Abstract

The leaf extracts of Phyllanthus amarus Schum and Thonn. a common Western Nigerian weed, was investigated for phytochemical constituents and antimicrobial activities. Hexane extracts demonstrated the highest extraction of 59% followed by Acetone (57%) and water (48%). Saponins, tannins, alkaloid flavonoids, balsam, anthraquinones and phenols were extracted in an acidic medium. Twelve microorganisms (8 bacterial species and 4 fungal species) were investigated for antimicrobial activities. Generally, the fungal species showed lower minimum inhibitory concentration (MIC) than the bacterial species. The test organisms showed close susceptibility to the leaf extracts when compared with Bacitracin and Erythromycin. Generally, the combination of the leaf extract with either bacitracin or erythromycin alone demonstrated synergistic effect thus showing the potential benefit of combining these standard antibiotics with the leaf extracts of P. amarus for combating infections.

Key words: Phyllanthus amarus, leaf extracts, phytochemicals, antimicrobial property antibiotic.