Évaluation in vitro des activités antioxydante et anti-Candida de l’huile essentielle de Salvia officinalis L: application potentielle dans la candidose vulvovaginale

Abstract

The vaginal ecosystem is a dynamic microbial environment primarily dominated by lactic acid bacteria, which help maintain vaginal homeostasis. Hormonal and physiological changes can disrupt this balance, allowing opportunistic microorganisms like Candida albicans to proliferate and cause vulvovaginal candidiasis (VVC), a common fungal infection in women of reproductive age. Conventional treatments mainly use topical antifungal creams, but these often contain broad-spectrum antimicrobials that may harm beneficial vaginal microbiota. This study aimed to evaluate in vitro the antioxidant, antifungal, and antimicrobial activities of Salvia officinalis L essential oil as a potential natural alternative for managing vulvovaginal candidiasis while minimizing harm to vaginal lactobacilli. The essential oil’s activity was compared to a commercial antifungal cream (Mycocide) against vaginal Candida isolates and two vaginal lactobacilli strains, including one clinical isolate and one commercial strain. The essential oil was extracted by hydrodistillation to an approximate yield of approximately 1.61% and exhibited antioxidant activity with an IC50 of approximately 37.96 by DPPH free radical scavenger assay and pH of 6. It also demonstrated concentration-dependent antimicrobial activity, with inhibition zones of 12.60 ± 0.26 mm against the S5 strain and 10.43 ± 0.32 mm against the commercial Lactobacillus strain at 100% concentration. Against Candida isolates, the inhibition zones reached 11.2 ± 0.15 mm at 100% concentration, decreasing progressively with dilution by aromatogram analysis. In comparison, the commercial cream demonstrated stronger antifungal and antimicrobial activities, with inhibition diameters reaching 16.5 ± 0.26 mm against the S5 strain and 15.4 ± 0.17 mm against Candida isolates at full concentration. However, the essential oil showed an additional antioxidant potential that may contribute to reducing oxidative stress and local inflammation associated with vulvovaginal candidiasis. These findings underscore the biological potential of S. officinalis essential oil as a natural antifungal agent with antioxidant properties. Although its antimicrobial efficacy is lower than that of the commercial antifungal cream, its selective action and potential to preserve the vaginal microbiota suggest it could serve as a promising complementary or alternative therapy for vulvovaginal candidiasis. Further in vivo and toxicological studies are needed to confirm its safety and clinical effectiveness.