萱草花黄酮对酒精性肝损伤氧化应激及肝细胞凋亡机制的探讨

目的 探讨萱草花黄酮对急性酒精性肝损伤小鼠肝细胞凋亡及相关蛋白表达的影响.方法 40只小鼠分为4组,分别为空白对照组、模型对照组和萱草花黄酮低、高剂量组,每组各10只.连续灌胃给药7d,末次给药1h后,造模组小鼠一次性灌胃50％乙醇12 mL/kg,空白对照组给予同体积蒸馏水.测定各组小鼠血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性;肝组织匀浆超氧化物歧化酶(SOD)、丙二醛(MDA)水平;HE染色观察肝脏病理学改变;利用流式细胞仪检测肝细胞悬液中细胞凋亡率;Western blot检测肝细胞caspase-3、Bcl-2和Bax蛋白的表达.结果 萱草花黄酮各组可降低血清AST、ALT活性;还可降低肝组织匀浆MDA水平,提高SOD的活性;肝组织病理学检查可见,萱草花黄酮高剂量组可使肝细胞变性、坏死的程度明显减轻,缓解肝组织的病理学改变;与模型组比较,萱草花黄酮各组肝细胞的凋亡率均有明显下降;Western blot结果显示萱草花黄酮各组caspase-3蛋白水平降低,Bcl-2蛋白表达增加,而Bax蛋白表达减少,Bax/Bcl-2比值降低.结论 萱草花黄酮对小鼠急性酒精性肝损伤具有明显的保护作用并且能够抑制肝细胞凋亡,其作用机制可能与其抗氧化作用及调节凋亡相关蛋白caspase-3、Bcl-2和Bax的表达有关.

Study on mechanism of total flavonoids from hemerocallis fulva on oxidative stress and hepatocyte apoptosis in alcoholic liver injury

Objective To study the influence of total flavonoids of hemerocallis fulva(TFHF) on hepatocyte apoptosis and related protein expression in mice with alcoholic hepatic injury.Methods A total of 40 mice were randomly divided into four groups:blank control,model control andsmall and high dose TFHF groups,10 cases in each group.The mice were given the continuous gavage administration for 7 d.Then the model group was given once gavage by 50％ ethanol 12.0 mL/kg after 1 h of the last administration.The blank control group was given the equal volume of distilled water.The activity levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum as well as the superoxide dismutase(SOD) activity and malondialdehyde (MDA) content in liver tissue hemogenate were detected.Hematoxylin and Eosin(HE) staining was performed for observing the pathological changes of the liver tissue.The flow cytometer was used to test the apoptosis ratio in hepatocyte suspension.The expressions of caspase-3,Bcl-2 and Bax protein were detected by Western blot.Results The various TFHF groups could decrease the activities of ALT and AST in serum (P＜0.05),while could decrease the MDA content in liver tissue hemogenate (P＜0.01) and increased the SOD activity;the liver tissue pathological examination showed that the high dose TFHF group could make the liver cell degeneration,alleviated the necrosis degree and relieved the pathological change of hepatic tissue;compared with the model group,the hepatocyte apoptosis rate in each TFHF group was decreased significantly;Western blotting results showed that the caspase-3 protein level in each TFHF group was decreased,expression of Bcl-2 protein was increased,whereas which of Bax protein was decreased and Bax/Bcl-2 ratio was reduced.Conclnsion TFHF has obvious protective effect on mice acute hepatic injury induced by ethanol,and can inhibit the hepatocyte apptosis,its action mechanism may be related to its antioxidation and regulation of caspase-3,Bcl-2 and Bax expression.