Antibacterial Activity of Three <i>Parmotrema</i> Species from Western Ghats of Karnataka against Clinical Isolates of Burn and Dental Caries

Abstract

The present study was conducted to evaluate the antibacterial efficacy of methanol extract of three species of macrolichen Parmotrema (Parmeliaceae) viz., P.tinctorum (Nyl.) Hale, P. grayanum (Hue.) Hale and P. praesorediosum (Nyl.) Hale from Western Ghats of Karnataka against clinical isolates of burn and dental caries. Identification of lichens was done by morphological, anatomical and color tests. The powdered lichen materials were extracted using methanol in soxhlet apparatus. Inhibitory potential of lichen extracts was evaluated against two isolates of Staphyloccus aureus (Sa-01 and Sa-02 from burn subjects) and two isolates of Streptococcus mutans (Sm-01 and Sm-02 from dental caries) by agar well diffusion assay. Lichen extracts were found inhibitory against all clinical isolates and the inhibitory activity was dose dependent. Among S. aureus and S. mutans isolates, Sa-02 and Sm-02 were inhibited to higher extent respectively by lichen extracts. Extract of P. praesorediosum inhibited S. aureus isolates to higher extent. Extracts of P. praesorediosum and P. tinctorum inhibited S. mutans isolates to higher extent. The lichens of this study were found promising sources for development of agents active against clinical    isolates. The observed activity of extracts could be ascribed to the  presence of secondary metabolites.