In vitro anticandidal potency of Syzygium aromaticum (clove) extracts against vaginal candidiasis

Abstract Background Candida vaginitis is a global health hazard that increases morbidity among women of childbearing age. Recent studies have revealed a high incidence of drug-resistant Candida strains. Additionally, treating Candida vulvovaginitis during pregnancy is challenging as antifungal therapy is associated with fetal abnormalities. Hence, it is important to develop novel therapeutic strategies to treat vulvovaginal candidiasis. Methods In this study, we used the disc diffusion method to evaluate the anticandidal activity of different Syzygium aromaticum extracts (methanol, ethyl acetate, n-hexane, and diethyl ether) against C. albicans, C. glabrata, and C. tropicalis. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis of different S. aromaticum extracts was performed to determine active components exhibiting anticandidal activity. Cytotoxicity of different clove extracts against the HUH7 cell line was evaluated. Results The ethyl acetate extract exhibited the highest antifungal activity against C. albicans, C. glabrata, and C. tropicalis with inhibition zone diameters of 20.9, 14.9, and 30.7 mm, respectively. The minimum inhibitory concentration of the S. aromaticum ethyl acetate extract was 250 μg/disc against C. tropicalis, and 500 μg/disc against C. albicans and C. glabrata, while the minimum fungicidal concentration was 0.5 mg/disc against C. tropicalis and 1 mg/disc against the C. albicans and C. glabrata. GC-MS analysis of the ethyl acetate extract revealed the main bioactive compound as eugenol (58.88%), followed by eugenyl acetate (23.86%), trans-caryophyllene (14.44%), and α-humulene (1.88%). The cytotoxicity assay indicated that the diethyl ether extract demonstrated the lowest toxicological effect against the HUH7 cell line, with a relative IC50 of 62.43 μg/ml; the methanolic extract demonstrated a higher toxicity (IC50, 24.17 μg/ml). Conclusion As the S. aromaticum extract exhibited high antifungal activity at low concentrations, it can be a potential source of natural antifungal drugs.