Ameliorative effects of nano-selenium against NiSO₄-induced apoptosis in rat testes

Nickel (Ni) is a common environmental pollutant, which has toxic effects on reproductive system. Nowadays, nano-selenium (Nano-Se) has aroused great attention due to its unique antioxidant effect, excellent biological activities and low toxicity. The aim of this study was to explore the protective effects of Nano-Se on NiSO₄-induced testicular injury and apoptosis in rat testes. Nickel sulfate (NiSO₄) (5 mg/kg b.w.) was administered intraperitoneally and Nano-Se (0.5, 1, and 2 mg Se/kg b.w., respectively) was given by oral gavage in male Sprague-Dawley rats. Histological changes in the testes were determined by H&E staining. The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and immunohistochemistry were performed to evaluate the apoptosis in testes. Expression levels of mitochondrial apoptosis-related genes and proteins were analyzed by RT-qPCR and Western blot. The results showed that Nano-Se improved lesions of testicular tissue induced by NiSO₄. Nano-Se significantly alleviated NiSO₄-induced apoptosis in rat testes, as well as significantly downregulated the Bak, cytochrome c, caspase-9 and caspase-3 and upregulated Bcl-2 expression levels, all of which were involved in mitochondria-mediated apoptosis. Altogether, we concluded that Nano-Se may potentially exert protective effects on NiSO₄-induced testicular injury and attenuate apoptosis, at least partly, via regulating mitochondrial apoptosis pathways in rat testes.