ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF AQUEOUS AND ETHANOL EXTRACTS OF PHYLLANTHUS NIRURI AND GARCINIA KOLA

Abstract

Plants with medicinal properties popularly refers to as gift of “mother nature” to mankind are in use for centuries in the traditional system of medicines. In this study, the antibacterial and antifungal activities of different concentrations (20mg/ml, 40mg/ml, and 60mg/ml) of aqueous and ethanol extracts of Phyllanthus niruri (whole plant) and Garcinia kola seeds were determined, using agar well diffusion method, against some selected pathogenic micro organisms. Antimicrobial susceptibility test showed the following zones of inhibition at various concentrations of the extracts respectively: Aqueous extract of P. niruri; S. typhi (18, 22, 24mm), P. aeruginosa (9, 11, 15mm), E. coli (23, 26, 30.50mm), ethanolic extract of P. niruri; S. typhi (25, 31.50, 35mm), P. aeruginosa (15, 19.50, 24mm), E. coli (27.50, 33, 38mm), aqueous extract of G. kola; S. typhi (11, 15.50, 19mm), P. aeruginosa (7, 11, 14mm), E. coli (13.50, 18.50, 22mm), ethanolic extract of G. kola; S. typhi (18, 22.50, 28mm), P. aeruginosa (14.50, 16, 22mm), E. coli (25, 29, 35mm). The results when compared to the standard controls, showed that both extracts of P. niruri and G. kola were effective against the bacterial isolates only. The minimum inhibitory concentrations (MIC) of the extracts from both samples against the test organisms, showed E. coli to be the most sensitive at the lowest concentration of 12.8 µg/mL, and all the test organisms, at maximum concentration of 64 µg/mL of the ethanol extract of G. kola. The antibacterial effects observed may be attributed to the presence of secondary metabolites in the extracts, while the non-antifungal effect could result due to resistance of the fungal strains to the active constituents of the extracts. Therefore, the extracts hold promising potential as antibacterial agents if well exploited.