目的  探讨葱白提取物(FOB)对心肌缺血/再灌注（I/R）损伤的影响及其机制。  方法  结扎成年大鼠36只左冠状动脉前降支30 min，再灌注120 min建立在体心肌缺血/再灌注损伤模型；培养乳鼠心肌细胞缺氧6 h，复氧18 h建立离体心肌细胞缺氧/复氧(H/R)损伤模型。分别随机分为对照组、I/R组(或H/R组)和FOB预处理+I/R组(或H/R组)。应用PowerLab多通道生理记录仪分析左心室功能；2，3，5-三苯基四唑氯铵（TTC）染色检测心肌梗死体积。流式细胞术检测细胞凋亡率；Western blotting和Real-time PCR检测细胞凋亡相关蛋白和mRNA(Bcl-2、Bax、Caspase-3)的表达；免疫荧光检测细胞色素C(cytochrome C, Cyt-C)的表达。  结果  在体大鼠实验中，与对照组比较，I/R组左心室收缩和舒张功能明显恶化(P<0.05)；与I/R组比较，FOB预处理能明显改善左心室收缩和舒张功能，且减小心肌梗死体积(P<0.05)。在培养心肌细胞实验中，与对照组比较，H/R组细胞凋亡率明显升高（P<0.01），Bcl-2蛋白及mRNA表达明显降低，而Bax、Caspase-3和Cyt-C的相关表达则明显升高(P<0.05)；与H/R组比较，FOB预处理显著降低细胞凋亡率(P<0.05)，增加Bcl-2蛋白及mRNA的表达水平，同时减少Bax、Caspase-3和Cyt-C的相关表达(P<0.05)。  结论  葱白提取物对心肌缺血再灌注损伤具有保护作用，其机制可能是通过线粒体途径减少心肌细胞凋亡从而发挥作用。

Objective  To explore the effects of fistular onion bulb extract (FOB) on myocardial ischemia/reperfusion (I/R) injury and possible regulation mechanism.   Methods  The left anterior descending (LAD) artery of 36 adult rat heart was ligated for 30 minutes and subsequently released for 120 minutes to establish the I/R injury model in vivo. Cultured neonatal rat cardiomyocytes were subjected to 6 hours of hypoxia followed by 18 hours of reoxygenation to establish the hypoxia/reoxygenation (H/R) model in vitro. The rats or cardiomyocytes were randomly divided into the control group, I/R group (or H/R group) and FOB pretreatment+I/R group (or H/R group). The left ventricular (LV) function was measured using PowerLab multichannel physiological recorder; the infarct size was detected by 2,3,5-triphenyl tetrazolium chlorid(TTC) staining. The apoptosis rate was detected by flow cytometry, Western blotting and Real-time PCR were used to detect the expression of apoptosis-related proteins and mRNA (Bcl-2, Bax and Caspase-3); Immunofluorescence was used to detect the expression of cytochrome C(Cyt-C).   Results  In the animal experiments, compared with the control group, the left ventricular systolic and diastolic functions were deteriorated (P<0.05); compared with the I/R group, the pretreatment of FOB significantly improved the left ventricular systolic and diastolic function, and decreased the infarct size (P<0.05). In cultured cardiomyocytes, compared with the control group, the apoptosis rate was significantly increased (P<0.01), the protein and mRNA expression of Bcl-2 decreased, meanwhile the expression of Bax, Caspase-3 and Cyt-C increased in the H/R group (P<0.05); Compared with the H/R group, the pretreatment of FOB significantly reduced the apoptosis rate (P<0.05), increased the protein and mRNA expression of Bcl-2, at the same time, decreased the expression of Bax, Caspase-3 and Cyt-C(P<0.05).   Conclusion  Fistular onion bulb extract has the protective effect on myocardial ischemia/reperfusion injury, and its possible mechanism is to reduce cardiomyocyte apoptosis through mitochondrial pathway.