Antimicrobial activity of Terminalia bellerica

Abstract

The antimicrobial activity of crude and methanol extract of Terminalia bellerica dry fruit was tested by disc diffusion method, against 9 human microbial pathogens. Crude aqueous extract of dry fruit at 4 mg concentration showed zone of inhibition ranging from 15.5-28.0 mm. S. aureus was found to be highly susceptible forming highest zone of inhibition, suggesting that T. bellerica was strongly inhibitory towards this organism. These pathogens were highly sensitive to the methanol extract forming 14.0 to 30.0 mm zone of inhibition suggesting that the methanol extract of T. bellerica was more effective than crude extract against most of the microbes tested except E. coli (enteropathogen) and P. aeruginosa. The minimal inhibitory concentrations (MICs) of crude and methanol extracts were determined by broth dilution technique which ranged from 300 to >2400 μg/ml and 250 pg to >2000 μg/ml respectively, indicating that T. bellerica was highly effective against S. aureus with lower MIC values. There were some biochemical alterations induced by T. bellerica. These results indicate that T. bellerica dry fruit possesses potential broad spectrum antimicrobial activity.