The protection of selenium on cadmium-induced inhibition of spermatogenesis via activating testosterone synthesis in mice

► We examine protection of Se pretreatment on Cd toxicity at three time points. ► Protection of Se on spermatogenesis is corroborated by FCM. ► Se ameliorates testosterone decrease induced by Cd. ► Se can activate StAR and testosterone synthetic enzymes activity. Selenium (Se) is an essential trance element in testis. However, the potential protective effects of Se against cadmium (Cd)-induced reproductive toxicity remained to be elucidated. Male ICR mice were orally administered by gavage with Na2SeO3 (0.1, 0.2, 0.4mg/kg BW) for 1h prior to CdCl2 (5mg/kg BW) alone or in combination for 15, 25 or 35days. Cd exposure caused a significant decrease in body weight, sperm concentration and motility as well as plasma testosterone level which was accompanied by decreased antioxidant enzymatic activity of SOD and GSH-Px and by increased lipid peroxidation (as malondialdehyde, MDA). Se pretreatment compensated deficits in the sperm parameters (concentration, motility and morphology) induced by Cd. Se (0.4mg/kg BW) treatment significantly increased serum testosterone level that was reduced by Cd (on 15th, 25th and 35th day) (P