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木犀草素预处理对缺血/再灌注大鼠肝脏的保护作用

王国光^*, 陆晓华, 丁敏, 汤文天, 李伟, 赵雪, 张翠1

皖南医学院1病理生理教研室；机能实验中心，芜湖 241002；芜湖市第五人民医院内科，芜湖 241000；皖南医学院弋矶山医院心内科，芜湖 241001

摘要

本研究用Sprague-Dawley大鼠建立肝脏缺血/再灌注损伤模型，探讨木犀草素预处理对大鼠肝脏缺血/再灌注损伤的保护作用及其机制，并观察血红素氧合酶-1 (heme oxygenase-1, HO-1)活性变化对肝缺血/再灌注损伤的影响。将大鼠随机分为正常组、模型组、木犀草素组、木犀草素 + 锌原卟啉(HO-1抑制剂)组及血红素组，每组8只。正常组、模型组和血红素组大鼠每日喂以正常饲料，木犀草素组和木犀草素 + 锌原卟啉组大鼠每日喂以补充木犀草素(200 mg/kg)的饲料，喂养4周。木犀草素 + 锌原卟啉组及血红素组大鼠于实验前6 h分别皮下注射锌原卟啉(25 μmol/kg)和血红素(20 μmol/kg)。除正常组大鼠肝脏不作缺血处理外，其余各组大鼠肝门夹闭阻断血流缺血60 min之后，再灌注60 min。测定血清丙氨酸氨基转移酶(alanine aminotransferase, ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase, AST)及超氧化物歧化酶(superoxide dismutase, SOD)活性和丙二醛 (malondialdehyde, MDA)含量；检测肝组织SOD活性、MDA含量及HO-1活性及蛋白表达情况；HE染色观察肝脏形态结构变化。结果显示：与模型组相比，木犀草素组和血红素组大鼠血清ALT、AST活性及MDA含量均明显下降，SOD活性显著增强(P < 0.01)；肝组织中MDA含量均明显下降，SOD及HO-1活性显著增强，HO-1蛋白表达量增加(P < 0.01)；木犀草素+锌原卟啉组大鼠血清ALT、AST活性含量较木犀草素组明显升高(P < 0.01)，肝组织SOD及HO-1活性下降，MDA含量升高(P < 0.01)。组织切片显示模型组肝细胞肿胀，小叶结构紊乱；木犀草素和血红素处理组肝细胞轻度肿胀，小叶结构清晰。结果提示，木犀草素通过降低MDA含量、提高SOD活性及HO-1蛋白表达，改善肝脏的抗氧化能力，减轻缺血/再灌注损伤。

关键词： 肝缺血/再灌注损伤; 木犀草素; 血红素氧合酶-1

分类号：R363.2

[Protective effects of luteolin preconditioning on rat liver under ischemia/reperfusion.] [Article in Chinese]

WANG Guo-Guang^*, LU Xiao-Hua, DING Min, TANG Wen-Tian, LI Wei1, ZHAO Xue, ZHANG Cui

Department of Pathophysiology； Experimental Center for Function Subjects, Wannan Medical College, Wuhu 241002, China； Department of Internal Medicine, the Fifth People’s Hospital of Wuhu, Wuhu 241000, China； Department of Cardiology, Yijishan Hospital, Wannan Medical College, Wuhu 241001, China

Abstract

The aim of the study is to explore the effects of luteolin preconditioning on hepatic ischemia/reperfusion injury in rats and its mechanism, and investigate the effects of the change of heme oxygenase-1 (HO-1) activity on hepatic ischemia/reperfusion injury. Sprague-Dawley rats were divided into 5 groups randomly: control, model, luteolin, luteolin + zinc protoporphyrin (ZnPP, an inhibitor of HO-1) and hemin groups (n = 8 for each group). The rats in control, model and hemin groups received a standard chow daily. The rats in luteolin and luteolin + ZnPP groups received a chow supplemented with luteolin (200 mg/kg) daily. After 4 weeks, ZnPP (25 μmol/kg) and hemin (20 μmol/kg) were injected hypodermically 6 h before ischemia/reperfusion in luteolin + ZnPP and hemin groups, respectively. Portal vein and hepatic artery supplying the middle and left hepatic lobe were clamped with an atraumatic vascular clip for induction of partial hepatic ischemia in all rats except control group. After the 60 min of hepatic ischemia, a 60-minute reperfusion period was initiated by removal of the arterial clip. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were detected in serum, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in serum and liver were measured with assay kit. The expression of HO-1 protein and activity of HO-1 were examined in liver. The results showed that the luteolin and hemin pretreatment led to significant decreased levels of AST and ALT in serum, increased activity of SOD and decreased content of MDA in serum and liver compared with model group (P < 0.01). In addition, the expression of HO-1 protein and activity of HO-1 were elevated in luteolin and hemin groups (P < 0.01). ZnPP markedly increased the levels of AST and ALT in serum, and decreased the activities of SOD and HO-1, elevated MDA content in liver when compared with those in luteolin group (P < 0.01). Cytoplasmic vacuolation and swelling of hepatocytes were revealed in the model group after ischemia/reperfusion. Treatments with luteolin and hemin markedly relieved the liver structural changes. These results suggest that HO-1 protects rat liver from ischemia/reperfusion injury, and luteolin reduces the content of MDA and increases the activity of SOD and the expression of HO-1, which indicate that luteolin can elevate the antioxidation in rat liver, and thus protects rat liver from ischemia/reperfusion injury.

Key words: hepatic ischemia/reperfusion injury; luteolin; heme oxygenase-1

收稿日期：2010-10-11　　录用日期：2010-12-31

通讯作者：王国光　　E-mail: guoguangw1226@sina.com

引用本文：

王国光, 陆晓华, 丁敏, 汤文天, 李伟, 赵雪, 张翠1. 木犀草素预处理对缺血/再灌注大鼠肝脏的保护作用[J]. 生理学报 2011; 63 (2): 177-183.

WANG Guo-Guang, LU Xiao-Hua, DING Min, TANG Wen-Tian, LI Wei1, ZHAO Xue, ZHANG Cui. [Protective effects of luteolin preconditioning on rat liver under ischemia/reperfusion.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (2): 177-183 (in Chinese with English abstract).