The effects of selenium on the growth and bone development in the weaned rats

Selenium is a crucial trace element, and a deficiency of selenium can cause oxidative stress damage and impede the growth and development of the body. L-Se-methylselenocysteine (L-SeMC) is a naturally occurring organic-selenium, which has higher bioavailability compared to inorganic-selenium such as Na2SeO3. In this study, weaned rats were fed with a selenium-deficient liquid diet to simulate the selenium-deficient breastfeeding. High and low doses of Se were supplemented in the liquid feed with L-SeMC and Na2SeO3, respectively. The results showed that the selenium-deficient diet reduced the growth rate and development of the weaned rats, leading to oxidative stress in the body and damaging liver and kidney function, as well as causing the histological lesions in heart and knee joints. Supplementing high doses (0.20 mg Se/kg) of L-SeMC and Na2SeO3 could increase the body weight of selenium-deficient rats by 10.48% and 4.47%, respectively. The symptoms caused by selenium deficiency were significantly relieved after supplementation with selenium, with L-SeMC being more effective than Na2SeO3. Furthermore, femoral bone mineral density (BMD) was increased by 77.0% with supplementation of L-SeMC in the selenium-deficient rats, while supplementation with Na2SeO3 resulted in only a 19.4% increase in BMD. These findings indicated that due to its higher bioavailability and superior ability to alleviate oxidative stress damage and growth retardation caused by selenium deficiency, L-SeMC is a better supplement for alleviating the oxidative stress and liver and kidney damage caused by selenium deficiency, and has a superior therapeutic effect on myocardial tissue and knee joint lesions compared to Na2SeO3.