ANTIMICROBIAL ACTIVITY OF LEAF EXTRACTS OF THREE MEDICINAL PLANTS

Abstract

Crude extracts from leaves of three medicinal plants namely: Chenopodium album, Moringa oleifera and Terminalia arjuna in four buffers: phosphate buffer saline (PBS), potassium phosphate buffer (PPB), sodium acetate buffer (SAB) and sodium phosphate buffer (SPB), were screened for their antimicrobial activity. The quantity of proteins in the extracts was estimated and antimicrobial activity of the extracts determined on the basis of inhibition zone using Agar well Diffusion Assay and Minimal Inhibition Concentration (MIC). The maximum protein (22.96 mg protein/100 ml) was found in the leaf extract of M.oleifera extracted  in PBS buffer. Minimum protein was 7.29 mg/100 ml in T. arjuna in the sodium phosphate buffer.All the plants showed significant activity against eight pathogens tested. The PBS buffer extract of M.oleifera showed the maximum inhibition against E.coli (31±0.23mm) and A. niger (30±0.05 mm) while the minimum inhibition was seen against P. vulagris but none for Fusarium spp. MIC values of all extracts tested against five bacterial species ranged from 11 to 188 μg/ml and against the three fungi between 24 to 387μg/ml, respectively. Extracts in phosphate buffer saline and sodium acetate buffer, had higher activity as compared to that in potassium phosphate and sodium phosphate buffers.