两色金鸡菊总黄酮对大鼠心肌缺血再灌注损伤保护作用的研究

Total flavonoids extracted from Coreopsis tinctoria Nutt.protects rats from myocardial ischemia/reperfusion injury

为探讨两色金鸡菊总黄酮(Coreopsis tinctoria Nutt flavonoids,CTF)对大鼠离体心脏缺血再灌注损伤的保护作用。采用Langendorff逆行恒压灌流方法建立离体大鼠心脏I/R模型。观察I/R期间CTF对左心室舒张压、左心室收缩压、室内压最大上升速率、室内压最大下降速率和心率的影响。测定心肌组织中超氧化物歧化酶、谷胱甘肽过氧化物酶活性和丙二醛含量;采用TTC染色法评价心肌梗死程度。结果显示,与模型组比,CTF预处理组的左心室发展压(LVDP)及±dp/dtmax的绝对值均显著升高;CTF预处理组可使心肌组织中的SOD和GSH-Px的含量显著增加;MDA的含量显著降低,心肌梗死程度也明显降低。由此可知,CTF对大鼠缺血再灌注心脏具有一定的保护作用,其机制可能与CTF可以提高氧自由基清除能力,抑制氧自由基产生,降低脂质过氧化损伤有关。

This study aimed to evaluate the protective effects of total flavonoids extracted from Coreopsis tinctoria Nutt.（CTF）against myocardial ischemis reperfusion injury（MIRI） in an isolated Langendorff rat heart model. Left ventricular developed pressure（LVDP） and the maximum rate of rise and fall of the LV pressure, respectively（±dp/dtmax）, heart rate were recorded.Superoxide dismutase（SOD）, glutathione peroxidase（GSH- Px） and malondialdehyde（MDA）levels were determined. Myocardial infarct size was estimated by 2,3,5- triphenyltetrazolium chloride（TTC）. Compared with I/R, pretreatment with CTF significantly improved the heart rate, increased LVDP, and increased SOD and GSH- Px levels. This pretreatment not only decreased the infarct size, but also reduced MDA levels. These results suggest that CTF exerted cardio- protective effects against I/R via improving the oxygen free radical scavenging ability, the inhibition of oxygen free radical and reducing lipid peroxidation.