Antifungal activity of propafenone on spp. strains: interaction with antifungals and possible mechanism of action.

The development of new antifungal drugs has become a global priority, given the increasing cases of fungal diseases together with the rising resistance to available antifungal drugs. In this scenario, drug repositioning has emerged as an alternative for such development, with advantages such as reduced research time and costs. Propafenone is an antiarrhythmic drug whose antifungal activity is poorly described, being a good candidate for further study. This study aims to evaluate propafenone activity against different species of spp. to evaluate its combination with standard antifungals, as well as its possible action mechanism. To this end, we carried out tests against strains of , , , , and based on the evaluation of the MIC, minimum fungicidal concentration and tolerance level, along with checkerboard and flow cytometry tests with clinical strains and cell structure analysis by scanning electron microscopy (SEM). The results showed that propafenone has a 50% MIC ranging from 32 to 256 µg ml, with fungicidal activity and positive interactions with itraconazole in 83.3% of the strains evaluated. The effects of the treatments observed by SEM were extensive damage to the cell structure, while flow cytometry revealed the apoptotic potential of propafenone against spp. Taken together, these results indicate that propafenone has the potential for repositioning as an antifungal drug.