Antibacterial Activity Of Phyllantus Amarus And Euphorbia Hirta Linn On Selected Bacterial Pathogens.

ABSTRACT

 The antibacterial activities of the leaves of two Nigerian medicinal plants were evaluated on four bacterial species namely Gram positive bacteria (Staphylococcus aureus and Enterococcus feacalis) and Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Ethanolic and aqueous extracts of the plants were studied. The in vitro antibacterial activity was performed by agar disc diffusion and micro dilution broth assays. All the extracts exhibited moderate to high level of broad spectrum antimicrobial activities against these microorganisms. The antibacterial activity was measured by the diameter zone of inhibition and minimum inhibitory concentration (MIC). The diameter of zone of inhibition ranges from 9mm-20mm at 2000µg/ml of crude extracts per disc. The MIC values were between 15.63g/ml - 500g/ml. The activities of the crude extracts were comparable to the reference antibiotics at standard concentration used per disc. Bactericidal and bacteristatic effects varied with solvent type of extract and method of test adopted. These findings are discussed in relation to the development of cheap and acceptable herbal medicines as a means of disease control and sources of novel molecules for combating the problem of microbial resistance to conventional antibiotics.