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19 pages, 1609 KiB  
Article
Formulation of Biological Sunscreen from Calendula arvensis Capitula Extracts: Antioxidant, Anti-Aging, Surface Tension, and UVB Protection Properties Assessed
by Najlae El-Otmani, Ikrame Zeouk and Ahmed Zahidi
Cosmetics 2024, 11(6), 216; https://doi.org/10.3390/cosmetics11060216 - 9 Dec 2024
Viewed by 504
Abstract
Skin protection against ultraviolet (UV) radiation has long been crucial due to its role in photoaging, sunburn, and wrinkles. This study focuses on developing a bio-based sunscreen from Calendula arvensis capitula extract. Various extraction methods (maceration, sonication, and infusion) and solvents (EtOH, EtOH-H [...] Read more.
Skin protection against ultraviolet (UV) radiation has long been crucial due to its role in photoaging, sunburn, and wrinkles. This study focuses on developing a bio-based sunscreen from Calendula arvensis capitula extract. Various extraction methods (maceration, sonication, and infusion) and solvents (EtOH, EtOH-H2O, and H2O) were explored in order to identify the most effective extract for use in a sunscreen formulation. Each extract was analyzed for its phenolic content, as well as antioxidant activities (assessed through DPPH, CAT, and FRAP assays). Enzyme inhibition assays for tyrosinase, elastase, and collagenase highlighted the low IC50 values of the hydroethanolic extract. Furthermore, the in vitro sun protection factor (SPF) against UVB radiation was measured using ultraviolet spectrophotometry. A phytochemical analysis showed phenolic levels between 8 and 27 mg GAE/g, flavonoid concentrations of 7–13 mg QE/g, and tannin levels of 1.15–1.68 mg/mL, alongside moderate antioxidant activity. The ethanol maceration extract reduced the interfacial tension to 2.15 mN/m in 600 s, outperforming the conventional emulsifier polysorbate 20. The sonicated hydroethanolic extract demonstrated remarkable SPF efficacy (SPF = 193.65 ± 0.02), far exceeding that of the standard zinc oxide (SPF = 11.88 ± 0.03). The proposed formulations meet the COSMOS standards, suggesting their potential for certification as biological products. Further clinical and in vivo studies are necessary to confirm their safety and commercial viability. Full article
(This article belongs to the Special Issue Skin Anti-Aging Strategies)
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Figure 1

Figure 1
<p>Surface tension (ST) and interfacial tension (IFT) profiles of <span class="html-italic">C. arvensis</span> extracts as a function of time and solvent conditions.</p>
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<p>Sun Protection Factor (SPF) screening of sunscreens based on <span class="html-italic">C. arvensis</span> extracts, with similar letters in the same concentration (%) indicate that there is no significant difference, <span class="html-italic">p</span> &lt; 0.05 (n = 3) (<b>a</b>), and analysis of the UVB absorbance spectra of the various <span class="html-italic">C. arvensis</span> extracts (<b>b</b>).</p>
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<p>A guideline illustration, inspired by the COSMOS technical reference, for calculating the biological percentage of plant extracts through an extraction process.</p>
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<p>Characterization of sunscreen formulation parameters at different time intervals (day 1, day 30, day 60, and day 90) for assessment of stability over time (n = 3): (<b>a</b>) pH values, (<b>b</b>) peroxide value, (<b>c</b>) conductivity, and (<b>d</b>) viscosity analysis.</p>
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20 pages, 3488 KiB  
Article
The Potential of Tecoma stans (Linn.) Flower Extract as a Natural Antioxidant and Anti-Aging Agent for Skin Care Products
by Panikchar Wichayapreechar, Anchalee Prasansuklab, Pimchanok Charoongchit and Ranit Charoenjittichai
Cosmetics 2024, 11(6), 214; https://doi.org/10.3390/cosmetics11060214 - 8 Dec 2024
Viewed by 304
Abstract
Tecoma stans belongs to the Bignoniaceae family and possesses various pharmacological activities, including antimicrobial, anti-inflammatory, antifungal, antioxidant, and wound-healing activities. Although numerous studies have highlighted the beneficial effects of T. stans extracts, the impacts of different solvents on its biological activities, particularly its [...] Read more.
Tecoma stans belongs to the Bignoniaceae family and possesses various pharmacological activities, including antimicrobial, anti-inflammatory, antifungal, antioxidant, and wound-healing activities. Although numerous studies have highlighted the beneficial effects of T. stans extracts, the impacts of different solvents on its biological activities, particularly its inhibitory effect on skin degradation enzymes (collagenase, elastase, and hyaluronidase assay), have not been reported. This study aims to explore the effects of different solvent extractions on the total phenolic and total flavonoid contents, antioxidant and anti-aging activities, and cytotoxicity. The most suitable extract was selected for incorporation into an anti-aging product. T. stans flowers were extracted using hexane, ethyl acetate, absolute ethanol, and deionized water through maceration. The aqueous extract yielded the highest extraction efficiency (40.73%), followed by absolute ethanol, ethyl acetate, and hexane. The phytochemical screening results revealed that all T. stans flower extracts contained phenolics, flavonoids, terpenoids, and alkaloids. Among the various solvents tested for T. stans flower extraction, absolute ethanol demonstrated the highest total phenolic content (24.10 ± 2.07 mg gallic acid equivalents (GAE)/g extract), followed by deionized water (20.83 ± 1.28 mg GAE/g extract). The highest total flavonoid content was observed in the ethyl acetate extract (205.11 ± 7.83 mg catechin equivalents (CE)/g extract), with ethanol showing a significantly lower concentration (140.67 ± 1.92 mg CE/g extract). In terms of antioxidant activity, the aqueous extract exhibited the most potent effects, with IC50 values of 0.600 ± 0.005 mg/mL for the DPPH assay and 0.207 ± 0.001 mg/mL for the ABTS•+ assay. For anti-aging assays, the absolute ethanolic extract demonstrated the highest enzyme inhibition activity at 1 mg/mL, with collagenase, elastase, and hyaluronidase inhibition rates of 89.49% ± 2.96%, 94.61% ± 2.33%, and 82.56% ± 2.27%, respectively. Moreover, at a concentration of 50 µg/mL, the absolute ethanolic extract exhibited lower cytotoxicity, with human keratinocyte (HaCaT) cell viability of 78% ± 8.47%, which was significantly higher than that of the other extracts. An anti-aging gel containing 0.05% w/w of the ethanolic T. stans extract demonstrated physical and physicochemical stability during three months of storage at ambient temperatures, 4 °C, 45 °C, as well as after six cycles of heating/cooling tests. These findings suggest that the ethanolic extract of T. stans flower has potential as a safe and effective anti-aging agent for cosmeceutical products. Full article
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Figure 1
<p><span class="html-italic">Tecoma stans</span> (Linn.) (<span class="html-italic">T. stans</span>). (<b>A</b>) The <span class="html-italic">T. stans</span> tree; (<b>B</b>) the <span class="html-italic">T. stans</span> flowers; and (<b>C</b>) the dried fine powder of <span class="html-italic">T. stans</span>.</p>
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<p>Collagenase inhibitory activities of <span class="html-italic">T. stans</span> extracts derived from solvents of differing polarities. Values are expressed as the mean ± SD from three independent experiments. An asterisk (*) indicates a significant difference (<span class="html-italic">p</span> &lt; 0.05) between sample concentrations within the solvent. The different letters (a–c) denote statistically significant differences among the solvents at a sample concentration of 0.5 mg/mL (<span class="html-italic">p</span> &lt; 0.05). The different letters (A–C) denote statistically significant differences among the solvents at a sample concentration of 1 mg/mL (<span class="html-italic">p</span> &lt; 0.05).</p>
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<p>Elastase inhibitory activities of <span class="html-italic">T. stans</span> extracts derived from solvents of differing polarities. Data are presented as the mean ± SD from three independent experiments. An asterisk (*) indicates a statistically significant difference (<span class="html-italic">p</span> &lt; 0.05) between sample concentrations within the solvent. The different letters (a–c) denote statistically significant differences among the solvents at a sample concentration of 0.5 mg/mL (<span class="html-italic">p</span> &lt; 0.05). The different letters (A–C) denote represent statistically significant differences among the solvents at a sample concentration of 1 mg/mL (<span class="html-italic">p</span> &lt; 0.05).</p>
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<p>Hyaluronidase inhibitory activities of <span class="html-italic">T. stans</span> extracts obtained using solvents of varying polarities. Data are shown as the mean ± SD from three independent experiments. An asterisk (*) indicates a statistically significant difference (<span class="html-italic">p</span> &lt; 0.05) between sample concentrations within the solvent. The different letters (a–c) denote statistically significant differences among the solvents at a sample concentration of 0.5 mg/mL (<span class="html-italic">p</span> &lt; 0.05). The different letters (A–D) denote statistically significant differences among the solvents at a sample concentration of 1 mg/mL (<span class="html-italic">p</span> &lt; 0.05).</p>
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<p>The percentage viabilities of HaCaT cells treated with different concentrations of <span class="html-italic">T. stans</span> extracts for 24 h. The values are expressed as the mean ± SD in triplicate experiments, with * <span class="html-italic">p</span> &lt; 0.05 and ** <span class="html-italic">p</span> &lt; 0.01 vs. control.</p>
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<p>Appearance of skincare formulation (<b>A</b>) without <span class="html-italic">T. stans</span> extract and (<b>B</b>) with <span class="html-italic">T. stans</span> extract.</p>
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<p>Appearance of skincare formulation with <span class="html-italic">T. stans</span> extract after stability test: (<b>A</b>) ambient temperature; (<b>B</b>) 4 °C in a refrigerator; (<b>C</b>) 45 °C in a hot-air oven; and (<b>D</b>) heating/cooling cycling.</p>
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18 pages, 1821 KiB  
Article
Chemical Composition and Assessment of the Anti-Inflammatory, Antioxidant, Cytotoxic and Skin Enzyme Inhibitory Activities of Citrus sinensis (L.) Osbeck Essential Oil and Its Major Compound Limonene
by Naoufal El Hachlafi, Amine Elbouzidi, Amine Batbat, Mohamed Taibi, Mohamed Jeddi, Mohamed Addi, Hanae Naceiri Mrabti and Kawtar Fikri-Benbrahim
Pharmaceuticals 2024, 17(12), 1652; https://doi.org/10.3390/ph17121652 - 8 Dec 2024
Viewed by 322
Abstract
Background/Objectives: Essential oils (EOs) from Citrus species have attracted attention for their diverse properties, including anti-inflammatory, antioxidant and cytotoxic effects, which address critical health challenges such as chronic diseases and skin disorders. Citrus sinensis (L.) Osbeck, which is a widely cultivated citrus fruit, [...] Read more.
Background/Objectives: Essential oils (EOs) from Citrus species have attracted attention for their diverse properties, including anti-inflammatory, antioxidant and cytotoxic effects, which address critical health challenges such as chronic diseases and skin disorders. Citrus sinensis (L.) Osbeck, which is a widely cultivated citrus fruit, is attracting increasing attention in the field of medicinal research due to its richness of limonene (comprising approximately 85–90% of the oil). This study investigates the chemical profile of CS-EO and biological activities of CS-EO and limonene. Methods and Results: This study used gas chromatography–mass spectrometry (GC-MS), confirming limonene as the predominant compound (70.15%) along with other minor constituents, including thujene (10.52%), myrcene (5.54%) and α-pinene (2.81%). The biological activities of CS-EO and limonene were examined, specifically focusing on their antioxidant, anti-inflammatory, cytotoxicity and dermatoprotective effects. Antioxidant potential was evaluated using DPPH, FRAP and beta-carotene assays, with CS-EO and limonene exhibiting comparable efficacy. Anti-inflammatory properties were assessed via inhibition assays of prostaglandin E2 (PGE2) and nitric oxide (NO) production, showing significant reductions in LPS-stimulated macrophages treated by CS-EO or limonene. Cytotoxicity testing on various cell lines indicated selective activity of the tested compounds, with low toxicity observed on human skin fibroblasts. Limonene and CS-EO were highly effective on HepG2 cellules, with IC50 values of 0.55 ± 0.01 µg/mL and 15.97 ± 1.20 µg/mL, respectively. Dermatoprotective effects were further confirmed using enzymes, where CS-EO and limonene showed remarkable inhibitory potential against elastase (IC50 of 65.72 ± 1.92 and 86.07 ± 1.53 µg/mL, respectively) and tyrosinase (IC50 of 102 ± 2.16 and 78.34 ± 1.15 µg/mL, respectively) enzymes compared to quercetin used as a standard (IC50 of 111.03 ± 0.1 and 124.22 ± 0.07 µg/mL, respectively). Conclusions: The findings of this study suggest the potential for the development of new therapeutic approaches based on CS-EO, which could be applicable in the pharmaceutical, cosmetic and nutraceutical fields and have protective benefits for skin health. Full article
(This article belongs to the Special Issue Pharmaceutical Application of Essential Oils)
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<p>Chromatogram of GC-MS analysis of CS-EO.</p>
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<p>Effect of CS-EO on cell viability. RAW 264.7 cells were stimulated with LPS (1 μg/mL) and incubated in the presence or absence of increasing concentrations (25–200 µg/mL) of CS-EO for 24 h.</p>
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<p>PGE<sub>2</sub> as a modulator of immune dynamics in inflammation and resolution.</p>
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<p>Effect of CS-EO and limonene on LPS-induced nitric oxide (NO) and prostaglandin E2 (PEG2) production. (<b>A</b>,<b>B</b>) RAW 264.7 cells were stimulated with LPS (1 μg/mL) and incubated in the presence or absence of increasing concentrations (25–200 µg/mL) of CS-EO and limonene (25–200 µg/mL) for 24 h. The nitrite concentration in the culture media was determined by the Griess reagent assay. (<b>C</b>,<b>D</b>) PGE<sub>2</sub> levels in the culture media were measured by a commercially available assay kit. Data are reported as mean ± SD of three independent experiments. # <span class="html-italic">p</span> &lt; 0.001 indicates a significant difference between the control and LPS-only treated groups. ** <span class="html-italic">p</span> &lt; 0.01 and *** <span class="html-italic">p</span> &lt; 0.001 show significant differences between the LPS-alone and CS-EO or limonene treatment groups.</p>
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<p>Cell viability of MCF-7, HCT-15, HepG2 and PBMC cells after 72 h of treatment with CS-EO, its respective major compound limonene and cisplatin (positive control) using MTT test.</p>
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<p>Schematic illustration of the possible mechanisms of action of CS-EO and limonene.</p>
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14 pages, 1651 KiB  
Article
Neutrophil Elastase Targets Select Proteins on Human Blood-Monocyte-Derived Macrophage Cell Surfaces
by Nadia Tasnim Ahmed, Apparao B. Kummarapurugu, Shuo Zheng, Gamze Bulut, Le Kang, Aashish Batheja, Adam Hawkridge and Judith A. Voynow
Int. J. Mol. Sci. 2024, 25(23), 13038; https://doi.org/10.3390/ijms252313038 - 4 Dec 2024
Viewed by 305
Abstract
Neutrophil elastase (NE) has been reported to be a pro-inflammatory stimulus for macrophages. The aim of the present study was to determine the impact of NE exposure on the human macrophage proteome and evaluate its impact on pro-inflammatory signals. Human blood monocytes from [...] Read more.
Neutrophil elastase (NE) has been reported to be a pro-inflammatory stimulus for macrophages. The aim of the present study was to determine the impact of NE exposure on the human macrophage proteome and evaluate its impact on pro-inflammatory signals. Human blood monocytes from healthy volunteers were differentiated to macrophages and then exposed to either 500 nM of NE or control vehicle for 2 h in triplicate. Label-free quantitative proteomics analysis identified 41 differentially expressed proteins in the NE versus control vehicle datasets. A total of 26 proteins were downregulated and of those, 21 were cell surface proteins. Importantly, four of the cell surface proteins were proteoglycans: neuropilin 1 (NRP1), syndecan 2 (SDC2), glypican 4 (GPC4), and CD99 antigen-like protein 2 (CD99L2) along with neuropilin 2 (NRP2), CD99 antigen (CD99), and endoglin (ENG) which are known interactors. Additional NE-targeted proteins related to macrophage function were also measured including CD40, CD48, SPINT1, ST14, and MSR1. Collectively, this study provides a comprehensive unbiased view of selective NE-targeted cell surface proteins in chronically inflamed lungs. Full article
(This article belongs to the Special Issue The Role of Protease and Protease Inhibitors in Human Diseases)
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<p>Experimental workflow for investigating the effects of NE treatment on the human blood-monocyte-derived macrophage (BMDM) proteome. BMDMs from healthy donors were split equivalently into 6-well plates and then incubated without (control (Ctl)) or with 500 nM of neutrophil elastase (+NE) for 2 h in triplicate.</p>
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<p>Summary of label-free quantification (LFQ) results. Results show the number of proteins quantified in each donor sample with NE treatment (black) and without NE treatment (gray) (<b>A</b>). Venn diagram shows the proteome overlap between donor samples (<b>B</b>). Venn diagram shows statistically significant (<span class="html-italic">t</span>-test; adjusted <span class="html-italic">p</span>-value &lt; 0.05) differentially regulated proteins in NE vs. Ctl (<b>C</b>). Heatmap showing the log2 fold-change values of protein levels in NE vs. control that were detected in 3/3 donors and statistically significant in 3/3 or 2/3 donor (* indicates the expression level is not statistically significant) (<b>D</b>).</p>
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<p>Down-regulated proteins. Enriched downregulated proteins from the GO cellular component annotation (<b>A</b>). Log10 of the median normalized LFQ abundances rank-plotted with 21 cell-membrane-annotated differentially downregulated proteins (yellow) labeled by gene. <span class="html-italic">GPC4</span> is labeled in red as it is downregulated in only 2/3 donor samples yet is a member of the proteoglycan family (<b>B</b>).</p>
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<p>Western blot and densitometry results for <span class="html-italic">NRP1</span> (<b>A</b>,<b>B</b>), <span class="html-italic">SDC2</span> (<b>C</b>,<b>D</b>), and <span class="html-italic">GPC4</span> (<b>E</b>,<b>F</b>) from NE-targeted BMDM lysates. Three separate blood monocyte donations were obtained from healthy donors and cultured in RPMI with GM-CSF for 8–10 days to differentiate cells to blood monocyte derived macrophages. Cells from each donor were treated with control vehicle or NE (200 or 500 nM) for 1 or 2 h. Cell lysates were collected, protein quantified, and Western analyses were performed for <span class="html-italic">NRP1</span> (<b>A</b>), <span class="html-italic">SDC2</span> (<b>C</b>), and <span class="html-italic">GPC4</span> (<b>E</b>). Left panels are representative Western blots for protein targets and as a control, β-actin. After densitometry of bands using ImageJ, relative expression corrected for β-actin was compared to control treated samples and summary data of relative expression for each protein shown in the panel on the right, <span class="html-italic">NRP1</span> (<b>B</b>), <span class="html-italic">SDC2</span> (<b>D</b>), and <span class="html-italic">GPC4</span> (<b>F</b>). Significant differences in relative expression for N = 3 per protein was determined; *, <span class="html-italic">p</span> &lt; 0.05; **, <span class="html-italic">p</span> &lt; 0.01; ***, <span class="html-italic">p</span> &lt; 0.001.</p>
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23 pages, 5880 KiB  
Article
Antimicrobial Nanoparticles Composed of Zein and Arginine-Phenylalanine-Based Surfactants for Wound Related Infections: Antioxidant and Skin-Related Anti-Enzymatic Activities and Toxicity
by Francisco Fábio Oliveira de Sousa, Zakaria Hafidi, María Teresa García, Maria del Carmen Moran, Sergio Vazquez and Lourdes Pérez
Antibiotics 2024, 13(12), 1149; https://doi.org/10.3390/antibiotics13121149 - 1 Dec 2024
Viewed by 445
Abstract
Background/Objectives: Cationic surfactants are potential antimicrobial candidates. Even so, they are the foremost irritative and incompatible group, which limits their usage. The incorporation of surfactants in biopolymer-based nanoparticles is a feasible strategy to improve their efficacy and reduce those drawbacks. Methods: [...] Read more.
Background/Objectives: Cationic surfactants are potential antimicrobial candidates. Even so, they are the foremost irritative and incompatible group, which limits their usage. The incorporation of surfactants in biopolymer-based nanoparticles is a feasible strategy to improve their efficacy and reduce those drawbacks. Methods: Surfactants with one amino acid on the polar head (lauroyl arginine methyl ester—LAM and phenylalanine dodecyl amide—PNHC12) and surfactants with two amino acids on the polar heads, arginine-phenylalanine (Lauroyl phenylalanine arginine methyl esther—C12PAM and phenylalanine-arginine dodecyl amide—PANHC12) were loaded to zein nanoparticles. Their antimicrobial and antibiofilm activities were evaluated. Also, the inhibitory activities of the surfactants and nanoparticles over skin-related enzymes were accessed in silico and in vitro, while their cytotoxicity was determined comparatively over immortal human keratinocytes (HaCaT) and human fibroblasts (3T3). Finally, the Vibrio fisheri luminescence reduction test was used to detect its ecotoxicity. Results: The nanoparticles were obtained successfully and exhibited good biocide activity against a wide range of pathogenic bacteria and yeasts. The surfactants were found active over the enzymes assayed: elastase > tyrosinase > collagenase > lipoxygenase, while the inhibitory activity was superior when nanoencapsulated over the enzymes tyrosinase and lipoxygenase. The surfactants and their corresponding nanoparticles presented acceptable cytotoxic levels, except for PNHC12 in both forms, while their ecotoxicity was limited and acceptable. Conclusions: Accordingly, the nanoencapsulation of the arginine-phenylalanine surfactants loaded to zein nanoparticles was found to be a smart strategy to enhance the antimicrobial activity and improve their selectivity over representative skin and connective tissues cell lines. These biological properties render the arginine-phenylalanine surfactant nanoparticles as promising candidates for antimicrobial and tissue repairing applications in wound treatments. Full article
(This article belongs to the Special Issue Nanoparticles as Antibacterial/Antibiofilm Agents)
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Graphical abstract

Graphical abstract
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<p>Chemical structures of N<sup>α</sup>-Lauroyl Arginine methyl ester (LAM), Phenylalanine lauroyl amide (PNHC<sub>12</sub>), N<sup>α</sup>-Lauroyl Phenylalanine Arginine methyl ester (C<sub>12</sub>PAM), and Phenylalanine Arginine lauroyl amide (PANHC<sub>12</sub>).</p>
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<p>Transmission electronic microscopy images of (<b>a</b>,<b>b</b>) blank and (<b>c</b>,<b>d</b>) Lauroyl arginine methyl ester (LAM) loaded-zein nanoparticles under different magnifications.</p>
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<p>Aggregation possibilities for zein nanoparticles loaded with arginine-phenylalanine surfactants. (<b>a</b>) The hydrophobic hydrocarbon chains are directly connected to the polymeric nanostructure, (<b>b</b>) nanomicelles with hydrophobic core formed by the surfactants are in contact with the polymeric structure, (<b>c</b>) combination of direct interaction of the surfactants with nanomicelles interactions, (<b>d</b>) surfactants’ polar heads are connected to the polymeric structure or (<b>e</b>) larger micelles or bilayers containing water are formed and agglomerate to the polymeric nanoparticles structure. (<b>f</b>) Blank zein nanoparticles and (<b>g</b>) the general cationic surfactant chemical structure.</p>
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<p>Minimum bactericide concentrations (MBC) (in µg/mL) of the surfactants in solution and nanoparticles: Lauroyl Arginine methyl ester (LAM) (<b>a</b>), Phenylalanine lauroyl amide (PNHC<sub>12</sub>) (<b>b</b>), Phenylalanine Arginine lauroyl amide (PANHC<sub>12</sub>) (<b>c</b>), and Lauroyl Phenylalanine Arginine methyl ester (C<sub>12</sub>PAM) (<b>d</b>). Concentrations assayed: 2.2, 4.4, 8.9, 17.8, and 35.6 µg/mL.</p>
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<p>Minimum fungicide concentrations (MFC) (in µg/mL) of the surfactants in solution and nanoparticles: Lauroyl Arginine methyl ester (LAM) (<b>a</b>), Phenylalanine lauroyl amide (PNHC<sub>12</sub>) (<b>b</b>), Phenylalanine Arginine lauroyl amide (PANHC<sub>12</sub>) (<b>c</b>) and Lauroyl Phenylalanine Arginine methyl ester (C<sub>12</sub>PAM) (<b>d</b>). Concentrations assayed: 2.2, 4.4, 8.9 17.8 and 35.6 µg/mL.</p>
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<p>Antibiofilm activity of the surfactant-loaded zein nanoparticles: LAM solution (<b>a</b>) and nanoparticles (<b>b</b>), PNHC<sub>12</sub> solution (<b>c</b>) and nanoparticles (<b>d</b>), PANHC<sub>12</sub> solution (<b>e</b>) and nanoparticles (<b>f</b>), and C<sub>12</sub>PAM solution (<b>g</b>) and nanoparticles (<b>h</b>) over Methicillin-resistant <span class="html-italic">Staphylococcus aureus</span> (MRSA). (*** and **** mean <span class="html-italic">p</span> &lt; 0.005 and <span class="html-italic">p</span> &lt; 0.001, respectively).</p>
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<p>Antibiofilm activity of the surfactants-loaded zein nanoparticles: LAM solution (<b>a</b>) and nanoparticles (<b>b</b>), PNHC12 solution (<b>c</b>) and nanoparticles (<b>d</b>), PANHC<sub>12</sub> solution (<b>e</b>) and nanoparticles (<b>f</b>), and C<sub>12</sub>PAM solution (<b>g</b>) and nanoparticles (<b>h</b>) over <span class="html-italic">Candida albicans</span>.(** and **** mean <span class="html-italic">p</span> &lt; 0.01 and <span class="html-italic">p</span> &lt; 0.001, respectively).</p>
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<p>Antioxidant activity of amino acid-based surfactants (LAM, PNHC<sub>12</sub>, C<sub>12</sub>PAM, and PANHC<sub>12</sub>) and their corresponding Nps at 35.6 µg/mL after 30 min and 24 h. (**, *** and **** mean <span class="html-italic">p</span> &lt; 0.01, <span class="html-italic">p</span> &lt; 0.005 and <span class="html-italic">p</span> &lt; 0.001, respectively).</p>
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<p>Inhibition of collagenase (<b>a</b>), elastase (<b>b</b>), tyrosinase (<b>c</b>), and lipoxygenase (<b>d</b>) by LAM, PNHC<sub>12</sub>, C<sub>12</sub>PAM, PANHC<sub>12</sub> and their corresponding NPs. EGCG: epigalocatequin-3-galate; DEX: dexamethasone.</p>
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<p>Molecular docking studies showing the various interaction types observed in the contact modes between the surfactant molecules (LAM, PNHC<sub>12</sub>, and C<sub>12</sub>PAM) and the protein pocket of collagenase (PDB ID: 7ESI), elastase (PDB ID: 1ELE), lipoxygenase (PDB ID: 4NRE), and tyrosinase (PDB ID: 4P6R) receptors.</p>
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<p>Cellular viability with LAM, PNHC<sub>12</sub>, PANHC<sub>12</sub>, and C<sub>12</sub>PAM in solution (at 35.6 and 17.8 µg/mL) and loaded to zein nanoparticles (at 35.6 and 17.7 µg/mL) over murine Swiss albino fibroblasts (3T3 cell line) (<b>a</b>–<b>d</b>) and immortal human keratinocytes (HaCaT cell line) (<b>e</b>–<b>h</b>).</p>
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22 pages, 2950 KiB  
Article
Egg Protein Compositions over Embryonic Development in Haemaphysalis hystricis Ticks
by Qiwu Tang, Tianyin Cheng and Wei Liu
Animals 2024, 14(23), 3466; https://doi.org/10.3390/ani14233466 - 30 Nov 2024
Viewed by 378
Abstract
Tick eggs contain a series of proteins that play important roles in egg development. A thorough characterization of egg protein expression throughout development is essential for understanding tick embryogenesis and for screening candidate molecules to develop novel interventions. In this study, eggs at [...] Read more.
Tick eggs contain a series of proteins that play important roles in egg development. A thorough characterization of egg protein expression throughout development is essential for understanding tick embryogenesis and for screening candidate molecules to develop novel interventions. In this study, eggs at four developmental stages (0, 7, 14, and 21 incubation days) were collected, and their protein extraction was profiled using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). On the first day of egg protein extraction, protein bands from day-1 eggs were re-collected and subsequently analyzed using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The dynamic changes in forty egg proteins during development were further investigated using LC-parallel reaction monitoring (PRM)/MS analysis. A total of 108 transcripts were detected in day-1 eggs. Based on protein functions and families, these transcripts were classified into eight categories: transporters, enzymes, immunity and antimicrobial proteins, proteinase inhibitors, cytoskeletal proteins, heat shock proteins, secreted proteins, and uncharacterized proteins. Identification of the protein bands revealed that nine bands predominantly consisted of vitellogenin and vitellin-A, while other notable proteins included cathepsins and Kunitz domain-containing proteins. LC-PRM/MS analysis indicated that 28 transcripts increased significantly in abundance, including 13/18 enzymes, 1/1 antimicrobial peptide, 2/2 neutrophil elastase inhibitors, 3/4 vitellogenins, 3/3 heat shock proteins, 3/3 cytoskeletal proteins, 1/1 elongation factor-1, and 1/1 uncharacterized protein. Conversely, five transcripts showed a decrease significantly, including 1/1 Kunitz domain-containing protein, 2/6 aspartic proteases, and 2/5 serpins. This research provides a comprehensive overview of egg proteins and highlights the dynamic changes in protein expression during embryonic development, which may be pivotal for understanding protein functions and selecting potential candidates for further study. Full article
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<p>SDS-PAGE analysis of protein extract from <span class="html-italic">H. hystricis</span> eggs. A total of 80 μg of protein extract was loaded per sample. Lane M represents the 15–250 kDa molecular weight marker. D1, D7, D14, and D21 correspond to eggs incubated for 1, 7, 14, and 21 days, respectively. Bands 1–12 indicate the protein bands excised for further analysis.</p>
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<p>Top 4 most prominent proteins identified in 12 bands from day-one eggs.</p>
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<p>Analysis of protein dynamics in <span class="html-italic">H. hystricis</span> tick eggs across different incubation days. Each sample was spiked with the stable isotope iRT KIT peptide as an internal standard. Tryptic peptides were analyzed using the nLC-1200 system. Protein abundances at 7, 14, and 21 days of incubation were normalized to the levels observed at day. D1, D7, D14, and D21 correspond to eggs incubated for 1, 7, 14, and 21 days, respectively.</p>
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10 pages, 1469 KiB  
Article
Human Keratin Matrices Suppress Matrix Metalloproteinase Activity to Support Wound Healing
by Allison N. Ramey-Ward, Shakesia Smith, Howard Walthall and Thomas H. Barrows
Int. J. Mol. Sci. 2024, 25(23), 12898; https://doi.org/10.3390/ijms252312898 - 30 Nov 2024
Viewed by 368
Abstract
Elevated protease activity is a hallmark of non-healing chronic wounds. Though multiple biomaterials exist that are successful in treating wounds, their roles in modulating the enzymatic environment of the wound are only beginning to be elucidated. Because keratin has long been known to [...] Read more.
Elevated protease activity is a hallmark of non-healing chronic wounds. Though multiple biomaterials exist that are successful in treating wounds, their roles in modulating the enzymatic environment of the wound are only beginning to be elucidated. Because keratin has long been known to be resistant to degradation by most enzymes, we studied a keratin biomaterial, the human keratin matrix (HKM), in the presence of enzymes identified to contribute to wound chronicity: neutrophil-derived elastase (NE), matrix metalloproteinase 1 (MMP-1), and MMP-9. Upon finding the suppression of MMP-9 activity in the presence of HKM without reducing enzyme protein levels, we further studied the ability of HKM to bind metal ions in the wound and showed the reduction of Zn2+ ion concentration in the presence of HKM. Finally, because of the enzyme resistance of keratin and the suppression of wound enzymes, we demonstrated that HKM was durable in the wound environment, and did not degrade in wound healing efficacy when left in place for two weeks compared to one week in a diabetic mouse model of wound non-healing. In this way, we show HKM is a unique and effective biomaterial for the treatment of chronic wounds through the modulation of wound MMP activity. Full article
(This article belongs to the Special Issue Molecular Advances in Burn and Wound Healing)
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<p>Human keratin matrix (HKM) reduces the activity of matrix metalloproteinase 9 (MMP-9) and resists degradation. (<b>a</b>) Bar graph showing the effect of HKM on neutrophil-derived elastase (NE) activity compared to the NE inhibitor elastatinal. (<b>b</b>) Bar graph showing the effect of HKM on MMP-9 activity compared to the MMP inhibitor N-Isobutyl-N-(4-methoxyphenylsulfonyl)glycyl hydroxamic acid (NNGH). (<b>c</b>) Bar graph showing the effect of HKM on MMP-1 activity compared to the MMP inhibitor NNGH. (<b>d</b>) Bar graph showing the weight of bulk HKM samples incubated with MMP-9 was not changed during the duration of the enzymatic activity assays (1 h) or up to 1 day after. Bars represent mean ± standard deviation of n = 3 independent replicates. * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001; ns = not significant by Brown–Forsythe and Welch analysis of variance (ANOVA) with Dunnett’s multiple comparisons.</p>
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<p>Human keratin matrix (HKM) does not reduce matrix metalloproteinase (MMP) activity by reduction in protein levels. (<b>a</b>) A bar graph showing MMP-1 protein levels after incubation with HKM as determined by ELISA. (<b>b</b>) A bar graph showing MMP-9 protein levels after incubation with HKM as determined by ELISA. Bars represent mean ± standard deviation. * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01 by Brown–Forsythe and Welch analysis of variance (ANOVA) with Dunnet’s multiple comparisons for n = 3 independent replicates.</p>
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<p>Human keratin matrix (HKM) reduces Zn<sup>2+</sup> ion concentration in solution. Bar graph shows the concentration of zinc ions in solution after incubation with HKM compared with metal ion chelator ethylenediaminetetraacetic acid (EDTA). Bars represent mean ± standard deviation for n = 3 independent replicates. ** <span class="html-italic">p</span> &lt; 0.01 by one-way analysis of variance (ANOVA) with Tukey’s multiple comparisons.</p>
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<p>Human keratin matrix (HKM) maintains healing efficacy for at least two weeks in a diabetic mouse wound model. (<b>a</b>) Diagram of mouse with 4 dorsal wounds each treated with 2 control and 2 HKM in randomized locations. (<b>b</b>) Picture of a mouse with wounds dressed. (<b>c</b>) Representative photo of a mouse at week 4, showing HKM wound closed and control wound still open. (<b>d</b>) Graph of wound size over time for each treatment: control (black, circle), HKM changed bi-weekly (blue, triangle). HKM is changed weekly (gold, square) and is reprinted with permission from previous work for comparison under the Creative Commons Attribution license [<a href="#B19-ijms-25-12898" class="html-bibr">19</a>]. Points represent the mean; error bars represent the standard error of the mean for n = 12 mice. **** <span class="html-italic">p</span> &lt; 0.0001 (control vs. HKM 2 Week), #### <span class="html-italic">p</span> &lt; 0.0001 (Control vs. HKM 1 Week), ^ <span class="html-italic">p</span> &lt; 0.05 (HKM 2 Week vs. HKM 1 Week) by two-way analysis of variance (ANOVA) with Tukey’s multiple comparisons. (<b>e</b>) Graph of the percentage of wounds healed for each treatment group at each timepoint (control—black, HKM changed weekly—gold [<a href="#B19-ijms-25-12898" class="html-bibr">19</a>], HKM changed bi-weekly—blue). *** <span class="html-italic">p</span> &lt; 0.001 by Fisher’s exact test.</p>
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19 pages, 4721 KiB  
Article
Antiaging Properties of Kalanchoe blossfeldiana Ethanol Extract—Ex Vivo and In Vitro Studies
by Justyna Stefanowicz-Hajduk, Anna Nowak, Anna Hering, Łukasz Kucharski, Piotr Graczyk, Mariusz Kowalczyk, Tadeusz Sulikowski and Anna Muzykiewicz-Szymańska
Molecules 2024, 29(23), 5548; https://doi.org/10.3390/molecules29235548 - 24 Nov 2024
Viewed by 559
Abstract
Species of the genus Kalanchoe have a long history of therapeutic use in ethnomedicine, linked to their remarkable medical properties. These species include Kalanchoe blossfeldiana succulents, which grow in tropical regions. Despite the great interest in this plant, there are no reports about [...] Read more.
Species of the genus Kalanchoe have a long history of therapeutic use in ethnomedicine, linked to their remarkable medical properties. These species include Kalanchoe blossfeldiana succulents, which grow in tropical regions. Despite the great interest in this plant, there are no reports about its therapeutic effects on the skin. In this study, the antioxidant properties of K. blossfeldiana ethanol extracts and the skin permeation of a topical hydrogel containing the extract (HKB) were assessed. Additionally, the content of active compounds in the K. blossfeldiana extract was evaluated by UHPLC-MS and HPLC-UV. The extract was analyzed with three antioxidant assays: ABTS, DPPH, and FRAP. Furthermore, the antielastase and antihialuronidase properties of the tested extract were assessed. Ex vivo penetration studies were performed using the Franz diffusion cells. The estimation of the cytotoxicity of HKB was performed by using an MTT assay ((4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) on the human fibroblasts HFF-1. The results obtained show that the antioxidant properties of K. blossfeldiana extract were similar to those of ascorbic acid, while antielastase and antihialuronidase tests indicated the strong antiaging and anti-inflammatory activity of the extract (IC50 was 26.8 ± 0.13 and 77.31 ± 2.44 µg/mL, respectively). Moreover, active ingredients contained in K. blossfeldiana extract penetrated through the human skin and accumulated in it. The cytotoxicity test showed that HKB had no significant effect on human fibroblasts at a concentration up to 0.5%. In conclusion, the hydrogel containing the K. blossfeldiana extract can be considered as an interesting and new alternative to dermatologic and cosmetic preparations. Full article
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<p>Chromatogram of phenolic acid identified in <span class="html-italic">K. blossfeldiana</span> ethanol extract from leaves. A—gallic acid; B—protocatechuic acid; C—gentistic acid; D—<span class="html-italic">m</span>-hydroxybenzoic acid; E—vanilic acid; F—hypogallic acid; G—<span class="html-italic">p</span>-hydroxybenzoic acid. The samples were diluted tenfold before HPLC analysis.</p>
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<p>Hyaluronidase activity in the presence of a <span class="html-italic">K. blossfeldiana</span> ethanol extract. The experiment was performed in three independent repetitions (<span class="html-italic">n</span> = 9). Error bars represent standard deviations.</p>
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<p>Elastase activity in the presence of a <span class="html-italic">K. blossfeldiana</span> ethanol extract. The experiment was performed in three independent repetitions (<span class="html-italic">n</span> = 9). Error bars represent standard deviations.</p>
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<p>The accumulation of phenolic acids in the skin. The content of individual phenolic acids was determined in the skin extraction fluid collected after the 24 h penetration study. All values are presented as mean ± SD, where n = 3; n.d.—not detected.</p>
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<p>The viability of HFF-1 cells treated with HKB at concentrations of 5% (<b>A</b>), 1% (<b>B</b>), and 0.5% (<b>C</b>) for 24 h. The results were obtained via an MTT assay and they are presented as the mean values of two experiments performed in three repetitions. Error bars indicate the standard deviation (±SD). Asterisks indicate significant differences (Student’s <span class="html-italic">t</span>-test, <span class="html-italic">p</span> &lt; 0.05) in comparison to the control (the cells treated with hydrogel without the extract).</p>
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<p>The microscopic observation of the viability of HFF-1 cells treated with HKB at concentrations of 5%, 1%, and 0.5% for 24 h. (<b>A</b>–<b>C</b>)—the control treated with hydrogel without the extract; (<b>D</b>,<b>G</b>,<b>J</b>)—cells treated with the extract amounts of 32, 640, and 1600 µg/cm<sup>2</sup> of 5% HKB; (<b>E</b>,<b>H</b>,<b>K</b>)—cells treated with the extract amounts of 32, 320, and 640 µg/cm<sup>2</sup> of 1% HKB; (<b>F</b>,<b>I</b>,<b>L</b>)—cells treated with extract amounts of 16, 64, and 320 µg/cm<sup>2</sup> of 0.5% HKB; magnification ×100.</p>
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16 pages, 929 KiB  
Systematic Review
Efficacy of Prophylactic Antibiotics in COPD: A Systematic Review
by Anh Tuan Tran, Amr Sayed Ghanem, Marianna Móré, Attila Csaba Nagy and Ágnes Tóth
Antibiotics 2024, 13(12), 1110; https://doi.org/10.3390/antibiotics13121110 - 21 Nov 2024
Viewed by 633
Abstract
Background/Objectives: Chronic obstructive pulmonary disease (COPD) is a global health problem and the third leading contributor to mortality worldwide. This systematic review aims to summarize the results of previous studies tackling the question of the efficacy of long-term prophylaxis of antibiotics in [...] Read more.
Background/Objectives: Chronic obstructive pulmonary disease (COPD) is a global health problem and the third leading contributor to mortality worldwide. This systematic review aims to summarize the results of previous studies tackling the question of the efficacy of long-term prophylaxis of antibiotics in COPD patients, with particular regard to exacerbation rate, time to first exacerbation, health status, airway bacterial load, inflammatory markers, cell counts in sputum samples, and potential adverse events. Results: Four studies found significant improvement in the exacerbation rate in patients receiving antibiotic intervention. One study found doxycycline to have negative effects on patients’ exacerbation outcomes. Two studies recorded a reduction in total airway bacterial load using quantitative culture of sputum samples, but the prevalence of antibiotic-resistant bacteria increased in all studies that measured it. No change in inflammatory markers was observed; however, there was a decline in neutrophil cell counts and, subsequently, reductions in neutrophil elastase concentrations. Methods: PubMed and Web of Science databases were searched for English-language studies presenting data on the prophylactic use of antibiotics in COPD management. All included studies are randomized controlled trials (RCTs) and meet the inclusion criteria. Conclusions: Based on current evidence from RCTs, the prophylactic antibiotic approach utilizing macrolides is the most effective in reducing the incidence of COPD exacerbation. However, the emergence of antibiotic-resistant pathogens is notable. Whether the beneficial effects of macrolides on exacerbation are due to their antibacterial or immunomodulant properties is still inconclusive. Future studies are needed to better understand the interactions between antibiotics and the airway microbiome during COPD exacerbation. Full article
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<p>PRISMA flow diagram.</p>
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22 pages, 1483 KiB  
Article
Valorisation of Winery By-Products: Revealing the Polyphenolic Profile of Grape Stems and Their Inhibitory Effects on Skin Aging-Enzymes for Cosmetic and Pharmaceutical Applications
by Rui Dias-Costa, Concepción Medrano-Padial, Raquel Fernandes, Raúl Domínguez-Perles, Irene Gouvinhas and Ana Novo Barros
Molecules 2024, 29(22), 5437; https://doi.org/10.3390/molecules29225437 - 18 Nov 2024
Viewed by 808
Abstract
Grape (Vitis vinifera L.) stems, a by-product of winemaking, possess significant potential value due to their rich polyphenolic composition, which allows their exploitation for cosmetic and pharmaceutical applications. This presents a promising opportunity for valorisation aimed at developing innovative products with potential [...] Read more.
Grape (Vitis vinifera L.) stems, a by-product of winemaking, possess significant potential value due to their rich polyphenolic composition, which allows their exploitation for cosmetic and pharmaceutical applications. This presents a promising opportunity for valorisation aimed at developing innovative products with potential health-promoting effects. In this study, the polyphenolic profile of extracts from grape stems of seven white grape varieties was determined using spectrophotometric and chromatographic methods, specifically high-performance liquid chromatography coupled with a photodiode array detector and electrospray ionization multi-stage mass spectrometry (HPLC-PDA-ESI-MSn), as well as on their ferric-reducing antioxidant power (FRAP) and radical scavenging capacity, using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS●+) radicals. This study also evaluated the anti-aging activity and skin depigmenting activity of these extracts. These findings revealed a diverse polyphenolic profile, encompassing proanthocyanidins and catechin derivatives (PCDs), phenolic acids, and flavonols. Among the varieties studied, ‘Códega do Larinho’ exhibited the highest concentrations of six distinct polyphenols and the highest total phenolic content. It also demonstrated the highest results for antioxidant capacity and elastase and tyrosinase inhibition. Pearson’s correlation analysis showed a significant positive correlation between certain PCDs with both FRAP and DPPH assays, as well as between the identified flavonols and anti-elastase activity. These results underscore the potential health benefits of grape stem extracts and emphasize the importance of their polyphenolic composition in enhancing antioxidant and anti-aging properties, thus supporting their application in different industries. Full article
(This article belongs to the Section Natural Products Chemistry)
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<p>Anti-elastase activity of grape stem extracts at 1 mg/mL. CL, ‘Códega do Larinho’; V, ‘Viosinho’; MF, ‘Malvasia Fina’; S, ‘Síria’; GR, ‘Gouveio Real’; A, ‘Arinto’; M, ‘Moscatel’. Data are presented as mean ± SD (<span class="html-italic">n</span> = 3). Different letters correspond to significant differences between varieties (<span class="html-italic">p</span> &lt; 0.05) according to a Welch test followed by a Dunn post hoc test.</p>
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<p>Anti-hyaluronidase activity of grape stem extracts at 1 mg/mL. CL, ‘Códega do Larinho’; V, ‘Viosinho’; MF, ‘Malvasia Fina’; S, ‘Síria’; GR, ‘Gouveio Real’; A, ‘Arinto’; M, ‘Moscatel’. Data are presented as mean ± SD (<span class="html-italic">n</span> = 3). Different letters correspond to significant differences between varieties (<span class="html-italic">p</span> &lt; 0.05) according to an ANOVA test followed by Tukey’s post hoc test.</p>
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<p>Anti-tyrosinase activity of grape stem extracts at 1 mg/mL concentration. CL, ‘Códega do Larinho’; V, ‘Viosinho’; MF, ‘Malvasia Fina’; S, ‘Síria’; GR, ‘Gouveio Real’; A, ‘Arinto’; M, ‘Moscatel’. Data are presented as median with range (<span class="html-italic">n</span> = 3). Different letters correspond to significant differences between varieties (<span class="html-italic">p</span> &lt; 0.05) according to a Kruskal–Wallis test followed by a Dunn post hoc test.</p>
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<p>Principal Component Analysis (PCA) scores (<b>A</b>) and loadings (<b>B</b>) plots of the polyphenolic content (TPC, total phenolic content; ODC, <span class="html-italic">ortho</span>-diphenol content, and FC, flavonoid content) and antioxidant capacity (FRAP, ferric-reducing antioxidant power; DPPH, DPPH<sup>•</sup> scavenging capacity; ABTS, ABTS<sup>•+</sup> scavenging capacity) of grape stems obtained of the seven white varieties assessed (CL, ‘Códega do Larinho’; V, ‘Viosinho’; MF, ‘Malvasia Fina’; S, ‘Síria’; GR, ‘Gouveio Real’; A, ‘Arinto’; M, ‘Moscatel’).</p>
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<p>Heatmap of correlations (r) between the polyphenolic composition, radical scavenging capacity (DPPH<sup>•</sup> and ABTS<sup>•+</sup>) reducing power antioxidant capacity using FRAP assay, and anti-elastase, anti-tyrosinase, and anti-hyaluronidase activities. Statistically significant correlations: * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01.</p>
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<p>Schematic representation of the methodology used in this study.</p>
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21 pages, 6419 KiB  
Article
Exiguolysin, a Novel Thermolysin (M4) Peptidase from Exiguobacterium oxidotolerans
by Brendan F. Gilmore, Tracy A. White, Alessandro Busetti, Matthew I. McAteer, Christine A. Maggs and Thomas P. Thompson
Microorganisms 2024, 12(11), 2311; https://doi.org/10.3390/microorganisms12112311 - 14 Nov 2024
Viewed by 502
Abstract
This study details a comprehensive biochemical and structural characterization of exiguolysin, a novel thermolysin-like, caseinolytic peptidase secreted by a marine isolate of Exiguobacterium oxidotolerans strain BW26. Exiguolysin demonstrated optimal proteolytic activity at 37 °C and pH 3, retaining 85% activity at 50 °C, [...] Read more.
This study details a comprehensive biochemical and structural characterization of exiguolysin, a novel thermolysin-like, caseinolytic peptidase secreted by a marine isolate of Exiguobacterium oxidotolerans strain BW26. Exiguolysin demonstrated optimal proteolytic activity at 37 °C and pH 3, retaining 85% activity at 50 °C, highlighting its potential stability under broad reaction conditions. SDS-PAGE and LC-MS analysis identified the enzyme as a 32 kDa M4-family metalloprotease. Exiguolysin activity was inhibited by 1,10-phenanthroline, confirming its dependence on metal ions for activity. Zymographic analysis and substrate specificity assays revealed selective hydrolysis of matrix metalloproteinase (MMP) substrates but no activity against elastase substrates. Analysis of the predicted gene sequence and structural predictions using AlphaFold identified the presence and position of HEXXH and Glu-Xaa-Xaa-Xaa-Asp motifs, crucial for zinc binding and catalytic activity, characteristic of ‘Glu-zincins’ and members of the M4 peptidase family. High-throughput screening of a 20 × 20 N-alpha mercaptoamide dipeptide inhibitor library against exiguolysin identified SH-CH2-CO-Met-Tyr-NH2 as the most potent inhibitor, with a Ki of 1.95 μM. Notably, exiguolysin selectively inhibited thrombin-induced PAR-1 activation in PC-3 cells, potentially indicating a potential mechanism of virulence in modulating PAR-1 signalling during infection by disarming PARs. This is the first detailed characterization of a peptidase of the M4 (thermolysin) family in the genus Exiguobacterium which may have industrial application potential and relevance as a putative virulence factor. Full article
(This article belongs to the Special Issue New Insights into the Diversity and Characterization of Extremophiles)
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<p>(<b>A</b>) Azocasein hydrolysis assay showing relative proteolytic activity of conditioned media from each isolate. BW26 exhibited the highest activity. Error bars represent mean ± SD from three biological replicates. Statistical significance between blank control and isolates is indicated (*** <span class="html-italic">p</span> &lt; 0.001). (<b>B</b>) Proteolysis zone produced by <span class="html-italic">E. oxidotolerans</span> grown on LB agar with 2% skim milk at 27 °C for 48 h. (<b>C</b>) <span class="html-italic">E. oxidotolerans</span> grown on a nitrocellulose membrane placed on LB agar with 2% skim milk, showing proteolytic activity as a clear halo under/around the membrane. (<b>D</b>) SDS-PAGE analysis of <span class="html-italic">E. oxidotolerans</span> protease extracted from LB + skim milk agar. Lanes 3, 4, and 5 show the protease band at ~35 kDa. Lanes 7 and 8 serve as negative controls with LB + skim milk agar.</p>
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<p>(<b>A</b>) Azocasein hydrolysis assay showing relative proteolytic activity of conditioned media from each isolate. BW26 exhibited the highest activity. Error bars represent mean ± SD from three biological replicates. Statistical significance between blank control and isolates is indicated (*** <span class="html-italic">p</span> &lt; 0.001). (<b>B</b>) Proteolysis zone produced by <span class="html-italic">E. oxidotolerans</span> grown on LB agar with 2% skim milk at 27 °C for 48 h. (<b>C</b>) <span class="html-italic">E. oxidotolerans</span> grown on a nitrocellulose membrane placed on LB agar with 2% skim milk, showing proteolytic activity as a clear halo under/around the membrane. (<b>D</b>) SDS-PAGE analysis of <span class="html-italic">E. oxidotolerans</span> protease extracted from LB + skim milk agar. Lanes 3, 4, and 5 show the protease band at ~35 kDa. Lanes 7 and 8 serve as negative controls with LB + skim milk agar.</p>
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<p>Phylogenetic tree of <span class="html-italic">Exiguobacterium</span> species based on 16S rRNA gene sequences. The tree was constructed using the Maximum Likelihood method with the Tamura–Nei model. Bootstrap values (1000 replicates) indicate branch reliability.</p>
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<p>Inhibition of azocasein hydrolysis by <span class="html-italic">E. oxidotolerans</span> protease in the presence of class-specific inhibitors: (<b>A</b>) E-64 (10 μM), (<b>B</b>) 1,10-phenanthroline (2 mM), and (<b>C</b>) PMSF (0.2 mM). Assays were performed at 37 °C for 1 h. Error bars indicate the mean ± standard deviation determined from biological replicates; asterisks indicate significant differences between control (0 mM) and treated samples, * (<span class="html-italic">p</span> &lt; 0.05), *** ( <span class="html-italic">p</span> &lt; 0.001), and **** (<span class="html-italic">p</span> &lt; 0.0001) using one-way ANOVA and Dunnett’s post-test analysis (<span class="html-italic">n</span> = <span class="html-italic">3</span>).</p>
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<p></p>
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<p>(<b>A</b>) pH profiling of azocasein hydrolysis by partially purified fractions of <span class="html-italic">E. oxidotolerans</span> protease. (<b>B</b>) Temperature-dependent activity of the protease measured by azocasein hydrolysis at different temperatures. Error bars indicate the mean ± standard deviation determined from biological replicates; asterisks indicate significant differences between either pH and 27 °C contol groups, * (<span class="html-italic">p</span> &lt; 0.05), **(<span class="html-italic">p</span> &lt; 0.01), and **** (<span class="html-italic">p</span> &lt; 0.0001) using one-way ANOVA and Dunnett’s post-test analysis (<span class="html-italic">n</span> = 3).</p>
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<p>(<b>A</b>) Thermolysin protein sequence of <span class="html-italic">E. oxidotolerans</span> BW026 starting from amino acid 202; highlighted regions show the peptide fingerprints (13-mer, 17-mer) idenfied by LC-MS-MS. (<b>B</b>) MKKFLATSLVASVLVVPTVVGA—predicted signal peptide motif; IDANSGKVI—consistent with the conserved PepSY domain in the pro-peptide of other thermolysin M4 peptidases [<a href="#B45-microorganisms-12-02311" class="html-bibr">45</a>]. HELTH—HEXXH motif in which bound histidine is a zinc ligand and Glu is the active site residue. EAVSD—Glu-Xaa-Xaa-Xaa-Asp motif useful for detecting members of the M4 thermolysin family. (<b>C</b>) Active protease structured predicted by AlphaFold v3, showing key residues annotated using ChimeraX.</p>
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<p>(<b>A</b>) Thermolysin protein sequence of <span class="html-italic">E. oxidotolerans</span> BW026 starting from amino acid 202; highlighted regions show the peptide fingerprints (13-mer, 17-mer) idenfied by LC-MS-MS. (<b>B</b>) MKKFLATSLVASVLVVPTVVGA—predicted signal peptide motif; IDANSGKVI—consistent with the conserved PepSY domain in the pro-peptide of other thermolysin M4 peptidases [<a href="#B45-microorganisms-12-02311" class="html-bibr">45</a>]. HELTH—HEXXH motif in which bound histidine is a zinc ligand and Glu is the active site residue. EAVSD—Glu-Xaa-Xaa-Xaa-Asp motif useful for detecting members of the M4 thermolysin family. (<b>C</b>) Active protease structured predicted by AlphaFold v3, showing key residues annotated using ChimeraX.</p>
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<p>Inhibitor screening results showing 1/Fi values for 400 inhibitors tested against <span class="html-italic">E. oxidotolerans</span> thermolysin-like protease. Fi values were derived from substrate hydrolysis progress curves.</p>
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<p>Effect of <span class="html-italic">E. oxidotolerans</span> thermolysin-like protease on calcium mobilization in PC-3 cells. (<b>A</b>) No calcium mobilization was observed when cells were treated with protease alone. (<b>B</b>) PAR-1 activation by TFLLRN (10 μM) was unaffected by protease pre-treatment. (<b>C</b>) Protease inhibited thrombin-induced PAR-1 activation, suggesting proteolytic cleavage of the receptor. This disarming effect was reversed by ME-Pro-Arg-NH2. (<b>D</b>) No calcium mobilization was observed in HCT15 cells when treated with protease alone. Cells were pre-treated with Fluo-4 Direct calcium dye before addition of the protease. (<b>E</b>) Calcium mobilization in HCT15 cells was observed through PAR-2 activation by trypsin (100 ng/mL) following 10 min pre-treatment with thermolysin-like protease, suggesting no inhibitory effect on PAR-2 signalling. (<b>F</b>) PAR-2 activation of HCT15 cells by SLIGKV was not impacted by protease treatment, indicating selectivity of the protease for PAR-1 over PAR-2.</p>
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10 pages, 2415 KiB  
Article
Neutrophils Respond Selectively to Physical Cues: Roughness Modulates Its Granule Release, and NETosis
by Gayathiri Elangovan, Daniel J. Fernandes, Andrew Cameron, Souptik Basu, Joao Martins De Mello Neto, Peishan Jiang, Peter Reher, Stephen Hamlet and Carlos Marcelo S. Figueredo
J. Funct. Biomater. 2024, 15(11), 342; https://doi.org/10.3390/jfb15110342 - 13 Nov 2024
Viewed by 657
Abstract
Our study examined how different titanium alloy Ti6Al4V (Ti64) and zirconia (ZrO2) surfaces, ranging from rough to very smooth, affect the expression of elastase (NE), matrix metalloproteinase (MMP)-8, MMP-9, and extracellular traps (NETs) by neutrophils. Discs of Ti64 and ZrO2 [...] Read more.
Our study examined how different titanium alloy Ti6Al4V (Ti64) and zirconia (ZrO2) surfaces, ranging from rough to very smooth, affect the expression of elastase (NE), matrix metalloproteinase (MMP)-8, MMP-9, and extracellular traps (NETs) by neutrophils. Discs of Ti64 and ZrO2, 10 mm in diameter and 1.5 mm thick, were created using diamond-impregnated polishing burs and paste to produce rough (Ra > 3 µm), smooth (Ra ≥ 1 to 1.5 µm), and very smooth (Ra < 0.1 µm) surfaces. Neutrophils from Wistar rats were cultured on these surfaces, and the culture supernatants were then examined for NE, MMP-8, and MMP-9 using ELISA. At the same time, NET formation was demonstrated immunohistochemically by staining neutrophils with CD16b and DNA with DAPI. Overall, the expressions of NE and MMP-8 were significantly higher from neutrophil culture on Ti64 and ZrO2 rough surfaces compared to the very smooth surface (R > S > VS) after 2 h and 4 h of culture. The expression of MMP-9 also increased with culture time; however, no significant surface effects on expression were observed. Similarly, rough Ti64 and ZrO2 surfaces (R & S) also showed significantly larger NET formation compared to the very smooth surface (VS) after 4 h and 8 h cultures. Our findings suggest that increasing surface roughness on Ti64 and ZrO2 triggers higher NE, MMP-8, and NET formation secretion. Full article
(This article belongs to the Section Biomaterials and Devices for Healthcare Applications)
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<p>The morphology of the surfaces analysed by scanning electron microscope. (<b>A</b>) Ti64; (<b>B</b>) ZrO<sub>2</sub>. Scale bar at 50 μm.</p>
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<p>Neutrophil enzyme excretion between Ti64 (Ti) and ZrO<sub>2</sub> (Zr) surfaces at 1 h, 2 h, and 4 h (<b>A</b>) Neutrophil elastase, (<b>B</b>) MMP-8, (<b>C</b>) MMP-9. * <span class="html-italic">p</span> ≤ 0.05; ** <span class="html-italic">p</span> ≤ 0.001.</p>
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<p>Comparison of (<b>A</b>) NET area formed and (<b>B</b>) NET circularity (shape) on rough and very smooth titanium (Ti64) VS zirconia (ZrO<sub>2</sub>) surfaces at 2 h, 4 h, and 8 h quantified using cell profiler software. * <span class="html-italic">p</span> ≤ 0.05; ** <span class="html-italic">p</span> ≤ 0.001.</p>
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<p>Representative confocal microscopic images of NETs formed on rough (<b>A</b>), smooth (<b>B</b>), and very smooth titanium (Ti64) (<b>C</b>) and zirconia (ZrO<sub>2</sub>) (<b>D</b>) surfaces at 2 h, 4 h, and 8 h. The scale bar’s dimension is 20 μm.</p>
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21 pages, 6495 KiB  
Article
The Coexistence of Klebsiella pneumoniae and Candida albicans Enhanced Biofilm Thickness but Induced Less Severe Neutrophil Responses and Less Inflammation in Pneumonia Mice Than K. pneumoniae Alone
by Pornpimol Phuengmaung, Chiratchaya Chongrak, Wilasinee Saisorn, Jiradej Makjaroen, Uthaibhorn Singkham-in and Asada Leelahavanichkul
Int. J. Mol. Sci. 2024, 25(22), 12157; https://doi.org/10.3390/ijms252212157 - 12 Nov 2024
Viewed by 752
Abstract
Due to the possible coexistence of Klebsiella pneumoniae (KP) and Candida albicans (CA), strains of KP and CA with biofilm production properties clinically isolated from patients were tested. The production of biofilms from the combined organisms (KP+CA) was higher than the biofilms from [...] Read more.
Due to the possible coexistence of Klebsiella pneumoniae (KP) and Candida albicans (CA), strains of KP and CA with biofilm production properties clinically isolated from patients were tested. The production of biofilms from the combined organisms (KP+CA) was higher than the biofilms from each organism alone, as indicated by crystal violet and z-stack immunofluorescence. In parallel, the bacterial abundance in KP + CA was similar to KP, but the fungal abundance was higher than CA (culture method), implying that CA grows better in the presence of KP. Proteomic analysis was performed to compare KP + CA biofilm to KP biofilm alone. With isolated mouse neutrophils (thioglycolate induction), KP + CA biofilms induced less prominent responses than KP biofilms, as determined by (i) neutrophilic supernatant cytokines (ELISA) and (ii) neutrophil extracellular traps (NETs), using immunofluorescent images (neutrophil elastase, myeloperoxidase, and citrullinated histone 3), peptidyl arginine deiminase 4 (PAD4) expression, and cell-free DNA. Likewise, intratracheal KP + CA in C57BL/6 mice induces less severe pneumonia than KP alone, as indicated by organ injury (serum creatinine and alanine transaminase) (colorimetric assays), cytokines (ELISA), bronchoalveolar lavage fluid parameters (bacterial culture and neutrophil abundances using a hemocytometer), histology score (H&E stains), and NETs (immunofluorescence on the lung tissue). In conclusion, the biofilm biomass of KP + CA was mostly produced from CA with less potent neutrophil activation and less severe pneumonia than KP alone. Hence, fungi in the respiratory tract might benefit the host in some situations, despite the well-known adverse effects of fungi. Full article
(This article belongs to the Special Issue Mechanisms in Biofilm Formation, Tolerance and Control: 2nd Edition)
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<p>Crystal violet-stained biofilms in 96-well-plates with representative pictures at 72 h post-incubation of the control group (no organisms), <span class="html-italic">Klebsiella pneumoniae</span> (KP), <span class="html-italic">Candida albicans</span> (CA), and combined organisms (KP + CA) (<b>A</b>,<b>B</b>) are demonstrated. Characteristics of the biofilms from KP, CA, and KP + CA as indicated by microbial burdens (culture methods) (<b>C</b>), intensity score from the fluorescent-stained cover glasses to detect bacterial extracellular matrix (ECM) using AF647 (red color fluorescence), nucleic acid stained by SYTO9 (AF488; green color fluorescence), and fungal cell wall using calcofluor white (AF460; blue color fluorescence against chitin on fungal cell wall) with representative fluorescent images (<b>D</b>,<b>E</b>) are also demonstrated. Expression of some bacterial genes from biofilms of KP alone and KP + CA in the early phase of biofilm production (within 4 h post-incubation) (<b>F</b>) was shown. Data were retrieved from triplicate independent experiments. Fluorescent intensity was analyzed by the ZEN imaging software (Carl Zeiss, Oberkochen, Germany).</p>
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<p>The proteomic analysis of the biofilms from <span class="html-italic">Klebsiella pneumoniae</span> (KP, consisting of sessile KP with extracellular matrix) relative to the proteins from KP in planktonic form (non-biofilm-producing form without extracellular matrix), as indicated by a volcano plot with a picture indicating the functions of the important proteins for KP biofilm synthesis (<b>A</b>), and the biological analysis, using DAVID v2021q4 Bioinformatics resource 2021 software for protein gene ontology (GO), of the upregulated proteins (blue color) and downregulated proteins (brown color) (<b>B</b>–<b>G</b>), is demonstrated. cps, capsular polysaccharide; treC, trehalose-6-phosphate hydrolase; sugE, intima protein; LuxS, S-ribosylhomocysteine lyase; wzm, transport polymerase protein; wbbm, glycosyl transferase; MrkH, mannose-resistant <span class="html-italic">Klebsiella</span>-like H (a c-di-GMP-dependent transcriptional activator; a biofilm switch molecule); MrkABCDF, mannose-resistant <span class="html-italic">Klebsiella</span>-like ABDCF; fim, fimbriae; LPS, lipopolysaccharide; LpxA, UDP-N-acetylglucosamine acyltransferase; LpoA, penicillin-binding protein activator; KdsB, 3-deoxy-manno-octulosonate cytidyltransferase; RpoA, DNA-directed RNA polymerase subunit alpha; RpoC, DNA-directed RNA polymerase subunit beta. In the hypothetic picture, white color arrows indicate capsular polysaccharide (CPS)-associated proteins [<a href="#B18-ijms-25-12157" class="html-bibr">18</a>], orange arrows are proteins of the type II quorum sensing (QS) system and LPS synthesis [<a href="#B31-ijms-25-12157" class="html-bibr">31</a>], light and dark blue arrows are type III fimbriae-associated proteins (fimbriae-associated biofilms), and the bright orange arrow is type I fimbriae (non-biofilm fimbriae) [<a href="#B17-ijms-25-12157" class="html-bibr">17</a>].</p>
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<p>The proteomic analysis from biofilms of the mixed <span class="html-italic">Klebsiella pneumoniae</span> plus <span class="html-italic">Candida albicans</span> (KP + CA) relative to KP alone, as indicated by a volcano plot with a picture indicating the functions of the important up- and downregulated proteins with a hypothetic picture of the possible connection (quorum sensing) between the Candida quorum sensing molecules, including farnesol (inhibitor of fungal filamentation) and tyrosol (activator of fungal filamentation) (<b>A</b>), with the biological analysis, using v2021q4 DAVID Bioinformatics resource 2021 software for protein gene ontology (GO), of the upregulated proteins (blue color) and downregulated proteins (brown color) (<b>B</b>–<b>G</b>), is demonstrated. cps, capsular polysaccharide; treC, trehalose-6-phosphate hydrolase; sugE, intima protein; LuxS, S-ribosylhomocysteine lyase; wzm, transport polymerase protein; wbbm, glycosyl transferase; fim, fimbriae; LPS, lipopolysaccharide; LpoA, penicillin-binding protein activator LpoA; LpoB, penicillin-binding protein activator LpoB; ArnA, bifunctional polymyxin resistance protein ArnA; UreE, urease accessory protein UreE; ClpX, ATP-dependent Clp protease ATP-binding subunit ClpX; DnaK, chaperone protein DnaK; HscA, chaperone protein HscA; GroES, chaperonin GroEL; LsrB, autoinducer 2-binding protein LsrB.</p>
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<p>Schema of the experiments creating biofilms of <span class="html-italic">K. pneumoniae</span> (KP), <span class="html-italic">C. albicans</span> (CA), combined organisms (KP + CA), or control (culture media without organisms) (<b>A</b>) and the characteristics of the experiments as indicated by microbial burdens (culture for bacteria and fungi) (<b>B</b>), neutrophil viability (<b>C</b>), supernatant cytokines (TNF-α, IL-6, IL-1β, and IL-10) (<b>D</b>–<b>G</b>), cell-free DNA (<b>H</b>), and <span class="html-italic">peptidyl arginine deiminase 4</span> (<span class="html-italic">PAD4</span>) expression (<b>I</b>) are demonstrated. Data were retrieved from triplicate independent experiments.</p>
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<p>The neutrophil extracellular traps (NETs) in the biofilms of <span class="html-italic">K. pneumoniae</span> (KP), <span class="html-italic">C. albicans</span> (CA), combined organisms (KP + CA), or control (culture media without organisms) as indicated by the immunofluorescence of neutrophil elastase (NE; green color) and myeloperoxidase (MPO; red color) with the representative immunofluorescent pictures (<b>A</b>) and the immunofluorescence for citrullinated histone 3 (CitH3) with the representative pictures (<b>B</b>) are demonstrated. Notably, 4′,6-diamidino-2-phenylindole (DAPI; blue color) was used for the nuclear staining. Data were retrieved from triplicate independent experiments. ***, <span class="html-italic">p</span> ≤ 0.001.</p>
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<p>Schema of the experiments of the pneumonia model in C57BL/6 mice with dexamethasone administration for 5 days before intratracheal administration with <span class="html-italic">K. pneumoniae</span> (KP), <span class="html-italic">C. albicans</span> (CA), combined organisms (KP + CA), or control (vehicle without organisms) as indicated by survival analysis (<b>A</b>), serum creatinine (<b>B</b>), serum alanine transaminase (<b>C</b>), serum cytokines (TNF-α, IL-6, IL-1β, and IL-10) (<b>D</b>–<b>H</b>), cell-free DNA (<b>I</b>), microbial burdens in blood and in bronchoalveolar lavage (BALF) (<b>J</b>,<b>K</b>), neutrophils in the BALF (<b>L</b>), and the lung injury score based on hematoxylin- and eosin-stained histopathology (<b>M</b>) are demonstrated. (n = 10/group and n = 6–8/group for others.). *, <span class="html-italic">p</span> ≤ 0.05.</p>
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<p>Representative pictures of hematoxylin- and eosin-stained histopathology of mouse lungs with intratracheal administration by <span class="html-italic">K. pneumoniae</span> (KP), <span class="html-italic">C. albicans</span> (CA), combined organisms (KP + CA), or control (no organisms) are demonstrated to indicate lung consolidation (white blood cell infiltration in the alveolar space) in KP-only and KP + CA mice.</p>
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<p>Neutrophil extracellular traps (NETs) in the lung lesion of pneumonia mice with intratracheal administration by <span class="html-italic">K. pneumoniae</span> (KP), <span class="html-italic">C. albicans</span> (CA), combined organisms (KP + CA), or control (no organisms) as indicated by the immunofluorescence of neutrophil elastase (NE; green color), myeloperoxidase (MPO; red color), and citrullinated histone 3 (CitH3; red color) with representative pictures (<b>A</b>,<b>B</b>) are demonstrated. Notably, DAPI (blue color) was used for nuclear staining (n = 6–8/group).</p>
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12 pages, 3313 KiB  
Article
Quercetin Protects Goat Sperm Motility by Inhibiting Neutrophil Extracellular Traps and Maintaining Plasma Membrane and Acrosome Integrity
by Zhengkai Wei, Hongrong Hong, Wei Liu, Kaifeng He, Jiaxuan Wang, Xin Guo, Dezhi Zhang, Qianyong Li and Zhengtao Yang
Vet. Sci. 2024, 11(11), 553; https://doi.org/10.3390/vetsci11110553 - 10 Nov 2024
Viewed by 682
Abstract
Enhancing or protecting sperm motility has always been a pivotal approach to improving the ewe pregnancy rate. Sperm motility is highly susceptible to the immune status of the reproductive tract. Neutrophil extracellular traps (NETs) have been demonstrated to capture sperm and impair its [...] Read more.
Enhancing or protecting sperm motility has always been a pivotal approach to improving the ewe pregnancy rate. Sperm motility is highly susceptible to the immune status of the reproductive tract. Neutrophil extracellular traps (NETs) have been demonstrated to capture sperm and impair its motility in human, swine, and goat species. Quercetin is a flavonoid derived from Cuscuta Chinensis Lam., which can protect sperm from oxidative damage. In this study, we investigated whether inflammation decreases sperm motility and tried to clarify the potential protective mechanism of quercetin on goat sperm motility. Sperm-triggered NETs were analyzed by immunofluorescence analysis. Sperm acrosome integrity was detected by using giemsa staining. Quercetin exhibited no cytotoxicity towards sperm and PMNs within the concentration range of 20–80 μM. PMNs impaired both the survival rate and rapid linear motility of sperm, while quercetin significantly enhanced these parameters. PMNs captured sperm through NETs composed of DNA, citrullinated histone 3 (citH3), and neutrophil elastase (NE); however, quercetin effectively inhibited the release of sperm-stimulated NETs. The stimulation of PMNs with sperm resulted in a significant increase in levels of ROS and MDA, which decreased by quercetin. Moreover, PMNs caused integrity violation to both the plasma membrane and acrosome in sperm; this effect was significantly alleviated by quercetin. In conclusion, quercetin effectively ameliorated PMN-reduced sperm motility through the inhibition of NETs and oxidative stress, and preserving sperm plasma membrane and acrosome integrity, thereby providing preliminary insights into the underlying mechanisms and theoretical support for the development of potential sperm protectors. Full article
(This article belongs to the Special Issue Sperm Biotechnology in Animals Reproduction)
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<p>Chemical structure of quercetin.</p>
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<p>Effects of quercetin on sperm and PMNs activity. (<b>A</b>) Effects of quercetin on sperm activity. Quercetin exhibited no cytotoxic effects on sperm. (<b>B</b>) Effects of quercetin on PMNs activity. Quercetin did not influence the PMNs activity. (<b>C</b>) Effects of quercetin on sperm and PMNs activity. Quercetin showed non-toxicity to both PMNs and sperm. The values are presented as means ± SEM (n = 5, “<span class="html-italic">ns</span>” signifies not significant; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p>
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<p>Effects of quercetin on goat sperm survival and rapid linear motility. (<b>A</b>) Effects of quercetin on goat sperm survival rate. PMNs significantly reduced the sperm survival rate, but quercetin at concentrations of 20, 40, and 80 μM increased the sperm survival rate decreased by PMNs at 1, 1.5, and 3 h. Notably, only quercetin at 20 μM continued to provide protection at 6 h. (<b>B</b>) Effects of quercetin on goat sperm’s rapid linear motility. PMNs significantly reduced sperm’s rapid linear motility. Quercetin at 20 and 40 μM was able to increase the sperm’s rapid linear motility that decreased by PMNs at 1, 1.5, 3, and 6 h. The values are presented as means ± SEM (n = 5, “<span class="html-italic">ns</span>” signifies not significant; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p>
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<p>Visualization of quercetin on sperm inducing the formation of NETs. Goat sperm triggered the production of NETs, characterized by DNA scaffolds (Red) decorated with citH3 (Green) and NE (Green), and quercetin-reduced sperm induced the formation of NETs (white arrows).</p>
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<p>Quantitation of quercetin on sperm-induced NETs. Zymosan (1 mg/mL, Sigma) served as the positive control group. Quercetin effectively reduced NET production stimulated by sperm compared to the sperm and PMNs group, demonstrating that quercetin could decrease sperm-induced NET release. The values are presented as means ± SEM (n = 5; ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p>
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<p>Quercetin effectively inhibited NETs by attenuating ROS production. Zymosan (1 mg/mL, Sigma) served as the positive control group. Sperm or Zymosan significantly increased ROS production compared to PMNs. Treatment with quercetin significantly attenuated ROS generation compared to the sperm–PMNs mixture group. The values are presented as means ± SEM (n = 5; *** <span class="html-italic">p</span> &lt; 0.001).</p>
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<p>Effects of quercetin on CAT, GSH-Px, and MDA levels. (<b>A</b>) CAT levels (n = 3). (<b>B</b>) GSH-PX levels (n = 5). (<b>C</b>) MDA levels (n = 5). Goat sperm significantly increased CAT, GSH-Px, and MDA levels, while quercetin enhanced CAT and GSH-PX activity and reduced MDA levels. The values are presented as means ± SEM (n = 5, “<span class="html-italic">ns</span>” signifies not significant; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p>
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<p>Effects of quercetin on acrosome and plasma membrane integrity. (<b>A</b>) Acrosome integrity. (<b>B</b>) Plasma membrane integrity. PMNs caused integrity violation to both the plasma membrane and acrosome in sperm; however, this effect was significantly alleviated by quercetin. The values are presented as means ± SEM (n = 5; * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p>
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11 pages, 3130 KiB  
Communication
Aeruginosin 525 (AER525) from Cyanobacterium Aphanizomenon Sp. (KUCC C2): A New Serine Proteases Inhibitor
by Donata Overlingė, Marta Cegłowska, Robert Konkel and Hanna Mazur-Marzec
Mar. Drugs 2024, 22(11), 506; https://doi.org/10.3390/md22110506 - 8 Nov 2024
Viewed by 778
Abstract
Aeruginosins (AERs) are one of the most common classes of cyanobacterial peptides synthesised through a hybrid non-ribosomal peptide synthase/polyketide synthase pathway. They have been found in Microcystis, Nodularia spumigena, Oscillatoria/Plantothrix, and Nostoc. The presence of AER in Aphanizomenon [...] Read more.
Aeruginosins (AERs) are one of the most common classes of cyanobacterial peptides synthesised through a hybrid non-ribosomal peptide synthase/polyketide synthase pathway. They have been found in Microcystis, Nodularia spumigena, Oscillatoria/Plantothrix, and Nostoc. The presence of AER in Aphanizomenon isolated from the Curonian Lagoon was reported for the first time in our previous work. Here, the structure of aeruginosin 525 (AER525), isolated from Aphanizomenon sp. KUCC C2, was characterised based on high-resolution mass spectrometry. This new AER variant shows potent activity against thrombin. It also inhibits trypsin and carboxypeptidase A but has no effect on elastase and chymotrypsin. In terms of the N-terminal residue and biological activity, AER525 displaces some similarity to dysinosins, which belongs to the most potent inhibitors of thrombin among AERs. The findings underline the potential of AER525 as a new anticoagulant agent. Full article
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<p>Mass fragmentation spectra of AER525 collected using QTRAP5500.</p>
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<p>Mass fragmentation spectra of AER525 collected using HRMS SYNAPT XS QTOF systems.</p>
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<p>The activity of <span class="html-italic">Aphanizomenon</span> sp. KUCC C2 fractions against trypsin (tested at a concentration of 45 µg mL<sup>−1</sup>).</p>
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<p>The activity of <span class="html-italic">Aphanizomenon</span> sp. KUCC C2 fractions against thrombin (tested at a concentration of 45 µg mL<sup>−1</sup>).</p>
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