Antifungal efficacy of caffeic acid and nano-caffeic acid particles against candidiasis: an in vitro study.

Background/purpose: Candidiasis is the most common oral fungal infection. Several medications have been introduced to manage this infection. This study investigated the antifungal effect of caffeic acid and nano-caffeic acid.

Materials and methods: The size and particle dispersion index (PDI) of caffeic acid-containing niosome vesicles were measured after their production. The zeta potential was measured using a Zetasizer Nano ZS, and the amount of nano-caffeic acid released from the vesicles was measured. Candida isolates were cultured in Malt Extract Agar medium. Nystatin, fluconazole, caffeic acid and nano-caffeic acid were studied according to the Clinical and Laboratory Standards Institute (CLSI) protocol (M27-A3/S4), a broth microdilution test was performed, and the minimum inhibitory concentration (MIC) was determined. The data were analyzed using the Mann‒Whitney and Kruskal‒Wallis tests.

Results: The optimal formulation had 100 mg Tween 60, 100 mg Span 60, 200 mg cholesterol, a size of 271.83 ± 3.11 nm, a PDI of 0.21 ± 0.02, a zeta potential of 5.58 ± 0.47 mV and an encapsulation efficiency (EE%) of 42.34 ± 4.34%. The size, absolute zeta potential and EE% increased significantly with increasing cholesterol content from zero to 200  mg (P < 0.05). Caffeic acid, nano-caffeic acid, carrier, fluconazole and nystatin had the lowest to highest antifungal activity, respectively.

Conclusion: According to the MIC₅₀ and MIC₉₀ values, nystatin, fluconazole, carrier, nano-caffeic acid and caffeic acid had the highest to lowest inhibitory efficiency against Candida species, respectively.