EGCG对大鼠肺缺血再灌注损伤的保护作用研究

Protective effect study of EGCG on lung ischemia-reperfusion injury

目的探讨表没食子儿茶素没食子酸酯对大鼠肺缺血再灌注损伤的保护作用及潜在机制。方法30只雄性SD大鼠随机均分为假手术组,模型组和表没食子儿茶素没食子酸酯组。通过夹闭大鼠右侧肺门45分钟,再灌注6小时构建肺缺血再灌注损伤模型。PAS染色检测肺组织病理形态;物理法检测肺组织湿干之比(W/D),ELISA和RT-PCR分别检测血清和肺组织中白介素-6(IL-6),白介素1β(IL-1β)和肿瘤坏死因子(TNF-α)表达水平;硫代巴比妥酸(TBA)法检测丙二醛(MDA)的含量;黄嘌呤氧化酶法检测过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)和超氧化物歧化酶(SOD)活性;Western blotting检测肺组织Wnt和β-catenin表达水平。结果与假手术组相比,模型组Wnt、β-catenin、IL-6、IL-1β、TNF-α和MDA的表达水平以及肺组织W/D之比和肺组织病理损伤均明显增加,而CAT,GPX和SOD活性均明显下降;与模型组相比,表没食子儿茶素没食子酸酯组Wnt、β-catenin、IL-6、IL-1β、TNF-α和MDA的表达水平以及肺组织W/D之比和肺组织病理损伤均明显降低,而CAT,GPX和SOD活性均明显增高。结论表没食子儿茶素没食子酸酯可通过抑制炎症和脂质过氧化,清除氧自由基而减轻肺缺血再灌注损伤,其作用机制与抑制Wnt/β-catenin信号通路激活相关。

Objective To explore the protective effect and potential mechanism of epigallocatechin gallate(EGCG)on lung ischemia reperfusion injury(LIR).Methods 30 male SD rats were randomly equally divided in to the sham,LRI and EGCG groups.The model of lung ischemia reperfusion injury was induced by clamping right lung pedicles for 45min.After 6h re-perfusion,the serum and lung tissue were collected.PAS staining was used to examine the pathology of lung tissue.Physical method was exploited to detect the dry/wet ratio(W/D)of lung.ELISA and RT-PCR were used to measure the expression of interleukin-6(IL-6),interleukin-1 beta(IL-1β)and tumor necrosis factor(TNF-α)in the serum and lung tissue,respectively.Thiobarbituric acid(TBA)was used to assay the content of malondialdehyde(MDA).The activity of xanthine oxidase(CAT),glutathione peroxidase(GPx)and superoxide dismutase(SOD)were tested by hydrogen peroxide enzyme.Western blotting was used to detect the expression of of Wnt and-caten in the lung tissue.Results Compared with the sham group,the expression level of Wnt,-catenin,IL-6,IL-1β,TNF-and MDA in the IRI group increased significantly with lower activity of CAT,GPX and SOD.Moreover,the W/D and the pathological injury of lung in the LIR group also increased significantly.Compared with the LIR group,the expression level of Wnt,-catenin,IL-6,IL-1β,TNF-and MDA in the EGCG group decreased significantly with higher activity of CAT,GPX and SOD.Moreover,the W/D and the pathological injury of lung in the LIR group also decreased significantly.Conclusion EGCG can protect rats against lung ischemia-reperfusion injury by suppressing inflammation,antiquating lipid peroxidation and scavenging oxygen free radicals.The mechanism of which is associated suppressing the activating Wnt/-catenin signal pathway.