This study aimed to assess the antimicrobial activity of endophytic Phyllosticta fallopiae L67 isolated from Aloe vera against diabetic wound microorganisms and characterise their active fraction for biologically important metabolites. The dichloromethane (DCM) extract exhibited the most significant activity with inhibition zones ranging from 11.33 to 38.33 mm. The minimal inhibitory and lethality concentrations of DCM extract ranged from 78.13 to 2500.00 µg/ml and 625.00 to 5000.00 µg/ml, respectively. The extract showed teratogenicity and lethality in the zebrafish model, where peritoneal and hepatic oedema occurred at 62.50 µg/ml, and no abnormality appeared at 31.25 µg/ml. The extract also inhibited more than 82% biofilm formation. Bioassay-guided fractionation on DCM extract yielded 18 fractions and the most active fraction was subjected to UPLC-QTOF-MS/MS analysis. Flavones, stilbenes, flavanonols, isoflavonoids, phenolic glycosides and phenol derivatives were detected. In conclusion, endophytic P. fallopiae possessed bioactive metabolites with significant antimicrobial activity against diabetic wound microorganisms.
Pressure ulcers are commonly associated with microbial infections on the wounds which require an effective wound dressing for treatment. Thus far, the available silver dressing has shown tremendous result, however, it may cause argyria and complicate the internal organ function. Hence, our study aims to develop and characterize phomopsidione-loaded chitosan-polyethylene glycol nanocomposite hydrogel (C/PEG/Ph) as an antimicrobial dressing. Physically, the C/PEG/Ph hydrogel demonstrated a uniform light blue color, soft, flexible, and elastic, with no aggregation form. The evaluation via Fourier Transform Infrared (FTIR) exposed the C/PEG/Ph hydrogel has a notable shift towards lower frequency at 1600 and 1554 cm-1. For drug release test, the phomopsidione attained plateau at 24 h, with a total release of 67.9 ± 6.4% from the C/PEG/Ph hydrogel. There was a null burst release effect discovered throughout the experimental period. The C/PEG/Ph hydrogel showed significant results against all 4 Gram-negative bacteria and 1 yeast, with 99.99-100% reduction of microbial growth. The findings revealed that the C/PEG/Ph hydrogel can potentially act as an antimicrobial dressing for pressure ulcers.