Antifungal, antibiofilm and anti-resistance activities of Brazilian monofloral honeys against Candida spp.

Abstract

Candida is a fungus commonly involved in diseases of the skin and mucous membranes and has a high resistance to antifungal drugs. Moreover, there are few therapeutic options to treat these infections. Honey is a popular product that is easily accessible and has a diverse chemical composition, such as phenolic compounds that can have an antimicrobial effect in various metabolic pathways. Therefore, in this study, we aimed to characterize the antifungal activity of tree popular Brazilians honey against Candida species. Aroeira, Eucalyptus and Assa-Peixe honey was characterized by total phenolics and its antifungal activity on Candida species was tested by the microdilution method, antibiofilm activity, yeast to hypha (Y–H) transition, combination assays, multistage resistance study, and antibi-scanning electron microscopy of the fungi. Aroeira honey showh potent antifungal activity in vitro against planktonic cells of C. albicans (MIC 20–30% w/v) and non-albicans (MIC 30–40% w/v) and also breaks down mature biofilms formed by these yeasts at 40% w/v. Urethral catheters sensitized with 30% Aroeira honey reduced adhesion and biofilm formation by C. albicans. Aroeira honey did not induce resistance in C. albicans during the 21-day exposure. Its ability to alter fungal membrane structure contributes to the synergistic effects of Aroeira honey with commercial antifungal agents (miconazole, ketoconazole, itraconazole). Aroeira honey inhibits yeast-to-alpha transition in C. albicans, and its prior exposure for 1 h reverses the azole resistance profile of a highly resistant strain of C. albicans. Taken together, these results indicate that Aroeira honey is a promising therapeutic agent against superficial candidiasis.