表没食儿茶素没食子酸酯对脑出血大鼠脑组织氧化应激和线粒体的影响

Experimental study of the effects of epigallocatechin-3-gallate on oxidative stress and mitochondrial funcion in rat models with intracerebral hemorrhage

目的在探讨急性脑出血动物模型中表没食儿茶素没食子酸酯(Epigallocatechin-3-gallate,EGCG)对脑出血血肿周围组织中氧化应激和脑组织中线粒体膜电位的影响。方法60只成年健康SD大鼠,随机分为假手术组(Sham组)、0.9%氯化钠溶液对照组(ICH组)和治疗组(EGCG组),EGCG组给予腹腔注射EGCG 50 mg/kg,Sham组和ICH组给予等量0.9%氯化钠腹腔注射,连续7 d。采用立体定向仪向大鼠左侧尾状核注入0.5单位的胶原酶,建立脑出血动物模型。模型建立后48 h,3组大鼠中分别随机分出2个亚组,每个亚组10只大鼠,一个亚组观察大鼠神经行为学评分,另一个亚组大鼠直接麻醉后处死,取血肿周围脑组织,应用流式细胞术检测血肿周围脑组织中线粒体膜电位(MMP)和活性氧自由基(ROS)的水平,应用分光光度法检测血肿周围脑组织中超氧化物歧化酶(SOD)含量。结果与假手术组相比,ICH组大鼠mNSS评分明显升高,与ICH组比较,EGCG组大鼠mNSS评分明显降低;与假手术组相比,ICH组大鼠脑组织中MMP降低,ROS水平升高,SOD含量下降(P<0.01);EGCG组与ICH组相比大鼠脑出血血肿周围组织中MMP显著升高,ROS水平明显下降,SOD含量增加(P<0.01)。结论脑出血后血肿周围脑组织中ROS含量明显增加,线粒体膜电位下降,SOD含量显著降低,提示脑出血后血肿周围脑组织出现氧化应激损伤,伴有线粒体功能异常,EGCG能够减轻脑出血血肿周围脑组织中氧化应激损伤,对线粒体功能有保护作用。

Objective To investigate the effects of epigallocatechin-3-gallate(EGCG)on oxidative stress and mitochondrial membrane potential(MMP)in brain tissues of rat models with intracerebral hemorrhage(ICH).Methods A total of 60 rats were randomly divided into sham operation group,control group(0.9%sodium chloride solution)and observation group(EGCG).The saline or EGCG was administrated intraperitoneally daily for 7 days.All the rats in the three groups were divided randomly into two subgroups,with 10 rats in each subgroup,and the neurologic behavior score was performed in one subgroup,moreover,in the other subgroup,the mitochondrial membrane potential and the levels of reactive oxygen spcies(ROS)in brain tissues were detected by flow cytometry,and the levels of superoxide dismutase(SOD)were detected by spectrophotometry.Results The mNSS scores in control group were significantly higher than those in sham operaton group,which in observation group were significantly higher than those in control group.As compared with those in sham operation group,the levels of MMP and SOD in control group were significantly decreased,however,the levels of ROS were significantly increased in control group(P<0.01).Moreover the levels of MMP and SOD in observation group were significantly higher than those in control group,however,the levels ROS were significantly lower than those in control group(P<0.01).Conclusion The oxidative stress has occurred in rat models with intracerebral hemomrrhage,accompaning with damaged mitochondrial function.EGCG can effectively protect the mitochondrial function and relieve the oxidative stress damage.