Comparative Evaluation of Antibacterial and Anti-Yeast Potential of Aloe vera and Cymbopogon flexuosus Extracts against Human Pathogens

Abstract

The rapid emergence of antimicrobial resistance and the increasing prevalence of opportunistic yeast infections necessitate the exploration of alternative antimicrobial agents from natural sources. Medicinal plants represent a promising reservoir of bioactive compounds with broad-spectrum antimicrobial properties. In the present study, methanolic and ethanolic extracts of Aloe vera and Cymbopogon flexuosus were evaluated for their antibacterial and anti-yeast activities against selected human pathogenic microorganisms. Antimicrobial efficacy was assessed using well diffusion, filter paper disc diffusion, invert plate assays, and minimum inhibitory concentration (MIC) determination. The methanolic extract of Aloe vera gel exhibited pronounced antibacterial activity, particularly against Escherichia coli (33.00 mm inhibition zone), followed by Bacillus brevis and Bacillus cereus. Cymbopogon flexuosus extracts demonstrated strong activity against Gram-positive bacteria, with maximum inhibition against B. cereus (31.00 mm). Both plant extracts showed notable anti-yeast activity against Saccharomyces cerevisiae and Rhodotorula species. MIC values ranged from 370–1290 µg mL⁻¹ for A. vera and 950–1500 µg mL⁻¹ for C. flexuosus. The results indicate that solvent polarity significantly influences antimicrobial efficacy. Overall, the findings validate the broad-spectrum antimicrobial potential of Aloe vera and Cymbopogon flexuosus, highlighting their potential as natural alternatives to synthetic antimicrobial agents.