富硒绿茶对大鼠非酒精性脂肪肝Ca2+-ATPase活性和表达的影响

目的：研究恩施富硒绿茶对大鼠非酒精性脂肪肝病（nonalcoholic fatty liver disease，NAFLD）中肝脏肌浆网/内质网Ca2+-ATPase（sarco（endo）plasmic reticulum Ca2+-ATPase，SERCA）活性及其表达的影响，探讨富硒绿茶防治NAFLD的可能作用机制。方法：将32 只Wistar大鼠分成4 组，分别饲喂标准饲料＋常规饮水（NC组）、高脂饲料＋常规饮水（HC组）、高脂饲料＋普通绿茶（TC组）、高脂饲料＋富硒绿茶（SeC组）。9 周后处死，观察大鼠一般情况，测定肝细胞内Ca2+含量、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）水平、肝脏组织ATPase活性；采用免疫组化染色和Western blotting检测肝脏内总SERCA蛋白表达，观察各指标变化情况。结果：HC组大鼠肝细胞内Ca2+含量明显增高，Na+-K+-ATPase、Ca2+-ATPase活性降低，SERCA蛋白表达降低；富硒绿茶干预后Ca2+含量降低，酶活性升高，表达增加，较普通绿茶效果明显。结论：富硒绿茶对高脂饮食诱导的大鼠非酒精性脂肪肝病具有干预作用，可能是通过降低肝细胞内Ca2+和TNF-α含量而改善肝脏能量代谢障碍，同时提高了SERCA活性，增强其蛋白表达而实现的。

Effect of Selenium-Enriched Green Tea on Activity and Expression of Sarco(endo)Plasmic Reticulum Ca2+-ATPase (SERCA) in Rats with Nonalcoholic Fatty Liver Disease (NAFLD)

Objective: To investigate the effect of selenium-enriched green tea on the activity and expression of sarco(endo)
plasmic reticulum Ca2+-ATPase (SERCA) on model rats with experimental non-alcoholic fatty liver disease (NAFLD) and
explore the possible mechanisms for the prevention and treatment of NAFLD. Methods: Totally 32 Wistar rats were divided
into 4 groups randomly and fed with standard diet and water (NC), high-fat diet and water (HC), high-fat diet and tea (TC),
high-fat diet and selenium-enriched tea (SeC), respectively. After 9 weeks, the rats were killed to investigate the changes in
Na+-K+-ATPase and Ca2+-ATPase activities. Meanwhile, hepatic tumor necrosis factor-α (TNF-α) and Ca2+ levels and the
protein expression of SERCA in hepatocytes was evaluated by immunohistochemistry (IHC) and Western blotting. Results:
The protein expression of SERCA and the activities of Na+-K+-ATPase and Ca2+-ATPase were significantly decreased and
the Ca2+ level was remarkably increased in HC group. The activity and expression of Na+-K+-ATPase and Ca2+-ATPase in
liver were markedly upregulated in intervention group. On the contrary, the level of Ca2+ in SeC group was greatly reduced
when compared with ordinary tea. Conclusion: Selenium-enriched green tea can improve hepatic energy metabolism
disorder, protect liver function, and prevent liver damage in NAFLD rats.