Antimicrobial activity of Diospyros melanoxylon bark from Similipal Biosphere Reserve, Orissa, India

Abstract

The antimicrobial activity of five extracts of Diospyros melanoxylon Roxb. bark collected from Similipal Biosphere Reserve, Orissa was evaluated against human pathogenic bacteria and fungi. The extracts
including both polar and non polar solvents; petroleum ether, chloroform, ethanol, methanol and aqueous were evaluated for their antimicrobial activity against three gram positive and five gram
negative bacteria as well as three fungal strains. Although, all the five extracts exhibited promising antibacterial activities, yet maximum activity was observed in ethanol extract. In case of antifungal
activity, except petroleum ether extract none of the extracts were found to be active against the fungal strains. MIC values for most of the extracts ranged from 1.5 to 6 mg/ml, while MBC values varied from 3
mg/ml to values greater than 12 mg/ml. Phytochemical analysis exhibited the presence of steroids, alkaloids, glycoside, proteins, tannins, phenolic compounds, carbohydrates, gums and mucilage in
acetone, methanol and ethanol extracts with maximum phytochemicals in ethanol extract. Least phytochemicals was observed in case of petroleum ether. These results, so obtained, demonstrate the
broad spectrum activity of D. melanoxylon bark extracts which may be useful in treatment of various microbial infections. However, the active components responsible for antimicrobial activity need to be
evaluated.