Antimicrobial activity screening of crude extract from leaves of Cassia nigricans Vahl.

Abstract

The antimicrobial activity of the methanol, ethyl acetate, chloroform and petroleum ether extracts of the leaves of

Cassia nigricans Vahl was investigated against Staphylococcus aureus, Streptococcus pyogenes, Corynebacterium pyogenes, Salmonella typhi, Escherichia coli and Pseudomonas aeroginosa, using agar diffusion technique. Results showed that the extract were effective against all the test microorganisms. The minimum inhibitory concentrations of the extracts of methanol, ethyl acetate and chloroform were found to be 2 x 10⁴ µg/ml, while the petroleum ether showed no inhibition. The results of the study provide scientific basis for the use of the plant extract in the treatment of wounds and skin diseases. It is concluded that the active principles possessing antimicrobial activity may be extracted from the leaves of Cassia nigricans Vahl by methanol, ethyl acetate and chloroform.