Inhibitory effects of cold atmospheric plasma on the growth, virulence factors and HSP90 gene expression in Candida albicans

Abstract

In spite of the abundance of antifungal therapies, 75% of women in the world suffer from the second most common cause of vaginal infection named vulvovaginal candidiasis. This complication is characterized with overgrowth of Candida albicans. The low efficacy and side effects of current antifungal therapies have convinced the researchers to look for a non-antibiotic based treatment such as cold atmospheric plasmas (CAP). The aim of this research was to evaluate the effects of CAP on C. albicans growth, ergosterol and biofilm formation. In addition, antibiotic resistance, phospholipase and proteinase activity, and structural properties were examined with different exposure duration. Putative critical effect of CAP on the expression of HSP90 as a target of anti-fungal therapy was investigated. ROS production in C. albicans exposed to CAP was assessed. For this purpose, C. albicans subjected to 0, 90, 120, 150, 180 and 210 s of He/O2 (2%), and non-treated cells as control were examined in terms of the mentioned virulence factors. The results showed that CAP had a significant effect on inhibition of C. albicans growth, Inhibition of biofilm formation, ergosterol content, and fluconazole and amphotericin B antibiotic sensitivity were significant in 210 s treatment group. This effect was validated based on changes of the cell architecture and morphology given the microscopy imaging results. The expression of HSP90 in both C. albicans ATCC 10231 and C. albicans PFCC 9362 was inhibited in 210 s of exposition. CAP exposition induced intracellular ROS, which may cause membrane damage and cell death in C. albicans. Taken together, the potential of CAP for therapeutic purposes in C. albicans-induced fungal infections is supported.