ANTIMICROBIAL ACTIVITY OF DIFFERENT SOLVENT EXTRACTS OF SOME CASSIA SPECIES

Abstract

Hexane, chloroform, ethyl acetate and methanol extracts of leaves of Cassia alata, C. auriculata, C. fistula and C. tora were screened for their antimicrobial activity against human pathogenic bacterial and fungal strains. Antimicrobial activity was carried out by disc diffusion method, determination of minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC) and minimum fungicidal concentrations (MFC) against four strains of Gram positive bacteria, three strains of Gram negative bacteria and three species of fungi. The antimicrobial activity of various extracts of Cassia species showed varied levels of antimicrobial activity against the studied bacterial and fungal pathogens. The mean zone of inhibition produced by all the tested extracts ranged from 6.3±0.5 to 25.6±0.2 mm. The MIC, MBC and MFC values were between 62.5 and 1000 µg/mL. The ethyl acetate extract of C. tora showed good antimicrobial activity with the highest mean zone of inhibition (25.6±0.2 mm), lowest MIC (62.5 µg/mL) and MBC (125 µg/mL) values followed by ethyl acetate extract of C. auriculata (24.6±0.2 mm; MIC=62.5; MBC=125 µg/mL) against  S. aureus.