Phytochemical analysis and antibacterial activities of aqueous and ethanolic crude extracts of soursop (Annona muricata) leaves against selected clinical pathogens

Abstract

This study investigates phytochemical composition and the antimicrobial activities of aqueous and ethanol extracts of soursop (Annona muricata) leaves against some selected bacterial pathogens. Susceptibility effects of these extracts were determined by disc diffusion method against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus pyogenes and Staphylococcus aureus. The results showed that the efficacy of the aqueous extracts was more pronounced against the test bacterial, especially P. aeruginosa at minimum inhibitory concentration (MIC) of 0.2 mg/mL. The ethanol extract was more pronounced again S. pyogenes with diameter of zones of inhibition ranging from 15.00 – 32.00 mm at concentrations of 0.2 – 0.8 mg/mL respectively. The pathogens were susceptible to the aqueous extracts of the leave at concentrations between 0.4 – 0.8 mg/mL. Phytochemical compounds such as tannins, saponins, terpenoids, alkaloids, glycosides, and phenols were detected in A. muricata leaf extract. The significant antimicrobial properties of the leaf extract could be attributed to the presence of these bioactive compounds. Thus, this investigation proves to an extent that the Soursop leaf extracts when used against microorganisms, has sufficient antimicrobial property.