齐墩果酸预处理对大鼠肝脏缺血再灌注损伤中细胞凋亡的影响

The Role of Oleanolic Acid Pretreatment on Cell Apoptosis in Rat Livers with Ischemia-reperfusion Injury

目的观察齐墩果酸（OA）预处理对肝脏缺血再灌注损伤中细胞凋亡的影响，探讨齐墩果酸预处理对肝脏保护作用的机制。方法雄性SD大鼠40只，随机分为假手术组（SH组）、缺血再灌注组（IR组）、0．5％羧甲基纤维素钠组（CM组）和齐墩果酸预处理组（齐墩果酸组），齐墩果酸组以100mg／kg的齐墩果酸混悬液，SH和IR组以相同容积的水，CM组以相同容积的0．5％CMC—Na分别每日灌胃1次，连续7d。第8天建立70％肝脏缺血再灌注模型，肝脏缺血60min后行再灌注3h。检测大鼠血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）和LDH水平；检测肝组织内丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽（GSH）水平变化；通过HE染色观察肝组织形态，利用Tunel染色检测肝组织凋亡状态；Westernblot检测肝脏组织caspase3和p53蛋白表达水平。结果与IR组相比齐墩果酸组血清肝酶水平及肝组织中MDA水平显著降低，而s0D和GSH活性则显著升高；与IR组相比齐墩果酸组肝组织病理形态学损伤明显减轻；缺血再灌注后可见明显的肝实质细胞凋亡现象，齐墩果酸组凋亡细胞较IR组显著下降，且caspase3和p53蛋白表达亦减少。结论齐墩果酸预处理可减轻肝脏缺血再灌注损伤，可能与抑制caspase3和p53蛋白表达从而抑制细胞凋亡有关。

Objective To investigate the effect of oleanolic acid on cell apoptosis in rat livers with ischemiareperfusion Injury. Methods Forty healthy Wistar rats were randomly divided into 4 groups including sham-operated group（SH）which was reperfused with water,Ischemia-Reperfusion group（IR）which was reperfused with water,0. 5% sodium carboxymethyl cellulose group（CM）which was reperfused with 0. 5% sodium carboxymethyl cellulose and oleanolic acid group（OA）which was reperfused with oleanolic acid. The four groups were all reperfused seven days. At the eighth day, 70 % liver ischemia reperfusion models were established, and after the liver ischemia 60 min, reperfused 3 h. The serum ALT,AST and LDH were detected as liver damage markers. MDA,SOD and GSH in liver were measured. The expressions of caspase3 and p53 were detected by western blot. The apoptosis was measured by Tunel. The histological observation was carried out with hematoxylin and eosin staining. Results Compared with the IR group, the activity of plasma enzyme and the concentration of MDA in hepatic tissue in the OA group were markedly reduced,while the activity of SOD and GSH were enhanced. There were obvious hepatocellular apoptosis after reperfusion and the apoptptic index in the OA group was significantly lower than of the IR group. The expressions of caspase3 and p53 were significant lower in the OA group than of the IR group. Conclusion Oleanolic acid could reduce hepatocellular apoptosis after reperfusion, and thus produce a protective effect on hepatic ischemia-reper- fusion injury.