SF-1 mediates reproductive toxicity induced by Cerium oxide nanoparticles in male mice

Cerium oxide nanoparticles (CeO₂ NPs) have potential application for use in biomedical and in various consumer products. However, it is largely unclear whether CeO₂ NPs have effects on male reproductive function.

In this study, male mice were examined for toxicity, if any, following chronic oral administration of CeO₂ NPs for 32 days. In each animal, epididymides were examined for sperm motility and DNA integrity. Bloods were tested for testosterone levels. Testicular tissues were collected to determine the element Ce content, the daily sperm production (DSP), marker enzymes such as ACP, G6PD, γ-GT and SDH, mRNA expression levels of steroidogenesis genes Star, P450scc, P450c17, 3β-Hsd, and 17β-Hsd, as well as steroidogenic factor-1 (SF-1) gene/protein levels.

The results showed that CeO₂ NPs (20 mg/kg and 40 mg/kg) increased the element Ce content in testis, the testis histopathological patterns and sperm DNA damage whereas decreased the testis weight, DSP and sperm motility. There were also remarkable reduction in testosterone levels and marker enzymes activities, down-regulated mRNA expression levels of several steroidogenesis genes such as Star, P450scc, P450c17, 3β-Hsd, and 17β-Hsd, as well as altered gene and protein expressions of SF-1.

These results reveal the male reproductive toxicity of chronic exposure of CeO₂ NPs in mice, hinting that the utilization of CeO₂ NPs need to be carefully evaluated about their potential reproductive toxicity on the human health.