Antimycobacterial Activity of Lichens

Abstract

Ethanol extracts of nine lichen species, namely Everniastrum cirrhatum. (Fr.) Hale ex Sipman (Parmeliaceae), Flavoparmelia caperata. (L) Hale (Parmeliaceae), Heterodermia leucomela. (L) Poelt (Physciaceae), Lecanora flavidorufa. Hue (Lecanoraceae), Leptogium pedicellatum. P.M. Jorg (Collemataceae), Lobaria isidiosa. (Bory) Trevisan (Stictaceae), Rimelia reticulata. (Taylor) Hale and Fletcher (Parmeliaceae), Phaeophyscia hispidula. (Ach.) Essl (Physciaceae), and Stereocaulon foliolosum. Nyl. (Stereocaulaceae), were evaluated for antimycobacteral properties against Mycobacterium tuberculosis. H₃₇Rv and H₃₇Ra strains using the radiometric BACTEC method. Among the tested lichens, the virulent strain of M. tuberculosis. H₃₇Rv was found more susceptible to ethanol extract of F. caperata. and H. leucomela. (MIC 250 µg/mL). E. cirrhatum., R. reticulata., and S. foliolosum. were found active at the concentration of 500 µg/mL. L. isidiosa., L. pedicellatum., P. hispidula., and L. flavidorufa. did not exhibit activity at the maximum tested concentration of 1000 µg/mL.

Keywords:

• Antimycobacterial agents
• BACTEC
• lichens
• Mycobacterium tuberculosis
• radiometric assay