Antifungal activity of biogenic tellurium nanoparticles against Candida albicans and its effects on squalene monooxygenase gene expression.

In this study, we evaluated the antifungal activity of biogenic tellurium nanoparticles (Te NPs) against Candida albicans (ATCC14053). In addition, the effect of these biogenic NPs on squalene monooxygenase activity and the squalene monooxygenase gene (ERG1) expression level was evaluated. Squalene monooxygenase is an important enzyme involved in the synthesis of ergosterol, cholesterol, and phytosterols. Because of the importance of the noted compound, the squalene monooxygenase gene could be considered a good antifungal target. Results showed that biogenic Te NPs had antifungal effect against C. albicans. The minimal fungicidal concentration-minimal inhibitory concentration ratios of the biogenic Te NPs revealed that these NPs exhibited fungicidal effects against the test strain. The results of an enzyme assay using quantitative high-performance liquid chromatography showed squalene accumulation in C. albicans cells because of enzyme inhibition. Real-time PCR analysis showed an increase in the expression of the ERG1 gene in C. albicans cells, which were treated with Te NPs (0.2 mg/mL). It is conclution that Te NPs can inhibit the squalene monooxygenase enzyme, and, as a result, this inhibition phenomenon can cause an increase in the expression level of the ERG1 gene. This is the first report of the anti-Candida effect of biogenic Te NPs and its possible mechanisms.