Atividade antibiofilme in vitro e ex vivo da riparina 2 e seus homólogos nor- 2 e dinor- 2 contra dermatófitos.

Abstract

Dermatophytosis is a fungal disease that affects the skin, hair and nails mainly by Trichophyton rubrum, Microsporum canis and Nannizzia gypsea. Treatment occurs by administering ketoconazole, itraconazole and terbinafine. However, the ability of dermatophytes to develop biofilms makes therapy difficult, as it impairs the permeation of drugs in infected tissues. So, research to find new anti-dermatophyte biofilm drugs is crucial. Therefore, the aim of this study was to evaluate the antifungal activity of Riparin 2 and its synthetic counterparts NOR-2 and DINOR-2 against the fungal growth of biofilms of T. rubrum, M. canis and N. gypsea. For this, the microdilution technique was used with ciclopirox as a positive control. The quantification of in vitro biofilm biomass was evaluated after staining with 0.5% crystal violet, and the viability of the biofilm by quantification of the CFU number. The ex vivo model was performed on fragments of human nails, which were evaluated by visualization in light microscopy and quantification of the CFU number (viability). The compounds RIP2 and NOR-2 showed antifungal activity against strains of T. rubrum, M. canis and N. gypsea, but DINOR2 did not show significant antifungal activity against dermatophytes. Furthermore, RIP2 and NOR-2 significantly reduced the viability of biofilms in vitro and ex vivo (p < 0.05). RIP2 was more potent than NOR-2, possibly due to the distance between the chemical chain portions in these compounds. Therefore, this study can serve to direct the research of compounds with anti-dermatophyte activity, since the RIP2 and NOR-2 molecules showed promise in terms of antifungal and antibiofilm activity.