Iodine induces toxicity against Candida albicans and Candida glabrata through oxidative stress

Candida species are antifungal-resistant opportunistic infections that spread through contaminated medical staff hands and hospital surfaces creating a nosocomial infection risk. Iodine´s antibacterial properties are well established; however, its antifungal properties remain unknown. The objective of this study was to investigate the antifungal effects of lugol on cell viability and oxidative stress on Candida albicans and Candida glabrata strains.

MTT reduction test and sensitivity growth assay were used to determine viability and minimal inhibitory concentration, colorimetric tests were used to analyzing lipoperoxidation and antioxidant status in C. albicans, parental C. glabrata, C. glabrata lacking catalase gene (cta1) and superoxide dismutase 1 and 2 double mutants (sod1∆ sod2∆) strains exposure to lugol were used.

In both C. albicans and C. glabrata wild types lugol treatment decreased cellular viability in a dose-dependent manner at 30 mm. The cytotoxic lugol effect was characterized by the increase of oxidative stress and the reduction of superoxide dismutase and catalase enzyme activities. C. glabrata strains lacking catalase (cta1) and superoxide dismutase 1 and 2 double mutants (sod1∆ sod2∆) were less resistant to lugol than parental C. glabrata strains.

In Candida strains iodine lugol solution has antifungal properties, producing cytotoxicity and oxidative stress. Superoxide dismutase 1 and 2 activities are involved in resistance of Candida to iodine.