Characterization of vaginal Candida isolates and assessment of the antifungal potential of Crude Alkaloid-Enriched Plant Extracts

Background: Vaginal candidiasis remains a major global health issue, increasingly complicated by antifungal resistance. This study aimed to isolate and characterize Candida species from vaginal infections and to evaluate the antifungal efficacy of selected alkaloid-rich plant extracts as potential natural alternatives to conventional drugs.
Materials & Methods: Vaginal swabs were collected from women clinically diagnosed with candidiasis. Fungal isolates were identified through conventional morphological and biochemical tests and confirmed using the Vitek-2 Compact system. Susceptibility to miconazole, amphotericin B, nystatin, and ketoconazole was determined by the disk diffusion method. Crude alkaloid extracts from black pepper (Piper nigrum), green tea leaves (Camellia sinensis), pomegranate peels (Punica granatum), and eggplant (Solanum melongena) were prepared, characterized by GC–MS, and evaluated for antifungal activity using agar well diffusion assays.
Findings: Candida albicans represented the predominant species (57.6%), followed by C. tropicalis (22.4%) and C. glabrata (20.0%). Most isolates were highly sensitive to miconazole but showed resistance to nystatin. GC–MS profiling revealed key alkaloids piperine, caffeine, pelletierine, and solasodine as major constituents. Among tested extracts, black pepper exhibited the highest antifungal activity (26 mm inhibition zone), while eggplant showed the lowest (15.5 mm). A significant, concentration-dependent increase in inhibition was observed for all extracts (p-value < 0.05).
Conclusion: Alkaloid-rich plant extracts, particularly those from black pepper, exhibit strong antifungal activity against vaginal Candida isolates and may serve as promising leads for developing novel natural antifungal agents. Further research is needed to determine their minimum inhibitory concentrations and clarify their mechanisms of action.