In view of an optimal gut antifungal therapeutic strategy: an in vitro susceptibility and toxicity study testing a novel phyto-compound.

OBJECTIVE:  In view of the raising concern for gut fungal infection, the aim of the present research was to carry out a systematic in vitro study testing the antifungal activity and possible toxicity of a polygodial-anethole compound (Kolorex) in several strains of Candida albicans and in other fungal pathogens. METHODS:  The in vitro susceptibility tests were carried out on 4 strains of C. albicans (C. krusei, C. lipolytica, C. tropicalis, C. utilis), Aspergillus flavus and A. fumigatus. Cultures were also analyzed by varying medium, pH and inoculum size, and a time-course killing test was carried out. RESULTS:  In the present study the polygodyal–anethole compound showed remarkable in vitro activity against the most common fungi, which was significantly better than polygodyal alone. Moreover, such mixture compound was shown to exert its activity against a wide spectrum of fungi, including C. lipolytica and C. tropicalis, which required significantly higher MIC of polygodyal to be unfeasible in clinical application. The activity of the polygodyal–anethole compound was significantly better than polygodyal alone with high inoculum size and low pH. Moreover, it proved to exert a significantly faster biological activity against low inoculum. CONCLUSIONS:  This study suggests that the mixture compound Kolorex has a very good profile of antifungal activity in terms of effectiveness and spectrum of action while being devoid of any significant toxicity.