Abstract

This study was undertaken to identify medicinal plants that are effective against multiple human pathogens and to partially purify the active component through thin layer chromatography. Antibacterial activity of selected plant extracts were assayed by agar cup diffusion. Minimum inhibitory concentrations were determined against all the pathogens. Sensitivity of the pathogens was also checked with four standard antibiotics. In addition, the stabilities of the active compounds were checked at different temperature and pH conditions. Extracts were separated using TLC and relative mobilities of bioactive components were determined by contact bioautography. Ethanolic extracts of Amla (Emblica officinalis) fruit, Neem (Azadirachta indica) leaves, Aloe (Aloe vera) leaves, Assam Tea (Camellia sinensis assamica) leaves and Clove (Syzygium aromaticum) buds were found to inhibit the growth of methicillin resistantStaphylococcus aureus, Vibrio cholerae and Pseudomonas aeruginosa. Bioactive components were stable over a range of pH values and temperatures.

Key words: Azadirachta indica, Aloe vera, Camellia sinensis assamica, Syzygium aromaticum, Staphylococcus aureus, Vibrio cholerae, Pseudomonas aeruginosa.