Antibacterial activity of tannins from the leaves of Solanum trilobatum Linn

Compounds of pharmacological interest (tannins) were isolated from the plant species, Solanum trilobatum Linn and assayed against the bacteria, Staphylococcus aureus, Streptococcus pyrogens, Salmonella typhi, Pseudomonas aeruginosa, Proteus vulgaris and Escherichia coli using agar diffusion method. Tannins exhibited antibacterial activities against all the tested microorganisms. S.aureus was the most resistant to tannins isolated from the plant material followed by Streptococcus pyrogens, Salmonella typhi, Escherichia coli, Proteus vulgari and Pseudomonas aeruginosa. Minimum inhibitory concentration of the tannins ranged between 1.0 and 2.0 mg/ml while the minimum bactericidal concentration ranged between 1.5 and 2.0 mg/ml.