Evaluation of Antibacterial Activity of Sclerocarya birrea (A. Rich) Hochst Stem Bark Extracts

Abstract

A research was conducted to evaluate the antibacterial potential of aqueous and methanolic stem bark extracts of Sclerocarya birrea against potential gastro-intestinal pathogens of humans. The aqueous and methanol extracts of S. birrea stem bark were evaluated for antibacterial activity using agar-diffusion method. The methanol extract gave higher antibacterial activity than aqueous extract. The order of susceptibility of test microorganisms to methanol extract revealed that Escherichia coli>Salmonella typhi>Shigella flexneri. The minimum inhibitory concentration (mg/ml) of methanol extract against the bacterial isolates is; E. coli (15 mm), S. typhi (14 mm) and Shigella flexneri (11 mm). The effects of the extracts are concentration dependent, increase with increase in concentration. The phytochemical analysis of the extracts presence the presence of ten (10) active constituents as follows: Flavonoids, proteins, alkaloids, anthraquinones, tannins, saponins, terpenoids/steroids, diterpenoids, cardiac glycosides and carbohydrates. Nine out of the ten phytochemicals except for alkaloids were found in the methanolic extracts; while seven active phytochemicals (except anthraquinones, saponins and cardiac glycosides) were present in the aqueous extracts. The results of the present study inferred that, the use of the plant in the treatment of gastro-intestinal disorders caused by some bacterial pathogens was proved vital.