中文摘要：

目的研究川陈皮素后处理对小鼠心肌缺血再灌注损伤的作用及其机制。方法选择健康雄性C57BL/6小鼠48只,随机均等分为4组：假手术组（Sham组）、缺血再灌注组（I/R组）、川陈皮素后处理组（NOB组）、川陈皮素后处理＋PI3K特异性抑制剂LY294002组（NL组）。通过结扎小鼠左冠状动脉前降支30 min,再灌注120 min,制作小鼠心肌缺血再灌注模型。采用Evans Blue和TTC双重染色法测量心肌缺血危险区及梗死区面积;TUNEL染色法检测各组小鼠心肌细胞凋亡指数;硫代巴比妥酸（TBA）法测定丙二醛（MDA）浓度,黄嘌呤氧化酶法测定超氧化物歧化酶（SOD）活性;Western blot检测各组心肌的Akt、Bcl-2、Bax、Caspase-3蛋白表达量,计算Bcl-2/Bax比值。结果与Sham组相比,I/R组心肌梗死面积及心肌细胞凋亡显著增加,心肌Akt、Bcl-2下调,Bax、Caspase-3上调,Bcl-2/Bax下降,MDA显著升高,SOD显著降低（P〈0.001）。与I/R相比,NOB组心肌梗死面积、心肌细胞凋亡显著减少,心肌Akt、Bcl-2上调,Bax、Caspase-3下调,Bcl-2/Bax升高,MDA显著降低,SOD显著升高（P〈0.001）。与NOB组相比,NL组心肌梗死面积及凋亡显著升高,心肌Akt、Bcl-2下调,Bax和Caspase-3上调,Bcl-2/Bax下降,MDA显著升高,SOD显著降低（P〈0.001）。结论川陈皮素可减轻心肌缺血再灌注损伤,减少心肌细胞凋亡,其机制与PI3K-Akt通路激活降低氧化应激有关。

英文摘要：

Objective To investigate the effects of nobiletin post-conditioningon myocardial ischemia-reperfusion injury and the possible mechanisms. Methods Forty-eight healthy male C57 BL /6 rats were randomly allocated into sham operation group（Sham group）,ischemia/reperfusion injury group（I/R group）,nobiletin post-conditioning group（ NOB group） and nobiletin post-conditioning group ＋ LY294002 group（ NL group）. Myocardial I/R injury was established by occlusion of anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion. The infarct size and the area at risk were measured by double-staining of Evans Blue and TTC. Myocardial apoptosis was detected by TUNEL. The concertration of MDA was measured by thiobarbituric acid（ TBA）and xanthine oxidase was used to measure SOD. Western blot was adopted to detect the expression of the Akt,Bcl-2,Bax,Caspase-3 and ratio of Bcl-2/Bax. Results Compared with the sham group,the infarct size and apoptosis of I/R group was significantly increased,the expression of Bax and caspase-3 was up-regulated,Akt and Bcl-2 were decreased,and the ratio of Bcl-2/Bax was decreased,the concertration of MDA was significantly increased,but SOD was significantly decreased（ P〈 0. 001）. Compared with the I/R group,the infarct size and apoptosis of NOB group were significantly decreased,the expression of Akt and Bcl-2 was up-regulated,while the expression of Bax and caspase-3 was down-regulated,and the ratio of Bcl-2/Bax was increased,the concertration of MDA was significantly decreased,but SOD was significantly increased（ P〈0.001）. Compared with the NOB group,the infarct size and apoptosis of NL group were significantly increased,the expression of Akt and Bcl-2 was down-regulated,while the expression of Bax and caspase-3 was up-regulated,and the ratio of Bcl-2/Bax was decreased,the concertration of MDA was significantly increased,but SOD was significantly decreased（ P〈0.001）. Conclusion Nobiletin postconditioning attenuates myocardial i