SCREENING AND ANTIMICROBIAL ACTIVITIES OF BITTER LEAF (VERNONIA AMYGDALINA)

This study was conducted to investigate the phytochemical constituents and antimicrobial activities of the aqueous extract of Bitter Leaf (Vernonia amygdalina). Fresh leaves of Vernonia amygdalina were collected, air-dried, pulverized, and extracted using distilled water. Standard qualitative phytochemical screening methods were employed to identify the presence of various secondary metabolites. The antimicrobial efficacy of the extract was evaluated against Staphylococcus aureus, Escherichia coli, and Candida albicans using the agar well diffusion method, and the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. The activity of the extract was compared with a standard antibiotic (Gentamicin). The phytochemical analysis revealed the presence of saponins, terpenoids, flavonoids, fatty acids, quinones, tannins, and phenols. Steroids, alkaloids, and oxalates were absent. The antimicrobial assay showed that the aqueous extract exhibited inhibitory activity against all test organisms, with varying zones of inhibition. The extract was most potent against E. coli (MIC of 62.5 mg/mL) and least potent against S. aureus (MIC of 250 mg/mL). While the zones of inhibition for the extract were smaller than those of the Gentamicin control, the results confirm significant antimicrobial properties. In conclusion, the presence of bioactive compounds and the demonstrated antimicrobial activity provide a scientific basis for the traditional use of Vernonia amygdalina in treating infectious diseases. It is recommended that further studies be conducted to isolate the active compounds and to establish safe dosage levels for its development as a complementary herbal medicine.