There are only limited informations in the literature on the antifungal activity of essential oils toward human fungal pathogens in vivo. In the present study the antifungal activity of mint (Mentha x pipperita L.) essential oil was examined against widely spread pathogenic fungal strain Trichophyton mentagrophytes, which causes superficial skin infections in humans. The in vivo evaluation of the antifungal activity of the essential oil was made on two-month old male Wistar rats. We examined the therapeutic potency against experimentally induced dermatomycoses in rats. The therapeutic efficacy of 1% solution of essential oil as well as commercial preparation-bicutrin, was evaluated daily in two ways; macroscopic examination of lesions and screening for the presence of the infectious agent by culturing skin scales from the infected area. First symptoms were observed eight days after experimental infection, as well-defined clinical parameters (scaly, erythematous to black lesions). These lesions exhibiting in bloody wound (2 cm in diameter) at the 20th day of experiment, when we started with treatment with essential oil. At the 24th day of treatment, wounds become crusty, while at the 36th day there were no visually observed scaly or any other lesions. After this period of treatment, macroscopic examination showed clean area of inoculation, whereas the fungus could still be recovered from the infected areas. So, we prolonged treatment with essential oil until the reinoculation showed negative results (40 days). During the 20-day observation period the oil-treated animals were cured completely.
These results should stimulate studies on improved formulations, determination of optimal concentrations of essential oils and their components, for clinical applications, what will be included in our further investigation.