Bioactivity-guided Isolation of Antimicrobial and Antioxidant Metabolites from Ganoderma lucidum
Jomari T. Baccay 1, Krisha Marie D.L. Saquilayan 1, Orrei G. Singco 1, and Julie Charmain O. Bonifacio*
1Department of Biology, College of Science, Polytechnic University of the Philippines
Impaired wound healing can result in persistent infections, emphasizing the need to manage bacteria and minimize oxidative stress for effective healing. This study investigated the wound-healing potential of chitosan and Ganoderma lucidum methanolic extract (GLME) in vitro. Both substances were processed, characterized, and evaluated for their biological properties to aid wound healing. GLME exhibited diverse functional groups through FT-IR analysis, indicating its complex chemistry. Extracted chitosan closely resembled commercial chitosan, implying similar chemical composition. The extracted chitosan showed higher deacetylation than typical crustacean-derived chitosan. GLME contained carbohydrates, proteins, steroids, terpenoids, flavonoids, and saponins, while chitosan only contained carbohydrates, as revealed by phytochemical analysis. In antimicrobial tests, extracted chitosan effectively inhibited Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 250 µg/mL, whereas GLME had no impact. Chitosan and amikacin jointly inhibited P. aeruginosa and showed additive effects against E. coli. Chitosan and clindamycin combined additively against S. aureus. GLME exhibited greater antioxidant activity than extracted and commercial chitosan in the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay and the ferric reducing antioxidant power (FRAP) assay. Biological activities, such as the antimicrobial and antioxidant activity of the fungal chitosan and GLME extracted from the propagated and cultivated G. lucidum mushroom, have significantly promoted successful wound healing by addressing microbiological clearance and reducing oxidative stress. This study underscores the value of exploring natural sources for wound healing agents with improved antimicrobial and antioxidant properties.