Antibacterial Activity and Phytochemical Screening of Vernonia amygdalina (Bitter Leaf) Against Salmonella typhi and Staphylococcus aureus,

Abstract

This study investigated the antibacterial activity and phytochemical constituents of Vernonia amygdalina (bitter leaf) against two pathogenic bacteria: Salmonella typhi and Staphylococcus aureus. Leaf samples were collected from Katsina Central Market, processed, and extracted using ethanol and aqueous solvents. Antibacterial activity was evaluated through the disc diffusion method, and phytochemical screening was conducted to identify bioactive compounds. Results showed that both ethanol and aqueous extracts exhibited antibacterial activity, with ethanol extract demonstrating greater efficacy. At 100 mg/mL, the ethanol extract produced inhibition zones of 15 mm and 14 mm against S. typhi and S. aureus, respectively, compared to 13 mm and 11 mm by the aqueous extract. Phytochemical analysis revealed the presence of tannins, saponins, flavonoids, and phenols in the aqueous extract, while only tannins and saponins were found in the ethanol extract. Alkaloids were absent in both. These findings suggest that V. amygdalina possesses significant antibacterial properties attributable to its phytochemical content and could serve as a potential source for the development of novel antimicrobial agents. Further studies are recommended to explore its antifungal and antiparasitic potentials and to isolate and characterize the specific active compounds.