The antimicrobial, antibiofilm, and wound healing properties of ethyl acetate crude extract of an endophytic fungus Paecilomyces sp. (AUMC 15510) in earthworm model

Wound Healing, Metabolite Profiling, and In Silico Studies of Aspergillus terreus

Burn injuries, which significantly affect global public health, require effective treatment strategies tailored to varying severity. Fungi are considered a sustainable, easily propagated source for lead therapeutic discovery. In this study, we explored the burn wound healing potential of Aspergillus terreus through a combination of in vitro, in vivo, metabolite profiling, and in silico analysis. The in vitro scratch assays performed with human skin fibroblast cells showed promising wound healing activity. Furthermore, the burn-induced rats model showed a marked improvement in cutaneous wound healing, evidenced by an accelerated rate of wound closure and better skin regeneration after A. terreus extract treatment at 14 days. The results of this study demonstrated significant enhancements in wound closure and tissue regeneration in the treated rat model, surpassing the outcomes of standard treatments. This controlled healing process, evidenced by superior collagen synthesis and angiogenesis and confirmed by histopathological studies, suggests that A. terreus has potential beyond the traditionally studied fungal metabolites. The metabolite profiling of 27 bioactive compounds was further investigated by docking analysis for the potential inhibition of the NF-κB pathway, which has an important function in inflammation and wound repair. The compounds eurobenzophenone A (7), aspernolide D (16), asperphenalenone A (23), aspergilate D (15), kodaistatin A (18), and versicolactone A (14) showed the highest binding affinity to the target protein with a pose score of -16.86, -14.65, -12.65, -12.45, -12.19, and -12.08 kcal/mol, respectively. Drug-likeness properties were also conducted. The findings suggest the potential wound healing properties of A. terreus as a source for lead therapeutic candidate discovery.

Antimicrobial activities of Diltiazem Hydrochloride: drug repurposing approach

Background

The growing concern of antibiotic-resistant microbial strains worldwide has prompted the need for alternative methods to combat microbial resistance. Biofilm formation poses a significant challenge to antibiotic efficiency due to the difficulty of penetrating antibiotics through the sticky microbial aggregates. Drug repurposing is an innovative technique that aims to expand the use of non-antibiotic medications to address this issue. The primary objective of this study was to evaluate the antimicrobial properties of Diltiazem HCl, a 1,5-benzothiazepine Ca2 + channel blocker commonly used as an antihypertensive agent, against four pathogenic bacteria and three pathogenic yeasts, as well as its antiviral activity against the Coxsackie B4 virus (CoxB4).

Methods

To assess the antifungal and antibacterial activities of Diltiazem HCl, the well diffusion method was employed, while crystal violet staining was used to determine the anti-biofilm activity. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay was utilized to evaluate the antiviral activity of Diltiazem HCl against the CoxB4 virus.

Results

This study revealed that Diltiazem HCl exhibited noticeable antimicrobial properties against Gram-positive bacteria, demonstrating the highest inhibition of Staphylococcus epidermidis, followed by Staphylococcus aureus. It effectively reduced the formation of biofilms by 95.1% and 90.7% for S. epidermidis, and S. aureus, respectively. Additionally, the antiviral activity of Diltiazem HCl was found to be potent against the CoxB4 virus, with an IC50 of 35.8 ± 0.54 μg mL-1 compared to the reference antiviral Acyclovir (IC50 42.71 ± 0.43 μg mL-1).

Conclusion

This study suggests that Diltiazem HCl, in addition to its antihypertensive effect, may also be a potential treatment option for infections caused by Gram-positive bacteria and the CoxB4 viruses, providing an additional off-target effect for Diltiazem HCl.

Antimicrobial and cytotoxic activities of flavonoid and phenolics extracted from Sepia pharaonis ink (Mollusca: Cephalopoda)

BACKGROUND

Several studies have been reported previously on the bioactivities of different extracts of marine molluscs. Therefore, we decided to evaluate the cytotoxic and antimicrobial activities of S. pharaonis ink as a highly populated species in the Red Sea. We extracted the flavonoids from the ink and analyzed their composition. Then we evaluated systematically the cytotoxic and antimicrobial properties of this extract. A pharmacokinetic study was also conducted using SwissADME to assess the potential of the identified flavonoids and phenolic compounds from the ink extract to be orally active drug candidates.

RESULTS

Cytotoxic activity was evaluated against 5 cell lines (MCF7, Hep G2, A549, and Caco2) at different concentrations (0.4 µg/mL, 1.6 µg/mL, 6.3 µg/mL, 25 µg/mL, 100 µg/mL). The viability of examined cells was reduced by the extract in a concentration-dependent manner. The highest cytotoxic effect of the extract was recorded against A549 and Hep G2 cancer cell lines cells with IC50 = 2.873 and 7.1 µg/mL respectively. The mechanistic analysis by flow cytometry of this extract on cell cycle progression and apoptosis induction indicated that the extract arrests the cell cycle at the S phase in Hep G2 and MCF7, while in A549 cell arrest was recorded at G1 phase. However, it causes G1 and S phase arrest in Caco2 cancer cell line. Our data showed that the extract has significant antimicrobial activity against all tested human microbial pathogens. However, the best inhibitory effect was observed against Candida albicans ATCC 10,221 with a minimum inhibitory concentration (MIC) of 1.95 µg/mL. Pharmacokinetic analysis using SwissADME showed that most flavonoids and phenolics compounds have high drug similarity as they satisfy Lipinski's criteria and have WLOGP values below 5.88 and TPSA below 131.6 Å2.

CONCLUSION

S. pharaonis ink ethanolic extract showed a promising cytotoxic potency against various cell lines and a remarkable antimicrobial action against different pathogenic microbial strains. S. pharaonis ink is a novel source of important flavonoids that could be used in the future in different applications as a naturally safe and feasible alternative of synthetic drugs.

Ice nucleation active bacteria metabolites as antibiofilm agent to control Aeromonas hydrophila and Streptococcus agalactiae infections in Aquaculture

OBJECTIVES

The aim of this study was to quantify and identify metabolites of Ice Nucleation Active (INA) bacteria as an anti-biofilm agent against biofilms of fish pathogens such as Aeromonas hydrophila and Streptococcus agalactiae.

RESULTS

Ice nucleation active bacteria, which have the ability to catalyze ice nucleation, isolated from rainwater in previous studies, were used. All INA isolates were tested in several assays, including the antimicrobial test, which uses streptomycin as the positive control and none of the isolates were found positive in the antimicrobial test. As for the quorum quenching assay, it was found that four out of ten isolates were able to disturb the communication system in Chromobacterium violaceum wild type, which was used as the indicator bacteria. On the next assay, all ten isolates were tested for Biofilm Inhibition and Destruction and showed anti-biofilm activity with the highest percentage inhibition of 33.49% by isolate A40 against A. hydrophila and 77.26% by isolate A19 against S. agalactiae. C1 performed the highest destruction against A. hydrophila and S. agalactiae, with percentages of 32.11% and 51.88%, respectively. As for the GC-MS analysis, supernatants of INA bacteria contain bioactive compounds such as sarcosine and fatty acids, which are known to have antibiofilm activity against several biofilm-forming bacteria. Through 16s rRNA sequencing, identified bacteria are from the Pantoea, Enterobacter, and Acinetobacter genera. As for the conclusion, ice nucleation active bacteria metabolites tested showed positive results against pathogenic bacteria Aeromonas hydrophila and Streptococcus agalactiae in destructing and inhibiting biofilm growth.

In-vivo and in-vitro wound healing and tissue repair effect of Trametes versicolor polysaccharide extract

Regarding different medical benefits of fungi, using the medical mushroom extracts as wound-healing agents is gaining popularity. This study, evaluated the wound healing characteristics of Trametes versicolor. Anti-oxidant activity addressed by employing the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay resulting 53.7% inhibitory effect. Besides, for anti-microbial ability determination, the MIC (Minimum Inhibitory Concentration) of extract measured which Escherichia coli growth was inhibited at 1.1 mg/ml, and Staphylococcus aureus did not grow at 4.38 mg/ml of extract. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method indicated dose dependence of the extract with 63 ± 3% and 28 ± 3% viability at 1250 μg/ml and 156.25 μg/ml of extract, which higher concentration caused higher cell viability. The outcome of gene expression analysis determined that overall expression of FGF2 (Fibroblast Growth Factor 2), IL-1β (Interleukin-1β), and TGF-β1 (Transforming Growth Factor-β1) was 4 times higher at 48 h than at 24 h in treated cells, suggesting a stimulating effect on cell growth. An in-vivo animal model suggested enhanced wound healing process after treatment with 0.01 g of extract. Furthermore, the number of fibroblasts, epidermal thickness, and collagen fiber was respectively 2, 3, and threefold higher in treated mice when compared to untreated mice. The treated wounds of mice showed 100% and 60% of untreated mice of healing within 14 days. The results of this research show promise for the fungus-based wound healing treatments, which may help with tissue regeneration and the healing of cutaneous wounds.

In vitro and In silico assessment of antischistosomal activities of ethanolic extract of Cornulacamonacantha

Schistosomiasis is the second most prevailing parasitic disease worldwide. Although praziquantel is considered an effective drug in the treatment against schistosomiasis to some extent, there is an emerging drug resistance that widely recorded. Therefore, there is an urgent need to develop effective and safe anti-schistosomal drugs. In this study, Cornulaca monacantha (C. monacantha), a sub-saharan plant, was extracted using aqueous ethanol and characterized by High-Performance Liquid Chromatography (HPLC). Major constituents of the extract are belonging to flavonoids, tannins and phenolic glycosides. Worms' viability and surface morphology of Schistosoma mansoni (S. mansoni) adult worms treated with the extract were assessed using in vitro viability assay, Scanning Electron Microscopy (SEM), and histological examination. The extract (80-350 μg/ml) reduced viability percentage of worms by 40-60% and caused degeneration of both oral and ventral suckers, tegumental, sub-tegumental and muscular damage. Molecular docking approach was utilized to assess the binding affinities of the extracted compounds with S. mansoni alpha-carbonic anhydrase (SmCA), an essential tegument protein. Pharmacokinetic analysis using SwissADME showed that 7 compounds have high drug similarity. This study confirms the in vitro schistomicidal activity of C. monacantha extract against S. mansoni adult worms and suggests potential SmCA inhibition.