儿茶素没食子酸酯对心肌细胞氧化应激损伤的影响及机制研究

Effect of epigallocatechin gallate on oxidative stress of cardiomyocytes and its mechanism

目的探讨儿茶素没食子酸酯(epigallocatechin gallate,EGCG)对心肌细胞氧化应激损伤的影响及作用机制。方法3~4月龄Wistar大鼠分离提纯心肌细胞,用H2O2作为刺激剂,建立氧化应激损伤模型。随机分为4组:对照组、模型组、EGCG低剂量治疗组(60μmol/L)、EGCG高剂量治疗组(100μmol/L)。MTT法检测细胞存活率;比色光度法检测细胞内丙二醛(MDA)、乳酸脱氢酶(LDH)含量及超氧化物歧化酶(SOD)、还原性谷胱甘肽(GSH)酶活性;ELISA检测NO分泌量;Wstern Blot方法检测BDNF蛋白表达。结果与对照组相比,模型组的细胞MDA、LDH的含量升高(P<0.05),而SOD和GSH的酶活性及NO的分泌量下降(P<0.05),且BDNF蛋白的表达显著降低(P<0.05);与模型组相比,EGCG组能显著降低MDA、LDH的含量(P<0.05),而SOD和GSH的酶活性及NO的分泌量显著增加(P<0.05),BDNF蛋白的表达升高(P<0.05),且EGCG高剂量组促分泌效果比低剂量组更加明显。结论EGCG组能明显提高心肌细胞成活率,通过调控氧化应激相关因子的表达,对心肌细胞氧化应激损伤具有保护作用,这种作用机制可能与EGCG激活细胞内BDNF信号转导通路有关,最终减轻心肌细胞氧化应激的损伤。

Objective To investigate the effect of epigallocatechin gallate(EGCG)on oxidative stress damage of cardiomyocytes and its mechanism.Methods The cardiomyocytes of Wistar rats aged 3-4 months were isolated and purified,and H2 O2 was used as a stimulant to establish an oxidative stress injury model.They were randomly divided into 4 groups:control group,model group,EGCG low-dose treatment group(60μmol/L),EGCG high-dose treatment group(100μmol/L).MTT method was used to detect cell viability.Colorimetric method was used to detect intracellular malondialdehyde(MDA),lactate dehydrogenase(LDH)content and superoxide dismutase(SOD)and reduced glutathione(GSH)enzyme activities.ELISA was applied to detect NO secretion.Western Blot was used to detect BDNF protein expression.Results Compared with the control group,the content of MDA and LDH in the model group increased(P<0.05),while the enzyme activity of SOD and GSH and NO secretion decreased(P<0.05),and the expression of BDNF protein was significantly reduced(P<0.05);Compared with the model group,the EGCG group can significantly reduce the content of MDA and LDH(P<0.05),while the enzyme activity of SOD and GSH and the secretion of NO significantly increase(P<0.05),BDNF protein The expression of P was increased(P<0.05),and the secretory effect of the high-dose group was more obvious than that of the low-dose group.Conclusion EGCG can significantly increase the survival rate of cardiomyocytes,and protect cardiomyocytes from oxidative stress injury by regulating the expression of oxidative stress-related factors.This mechanism may be related to the activation of intracellular BDNF signal transduction pathway by EGCG,and results in the reduce of oxidative stress damage of cardiomyocytes.