Antibacterial Activity of the Aqueous Extracts of the Leaves, Fruits and Bark of Gmelina Arborea

Abstract

The antibacterial activity of the aqueous extracts of the leaves, fruits, and bark of Gmelina arborea against Escherichia coli was investigated in this study. Aqueous extraction was done, and three concentrations were prepared: 2.5 ml extract: 5 ml distilled H2O, 5.0 ml extract: 5 ml distilled H2O and 7.5 ml extract: 5 ml distilled H2O. Disk – diffusion method was used in the bioassay using E. coli after which, the filter paper discs were soaked separately in three concentrations of the Gmelina arborea extracts (bark, fruits, and leaves). The antibacterial activity was determined based on the zones of inhibition formed which was measured after 12, 24, 36, and 48 hours. The results showed that the highest average zone of inhibition (9.86 mm) was formed using the aqueous extracts of the fruits followed by the average zone of inhibition (8.45 mm) formed using the aqueous extracts of the bark and then that of the aqueous extracts of the leaves (7.44 mm). Thus, the aqueous extracts of the leaves, fruits, and bark of Gmelina arborea have antibacterial activity against E. coli antibacterial activity against E. coli.