ANTIFUNGAL EFFICACY OF Psidium guajava (GUAVA) AND Citrus sinensis (ORANGE) LEAVES EXTRACT AGAINST Candida albicans.

Abstract

This study evaluated the antimicrobial efficacy of Psidium guajava (Guava) and Citrus sinensis (Orange) leaf extracts against Candida albicans. The practical research was conducted at the microbiology laboratory of Imo State University, using plant materials sourced from the Federal Polytechnic Nekede, Owerri. The leaves were processed into fine particles and subjected to aqueous and ethanolic extraction via maceration. Phytochemical screening revealed the presence of flavonoids, tannins, saponins, phenols, and alkaloids in guava extracts, with ethanol extract showing stronger concentrations of flavonoids, tannins, and phenols. Orange extracts contained fewer phytochemicals, with alkaloids absent in both ethanol and aqueous forms. Antifungal activity assessed by agar well diffusion demonstrated dose-dependent inhibition, with guava ethanol extract producing the largest zone of inhibition (17.0 ± 0.5 mm at 100 mg/mL), followed by orange ethanol extract (10.0 ± 0.6 mm), guava aqueous extract (11.0 ± 0.8 mm), and orange aqueous extract (8.5 ± 0.4 mm). Fluconazole, the positive control, exhibited the highest activity (22.0 ± 0.3 mm). Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) assays confirmed fungicidal activity for all extracts (MFC/MIC ratio = 2), with guava ethanol extract being the most potent (MIC 12.5 mg/mL, MFC 25 mg/mL). Statistical analysis (ANOVA) showed significant differences among extracts (P < 0.05), with guava ethanol extract outperforming orange extracts. Overall, ethanol extracts exhibited stronger antifungal activity than aqueous extracts, and guava demonstrated greater efficacy than orange. These findings suggest that guava leaves, particularly ethanol extracts, possess promising antifungal potential attributable to their rich phytochemical content, and may serve as a natural alternative in managing Candida albicans infections.