Phytochemical screening, antioxidant and antimicrobial efficacy of Protorhus longifolia(Bernh. Ex C. krauss) Engl. (Anacardiaceae) seed extracts

The objective of this study was to elucidate the phytochemical, antioxidant and antimicrobial activities of Protorhus longifolia seed extracts in vitro. The phytochemical analysis revealed the presence of flavonoids, glycosides and sterols predominately in the methanol and ethanol extracts. Antioxidant activities were evaluated in vitro by DPPH-radical scavenging, H₂O₂ and ABTS⁺ assays. Methanol extract had the highest DPPH scavenging activity (95% at 200 μg/ml), while hexane extract had the lowest DPPH scavenging activity (16% at 25 μg/ml). Aqueous extract showed high percentage of scavenging activity in ABTS⁺ radical system compared to other assays. Amongst all the extracts, methanol extract showed significant inhibitory effect against Staphylococcus aureus (inhibition zone diameter 16mm) while different seed extracts showed no activity against Enterococcus faecalis. While in the case of fungal strains, only methanol extract showed antifungal activity against Candida albicans ATCC 10231 (< 9 mm) and Candida albicans (< 7 mm). The study indicates that methanol extract of seeds of P. longifolia exhibit strong antioxidant and antimicrobial activity and would be potential sources of antioxidant and antimicrobial agents of natural origin and could be used as potential alternative for treating various diseases.