Antifungal activity of traditional medicinal plants from Argentina: effect of their combination with antifungal drugs

Abstract

The incidence of fungal infections has experienced a marked increase in the last two decades being limited to a few drugs with serious drawbacks. Combination therapy has emerged as an approach to improve the efficacy of currently used antifungal therapy that also may delay the evolution of resistance. The objectives of this work are to present a bibliographic search on the plants used in traditional medicine in Argentina for ailments related to fungal infections and to investigate the antifungal activity of currently used antifungal drugs in combination with natural extracts. Results of the bibliographic investigation showed that 153 species belonging to 56 families and 120 genera from Argentina are applied to treat signs and symptoms considered to maintain ethnopharmacological uses related to fungal infections, mainly for skin and mucosal conditions. Regarding the evaluation of the antifungal activity of combinations between extracts and antifungal drugs, we observed that extracts from plants species belonging to a genera traditionally used for ailments related to fungal infections have more chances of enhancing the activity of amphotericin B, fluconazole and itraconazole. In addition, we observed that there is a greater chance of finding an enhancement in the activity of the commercial antifungals when the combination is performed with extracts that have shown activity in solitary. Nevertheless, inactive extracts that would have been discarded according to the classic strategy displayed activity in combination and they continue being potential candidates in the search for new antifungals.