Fungal infections, such as dermatophytosis, include some of the most common human diseases. Among the etiological agents most prevalent in these infections are the species of the genus Trichophyton, such as Trichophyton interdigitale, responsible, epidemiologically, for cases of onychomycosis and tinea in several countries of the world. Although there are substances for the treatment of these infections, most of the compounds present high toxicity to the patients, which, together with the emergence of antifungal resistance used in clinical practice, makes the search for new antifungal drugs essential. Among the potential targets for the discovery of new antifungal drugs, plants have been extensively studied. Among the potential targets for the discovery of new antifungal drugs, plants have been extensively studied. Among the plants studied, there are those that have been used empirically by the population for years in the treatment of fungal infections. In order to evaluate the in vitro and in vivo antifungal activity of three essential oils (EO1, EO2 and EO3), the antifungal potential of these essential oils was tested by minimum inhibitory concentration (MIC) against T. interdigitale strains, monotherapy and combination therapy with ketoconazole. In addition, the potential of these extracts was tested for the ability to modulate the fungicidal activity of bone marrow derived macrophages by quantifying the production of nitric oxide, reactive oxygen and nitrogen species, rate of phagocytosis and analysis of the intracellular proliferation profile. The cytotoxic activity of these compounds in macrophage viability was also tested at different concentrations. EO1 and EO2 were further tested for the ability to decrease fungal burden in a murine model of dermatophytosis. The MIC range for the compounds tested was 0,06-0,25% (% v/v) for EO1, 0,12-0,50% (% v/v) for EO2 and 0,50-1,00% (% v/v) for EO3, low values when compared to ketoconazole (0,30-2,00 μg/mL). In combination with ketoconazole, the essential oils presented mostly antagonistic activity and, in some cases, concentration-dependent indifference. It was observed that the compounds tested induce the production of reactive species of oxygen and nitrogen, as well as increase the phagocytic activity. The intracellular proliferation profile, however, showed no dependence on the action of essential oils. In murine model of dermatophytosis, it was observed that the treatment with EO1 and EO2 have the capacity to reduce the fungal burden in infected animals, indicating a promising potential of the use of the essential oils against Trichophyton interdigitale strains.

ANTIFUNGAL ACTIVITY in vitro AND in vivo OF ESSENTIAL OILS AGAINST DERMATOPHYTOSIS AGENTS