Antioxidant and antibacterial activities of lichen Usnea ghattensis in vitro

Various solvent extracts of the lichen Usnea ghattensis showed good antioxidant activity. A methanol extract prevented lipid peroxidation by 87% followed by 65% in Trolox at 20 microg/ml. It also showed superoxide anion scavenging activity and free radical scavenging activity 56% and 73%, respectively. The known antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA) and quercetin at similar concentrations showed superoxide anion scavenging activity of 68, 59 and 47% and free radical scavenging activity 83, 77 and 69%, respectively. In addition, these extracts were inhibitory against Bacillus licheniformis, Bacillus megaterium, Bacillus subtilis and Staphylococcus aureus with MIC values of 5-10 microg/ml.