银杏内酯B通过Nrf2/HO-1通路抑制糖尿病大鼠肝损伤机制研究

目的:研究银杏内酯B(GB)对糖尿病大鼠肝脏的保护作用及其机制。方法:通过高脂高糖饮食联合腹腔注射链尿佐菌素(STZ)制备2型糖尿病(T2DM)大鼠模型,设模型组、GB(5 mg/kg)组和二甲双胍(MET,300 mg/kg)组; 另设正常对照组(常规饲料喂养)。GB组和MET组均1次/d灌胃给药治疗,正常对照组和模型组1次/d灌胃给予0.9%氯化钠溶液,疗程8周。检测空腹血糖(FBG)水平和血清谷丙转氨酶(ALT)、谷草转氨酶(AST)水平; 分别通过HE、TUNEL染色法观察肝脏组织病理学改变和细胞凋亡状况,进行凋亡指数(AI)计算; 生化分析法检测肝组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(MDA)含量; Western blot法检测肝组织核因子E2相关因子2(Nrf2)、血红素加氧酶1(HO-1)、核因子-κB(NF-κB)表达。结果:与正常对照组相比,模型组FBG水平和血清ALT、AST水平均升高(P<0.05); 模型组肝小叶结构模糊、细胞气球样变、胞质内可见油脂滴、炎性细胞浸润等病变; 肝组织凋亡细胞数量明显增多,AI升高(P<0.05); SOD、GSH-Px活性均降低而MDA含量升高(P<0.05); Nrf2、HO-1表达均下调而NF-κB表达上调(P<0.05)。与模型组相比,GB组和MET组FBG水平和血清ALT、AST水平均降低(P<0.05); 肝组织病变和肝细胞凋亡状况均明显改善,AI降低(P<0.05); SOD、GSH-Px活性升高且MDA含量降低(均P<0.05); Nrf2、HO-1表达上调而NF-κB表达下调(均P<0.05)。结论:GB对糖尿病大鼠肝脏具有保护作用,可能与激活Nrf2/HO-1信号通路进而抑制氧化应激有关。

Ginkgolide B inhibits liver injury in diabetic rats through Nrf2/HO-1 pathway

Objective:To investigate the protective effect of Ginkgolide B(GB)on the liver of diabetic rats and its mechanism.Methods:The type 2 diabetes mellitus(T2DM)rat models were prepared by intraperitoneal injection of streptozotocin(STZ)after high-fat and high-sugar diet for 6 weeks,and then the model group,GB(5 mg/kg)group and metformin(MET,300 mg/kg)were set up.And the normal control group was set up(fed with regular feed).The drugs were given by intragastric administration once a day of the rats in the GB group and MET group,while the rats in normal control group and the model group were given 0.9% sodium chloride solution once a day,for treatment for 8 weeks.The level of fasting blood glucose(FBG)and the alanine aminotransferase(ALT),aspartate aminotransferase(AST)in serum was measured.The liver histopathological changes and cell apoptosis was observed by HE and TUNEL staining methods separately,and the apoptosis index(AI)were calculated; the activity of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and the content of malondialdehyde(MDA)in liver tissue were detected by biochemical analysis method; the expression of nuclear factor E2 related factor 2(Nrf2),heme oxygenase 1(HO-1)and nuclear factor-κB(NF-κB)in liver tissue were detected by Western blot method.Results:Compared with the normal control group,the level of FBG and ALT,AST in serum were increased(P<0.05); pathological examination showed that the liver lobule structure was blurred,the cells became balloon-like,oil droplets were visible in the cytoplasm and inflammatory cell infiltration; the apoptotic cells number in liver tissue increased,and the AI was increased(P<0.05); the activity of SOD and GSH-Px were decreased while the content of MDA was increased(P<0.05); the expression of Nrf2 and HO-1 were down-regulated while the expression of NF-κB was up-regulated(P<0.05).Compared with the model group,the level of FBG and ALT,AST in serum of the GB group and MET group were decreased(P<0.05); the liver tissue lesions and liver cell apoptosis were improved,the AI was decreased(P<0.05); the activity of SOD and GSH-Px were increased while the content of MDA was decreased(all P<0.05); the expression of Nrf2 and HO-1 were up-regulated while the expression of NF-κB was down-regulated(all P<0.05).Conclusion:GB has protective effect on the liver of diabetic rats,which may be related to the activation of the Nrf2/HO-1 signaling pathway to inhibit oxidative stress.