Avaliação in vitro da atividade antimicrobiana do Haloperidol em células planctônicas e biofilme de Candida spp. sensível e resistentes ao Fluconazol: determinação do possível mecanismo de ação

Abstract

Fungal infections are particularly noteworthy due to their high morbidity and mortality rates. Estimates suggest that 1 billion individuals may have or live with some type of fungal infection, which is estimated to cause 3.8 to 4 million deaths annually. Candidiasis is the most prevalent opportunistic fungal infection worldwide, caused by yeasts of the genus Candida and exhibiting a high prevalence of clinical isolates resistant to conventional antifungals, making the development of new therapies paramount. In this context, drug repositioning is a strategy that aims to utilize medications already available on the market for purposes different from their initial use, for which haloperidol, a first-generation antipsychotic, has demonstrated potential in the antimicrobial field. From this perspective, the present study aims to evaluate the activity of haloperidol, alone and in combination with classic antifungals, against fluconazole-sensitive and fluconazole-resistant clinical strains of Candida spp., and the possible mechanisms associated with its antifungal action. Broth microdilution tests were performed to determine the Minimum Inhibitory Concentration (MIC), as indicated in the Clinical & Laboratory Standards Institute document M27-A3, for haloperidol and antifungals, along with checkerboard assays and the fractional inhibitory concentration index, flow cytometry, DNA damage assessment by comet assay, assays of formed and forming biofilms, and biofilm assessment by SEM. The results showed MICs of haloperidol ranging from 26.67 to 256 μg/mL. Regarding drug interaction assays, synergistic interactions were found between haloperidol and azoles, fluconazole and itraconazole, respectively, and 12.5% synergism with amphotericin B. The results also revealed that haloperidol induces apoptotic processes in C. albicans and C. auris species, causing DNA damage and methylation and inducing the expression of genes related to oxidative stress, contributing to homeostatic dysregulation, causing severe damage and inducing cell death. Biofilm assays showed a reduction in the viability of the formed biofilm in all species tested, ranging from 34.91% to 51.30% at the MIC concentration of the strains. Similar behavior was observed in the forming biofilm, where the reduction in viability ranged from 38.99% to 51.32%. Thus, haloperidol has great potential for antifungal action and stands out as a promising therapeutic alternative that needs further scientific investigation for future uses with anti-Candida action