Antimicrobial Activity of five medicinal plants of Bangladesh

The antimicrobial activity of five medicinal plants was evaluated by disc diffusion method. Among those, some fraction of plant extracts (400 μg /disc) exhibited potent antimicrobial activity against five gram positive and seven gram negative bacteria and three fungi. Among the test samples of O. mungos, the carbon tetrachloride soluble fraction exhibited 12.0 mm and 13.0 mm zone of inhibition against B. megaterium and Aspergillus niger respectively. The crude methanol extract of S. nodiflora exhibited 14.0 mm zone of inhibition against Bacillus cereus whereas the carbon tetrachloride soluble fraction revealed 16.0 mm against Shigella boydii. The chloroform soluble fraction of P. sagitatta exhibited 16.0 mm zone of inhibition against Staphylococcus aureus and Shigella boydii. Among the test samples of M. macrophylla, the carbon tetrachloride soluble fraction showed 15.0 mm zone of inhibition against Salmonella paratyphi and 13.0 mm zone of inhibition against Aspergillus niger. The crude methanol extract of G. philippensis exhibited 18.0 mm zone of inhibition against Bacillus cereus.