Antioxidant and antimicrobial activities of a common liverwort from Darjeeling Himalaya

Abstract

The study was concerned with an examination of antioxidant and antimicrobial activities of methanolic extract of Marchantia convoluta (Merch.) L.. collected from Darjeeling Himalaya. The antioxidant activities were evaluated by means of five in vitro methods, viz. free radical-scavenging activity, Fe3+ -reducing power, metal-chelating ability, trolox equivalent antioxidant capacity (TEAC) and activity in hydroxyl radical-scavenging system. The total phenol content was 1.1 mg gallic acid equivalents g-1 dried thallus. After 30 min of reaction, the 100 mg lyophilized extract possessed 6.7 % free radical-scavenging activity. The same amount of extract exhibited 13.4 % 168.2 % metal-chelating and hydroxyl radical scavenging activities, respectively. The reducing activity was found to be 28.5 mg ascorbic acid equivalents g-1 dried thallus. Total antioxidant activity was 0.18 μg TEAC g-1 dried thallus. The antimicrobial activity was evaluated by testing the methanolic extract of the samples against five microorganisms including two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus), two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and one yeast (Candida albicans by disc-diffusion assay. M. convoluta thallus extract was more or less inhibitory against all of the test bacteria, however did not possess any antifungal property. S. aureus was found to be most sensitive target organism.