ABSTRACT
Anti-microbial and anti-oxidant activities were examined from four foliose forms of lichen species and two fruticose lichen species. The crude extract was recovered using the Soxhlet solvent extraction procedure employing three different solvents, such as petroleum ether, acetone, and methanol based on their polarity. The methanolic extract was used to investigate the anti-oxidant property. The extract of Usnea stigmatoides showed strong radical scavenging activity, with the IC50 value of 50.2275. The Parmotrema austrosinense, Usnea stigmatoides, and P. reticulatum species exhibited strong anti-oxidant activity. A higher absorbance value was recorded for P. nilgherrense, P. reticulatum, and Usnea stigmatoides with the phenolic concentrations of 38.49, 32.80, and 32.088 mg gallic acid equivalent (GAE)/g, respectively. A moderate pathogenic control was observed in methanolic extracts of P. nilgherrense with a zone of inhibition of 9.8 ± 0.28 mm against Staphylococcus aureus. The petroleum ether extracts did not show inhibition activity against selected human pathogens. The methanolic extracts of Ramalina conduplicans of fruticose lichen showed better anti-bacterial activity against Staphylococcus aureus. The present study will offer the baseline information for the future bioprospection studies on lichen substances.
