Abstract

The antibacterial activities of ethanolic and methanolic extracts of Senna alata leaves against three infectious bacteria (Escherichia coli, Salmonella spp and Staphylococcus aureus) were examined using agar well diffusion method. The methanolic and ethanolic extracts were found effective against the tested clinical isolates. For the methanol extract, the highest zone of inhibition was observed against Salmonella spp with a diameter of 22.67 ± 0.67mm, followed by E. coli (20.33± 1.20mm) and S. aureus (17.00± 0.58mm). The highest zone of inhibition for ethanol extract was observed against E. coli (18.33± 1.20mm), followed by S. aureus (17.33±0.78mm) and Salmonella spp (14.67±2.40mm). The extracts demonstrated considerable activity against both Gram positive and Gram negative bacteria with the methanol extract showing higher activity than the ethanol extract. E. coli showed more susceptibility to the methanol extract of S. alata from the concentrations of 500mg/ml to 62.5mg/ml while S. aureus and Salmonella spp showed lesser susceptibility. The Minimum inhibitory concentration (MIC) result also showed that the MIC of S. alata. The phytochemical analysis carried out on the leaves of S. alata detected the presence of Alkaloids, Saponins, Tannins, Flavonoids and was fairly present for Phenol. The findings in this study with Senna alata leaves having antibacterial activities thus require more attention and evaluation needed against a wider range of microorganism.