Protective effects of vitamin E on cadmium-induced apoptosis in rat testes

Cadmium (Cd) is a toxic metal that is involved in apoptosis. The present study was conducted to investigate the mechanism of Cd-induced apoptosis and the protective effects of vitamin E on rat testes. Thirty-two adult Wistar rats were divided into four groups. The control group was injected with saline and three other groups received Cd, Cd+vitamin E, and vitamin E. Intraperitoneal injection was performed for 28 days. On the 29th day, the rats were slaughtered, their peritoneum was opened, and their left testis removed and weighed. The mRNA expression of apoptosis and mitochondrial dynamics genes were assessed using real-time PCR, and caspase-3/7 activation using the caspase-3/7 Assay. The groups were not significantly different in terms of testicular weight. Compared with the control group, the mRNA expression levels of Bax and caspase-9 genes increased in the rats' testes receiving Cd, the mRNA expression levels of mitofusin 1 (Mfn1) and mitofusin2 (Mfn2) genes decreased, and those of Bcl-2 remained unchanged. Vitamin E was found to significantly decrease the mRNA expression of Bax and caspase-9 genes and increase the mRNA Mfn1, Mfn2, and Bcl-2 in the rats' testes receiving Cd. The ratio of Bax/Bcl-2 and caspase-3/7 activity increased in the Cd-exposed rats compared with the control. Vitamin E remarkably attenuated the Cd-induced effects. According to the obtained results, Cd exerts its apoptotic effects through the mitochondrial pathway by increasing the ratio of Bax/Bcl-2 and activating caspases in the rats' testes, and vitamin E plays a protective role against Cd-induced apoptosis.