肝细胞损伤模型中银杏内酯A保护机制及对Nrf2-抗氧化酶的影响

目的 探讨银杏内酯A对四氯化碳(CCl4)诱发的HepG2细胞损伤是否具有保护作用,并观察其对核因子E2相关因子2(Nrf2)调控的抗氧化酶的作用.方法 采用CCl4诱发HepG2细胞损伤,并予以不同剂量的银杏内酯A对其进行干预治疗,MTT法检测细胞活性,ELISA法检测细胞培养液中谷草转氨酶(AST)、谷丙转氨酶(ALT)浓度,并观察细胞8-羟基脱氧鸟苷(8-OHdG)、丙二醛(MDA)、Nrf2、血红素氧合酶1 (HO-1)、谷胱甘肽(GSH)水平.进而采用PI3K/Akt、MAPK通路拮抗剂干预,探索介导银杏内酯A发挥作用的上游通路.结果 与对照组比较,CCl4组HepG2细胞活性降低,细胞培养液AST、ALT浓度增加,细胞8-OHdG、MDA水平升高(P＜0.05).而与CCl4组比较,银杏内酯A可剂量依赖性的升高HepG2细胞活性,降低AST、ALT浓度,降低8-OHdG、MDA水平,同时显著升高Nrf2、HO-1、GSH水平(P＜0.05).此外,PI3 K/Akt拮抗剂LY294002与p38拮抗剂SB203580显著减弱了银杏内酯A对HepG2细胞的保护作用,并抑制了银杏内酯A对Nrf2、HO-1、GSH表达的上调作用(P＜0.05).结论 银杏内酯A对CCl4诱发的HepG2细胞损伤具有保护作用,其机制之一可能与通过PI3K/Akt、p38通路上调Nrf2、HO-1、GSH表达、抑制氧化应激反应有关.

Protective mechanism of Ginkgolide A and influence of Nrf2-antioxidase in hepatocyte injury model

Objective To investigate whether Ginkgolide A could attenuate carbon tetrachloride (CCl4)-induced HepG2 cell damages and to detect its effects on Nrf2-antioxidases.Methods HepG2 cells were cultured with CCl4 and treated with Ginkgolide A.Cell viability was detected using MTT assay.Levels of AST and ALT were measured using ELISA assay.In addition,levels of 8-hydroxy-2-deoxyguanosine (8-OHdG),malonaldehyde (MDA),heme oxygenase-1 (HO-1) and glutathione (GSH) were measured.In addition,inhibitors of PI3K/Akt and MAPK pathways were used to detect the pathways though which Ginkgolide A exerted its effects.Results Compared with the control group,the activity of HepG2 cells in CCl4 group decreased,the concentrations of AST and ALT in cell culture medium increased,and the levels of 8-OHdG and MDA in cells were increased (P ＜ 0.05).Compared to the CCl4 group,Ginkgolide A with a dose-dependent manner increased cell viability,decreased levels of AST,ALT,8-OHdG and MDA,as well as increased levels of Nrf2,HO-1 and GSH in HepG2 cells with a dose-dependent manner (P ＜ 0.05).However,PI3K/Akt inhibitor and p38 inhibitor abolished the effects of Ginkgolide A in the CCl4-cultured HepG2 cells (P ＜ O.05).Conclusion Ginkgolide A can ameliorate the CCl4-induced HepG2 cell damage,and Ginkgolide A may act by up-regulating the expression of Nrf2,HO-1 and GSH through PI3K/Akt and p38 pathways.