Interaction of Styrylpyridinium Compound with Pathogenic Candida albicans Yeasts and Human Embryonic Kidney HEK-293 Cells

Candida albicans-caused local and systemic diseases are a serious health issue worldwide, leading to high mycosis-associated morbidity and mortality. Efficient combinations of novel compounds with commonly used antifungals could be an important tool for fighting infections. The aim of this study was to evaluate the interaction of synthesized 4-(4-cyanostyryl)-1-dodecylpyridin-1-ium (CSDP(+)) bromide alone or in combination with fluconazole with yeast and mammalian cells. We investigated cytotoxicity of the tested agents to mammalian HEK-293 cells and the influence of CSDP(+) on the ability of C. albicans wt and a clinical isolate to adhere to HEK-293. Accumulation of lipophilic cation ethidium (Et(+)) was used to monitor the activity of efflux pumps in HEK-293 cells. The effect of CSDP(+) on the expression of the main efflux transporter genes and transcription factors in C. albicans cells as well as HEK-293 efflux pump gene ABCB1 was determined. The study showed that CSDP(+) alone and in combination with fluconazole was nontoxic to HEK-293 cells and was able to reduce C. albicans adhesion. The treatment of C. albicans cells with CSDP(+) in combination with fluconazole resulted in a considerable overexpression of the MDR1 and MRR1 genes. The findings suggest that these genes could be associated with efflux-related resistance to fluconazole. Measurements of Et(+) fluorescence and analysis of ABCB1 gene expression demonstrated that mammalian cells were not sensitive to concentrations of CSDP(+) affecting C. albicans.