Avaliação da atividade antifúngica da hidralazina, seu efeito sinérgico com itraconazol e mecanismo de ação sobre cepas de Candida spp. resistentes ao fluconazol

Abstract

Currently, fungal infections are responsible for high morbidity and mortality. Candida spp. is the fourth most pathogen isolated in blood infections wich affecting immunocompromised patients. The increase in the number of cases of fungal resistance and the ability of Candida spp. To form complex biofilms of difficult treatment show that the current pharmacological antifungal arsenal is limited. The redirection of drugs may be an effective alternative. Currently, the hydralazine vasodilator antihypertensive has been studied for its antitumor activity, but there is not studies about its antifungal activity. This study’s aim was to evaluate the antifungal activity of hydralazine alone and in combination with fluconazole or itraconazole on the clinical isolates of fluconazole resistant Candida albicans, C. tropicalis and C. parapsilosis. By the broth microdilution technique, the minimum inhibitory concentration (MIC) was determined according to the protocol of the Clinical and Laboratory Standards Institute. Hydralazine toxicity was evaluated on L929 murine fibroblasts. Flow cytometry assays were used to investigate the cell death mechanism and by the MTT colorimetric assay evaluated the reduction of cell viability of the Candida albicans biofilm. The statistical analysis was performed using the GraphPad 6.0 software through analysis of variance (ANOVA) by Tukey tests or by Student Newman Keuls (p <0.05). The MIC of the HYD ranged from 16 to 128 μg /mL and there was synergized with itraconazole reducing the combinations of HYD and ITRA, but not with fluconazole. The HYD was not toxic at the concentrations tested. Cellular viability reduction, increased mitochondrial depolarization, EROS production, phosphatidylserine externalization, and DNA damage were observed. The HYD presented antifungal activity against the biofilm of C. albicans in superior concentrations than the MIC. In conclusion, the HYD showed antifungal potential against strains of Candida spp.tested.