Antimicrobial and antioxidant activity of endophytic fungi isolated from ethnomedicinal plants of the “Sacred forests” of Meghalaya, India

Introduction: Medicinal plants growing in the ""sacred forests"" of Meghalaya (20.1°N-26.5°N latitude and 85.49°E-92.52°E longitude), in the north-eastern region of India are used by the traditional medical practitioners of the ethnic tribes of the region to treat a diverse range of diseases. Aim of the study: The aim of the study was to elucidate the antimicrobial and antioxidant potency of the most dominant fungal endophytes of some selected medicinal plants of the ""Sacred forests"". Material and methods: Isolation of the endophytes was done in water agar plates followed by subsequent pure culturing in potato dextrose agar plates. Molecular characterization of the endophytic fungal isolates was done by sequencing their β-tubulin gene. The antimicrobial properties of the culture broths and the crude ethyl acetate extracts of endophytic fungal metabolites were ascertained as per standard protocols against five human pathogens, namely, Bacillus cereus, Salmonella typhi, Escherichia coli, Staphylococcus aureus, and Candida albicans. The total antioxidant power and free radical scavenging activity of the metabolites was estimated using the ferric reducing antioxidant power (FRAP) and 1, 1-diphenyl-2- -picrylhydrazyl (DPPH) free radical assays. Results: Molecular characterization of the endophytes showed their relatedness to human pathogenic fungi. Minimum inhibitory concentration of the ethyl acetate extracts against the test pathogens ranged from 13-45 μg/ml. The metabolites of the endophytic fungi also showed high anti-oxidant activity. Conclusion: Endophytic fungi of the medicinal plants from the ""Sacred forests"" of Meghalaya, India are potential treasure troves of novel antimicrobial molecules and antioxidants.