Antibacterial activity of <i>Leptogium cochleatum</i> and <i>Leptogium moluccanum</i>

Abstract

There is an increase in the emergence and re-emergence of bacterial infections nowadays, and lichens are potential sources of pharmaceutically important secondary metabolites to halt this problem. Lichens are unique plant-like organisms which are relatively less explored in the Philippines. Here, lichen extracts of<italic> Leptogium cochleatum</italic> and <italic>Leptogium moluccanum</italic> were tested against <italic>Escherichia coli</italic>, <italic>Enterobacter agglomerans</italic>,<italic> Klebsiella pneumoniae,</italic> <italic>Pseudomonas aeruginosa</italic>, and <italic>Staphylococcus aureus</italic> using paper disk diffusion assay. Hexane extract of <italic>L. moluccanum</italic> led to a 17.14 mm zone of inhibition (ZOI) against <italic>K. pneumoniae,</italic> while hexane extract of <italic>L. cochleatum</italic> led to a 15.28 mm ZOI against <italic>E. agglomerans</italic>. Dichloromethane extracts of <italic>L. cochleatum</italic> exhibited a ZOI of 15.86 mm against <italic>E. agglomerans</italic> and 14.84 mm ZOI against <italic>E. coli</italic>. The bioactivities exhibited by the lichen extracts may be due to the secondary metabolites detected using thin layer chromatography. Indeed, lichen-derived bioactive compounds hold great promise for pharmaceutical applications for the benefit of human life.