The Antibacterial Activity of Aqueous and Ethanolic Leaf Extracts of Balanites aegyptiaca (l.) Del Plant on Some Selected Clinical Human Pathogens

Abstract

The antibacterial activity of the leaf extract of Balanites aegyptiaca plant was investigated on five selected clinical common human pathogens: Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhimurium, Shigella dysentriae and Escherichia coli, in vitro. The phytochemical screening, susceptibility testing and Minimal Inhibitory Concentrations were determined. Preliminary phytochemical screening of the leaf extracts indicated the presence of alkaloids, cardiac glycosides, flavonoids, glycosides, resins, saponins, steroids, tannins, and carbohydrates in varying concentrations. Ethanolic leaf extract was more effective. The extracts inhibited the growth of isolates with increasing concentrations, ranging from 8-12 mm zones of inhibitions, showing the susceptibility of the test organisms. S. dysentriae had the highest susceptibility for both extracts with 12 mm and 13 mm zones of inhibition for aqueous and ethanolic extracts respectively at the highest concentration of 400 mg/ml. S. aureus showed the least susceptibility with 8 mm for aqueous extract while S. typhimurium showed the least susceptibility for the ethanolic extract with 9mm zones of inhibition. The analysis of variance results on zones of inhibition revealed a significant difference for both extract treatments, concentrations, and interactions between the treatments and concentrations. The Minimal Inhibitory Concentrations determined from the corresponding concentration-response curves showed that S. dysentriae had the least value of 79.433 mg/ml while the aqueous extracts against S. aureus and S. typhimurium were the largest with 125.893 mg/ml value. The activity index and activity were also deduced to measure activity. The antimicrobial activity of leaf extracts of B. aegyptiaca on bacteria of the tested isolates have been established in this study and justify the claims by the traditional healers in its use to treat infectious diseases.