Advances in Animal and Veterinary Sciences
Research Article
The Nephropreventive and Antioxidant Effects of Navel Orange Peel
Hydroethanolic Extract, Naringin and Naringenin in N-Acetyl-Paminophenol-administered Wistar Rats
OSAMA M. AHMED1,*, HANAA I. FAHIM1, HEBA Y. AHMED2, BASANT MAHMOUD3, SAAD ALI SAAD
ALJOHANI4, WALAA H. ABDELAZEEM1
1
Physiology Division, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; 2Rodents Division, Department of Harmful Animals, Plant Protection Research Institute, Agriculture Research Center,
Egypt; 3College of Medicine, Al-Rayyan Colleges, Al Madinah Al Munawarah, 41411, Saudi Arabia; 4Biochemistry
Division, Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt.
Abstract | The purpose of present study was to assess the nephropreventive and antioxidant effects of navel orange peel
hydroethanolic extract, naringin and naringenin in N-acetyl-p-aminophenol (APAP)-administered male Wistar rats.
APAP was administered at dose 0.5 g/kg/b.w. every other day by oral gavage for 4 weeks to male Wistar rats. APAPadministered rats were treated with navel orange peel hydroethanolic extract (50 mg/kg b.w.), naringin (20 mg/kg b.w.)
and naringenin (20 mg/kg b.w.) every other day by oral gavage during the same period of APAP administration. The
treatment of APAP-administered rats with navel orange peel extract, naringin and naringenin significantly improved
the kidney function manifested by a significant decrease in the elevated serum urea, uric acid and creatinine levels.
In association, the deteriorated kidney histological changes represented by congestion, hypertrophied glomerulus,
vacuolization of the endothelial cells lining the glomerular tuft and interstitial nephritis in APAP-administered rats
were remarkably amended. The elevated kidney lipid peroxidation and the lowered glutathione content as well as
the suppressed antioxidant enzymes activities were significantly ameliorated. In conclusion, the navel orange peel
hydroethanolic extract, naringin and naringenin have improvement effects on kidney function and structural integrity
which may be mediated at least in part to via their antioxidant efficiencies.
Keywords | N-acetyl-p-aminophenol, Kidney injury, Navel orange peel, Naringin, Naringenin, Oxidative stress.
Editor | Kuldeep Dhama, Indian Veterinary Research Institute, Uttar Pradesh, India.
Received | July 22, 2018; Accepted | August 19, 2018; Published | November 23, 2018
*Correspondence | Osama M Ahmed, Physiology Division, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; Email:
osamamoha@yahoo.com
Citation | Ahmed OM, Fahim HI, Ahmed HY, Mahmoud B, Aljohani SAS, Abdelazeem WH (2019). The nephropreventive and antioxidant effects of navel
orange peel hydroethanolic extract, naringin and naringenin in n-acetyl-p-aminophenol-administered wistar rats. Adv. Anim. Vet. Sci. 7(2): 96-105.
DOI | http://dx.doi.org/10.17582/journal.aavs/2019/7.2.96.105
ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331
Copyright © 2019 Ahmed et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
INTRODUCTION
N
-acetyl-p-aminophenol (APAP), acetaminophen, is
one of the widely used and most popular drugs for
the therapy of pain and fever (Madinah et al., 2015). Although APAP is considered as a safe drug, its overdose
could result in severe liver and kidney injuries, and even
death (Kandemir et al., 2017; Bektur et al., 2016). APAP is
especially dangerous on the liver when it is taken over long
periods (Sarumathy, 2011). Although kidney injury is less
common than liver injury in APAP overdose, acute renal
failure and tubular damage can occur even in the absence
February 2019 | Volume 7 | Issue 2 | Page 96
of liver toxicity (Madinah et al., 2015). The liver, and to a
lesser extent the kidney and intestine, are the major organs implicated in the metabolism of APAP (Bessems and
Vermeulen, 2001). In its biotransformation, APAP is deactivated in the liver by drug-metabolizing enzymes such
as uridine diphosphate (UDP) glucuronosyltransferases
(UGTs) and sulfotransferases (SULTs) to cause glucuronylation and sulfation of metabolites which are readily excreted in urine without any signs of toxicity at therapeutic
doses (Mazaleuskaya et al., 2015; Kandemir et al., 2017).
At high doses, a significant portion of APAP is metabolized by the cytochrome P450 system leading to the proNE
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duction of reactive toxic metabolite, N-acetyl-p-benzoquinone imine (NAPQI) which is detoxified by interaction
with sulfhydryl groups by the reduced glutathione (GSH)
(El-Shaibany et al., 2016; Abdel-Zaher et al., 2008). The
NAPQI, that is not detoxified, begins lipid peroxidation
and ultimately induces kidney injury (El-Shaibany et al.,
2016). Therefore, the APAP toxicity is determined by the
amount of the produced NAPQI and the inadequate GSH
for APAP detoxification (Naguib et al., 2014). The elevated serum urea and creatinine levels are indicators of acute
tubular necrosis induced by APAP (Cobden et al., 1982;
Blazka et al., 1996). It was reported that free radicals produced by exposure to drug toxicity and oxidative damage
in an organism plays an important role in APAP-induced
hepatorenal injuries (Das et al., 2010).
the recommendations of the Experimental Animals Ethics
Committee of Faculty of Science, Beni-Suef University,
Egypt (The ethical approval number is BSU/FS/2014/4).
All efforts were done to minimize the suffering, distress
and discomfort of the animals.
CHEMICALS
APAP, naringin and naringenin were purchased from Sigma-Aldrich (St. Louis, MO, USA). All other chemicals
used in this investigation were of analytical grade.
EXTRACT PREPARATION
Navel orange (mutant of Citrus sinensis) fruits were obtained from local markets in Beni-Suef Governorate,
Egypt. They were authenticated by Dr. Walaa A. Hasan,
Lecturer of Plant Taxonomy, Department of Botany, FacNatural compounds having antioxidant activity could be ulty of Science, Beni-Suef University, Egypt. Navel orange
used as alternative treatments of APAP toxicity (Canayakin fruits were washed several times with fresh water to ensure
et al., 2016). Flavonoids are naturally occurring substances removal of any contamination. Then, they were peeled and
that have different therapeutic applications and pharmaco- the peels were air dried in shade area for 20 days. The dried
logical action (Hamid et al., 2012). Some flavonoids due to peels were coarsely powdered with an electrical grinder
their phenolic structures have antioxidant properties and and the powder was soaked in 70% aqueous ethanol for 72
inhibit free radical production (Topal et al., 2016). Citrus hours at room temperature. To fully mix the powder with
fruit extracts possess high quantity of flavonoids and ex- the extraction solvent, the suspensions were allowed to be
hibit potent free radical scavenging efficacy (Alam et al., stirred frequently. The hydroethanolic extract was then fil2016). Naringin and naringenin are citrus flavonoids that tered through Whatman filter paper and was evaporated
are strong scavengers of free radicals and prevent lipid per- under reduced pressure using Rotavapor to yield crude exoxidation (Cavia-Saiz et al., 2010; Adil et al., 2016). In tract of navel orange peel (Mostafa et al., 2016; Ahmed et
this regard, Dahal and Mulukuri (2015) stated that flavo- al., 2017).
noids prevent renal oxidative stress via increasing the rate
of GSH by induction of its synthesis or by a scavenger ef- EXPERIMENTAL DESIGN
The animals used in this study were allocated into five
fect of free radicals and reactive oxygen species (ROS).
groups (six rats for each) and were designed as follow:
In conductance with the previous literature, the present Group 1 (Normal control group): Rats of this group were
study aimed to evaluate the comparable nephropreventive regarded as normal control group and were orally adminisand antioxidant effects of navel orange peel hydroethanolic tered the equivalent volume of 1% carboxymethylcellulose
extract, naringin and naringenin in APAP-supplemented (CMC), every other day for 4 weeks by oral gavage.
Group 2 (APAP group): Animals of this group were remale Wistar rats.
garded as APAP control group and were orally administered APAP (dissolved in distilled water) at dose level of
MATERIALS AND METHODS
0.5 g/kg b.w. every other day for 4 weeks by oral gavage
(Tabassum and Agrawal, 2004).
EXPERIMENTAL ANIMALS
Group 3 (APAP + navel orange peel hydroethanolic exAdult male Wistar rats weighing 130-150 g (10-12 weeks) tract group): Rats of this group were administered APAP
were used in the present investigation. The animals ob- as group 2 and were treated with navel orange peel hytained from the animal house in the National Research droethanolic extract (dissolved in 1% CMC) at dose 50
Center, Cairo, Egypt, were housed in good aerated cages mg/kg b.w. (Mostafa et al., 2016) by oral gavage every othin Animal House of Zoology Department, Faculty of Sci- er day for 4 weeks.
ence, Beni-Suef University, Egypt at 12-hours daily light- Group 4 (APAP + naringin group): Rats of this group
dark cycles and temperature between 20-25°C. Animals were administered APAP as group 2 and were treated with
were supplemented daily standard pelleted diet and were naringin (dissolved in 1% CMC) at dose level of 20 mg/
given water ad libitum. The animals were kept for 2 weeks kg b.w. (Adil et al., 2016) by oral gavage every other day
under observation before the onset of the experiment to for 4 weeks.
exclude any intercurrent infection. All animal methodolo- Group 5 (APAP + naringenin group): Rats of this group
gies followed the guidelines and were in accordance with were administered APAP as group 2 and were treated with
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naringenin (dissolved in 1% CMC) at dose level of 20 mg/
kg b.w. (Mershiba et al., 2013) by oral gavage every other
day for 4 weeks.
BLOOD AND KIDNEY SAMPLING
By the end of the experiment, blood was collected from
jugular veins, left to coagulate at room temperature and
then centrifuged at 3000 round per minute (rpm) at room
temperature for 15 min. The sera were quickly separated
and kept in deep freezer at -30oC pending detection of
various biochemical investigations.
After blood sampling, animals were decapitated by cervical
dislocation and dissected. Pieces of kidney (5 mm3) of each
animal were fixed in 10% neutral buffer formalin for histopathological studies. Another 0.5 g of the kidney of each
rat was homogenized in 5 ml 0.9% NaCl. The homogenate
was centrifuged at 3000 rpm for 15 minutes and separated
supernatants were kept in deep freezer at -30 oC pending
detection of oxidative stress and antioxidant defense system markers.
BIOCHEMICAL ANALYSIS
Serum creatinine and urea levels were determined according to the methods of Fabiny and Ertingshausen (1971)
and Tabacco et al. (1979) respectively using reagent kits
obtained from Biosystem S.A. (Spain). Uric acid was assayed by enzymatic colorimetric method using kits obtained from Spinreact according to the method of Fossati
et al. (1980).
DETECTION OF OXDATIVE STRESS AND ANTIOXIDANT
DEFENSE SYSTEM PARAMETERS
air oven for 24 hours. The paraffin wax tissue blocks were
prepared for sectioning by microtome at 4 µm thickness.
Freshly prepared sections, floating on a 40°C water bath
containing distilled water, were collected on glass slides,
deparaffinized, stained with hematoxylin and eosin (H&E)
stains according to the method of Banchroft et al. (1996).
STATISTICAL ANALYSIS
All data were expressed as means ± standard error (SE).
Statistical analysis was done using Statistical Package for
Social Sciences (SPSS) computer software (version 22),
IBM software, USA. One-way analysis of variance (ANOVA) test was used to elucidate significance among group
means, followed by Tukey’s post-hoc test and least significance difference (LSD) to compare mean values pair-wise.
Differences were considered significant at p<0.05.
RESULTS
The serum creatinine, urea and uric acid levels were significantly elevated (P>0.05) in APAP-administered rats
recording percent changes of 83.01, 168.23 and 92.59 %
respectively as compared with normal control rats. The
treatment of APAP-administered rats with navel orange
peel extract produced a significant (P>0.05) amelioration
of the elevated creatinine, urea and uric acid levels recording percent changes of -45.36 -58.84 and -53.52 % respectively as compared with APAP-administered rats. Similarly, the treatment with naringin and naringenin significantly
(P>0.05) decreased the elevated serum creatinine, urea and
uric acid levels. The peel extract was the most potent in
improving the elevated creatinine level (Table 1).
Kidney LPO of APAP-administered rats was significantly increased (P>0.05) recording percentage change
of 53.19% as compared with normal control. Conversely,
GSH level was significantly declined (P>0.05) recording
-34.85% as compared with normal control. The treatment
of APAP-administered rats with peel extract produced a
significant decrease in kidney LPO (-22.16%) and a significant increase in kidney GSH content (16.46%) as compared with APAP–administered control rats. Similarly,
the naringin and naringenin treatment significantly ameliorated the elevated LPO and the lowered GSH content
as compared with APAP-administered control. The peel
extract was most potent in improving the elevated LPO
(-22.16%) while naringenin was the most effective in alleHISTOPATHOLOGICAL INVESTIGATION
After dissection, kidneys from each rat were rapidly ex- viating the lowered kidney GSH content (+22.10%) (Table
cised and then washed in saline solution by perfusion. 2).
Pieces from the kidney (5 mm3) of each rat were rapidly
taken and fixed in 10% neutral buffered formalin for 24 APAP administration results in a marked impairment in
hours. Then, they were rinsed in running tap water and se- kidney antioxidant enzyme activities as demonstrated by
rial dilutions of ethanol were used for dehydration process, the significant decline (P>0.05) in GST, GPx and SOD
cleared in xylene and embedded in paraffin at 56°C in hot activities. As a result of treatment of APAP-administered
Kidney lipid peroxidation (LPO) was detected by estimation of the formed manlondialdehyde (MDA) level according to the method of Beutler et al. (1963). Kidney glutathione (GSH) content was determined according to the
method of Preuss et al. (1989). Kidney glutathione peroxidase (GPx), glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities were assayed according
to the methods of Matkovics et al. (1998), Mannervikand
Guthenberg (1981) and Marklund, and Marklund (1974)
respectively. All reagents for detection of oxidative stress
and antioxidant parameters were prepared in our laboratory.
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Table 1: Effects of navel orange peel ethanolic extract, naringin and naringenin on serum urea, uric acid and creatinine
levels of acetaminophen-administered albino rats.
% Change
Uric acid (mg/dl)
% Change
Urea (mg/dl)
% Change
Creatinine (mg/dl) Parameter Groups
-
1.62 ±
0.143
-
25.66 ±
1.49
-
0.53 ±
0.042
Normal
92.59
3.12 ±
0.104a
168.23
68.83 ±
1.01a
83.01
0.97 ±
0.031a
APAP
-53.52
1.45 ±
0.088b
-58.84
28.33 ±
2.10b
-45.36
0.53 ±
0.042b
APAP + navel orange
peel extract
-56.41
1.36 ±
0.114b
-57.63
29.16 ±
2.31b
-42.26
0.56 ±
0.036b
APAP + naringin
-58.11
28.83 ±
-40.20
0.58 ±
APAP + naringenin
1.21 ±
2.52b
0.038b
0.147b
Data were expressed as mean ± SE. - Number of animals in each group was 6.
a
Significantly different from normal value at p < 0.05, b Significantly different from APAP value at p < 0.05.
Percentage (%) changes were calculated by comparing APAP-administered rats with normal control and APAP-administered
treated rats with APAP-administered rats.
-61.22
Table 2: Effects of navel orange peel extract, naringin and naringenin on LPO and GSH levels of kidney of acetaminophenadministered albino rats.
% Change
GSH (nmol/100mg tissue) % Change
LPO (nmol /100mg tissue)
Parameter Groups
-
26.11 ±
0.50
-
69.65±
1.73
Normal
-34.85
17.01 ±
0.45a
53.19
106.70 ±
1.25a
APAP
16.46
19.81 ±
0.60ab
-22.16
83.05 ±
4.64b
APAP + navel orange peel
extract
13.16
19.25 ±
0.64ab
-19.42
85.98 ±
4.07ab
APAP + naringin
-17.65
87.87 ±
APAP + naringenin
20.77 ±
4.23ab
0.90ab
Data were expressed as mean ± SE. - Number of animals in each group was 6.
a
Significantly different from normal value at p < 0.05, b Significantly different from APAP value at p < 0.05.
Percentage (%) changes were calculated by comparing APAP-administered rats with normal control and APAP-administered
treated rats with APAP-administered rats.
22.10
Table 3: Effects of navel orange peel extract, naringin and naringenin on GST, GPx and SOD levels of kidney of
acetaminophen-administered albino rats.
%
Change
SOD
%
(mU/100mg tissue) Change
GPx
(mU/100 mg tissue)
%
Change
GST
(U/100mg tissue)
Parameter Groups
-
98.57±
0.97
-
154.78 ±
1.27
-
109.50 ±
2.32
Normal
-19.57
79.27 ±
1.22a
-6.61
144.55 ±
1.10a
-17.08
90.79 ±
2.34a
APAP
-7.54
73.29 ±
1.46a
3.63
149.80 ±
0.50ab
11.51
101.24 ±
3.41
APAP + navel orange
peel extract
5.05
83.28 ±
2.36a
4.75
151.43 ±
0.87b
12.28
101.94 ±
3.25
APAP + naringin
3.52
149.65 ±
14.85
104.28 ±
APAP + naringenin
90.77 ±
1.38ab
2.69b
2.33ab
Data were expressed as mean ± SE. - Number of animals in each group was 6.
a
Significantly different from normal value at p < 0.05, b Significantly different from APAP value at p < 0.05.
Percentage (%) changes were calculated by comparing APAP-administered rats with normal control and APAP-administered
treated rats with APAP-administered rats
14.50
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rats with the peel extract, GST and GPx activities were
remarkably increased; the recorded percentage changes
were 11.51 and 3.63% respectively as compared with
APAP-administered rats. Furthermore, the treatment of
APAP-administered rats with naringin and naringenin
markedly increased the GST, GPx and SOD activities.
However, while the effect of navel orange peel and
naringin on kidney GPx activity was significant (P>0.05),
the effect of naringenin was significant on GST, GPx and
SOD activities. The naringenin was the most effective in
increasing the declined activities of GST and SOD while
naringin was the most potent treatment in improving GPx
activity (Table 3).
(G), normal proximal tubules (PT) and distal tubules
(DT) 1b-d: Photomicrograph of kidney section of APAPadministered rats showing congestion of renal blood vessel
(C), congestion of glomerulus (CG) in b, hypertrophied
glomerulus (HG), vacuolization of the endothelial cells
lining the glomerular tuft (V) in c and interstitial nephritis
(IF) in d. ×400
In spite of these alleviative effects of navel orange peel hydroethanolic extract, naringin and naringenin, there are
still slight congestion in the glomeruli and intertubular
blood vessels.
HISTOLOGICAL CHANGES
Kidney sections of normal rats demonstrated the normal
histoarchitecture of the glomerulus and surrounding tubules, proximal and distal tubules (Figure 1; Photomicrograph 1a). Oral administration of APAP caused several lesions in kidney tissue including congestion of renal blood
vessel and congestion of glomerulus (Figure 1; Photomicrograph 1b). It also produced hypertrophy of the glomerulus and vacuolization of the endothelial cells lining the
glomerular tuft (Figure 1; Photomicrograph 1c) as well as
interstitial nephritis (Figure 1; Photomicrograph 1d). On
the other hand, the treatment of the APAP-administered
rats with navel orange peel hydroethanolic extract improved APAP-induced kidney histological lesions and the
kidney attained its normal histological structure with normal glomerulus and tubules (Figure 2; Photomicrographs
2a & b). The same ameliorative effects appeared after treatments with naringin and naringenin (Figures 3 and 4).
Figure 1: Photomicrographs of H&E stained kidney
sections of normal and APAP-administered rats. 1a:
Photomicrograph of kidney section of normal rats showing
normal histologic structure of kidney; normal glomerulus
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Figure 2: Photomicrographs of H&E stained kidney
sections of APAP-administered rats treated with navel
orange peel hydroethanolic extract. 2a: Photomicrograph
of kidney section showing slight congestion of glomerulus
(CG). 2b: Photomicrograph of kidney section showing
normal structure of kidney; normal glomerulus (G),
proximal (Pt) and distal tubules (Dt). X400
Figure 3: Photomicrographs of H&E stained kidney
sections of APAP-administered rats treated with
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naringin. 3a: Photomicrograph of kidney section showing
congestion of renal blood vessel (C) and congestion of
glomerulus (CG). 3b: Photomicrograph of kidney section
showing normal structure of kidney; normal glomerulus
(G), proximal (Pt) and distal tubules (Dt). ×400
Figure 4: Photomicrographs of H&E stained kidney
sections of APAP-administered rats treated with
naringenin showing normal structure of kidney; normal
glomerulus, proximal and distal tubules. Slight glomerular
and intertubular congestion was observed in 4b. X400
DISCUSSION
Kidneys play an essential role in animals and humans
(Kandemir et al., 2017). They remove substances from the
body including various toxins, metabolic products and other foreign substances such as food additives, drugs and pesticides (Wudil and Sarki, 2015). APAP overdose remains
to be the most important cause of toxicity in many parts
of the world among all drug toxicities (Karakus et al. 2013;
Yayla et al., 2014; Canayakin et al., 2016). Hepatotoxic and
nephrotoxic effects of APAP overdose occur by a complex
sequence of events (Hinson et al. 2010). APAP-induced
nephrotoxicity becomes evident after hepatotoxicity in
most cases but the occurrence of renal tubular damage
and acute renal failure, even in the absence of liver injury,
should not be ignored (Eguia & Materson, 1997).
Oral administration of APAP in the present study, at dose
of 0.5 g/kg/b.w. every other day for 4 weeks, showed significant increase in serum levels of creatinine, urea and uric
acid. These results are in parallel with those of various past
publications (Brune et al., 2015; Adil et al., 2016 and Oseni et al., 2017).
Increase in serum urea level is an important marker of renal toxicity (Kandemir et al., 2017). Kidney disease and
function disorders may be manifested by serum urea accu-
February 2019 | Volume 7 | Issue 2 | Page 101
mulation exceeding its clearance rate (Oseni et al., 2017).
Similarly, increase in plasma creatinine level is considered
as kidney dysfunction biomarker (Yousef et al., 2010).
Overdoses of APAP cause many metabolic perturbances
including an increase in serum urea and creatinine (Srinivasan et al., 2014; Ghosh et al., 2010). These changes
occurred as a result of the inactivation of the mitochondrial pathway during APAP-induced cell death (Ijaz et
al., 2016). In addition, Ajami et al. (2010) explained the
increase in the urea and creatinine levels by the presence
of strong correlation between kidney injury and oxidative
stress. They also stated that the elevated ROS production
may alter the filtration surface area and modify the filtration coefficient; this could decrease the glomerular filtration leading to accumulation of creatinine and urea in the
blood.
The increase in serum creatinine, urea and uric acid levels
due to APAP ingestion in the current study were correlated closely with the histopathological changes in the kidney. These histopathological alterations include congestion
of glomerular tuft and renal blood vessel, glomerular hypertrophy, vacuolization of glomerular tuft cells and interstitial nephritis.
The treatment of rats with navel orange peel hydroethanolic extract for 4 weeks, in this study, significantly diminished
the elevated serum levels of kidney function parameters
including creatinine, urea and uric acid and ameliorated
kidney histological architecture and integrity. In accordance with present study, Ahmad et al. (2012) reported that
APAP induced elevation in serum creatinine and urea levels, but co-treatment with extract of orange peel substantially decreased the serum creatinine and urea levels.
In the current study, the levels of creatinine, urea and uric
acid were significantly decreased by naringin treatment
as compared to APAP control rats in association with reduced histological deteriorations in the kidney. These results are in line with those of Adil et al. (2016). Naringenin
administration also decreased the elevated levels of kidney
function parameters. In parallel with this finding, Hermenean et al. (2013) indicated the ability of naringenin to
protect the kidney against CCl4-induced renal toxicity in
male Swiss mice.
The nephroprotective effect of citrus by-products extracts
may be due to presence of phyto-constituents like polyphenolic compounds, especially the characteristic flavanone
glycosides which mainly include hesperidin, neohesperidin, naringin, rutin and narirutin (Alam et al., 2014). This
attribution may explain the most potent effects of navel
orange peel hydroethanolic extract on the elevated serum
creatinine level and kidney histological structure and integrity.
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Ingestion of APAP to rats induced a disturbance in the oxidant/antioxidant status characterized by a significant increase in kidney LPO and decrease in GSH content as well
as GPx, GST and SOD activities. These findings are in
accordance with those of many published works (Canayakin et al., 2016; Ijaz et al., 2016; Kandemir et al., 2017).
The stimulated oxidative stress may be mediated, at least in
part, through accumulation of the toxic metabolite NAPQI, a metabolite of APAP that has high affinity for GSH
leading to its depletion (Amin et al., 2017).
Kidney LPO was manifested by detection of MDA production. MDA is known as a secondary product of LPO
and is used as a marker of oxidative tissue damage resulting
from many chain reactions (Gülçin and Beydemir, 2013).
Some previous studies have stated that renal oxidative stress
is induced by increases in LPO products (e.g., MDA) and
suppression in antioxidant defensive system (Gebaly et al.,
2012). Elevated MDA levels in kidney and other tissues
have long been known to cause functional degradation;
thereby, the degradation of vital tissue leading to complications may be indirectly due to increased oxidative stress
and production of ROS (Pushpavalli et al., 2010).
GSH is a non-enzymatic antioxidant that protects the
tissues and organs against the adverse effects of ROS. It
plays a crucial role in eliminating free radical species such
as H2O2, superoxide radicals and membrane protein thiols (Bursal et al., 2013). It is also known as a substrate of
the GPx enzyme (Basu et al., 2012). In therapeutic doses,
APAP directly establishes a conjugated bond with glucuronic acid and sulphate, forming non-toxic conjugated
metabolites that are eliminated by the kidneys (Gamal ElDin et al., 2003). On the other hand, high doses of APAP
lead to tissue damage and stimulate programmed necrosis
or apoptosis, as well as deteriorating homeostasis, and ultimately induce mitochondrial function disorders (Wudil
and Sarki, 2015). Antioxidant such as SOD and GSH are
the first line defense system that confines the toxicity allied
with the free radicals (Saraswathi et al., 2014).
Enzymatic and non-enzymatic antioxidants play an important role by protecting the cells exposed to oxidative
damage (Canayakin et al., 2016). The increase in LPO was
accompanied by a significant reduction in the level of GSH
which is an important free radical and NAPQI scavenger
(Yayla et al., 2014) and plays a central role in the antioxidant defense system (Bursal et al., 2013).
The decreased SOD and GSH levels and the increased
LPO in the APAP-administered rats, in present study, were
in accordance with previous research studying APAP-induced nephrotoxicity (Ghosh and Sil, 2007; Yousef et
al., 2010; Abdul Hamid et al., 2012; Naguib et al., 2014;
Hommore et al., 2015).
February 2019 | Volume 7 | Issue 2 | Page 102
In the current study, the treatment of APAP-administered
rats with navel orange peel hydroethanolic extract for 4
weeks significantly decreased the renal LPO and remarkably increased the renal GSH content and GST and GPx
activities towards the normal control values. These effects
might be due to the antioxidant potential of citrus peel
hydroethanolic extract that contains many antioxidant
phytochemicals like naringin, hesperidin, neohesperidin
and narirutin (Anagnostopoulou et al., 2006). These results were confirmed with the observation of Mostafa et
al. (2016).
Similarly, the treatment with naringin and naringenin, in
the current study, significantly improved the APAP-induced elevation of kidney LPO and APAP-induced deteriorated effects on GSH content and GST, GPx and SOD
activities. While navel orange peel extract was the most
effective in suppressing kidney LPO, naringenin was the
most potent in ameliorating kidney GSH content as well
as GST and SOD activities. Thus, these results suggest
that navel orange peel extract, naringin and naringenin
have potential to suppress the oxidative stress and enhance
the antioxidant defense system in kidneys. These results
are in accordance with many previous publications. Guimarães et al. (2010) stated that citrus fruit extracts possess
large amounts of flavonoids and show potent free radical
scavenging activity. Cavia-Saiz et al. (2010) reported that
both naringin and naringenin are strong scavengers of free
radicals and prevent LPO. Anandhi et al. (2013) revealed
that naringin possesses potent antioxidant, anti-free radical scavenging and metal chelating properties. Mostafa
et al. (2016) found that the activities of antioxidant enzymes glutathione reductase (GR), GST, SOD and catalase (CAT) were markedly restored by pretreatment of
rats with sweet orange and mandarin peel extracts, as compared to the group administered APAP alone. Hermenean et al. (2013) demonstrated that the pre-treatment with
naringenin resulted in the return of antioxidant and renal
protective effects against injuries induced by CCl4
The improvement in the antioxidant defense system as a
result of treatments of APAP-administered rats with peel
hydroethanolic extract, naringin and naringenin, in the
present study, was associated with amendment of the kidney histological integrity and architecture; this reflects the
role of antioxidant defense system in mediating the ameliorative effects of these treatments on the kidney. Naringin
as well as navel orange peel extract and naringenin could
maintain the potency of the antioxidant defense system,
which in turn modulate the membrane integrity against
APAP-induced cellular injury (Adil et al., 2016).
CONCLUSION
Navel orange peel hydroethanolic extract, naringin and
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naringenin induced potent nephropreventive effects
which were evidenced by amelioration of the kidney
function parameters and histological integrity. These
nephropreventive effects may be mediated, at least in part,
via suppression of oxidative stress and enhancement of
antioxidant defense system.
ACKNOWLEDGEMENTS
The authors sincerely acknowledged Dr. Walaa A. Hasan,
Assistant professor of plant Taxonomy, Botany Department, Faculty of Science, Beni-Suef University, Egypt
for her assistance in recognition and classification of the
plant. The authors also would like to express their sincere
appreciation to Prof. Dr. Kawkab Abd El Aziz Ahmed,
Professor of Pathology, Pathology Department, Faculty of
Veterinary Medicine, Cairo University and Dr. Rasha R.
Ahmed, Professor of Molecular Cell Biology, Zoology Department, Faculty of Science, Beni-Suef University, Egypt
for their great help in the examination of liver sections and
description of histopathological changes.
CONFLICT OF INTERESTS
The authors declare that they have no competing interests.
AUTHORS CONTRIbUTION
Osama M. Ahmed proposed the research plan, guided the
experimental work and shared in writing and revising the
manuscript. Hanaa I. Fahim revised the manuscript and
also supervised the experimental work. Heba Y. Ahmed
and Basant Mahmoud participated in following up the
experimental work and shared in writing and revising the
manuscript. Saad A. S.Aljohani participated in writing
and revising the manuscript. Walaa H. Abdelazeem performed the experimental work and participated in writing
the manuscript.
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