Evaluation of phytochemical, in vitro antibacterial and rate of kill assay of Terminalia avicennioides leaf against some bacteria associated with diarrhoea

Abstract

The study was aimed to evaluate the phytochemical constituents, in vitro antibacterial and rate of kill assay of Terminalia avicennioides leaf extract against some bacteria associated with diarrhoea. The phytochemical constituents of the ethanol of Terminalia avicennioides leaf, aqueous, n- butanol, and ethyl acetate fractions of the leaf extract were determined using standard analytical methods. The antibacterial activities of the leaf extract and extract fractions against clinical isolates of Salmonella Typhimurium and Escherichia coli isolated from diarrhoeaic patients were determined in vitro by agar diffusion, dilution and time - kill methods. The result of phytochemical screening revealed the presence of carbohydrates, cardiac glycosides, saponins, flavonoides, tannins, alkaloids, phenols and triterpenes. The crude extract and extract fractions of T. avicennioides leaf were effective against the test bacterial isolates at varied concentration of extracts but the n-butanol fraction was more effective with Minimum inhibitory and Minimum Bactericidal Concentration of 6.25 and 12.5mg/ml. The clinical isolates of E. coli and S. Typhimurium were completely killed within 180 minutes of exposure to ethanol leaf extract and extract fractions at varied MBCs of 12.5 mg/ml and 25.0 mg/ml. The clinical isolates of E. coli and S. Typhimurium were more susceptible to n-butanol fraction within 120 minutes of exposure to the extract fraction.