Antimicrobial activity of Terminalia chebula

Terminalia chebula is a popular medicinal plant according to Ayurveda for its broad spectrum medicinal value including in the treatment of enteric disorders. Leaf extracts in water as well as in various organic solvents (namely methanol, ethanol, ethyl acetate and chloroform) were analyzed to testify its antibacterial activities against four different bacteria causing enteric disorders, viz. Escherichia coli, Salmonella sp, Shigella sp and Vibrio cholerae in vitro along with Saccharomyces cerevisiae. The analysis was carried out by taking the extracts at a concentration of 10 mg/ml and their activities were recorded by estimating zones of inhibition as produced by disc-diffusion method on Mueller-Hinton agar media. While all the organisms were resistant to chloroform extract and some of them to that of ethyl acetate, the methanol as well as the aqueous extracts of the plant showed the potential bactericidal activity, however nothing was evident against the yeast candidate. When compared with the traditional antibiotics, this activity was especially competent against Escherichia coli and Shigella sp, followed by Vibrio sp. and Salmonella spp. The broth dilution assay revealed that the bactericidal values fall in the range of 5000 to 8000 μg/ml.