马齿苋提取物对家兔心肌缺血再灌注损伤的保护作用及其机制

Protection of portulaca oleraces extract on myocardial ischemia-reperfusion injury in rabbits and its mechanism

目的探讨马齿苋提取物对家兔心肌缺血再灌注损伤的保护作用及其作用机制。方法将40只家兔随机分为5组,分别为假手术组、缺血再灌注组、马齿苋提取物低、中、高(0.04、0.08、0.12 g/ml)剂量组,每组8只。采用结扎左冠状动脉前降支30 min,再灌注120 min制备心肌缺血再灌注损伤模型。再灌注后取血清,采用比色法测定血清中肌酸激酶(CK),乳酸脱氢酶(LDH),丙二醛(MDA),超氧化物歧化酶(SOD)的含量,HE染色法观察心肌组织病理学改变。结果与假手术组比较,缺血再灌注组血清中的CK、LDH、MDA含量显著升高,SOD含量显著降低(P<0.05);与缺血再灌注组比较,马齿苋提取物不同剂量组家兔血清中的CK、LDH、MDA的含量显著下降,SOD含量显著升高(P<0.05)。马齿苋提取物可明显改善心肌组织病理形态学损伤,并随剂量的增大,病理学损伤程度越轻。结论马齿苋提取物对缺血再灌注损伤心肌有保护作用,其机制可能与减轻自由基损伤、增强抗氧化活性有关,且存在剂量依赖关系。

Objective To investigate the protection of portulaca oleraces extract（ PLE） on myocardial ischemia-reperfusion injury in rabbits and its mechanism.Methods 40 rabbits were randomly divided into five groups： sham operation group,ischemia-reperfusion group,PLE group and low-dose,middle-dose and highdose groups（0.04,0.08,0.12 g/ml）,eight in each group.The model of myocardial ischemia-reperfusion injury was made by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion.After reperfusion,the content of creatine kinase（ CK）,lactate dehydrogenase（ LDH）,malondialdehyde（ MDA）,superoxide dismutase（ SOD） were examined by colorimetric method,the pathologic changes of myocardial tissue was observed by HE staining. Results Compared with sham operation group,the level of blood CK,LDH and MDA in the ischemia-reperfusion group were significantly increased,the content of SOD was significantly decreased（ P〈0. 05）; compared with the ischemic-reperfusion group,the content of CK,LDH,MDA in the PLE groups decreased significantly,SOD content increased obviously（ P〈0.05）. The PLE can obviously improve the pathological morphological damage of myocardium,and with the increase of dosage,the pathological damage degree was lighter. Conclusion PLE has protective effect on myocardial ischemia-reperfusion injury,and its mechanism may be related to the reduction of free radical injury and the enhancement of antioxidant activity,and there was a dose dependence relationship between them.