Evaluation of Antimicrobial Activity of Methanol and Aqueous Extracts of Begonia cucullata against Selected Human Pathogenic Bacteria

Abstract

Background: Plants are a significant source of bioactive compounds with potential therapeutic properties. Due to the growing concern of antibiotic-resistant pathogens, exploring plant-based antimicrobials has become increasingly essential. This study evaluated the antimicrobial activity of methanol and aqueous extracts of Begonia cucullata against 12 bacterial strains to validate its traditional use and identify its potential bioactivity. Methods: Petroleum ether, Chloroform, Methanol and aqueous extracts of Begonia cucullata were prepared and tested for antimicrobial activity using the agar well diffusion method on Muller Hinton  agar media. The diameter of the inhibition zones was measured after 48 hours of incubation at 37°C. Minimum Inhibitory Concentrations (MICs) were determined using the broth microdilution method. Results: The methanol extract exhibited significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, and Proteus vulgaris with inhibition zones ranging from 13 to 18 mm. The aqueous extract also demonstrated activity against Klebsiella pneumoniae, Escherichia coli, Bacillus cereus and Pseudomonas aeruginosa with inhibition zones ranging from 8 to 18 mm. The MIC values for Bacillus cereus and Escherichia coli were 125 µg/mL, while Klebsiella pneumoniae showed inhibition at 62.5 µg/mL. Petroleum ether and chloroform extracts showed no antibacterial activity. Conclusion: The study confirms that the methanol and aqueous extracts of Begonia cucullata possess potent antibacterial properties against several pathogenic bacteria, highlighting their potential as natural antimicrobial agents. These findings suggest that Begonia cucullata could serve as a valuable source for developing plant-based therapeutics to combat antibiotic-resistant infections, warranting further investigation into its bioactive constituents.