional and emerging usage of Australian plants as food sources. A
taxonomy].
taxonomy].
taxonomy].
taxonomy].
Hurst E, (1942), The poison plants of N.S.W. Snelling Printing Works Pty Ltd, Sydney,
Australia. [An early review of toxic plants of New South Wales. This is particularly
Hall DG, Manku S, Wang F, (2001), Solution- and solid-phase strategies for the design,
survey. Journal of Combinatorial Chemistry, 3, 125-150. [This study reports on the screening
of natural product libraries for lead products. The toxicity of high doses of alkaloids is a
Harvey AL, (1993), An introduction to drugs from natural products. In Drugs From Natural
review of drug development from natural sources. This publication is useful for interested lay
Harvey AL, (2000), Strategies for discovering drugs from previously unexplored natural
products. Drug Discovery Today, 5, 7, 294-300. [A review of drug development from natural
sources. This publication is useful for interested lay persons as well as researchers in the field
Hegarty MP, Hegarty EE, Wills RBH, (2001), Food safety of Australian bush foods. Rural
examination of the toxicity and safety of plants traditionally used as foods by Australian
Aborigines, as well as those whose usage in the food industry is increasing. This is a good
Henderson L, Yue QY, Berquist C, Gerden B, Arlett P, (2002), St John’s wort (Hypericum
Pharmacology, 54, 4, 349-356. [An examination of the potential drug interactions when using
flavonoids as antioxidants in plants? Trends in Plant Science, 14, 3. [An review of the
Hertog HGL, Bueno de Mesquita HB, Fehily AM, Sweetnam PM, Elwood PC, Kromhout D,
(1996), Fruit and vegetable consumption and cancer mortality in the Caerphilly study. Cancer
Epidermiology, Biomarkers and Prevention, 5, 673-677. [This study reports on the effects of
Hostettmann K, Marston A, Ndjoko K, Wolfender JL, (2000), The potential of African plants
understanding the traditional usage of African plants as medicines. This is a good starting
Helvitica Acta, Basel. [An interesting review of the steps, procedures and potential for the
development of new drugs from plants. Whilst the emphasis is on African plants, the text
provides a good basis for understanding the research and development of natural
compounds].
[This study utilizes perfused guinea pig heart to examine the effects of the phytochemicals
Hu CQ, Chen K, Shi Q, Kilkuskie RE, Cheng YC, Lee KH, (1994), Anti- AIDS agents, 10.
Products, 57, 42-41. [This study reports on the structure/activity relationship of the flavonoid,
Chrysanthemum morifolium].
Hurst E, (1942), The poison plants of NSW, Snelling Printing Works Pty Ltd, Sydney,
Australia.. [An early examination of toxic Australian plants, particularly those of the NSW
Hussain HSN, Deeni YY, (1991), Plants in Kano ethnomedicine: screening for antimicrobial
activity and alkaloids. International Journal of Pharmacognosy, 29, 51-56. [This study
ethnomedicinal systems].
Hussein SMA, (1984), Field trials for the evaluation of the molluskicidal activity of Acacia
nilotica. Fitoterapia, 55, 305–307. [This study reports on the antimolluskicidal activity of
Acacia nilotica].
Hsu C, Yen G, (2008), Phenolic compounds: Evidence for inhibitory effects against obesity
and their underlying molecular signaling mechanisms. Journal of Molecular Nutrition and
Food Research, 52, 53-61. [This study reports on the relationship between cellular redox state
their major constituents against respiratory tract pathogens by gaseous contact, Journal of
Antimicrobial Chemotherapy, 47, 565-573. [This study reports on the antimicrobial activity
of essential oils and isolated phytochemical components against bacteria associated with
respiratory infections].
Iwu MM, (1993), Handbook of African medicinal plants. CRC Press, Boca Raton, Florida,
This is a good starting point in understanding African medicinal plants and ethno-
phytopharmacologies].
Frédérich M, (2006), Screening of 14 alkaloids isolated from Haplophyllum A. Juss. for their
oils of Callistemon rigidus (Myrtaceae) from Cameroun by GC/FID and GC/MS. Scientia
Pharmaceutica, 65, 315-319. [This study reports on the phytochemical analysis and structural
Johnston TH, Cleland JB, (1943), Native names and uses of plants in the north-eastern corner
of South Australia. Transactions of the Royal Society of South Australia, 67, 149-173. [An
early review of plants of South Australia, particularly those used by either Aborigines or by
Kalt FR, Cock, IE, (2011), The Medicinal Potential of Australian Native Plants from Toohey
Forest, Australia, The South Pacific Journal of Natural and Applied Sciences, 28, 41-47.
[This study reports on the antibacterial activity and toxicity of a variety of Australian native
Kalotas A, Goddard C, (1985), Punu, Yankunytjatjara plant use. Institute for Aboriginal
Kamboj VP, (2000), Herbal medicine. Current Science, 78, 35-39. [An examination of the
Kerr PG, Longmore RB, Betts TJ, (1996), Myricadiol and other taraxerenes from Scaevola
spinescens. Planta Medica, 62, 6, 519-22. [This study reports on the isolation and structural
Khan S, Balick MJ, (2001), Therapeutic Plants of Ayurveda: A Review of Selected Clinical
and Other Studies for 166 Species. The Journal of Alternative and Complementary Medicine,
27, 5, 405-515. [A comprehensive review of Ayurvedic medicinal plants. Due to the vast
number of plants used in Ayurveda, this study focuses on specific commonly used species.
Kim JM, Marshall MR, Cornell JA, Preston III JF, Wei CI, (1995), Antibacterial activity of
carvacrol, citral and geraniol against Salmonella typhimurium in culture media and in fish
cubes. Journal of Food Science, 60, 1364-1368. [This study reports on the potent
antibacterial activity of Backhousia citriodora phytochemical components against Salmonella
typhimurium].
Pharmacology, 53, 135–148. [A review of the importance of plant based medicines, from
very early studies in the early 1800’s through to current investigations. This is a valuable
Tetrahedron Letters, 3, 100-104. [An early phytochemical study of the terpenoid components
of Pittosporum phyllorides].
Koch M, (1898), A list of plants collected on Mt. Lyndhurst Run, S. Australia. Transactions
of the Royal Society of South Australia, 22, 101-118. [A listing of plants of the Mt Lyndhurst
and antiviral activity of aerial part from Laggera pterodonta. Journal of Health Research, 23,
4, 175-177. [This study reports on the antiviral activity of taraxerene triterpenoids against
herpes virus].
Lambert JD, Hong J, Yang G, Liao J, Yang CS, (2005), Inhibition of carcinogenesis by
their ability to inhibit carcinogenesis. Redox homeostasis and its role in carcinogenesis is
examined].
Lamont BB, Downes S, (1979), The longevity, flowering and fire history of the grasstrees
Xanthorrhoea preissii and Kingia australis. Journal of Applied Ecology, 1979, 16, 893–899.
[This study reports on the lifecycle and biology of 2 species of grass trees. This report is
useful for understanding the longevity and slow growth rate of this genus as well as the
Lassak EV, McCarthy T, (2006), Australian medicinal plants. New Holland Publishers,
traditional usage of Australian plants as medicines. Not only is the specific medicinal usage
of each plant explained, but the part used and often the medicinal preparation are reported.
Whilst much of the discussion of medicinal plant usage is anecdotal and in some cases the
taxonomic classifications have changed, this is a good starting point for anyone interested in
Aboriginal ethnopharmacology].
Latz PK, (1995), Bushfires and bushtucker. Aboriginal plant use in central Australia. IAD
Press, Alice Springs, Australia. [A general report on the traditional usage of Australian plants
by central Australian Aborigines. Uses for foods, medicines, tools etc are reported].
Lauterer J, (1895), Chemical and physiological notes on native and acclimatised mydriatic
plants of Queensland. Australasian Medical Gazette, 14, 457-460. [An examination of native
and introduced plant species of Queensland. This publication is interesting in a historical
context].
Lee TH, Juang SH, Hsu FL, Wu CY, (2005), Triterpene acids from the leaves of
Planchonella duclitan (Blanco) Bakhuizan. Journal of the Chinese Chemical Society, 52, 6,
1275-1280. [This study reports on the isolation and structural identification of triterpenes
Leslie EM, Deeley RG, Cole SPC, (2001), Toxicological relevance of the multidrug
resistance protein 1, MRP1 (ABCC1) and related transporters. Toxicology, 167, 1, 3-23. [This
study reports on the interaction between flavonoids and the multidrug resistance protein 1 and
Levetin E, McMahon K, (2003), Plants and Society. 3rd ed. McGraw-Hill, Dubuque, Iowa.
USA. [A review of the history and importance of plant usage, including the usage of plants as
medicines. This report is useful in understanding the historical development of plant based
medicinal systems].
Leyland E, (2002), Wajarri wisdom : food and medicinal plants of the Mullewa/Murchison
district of Western Australia as used by the Wajarri people Yamaji Language Centre,
Geraldton, W.A. [A comprehensive review of the traditional usage of Australian plants by the
Wajarri people of West Australian. Uses for foods and medicines are examined].
Li RW, Myers SP, Leach DN, Lin GD, Leach G, (2003), A cross-cultural study- anti-
25–32. [An interesting cross-cultural study of the anti-inflammatory activity of both Australia
and Chinese plants. The effect of Acacia ancistrocarpa extracts on the inflammatory enzyme
cyclooxygenase is reported].
Lis-Balchin M, Deans S, Hart S, (1996), Bioactivity of New Zealand medicinal plant oils.
International Symposium on Medicinal and Aromatic Plants. Crackier, LE, Nolan, L and
Shetty, K (eds). Acta Horticulcurae 426, 13-30. [An examination of the antimicrobial activity
of essential oils of New Zealand plants. Of particular interest is the antimicrobial activity of
Leptospermum species].
Low T, (1990), Bush medicine. A pharmacopoeia of natural remedies. Angus and Robertson,
more at the interested lay person than at researchers in the field although it is also of value to
Low D, Rawal BD, Griffin WJ, (1974), Antibacterial action of the essential oils of some
the oil Eucalyptus citriodora. Planta Medica, 26, 184-189. [This study reports on the
antibacterial activity of Eucalyptus citriodora essential oil against a range of bacterial
species].
MacDonald IAW, Reaser JK, Bright C, Neville LE, Howard GW, Murphy SJ, Preston G,
(2003), Invasive alien species in Southern Africa. National Reports and Directory of
Resources, Lusaka, Zambia. [A report of alien plant species in southern Africa. Several
Mahato SB, Pal BC, Price KR, (1989), Structure of acaciaside, a triterpenoid trisaccharide
Maiden JH, (1925), The forest flora of New South Wales. Volume 8, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1922), The forest flora of New South Wales, Volume 7, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1913), The forest flora of New South Wales. Volume 5, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1911), The forest flora of New South Wales. Volume 4, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1908), The forest flora of New South Wales. Volume 3, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1907), The forest flora of New South Wales. Volume 2, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1904), The forest flora of New South Wales. Volume 1, Government Printer,
Sydney, Australia. [An early review of plants of New South Wales, particularly those used by
in a historical context].
Maiden JH, (1898), Indigenous vegetable drugs. Agricultural Gazette of New South Wales, 9,
1106-1127. [An early review of plants of New South Wales, particularly those used by either
historical context].
Maiden JH, (1889), The useful native plants of Australia. Turner and Henderson, Sydney,
Australia. [An early review of plants of New South Wales, particularly those used by either
historical context].
Mandal R, Dhaliwal PK, (2007), Antifertility effect of Melia azedarach Linn. (dharek) seed
extract in female albino rats. Indian Journal of Experimental Biology, 45, 10, 853-860. [This
Manohar V, Ingram C, Gray J, (2000), Antifungal activities of origanum oil against Candida
albicans. Journal of Molecular Cell Biochemistry, 228, 111-117. [This study reports on the
African medicinal plants. II. Hypoxoside, a new glycoside of uncommon structure from
Hypoxis obtusa Bush, Tetrahedron, 38, 1683–1687. [This study reports on the isolation and
identification of a novel glycoside from the African medicinal plant Hypoxis obtusa].
Maslin BR, Conn EE, Dunn JE, (1987), Cyanogenic Australian species of Acacia: a
preliminary account of their toxic potential. In: Turnbull, J.W. (Ed.), Australian Acacias in
Proceedings, 16, 107–111. [This study reports on the toxicity of Australian Acacia species
Agricultural and Food Chemistry, 50, 7244-7248. [This study explores the linkage between
McChesney JD, (1993), Biological and chemical diversity and the search for new
pharmaceuticals and other bioactive natural products. In Human Medicinal Agents From
Plants, Balandrin MF, Kinghorn AD (Eds), American Chemical Society, Washington DC,
USA, 38-47. [A review of the the phytochemical diversity across plant species and the
McKenzie R, (1997), Australian native poisonous plants, Australian Society for Growing
Accessed 12 January 2010. [A review of the toxic plants of Australia. This report is
botanicals. Drug Information Journal, 32, 513-524. [This report describes the development
and usage of a useful invertebrate bioassay for the examination of toxicity in plant extracts].
Meert JG, (2003), A synopsis of events related to the assembly of eastern Gondwana.
which shaped the world, resulting in the differing environmental conditions and biodiversity
in different regions of the world. The emphasis is on the land mass known as Eastern
Meyer BN, Ferrigni NR, Putnam JE, Jacobsen LB, Nichols DE, McLaughlin JL, (1982),
Brine shrimp: a convenient general bioassay for active plant constituents. Planta Medica, 45,
31-34. [This report describes the development and usage of a useful invertebrate bioassay for
Mills S, Bone K, (2000), Principles and practice of phytotherapy – modern herbal medicine.
Churchill Livingstone, New York, 31-34. [This study reports on the effect of flavonoids on
Ming JC, Verra RR, Fraisso DJ, (1998), Chemical composition of essential oil of Callistemon
citrinus (curtis) Skeel from Reunion. Journal of Essential Oil Research, 10, 4, 429- 431.
[This study reports on the phytochemical composition of Callistemon citrinus essential oil].
Miniati E, (2007), Assessment of phenolic compounds in biological samples. Ann Ist Super
Sanità, 43, 4, 362-368. [This study reports on the antioxidant activity of phenolics
compounds and their ability to maintain redox homeostasis and prevent various diseases].
Misra LN, Huq F, Ahmed A, Dixit AK, (1997), Chemical composition of the essential oils of
Callistemon lanceolatus DC, and Callistemon polandi F.M. Bailey. Journal of Essential Oil
Research, 9, 6, 625- 628. [This study reports on the phytochemical composition of the
Moerman DE, (1998), Native American Ethnobotany. Timber Press, Portland Oregon, USA.
[A review of the ethnobotany north American plants. This is a good starting point for anyone
terpinen-4-ol, the main bioactive component of Melaleuca alternifolia Cheel (tea tree) oil
against azole-susceptible and -resistant human pathogenic Candida species. BMC Infectious
Diseases, 6, 158. [This study reports on the antifungal activity of Melaleuca alternifolia
Nahak G, Sahu RK, (2010), In vitro antioxidative acitivity of Azadirachta indica and Melia
[This study reports and compares the antioxidant activities of the leaves 2 related plant
Journal of Medical Chemistry, 31, 1250-1253. [This study reports on cytotoxicity of flavanol
Nash D, (2000), Aboriginal plant use and technology. Australian National Botanic Gardens,
ACT, Australia. [A general review of Australian plant usage, easily comprehensible without a
scientific background].
Nel JL, Richardson DM, Rouget M, Mgidi TN, Mdzeke N, Le Maitre DC, van Wilgen BW,
plant species in South Africa: towards prioritising species and areas for management action.
South African Journal of Science, 100, 53-64. [A listing of invasive alien plant species
Agricultural and Food Chemistry, 54, 9820-9826. [This study reports on the ascorbic acid
levels and antioxidant activities of the fruit of several endemic Australian plants. Of
antioxidants].
Netzel M, Netzel G, Tian Q, Schwartz S, Konczak I, (2007), Native Australian fruits – a
novel source of antioxidants for food. Innovative Food Science and Emerging Technologies,
8, 339-346. [This study reports on the ascorbic acid levels and antioxidant activities of the
fruit of several endemic Australian plants. Of particular importance for this volume is the
Newman DJ, Cragg GM, (2007), Natural products as sources of new drugs over the last 25
years. Journal of Natural Products, 70, 3, 461–477. [This publication explains the
years].
Newman DJ, Cragg GM, Snader KM, (2000), The influence of natural products on drug
discovery. Natural Product Reports, 17, 215-234. [This publication explains the importance
O’Connell JF, Latz PK, Barnett P, (1983), Traditional and modern plant use among the
Alyawara of central Australia. Economic Botany, 37, 80-109. [A review of the uses of plants,
Opdyke DLJ, (1976), Citral. Monographs on fragrance raw materials. Food and Cosmetics
Toxicology, 14, 615. [An examination of the chemistry of citral from Backhousia citriodora].
Oyedeji AO, Ekundayo O, Olawore ON, Adeniyi BA, Koenig WA, (1999), Antimicrobial
activity of the essential oils of five Eucalyptus species growing in Nigeria. Fitoterapia 70,
Page S, Olds M (Eds), (2004), Botanica : The Illustrated A - Z of Over 10,000 Garden Plants
for Australian Gardens and How to Cultivate Them. Random House, Australia. [A
generalized listing of Australian plants together with their characteristics and growth
identification].
Amsterdam. [A general examination of the known plants of the New Guinea region].
Palmer E, (1883), On plants used by the natives of North Queensland, Flinders and Mitchell
Rivers for food, medicine and clothing. Journal and Proceedings of the Royal Society of New
South Wales, 17, 93-113. [An early examination of ethnobotanical use of plants by northern
Queensland Aborigines as medicines. The review examines the use of plants as both foods
Medicine, 4, 465-473. [This article reviews Indian Ayurvedic and traditional Chinese
medicine systems and compares them. This review is a good starting point for readers with
Penfold AR, Grant R, (1925), The germicidal values of some Australian essential oils and
their pure constituents. Journal of the Royal Society of New South Wales, 60, 167-70. [An
early study reporting on the antimicrobial activity of the essential oils of some Australian
Penfold AR, Grant R, (1925), The germicidal values of some Australian essential oils and
their pure constituents, together with those for some essential oil isolates, and synthetics. Part
III. Journal of the Royal Society of New South Wales, 59, 346-349. [An early study reporting
on the antimicrobial activity of the essential oils of some Australian plants including
Melaleuca species].
Pennacchio M, Kemp AS, Taylor RP, Wickens KM, Kienow L, (2005), Interesting biological
from Eremophila species. Journal of Ethnopharmacology, 53, 2-27. [An examination of the
studies].
Pennacchio M, Alexander E, Ghisalberti EL, Richmond GS, (1995), Cardioactive Effects of
Polombo EA, Semple SJ, (2001), Antibacterial activity of Australian medicinal plants.
Journal of Ethnopharmacology, 77, 151-157. [This study reports on the antimicrobial activity
Porter NG, Wilkins A, (1999), Chemical, physical and antimicrobial properties of essential
[This study reports on the antimicrobial activity of Leptospermum scoparium and Kunzea
15, 2019–2020. [This study reports on the isolation and structural identification of 2-methyl-
Ramsewak RS, Nair MG, Strasburg GM, DeWitt DL, Nitiss JL, (1999), Biologically active
carbazole alkaloids from Murraya koenigii. Journal of Agricultural Food Chemistry, 47, 444-
447. [This study reports on the mosquitocidal and antimicrobial bioactivities, as well as the
Livingstone, Edinburgh, UK. [This is a general pharmacology text, useful for explaining
pharmacological effects].
Reid E, Betts TJ, (1979), The records of Western Australian plants used by Aboriginals as
medicinal agents. Planta Medica, 36, 164-173. [A study of plants of the north Queensland
Use of Scopolamine. Therapeutic Drug Monitoring, 27, 5, 655-665. [This study reports on
alkaloid scopolamine].
[This study reports on the antioxidant activity of phenolics compounds and their ability to
flavonoids and phenolic acid. Free Radical Biology and Medicine, 20, 933-956. [This study
reports on the antioxidant activity of phenolics compounds and their ability to maintain redox
Botany, 481, 35-59. [A review of the botany and enthnopharmacological usage of plants of
Aborigines. Journal of the Adelaide Botanic Gardens, 15, 2, 101-106. [A review of the
Robbers JE, Tyler VE, (2000), Herbs of Choice – the therapeutic use of phytomedicinals.
Haworth Herbal Press, Binghampton, New York, 69-89. [This study reports on the
Roth I, Lindorf H, (2002), South American medicinal plants. Botany, remedial properties and
general use. Springer, Berlin, Germany. [A review of the plants of South America that have
traditionally been used as medicines. Ethnopharmacology, botany and biology are examined].
Roth WE, (1903), Superstition, magic and medicine. North Queensland Ethnography Bulletin
citriodora oil. Simply Essential, 38, 6-8. [This study reports on the antimicrobial activity of
Biology, 44, 3, 194-201. [This study reports on the antimicrobial activity of Callestemon
Santos RL, (1997), The Eucalyptus of California. Seeds of good or seeds of evil. Ally-Cass
USA].
Sartorelli P, Marquioreto AD, Amaral-Baroli A, Lima MEL, Moreno PRH, (2007), Chemical
composition and antimicrobial activity of the essential oils from two species of Eucalyptus.
Phytotherapy Research, 21, 231-233. [This study reports of the phytochemistry and
is described].
Biology, 44, 3, 194-201. [This study reports on the antimicrobial activity of Callistemon
Ecology, 845-873. [This study reports on the phytochemistry and antibacterial activity of
Semple SJ, Reynolds GD, O’Leary MC, Flower RLP, (1998), Screening of Australian
medicinal plants for antiviral activity. Journal of Ethnopharmacology, 60, 163-172. [This
study reports on the antiviral activity of several Australian Aboriginal medicinal plants
and the plant extracts from Amaryllidaceae. Phytotherapy Research, 17, 10, 1220-1223. [This
study reports on the antimalarial activity of extracts of plants of the family Amaryllidaceae as
Setzer MC, Setzer WN, Jackes BR, Gentry GA, Moriarity DM, (2001), The medicinal value
membrane calcium channels. General Pharmacology, 29, 2, 251–255. [This study reports on
Shai LJ, McGaw LJ, Aderogba MA, Mdee LK, Eloff JN, (2008), Four pentacyclic
triterpenoids with antifungal and antibacterial activity from Curtisia dentata (Burm. F) C.A.
Sm. leaves. Journal of Ethnopharmacology, 119, 2, 238-244. [This study reports on the
leaves].
questions and promises. Journal of Nutritional Biochemistry, 16, 449 - 466. [This study
reports on the potential and mechanism of resveratrol in the inhibition of cancer cell growth].
Forum, 3, 21-36. [A review of the plant usage of the Pukatja (formerly Ernabella) Aboriginal
clypeolata essential oil. Flavor and Fragrance, 20, 127-130. [This study reports on the
antmicrobial activity of Achillea clypeolata essential oil against a range of bacterial species.
Journal of the Adelaide Botanic Gardens, 14, 1-65. [A comprehensive review of the
ethnobotany of the Northern Territory, Australia. The discussion of medicinal plant usage is
of particular interest].
Stanley TD, Ross EM, (1989), Flora of South-eastern Queensland, Volume 3, Miscellaneous
examines the biology of flora from south eastern Queensland Australia. Of particular interest
suballiance of Myrtaceae. Telopea 2, 379-383. [A listing of the taxonomic changes within the
genus Leptospermum].
The Digitalis Investigation Group, (1997), The effect of digoxin on mortality and morbidity
in patients with heart failure, New England Journal of Medicine, 336, 525-533. [This study
reports on the medicinal potential of the cardiac glycoside digoxin in patients with heart
failure].
Tindale MD, Roux DG, (1969), A phytochemical survey of the Australian species of Acacia.
Acacias].
Trivedi NA, Hotchandani SC, (2004), A study of the antimicrobial activity of oil of
Eucalyptus. Indian Journal of Pharmacology, 36, 2, 93-95. [This study reports on the
glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in mice.
Journal of Nutrition, 133, 2125-2130. [This study explores the linkage between redox
van Veldhuisen DJ, de Boer RA, (2009), Low-dose digoxin in heart failure. International
Melia azedarach].
Wang Y, Lee K, Chan F, Chen S, Leung L, (2006), The red wine polyphenol resveratrol
Sciences, 92, 1, 71 - 77. [This study reports on the potential of resveratrol to inhibit estrogen
Wardle P, (1991), The vegetation of New Zealand. Cambridge University Press, Cambridge,
UK. [A generalised explanation of the plants of New Zealand. This is suitable for interested
lay persons].
Watt JM, Breyer-Brandwijk MG, (1962), Medicinal and poisonous plants of southern and
eastern Africa. E. and S. Livingstone, Edinburugh, UK. [A review of the medicinal and toxic
Mankind, 7, 137-146. [An early review of Aboriginal plant use. This is particularly
Webb LJ, (1959), Some records of medicinal plants used by the aborigines of tropical
Queensland and New Guinea. Proceedings of the Royal Society of Queensland, 71, 103. [An
early review of Aboriginal plant use in Queensland and New Guinea. This is particularly
Webb LJ, (1949), Australian Phytochemical Survey, Part 1. CSIRO Bulletin, number 241,
Webb LJ, (1948), Guide to the medicinal and poisonous plants of Queensland. CSIRO
bulletin number 232, Government Printer, Melbourne, Australia. [An early review of
Australian toxic and medicinal plants. This is particularly interesting in a historical context].
(1995), Cytotoxic activity of Amaryllidaceae alkaloids. Planta Medica, 61, 77-79. [This
antibacterial components of some New Zealand honeys. Food Chemistry, 70, 427-435. [This
study examines the antibacterial chemical components of New Zealand honeys, especially by
White ME, (1998), The Greening of Gondwana, 3rd Edition. Kangaroo Press, Australia.
[This is a comprehensive examination of the evolutionary events and changes that have
White EP, (1944a), Part IX. Isolation of β-phenylethylamine from Acacia species, New
Zealand. Journal of Science and Technology, 25 (Sec. B), 139–142. [This is an early
White EP, (1944b), Part XIII. Isolation of tryptamine from some Acacia species, New
citriodora: antibacterial and antifungal activity. Journal of Agricultural and Food Chemistry,
51, 76-81. [This study reports on the antibacterial and antifungal activities of Backhousia
Woolls W, (1867), A contribution to the flora of Australia. F. White, Sydney, Australia. [An
Wu JH, Huang CY, Tung YT, Chang ST, (2008), Online RP-HPLC-DPPH Screening Method
Journal of Agricultural and Food Chemistry, 56, 328-332. [This report describes the
development and usage of a method for the quantification of free radical scavenging activity
in plant extracts. The free radical scavenging activity of Acacia confusa is reported].
Yen F, Wu T, Lin L, Cham T, Lin C, (2008), Concordance between antioxidant activities and
flavonol contents in different extracts and fractions of Cuscuta chinensis. Journal of Food
Chemistry, 108, 455-462. [This study reports on the antioxidant activity of flavones and
Youdim KA, Spencer JPE, Schroeter H, Rice-Evans CA, (2002), Dietary flavonoids as
potential neuroprotectors. Biological Chemistry, 383, 503-519. [This study reports on the
Immunopharmacology, 40, 151–162. [This study reports on the anti-apoptotic activity of the
1208-1216. [This study reports on the interaction between flavonoids and the breast cancer
Zola N, Gott B, (1992), Koorie plants, Koorie people. Traditional Aboriginal food, fibre and
healing plants of Victoria. Koorie Heritage Trust, Melbourne Australia. [A review of the
plants traditionally used by Australian Aborigines from Victoria as foods and medicines. This