富硒酵母对铜负荷导致小鼠肝损伤的保护作用

目的探讨富硒酵母对小鼠铜负荷致肝损伤的保护作用。方法采用过量(512mg/kgbw·d)硫酸铜灌胃致小鼠肝损伤后,给予低、中、高(20、40、60mg/kgbw·d)的富硒酵母4w,观察补硒对肝脏丙二醛(MDA)含量、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性以及血清和肝组织中铜含量的影响,并进行肝脏病理组织学检查和肝细胞凋亡检测,同时测定血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)活性。结果过量硫酸铜能导致小鼠肝脏损伤,与低、高剂量富硒酵母添加组相比,补充中剂量富硒酵母能显著缓解这种损伤,表现为血清和肝组织的铜含量显著降低,肝组织中SOD、GSH-Px活性增强,MDA含量减少,肝细胞凋亡显著减少。结论适量的富硒酵母能降低铜负荷导致的小鼠肝功能损伤,其机制可能与减轻铜离子介导的脂质过氧化有关。

THE PROTECT IVE EFFECTS OF SELENIUM-ENRICHED YEASTS ON LIVER DAMAGE CAUSED BY COPPER OVERLOAD IN MICE

Objective To examine the protective effects of selenium-enriched yeasts on liver damage caused by copper overload. Method Liver damage in mice was induced by intragastric administration with overloaded copper sulphate (512 mg/kg bwd), and given with low, moderate and high (20, 40, 60 mg/kg bw·d) dosages of selenium-enriched yeasts for 4 w. The hepatic malondialdehyde (MDA), activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum and copper contents in serum and liver tissue were also determined. Hepatocyte apoptosis and pathological analysis of liver tissues were also performed. Results In comparison to low and high dosages, supplementation of moderate dosage of selenium significantly alleviated the liver damages induced by copper overload. This was shown by significant decrease of Cu contents both in serum and liver, increased activities of SOD and GSH-Px as well as decrease of MDA in hepatic tissue and hepatocyte apoptosis. Conclusion Optimal dosage of selenium-enriched yeasts can reduce the liver damages induced by copper overload in mice. The mechanism might be related to the reduction of copper-mediated lipid peroxidation by selenium.