天山花楸叶总黄酮对大鼠心肌缺血/再灌注损伤的保护作用

目的观察天山花楸叶总黄酮对大鼠心肌缺血/再灌注(I/R)损伤的保护作用,探讨其作用机制。方法采用改良的Langendorff逆行恒压灌流方法,建立大鼠离体心脏I/R损伤模型,观察天山花楸叶总黄酮(4.0、6.0mg·L-1)对心脏I/R损伤后心功能、心肌组织中超氧岐化酶(SOD)活性和丙二醛(MDA)含量变化的影响。利用DPPH、羟自由基、超氧阴离子、脂质过氧化反应体系,检测了天山花楸叶总黄酮(6.25、12.5、25、50、100mg·L-1)体外抗氧化能力。结果天山花楸叶总黄酮(6.0mg·L-1)可明显改善离体心脏I/R损伤后左心室发展压(LVDP)和左室压力升高或降低最大速率(±dp/dtmax),明显增加冠脉流量;天山花楸叶总黄酮(6.0mg·L-1)处理后I/R损伤心肌组织中SOD活性升高,MDA含量减少。天山花楸叶总黄酮(6.25～100mg.L-1)可浓度依赖性地清除DPPH自由基、羟自由基和超氧阴离子自由基,并抑制脂质过氧化反应。结论天山花楸叶总黄酮对心肌缺血/再灌注损伤具有明显保护作用,与其具有较强的抗氧化活性有关。

Protective effect of total flavonoids from Sorbus TianschanicaL leaf against myocardial ischemia/reperfusion injury in rats

Aim To investigate the protective effect and the underline mechanisms of total flavonoids from Sorbus Tianschanica L leaf (TFST) against myocardial ischemia/reperfusion (I/R) injury.Methods The I/R injury model of rat isolated heart was prepared by improved Langendorff retrograde perfusion method.Following the treatment,the coronary blood flow levels (CF),left ventricular developed pressure (LVDP) and maximal rise/fall rate of left ventricular pressure (±dp/dt_(max)) were monitored as the myocardial function.The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in myocardial tissue were measured by the commercial kits. The in vitro anti-oxidative capacity of TFST was detected by the DPPH and lipid peroxidation reaction system.Results Compared with I/R injury group, pre-incubation with TFST (6.0 mg·L~(-1)) significantly improved the LVDP,±dp/dt_(max) and CF during reperfusion. TFST (6.0 mg·L~(-1)) treatment significantly increased the SOD activities and reduced the MDA levels in myocardium tissue.Moreover,TFST (from 6.25 to 100.0 mg·L~(-1)) scavenged the DPPH, hydroxyl radical and superoxide anion free radicals, and inhibited the lipid peroxidation reaction in a concentration-dependent way.Conclusions All the results demonstrate that TFST possesses the cardioprotective effect on ischemia/reperfusion injury.This efficacy may be due to its antioxidative activity.