Antioxidant and antibacterial properties of some cultured lichens

The lichen species namely Usnea ghattensis, Heterodermia podocarpa, Arthothelium awasthii and Parmotrema tinctorum have been cultured in vitro and were screened for their antioxidant and antibacterial potential using different assay systems. The methanol extract of lichens showed antioxidant and antibacterial activities according to the order U. ghattensis>A. awasthii>H. podocarpa>P. tinctorum. The IC(50) values for the antioxidant activities of U. ghattensis and A. awasthii are less or equivalent to that of standard antioxidants. The methanolic extracts of the mycobiont and photobiont cultures of lichenU. ghattensis and A. awasthii were effective against Bacillus licheniformis, Bacillus megaterium, Bacillus subtilis and Staphylococcus aureus. The minimum inhibitory concentration (MIC) of the extract was found between 5 and 10microg extract/ml. The results suggested that the extract of mycobiont and photobiont cultures of lichen U. ghattensis and A. awasthii could be of use as an easily accessible source of natural antioxidants and antibacterial properties for the possible food supplement or in the pharmaceutical industry.