Antifungal treatment with carvacrol and eugenol of oral candidiasis in immunosuppressed rats

Carvacrol and eugenol, the main (phenolic) components of essential oils of some aromatic plants, were evaluated for their therapeutic efficacy in the treatment of experimental oral candidiasis induced by Candida albicans in immunosuppressed rats. This anticandidal activity was analyzed by microbiological and histopathological techniques, and it was compared with that of nystatin, which was used as a positive control. Microbiologically, carvacrol and eugenol significantly (p<0.05) reduced the number of colony forming units (CFU) sampled from the oral cavity of rats treated for eight consecutive days, compared to untreated control rats. Treatment with nystatin gave similar results. Histologically, the untreated control animals showed numerous hyphae on the epithelium of the dorsal surface of the tongue. In contrast no hyphal colonization of the epithelium was seen in carvacrol-treated animals, while in rats treated with eugenol, only a few focalized zones of the dorsal surface of the tongue were occupied by hyphae. In the nystatin treated group, hyphae were found in the folds of the tongue mucosa. Thus, the histological data were confirmed by the microbiological tests for carvacrol and eugenol, but not for the nystatin-treated group. Therefore, carvacrol and eugenol could be considered as strong antifungal agents and could be proposed as therapeutic agents for oral candidiasis.