In vitro Antimicrobial Activity of Extracts from Careya arborea Roxb Leaves

摘要

Antimicrobial activity of Careya arborea Roxb., leaf extracts was determined using cup-plate diffusion, two-fold serial dilution method. In cup-plate method, inhibition zone sizes were used to determine the susceptibility to extracts. The results showed that C. arborea leaf extracts showed potential antibacterial activity against S. aureus and B. subtilis . Ethyl acetate and ethanol extracts showed the highest zones of inhibition for Gram positive and Gram negative bacteria and for fungus C. albicans. Careya arborea leaf extracts were able to have a MIC range of 0.938-15 mg mL^-1, in two-fold dilution method. The ethylacetate extract exhibited significantly better inhibition compared to other extracts. Gram-positive B. subtilis , Gram-negative E. coli and fungus C. albicans were found to be most susceptible to ethylacetate extract. The extracts have shown to be bacteriostatic and fungistatic at low concentrations. Phytochemical screening of the extracts revealed the presence of phyto-compounds such as triterpenoids, steroids, flavonoids and tannins as major phytoconstituents with known antimicrobial agents. These phyto-constituents may be responsible for the antimicrobial activity of C. arborea .