Evaluation of the Antibacterial Properties of Ethanolic and Aqueous Leaf Extracts of Momordica charantia against Some Bacterial Isolates

Abstract

Momordica charantia is known for its nutritional and medicinal properties, including antimicrobial and anti-inflammatory activities. This study evaluated the antibacterial activities of ethanolic and aqueous leaf extracts of Momordica charantia against the test isolates:  Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The leaves were washed, air-dried, pulverized and extracts were obtained. These extracts were then evaluated for antibacterial activity following standard microbiological protocols. The results showed that the zones of inhibition increased with an increase in concentration for both extracts. The ethanolic extract exhibited the highest inhibition against K. pneumoniae (16.00 mm), while P. aeruginosa showed 6.00 mm. The aqueous extract exhibited the highest inhibition against K. pneumoniae (14.00 mm) and the least against E. coli (6.00 mm). Overall, ethanolic extracts demonstrated greater antibacterial activity than aqueous extracts. For MIC, 100 mg/mL of ethanolic extract inhibited all test organisms, although K. pneumoniae showed sensitivity at 50 mg/mL. The aqueous extracts inhibited K. pneumoniae and P. aeruginosa, but not E. coli and S. aureus. MBC results revealed that ethanolic extracts exerted bactericidal effects on S. aureus and P. aeruginosa, while only bacteriostatic effects were observed against E. coli and K. pneumonia, In contrast, only bacteriostatic effects were observed against E. coli and K. pneumoniae. These findings indicate that the ethanolic extract is more potent against the test isolates than the aqueous extract, which could be attributable to its rich phytochemical content, making it a promising candidate for further studies.