PHYTOCHEMISTRY AND ANTIBACTERIAL ACTIVITY OF TAMARINDUS INDICA STEM BARK EXTRACTS
M. Yusha’u, D.A. Gabari and N.T. Dabo.
Department of Microbiology, Bayero University, P. M. B. 3011, Kano.
Tamarindus indica (L.),Leguminosae, is a plant mostly found and used medicinally in West Africa including Nigeria. The stem-bark powder of the plant was extracted with ethanol using percolation method and the extract was further fractionated in 50mls each of chloroform and distilled water (1:1). The extract and fractions were tested for the presence of secondary metabolites using standard procedures. They were further tested for antibacterial activity against clinical isolates of Salmonella typhi, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Vibrio cholerae and Vibrio parahaemolyticus using disc diffusion and broth dilution techniques. The results of phytochemical screening indicated the presence of secondary metabolites including alkaloids, glycosides, reducing sugars, tannins and saponins in ethanol extract and water fraction of the extract. Bioassay test results showed that Klebsiella pneumoniae, Proteus mirabilis, Vibrio cholerae and Vibrio parahaemolyticus were sensitive to ethanol extract and water fraction of the plant with highest sensitivity to water fraction against E. coli (19 mm) at 125 µg/disc using disc diffusion test and having MIC and MBC values of 500 and 1000 µg/ml respectively. The plant extract and fraction were found show inhibitory activity against the test isolates which may be related to the presence secondary metabolites, some of which are reported to be responsible for antimicrobial properties of medicinal plants. The results suggest that Tamarindus indica used in this study has the potential for the production of drugs against bacterial infections.
Keywords: Tamarindus indica, Secondary metabolites, Antibacterial activity and Bacteria.