Anti-dermatophyte activity of Leguminosae plants from Southern Brazil with emphasis on Mimosa pigra (Leguminosae)

Intensive prophylactic use of antifungals leads to the increase of drug resistance and the need for new and more effective treatments are real. Plants from Leguminosae family are rich in flavonoids, for which numerous biological activities have been described, including antifungal effects.

To screen methanolic extracts from Leguminosae species looking for alternative sources for antifungal agents (anti-dermatophyte and anti-Candida) and their innocuity.

Antifungal activity was evaluated using the strains Candida albicans, C. krusei, C. glabrata, C. tropicalis, C. parapsilosis, Epidermophyton floccosum, Trichophyton mentagrophytes, T. rubrum and, Microsporum gypseum in the broth microdilution method. Later, the minimum inhibitory concentration (MIC) for Mimosa pigra, Eriosema heterophyllum, and Chamaecrista nictitans was determined. The most promising extract was fractionated and cytotoxicity and genotoxicity of the most active fraction were also assayed.

Fungicide and/or fungistatic activity against dermatophyte strains were presented by 60% of the methanolic extracts assayed. M. pigra, E. heterophyllum, and C. nictitans methanolic extracts could inhibit dermatophyte strains at concentrations ranging from 1.9 to 1000μg/mL. M. pigra showed the lowest MIC values for a dichloromethane fraction (1.9μg/mL) without DNA damage at 10 and 50μg/mL and 100% of cell viability of human leukocytes.

Our results indicate that methanolic extracts from Leguminosae plants are potential sources of antifungal compounds, mainly the extract and fractions from M. pigra. The dichloromethane fraction from M. pigra did not showed in vitro toxicity according to the applied assays.