EGCG对小鼠肝缺血再灌注损伤的保护作用  

Epigallocatechin-3-gallate-induced protection against liver ischemia-reperfusion injury in the mouse

作　　者：曾贤慧[1] 罗小玲[1] 沈筱芸[1] 王江燕[1] 冯雁[1] 

机构地区：[1]广西医科大学附属肿瘤医院,南宁530021

出　　处：《现代免疫学》2015年第3期193-199,共7页Current Immunology

基　　金：广西医科大学青年科学基金(02602211011);广西自然科学青年基金(2013GXNSFBA019186);广西科学研究与技术开发计划(1298003-2-9)

摘　　要：本研究旨在探讨表没食子儿茶素没食子酸酯[(-)-Epigallocatechin-3-gallate,EGCG]对BALB/c小鼠肝缺血再灌注损伤的保护作用。取健康雄性Balb/c小鼠18只,随机分3组(n=6),分别为:对照组(Sham组)、缺血再灌注组(I/R组)和I/R+EGCG处理组(EGCG组)。各组分别于再灌注末摘除眼球取血样,处死小鼠收集肝组织。测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)水平;取缺血再灌注肝叶(左外叶肝)组织行HE染色后光镜下观察其病理形态学改变;免疫组织化学测定TLR4(Toll-like receptor4,TLR4)和NF-κB P65(nuclear transcription fator-kappa B P65)蛋白的表达量。结果发现,经EGCG预处理后,EGCG组小鼠血清AST、ALT的水平明显低于IR组(P<0.05),而显著高于Sham组(P<0.01)。HE染色结果显示,EGCG组左外叶肝组织损伤程度明显小于IR组,但较Sham组显著增大。免疫组化结果显示,EGCG组TLR4及NF-κB P65蛋白的阳性表达评分分别为(6.67±1.97分,5.67±1.51分)比I/R组(9.00±1.55分,8.33±2.25分)明显降低(P<0.05),较Sham组(3.00±0.98分,2.83±0.98分)显著升高(P<0.01)。设对照组基准值为1.00,real time-PCR结果示,I/R组左外叶肝组织中IL-1b和TNF-α的mRNA相对表达水平较EGCG组明显增高(P<0.05),同时EGCG组较Sham组显著增高(P<0.01)。研究表明,EGCG可抑制炎症反应,减少肝组织缺血再灌注损伤,其机制可能与EGCG调节TLR4/NF-κB P65信号通路及通路下游TNF-α、IL-6等炎症分子表达的变化有关。To investigate the protection against ischemia-reperfusion injury by Epigallocatechin-3-gallate（EGCG）in vivo,18 male Balb/c mice were randomly divided into three groups（n=6）：the sham-operation group（Sham group）,the ischemia-reperfusion group（I/R group）and the EGCG pretreated I/R group（EGCG）group.The mice were sacrificed at the end of reperfusion,and serum levels of alanine aminotransferase（ALT）,aspartate aminotransferase（AST）were measured.HE staining was used to observe the changes of the hepatic histopathology,and immunohistochemistry was applied to examine the protein levels of NF-κB P65 and TLR4.The results showed that,serum levels of ALT and AST in the EGCG group were higher than those in the sham group,but significantly lower than those of the I/R group（P〈0.05）.Histological examination showed that,the injury of the left lob of the liver was less severe in the EGCG group than that in the I/R group,but more severe than that in the sham group.In addition,the histoimmunological examination demonstrated that,when the expression of TLR4 and NF-κB P65 at the protein level was compared among the 3groups,it was shown that the EGCG group was higher than that of the sham group,but lower than that of the I/R group.All together,these findings suggest that EGCG can protect against hepatic ischemia-reperfusion injury in the mouse.The mechanism（s）underlying these effects of EGCG may involve the production of inflammatory factors NF-κB P65 and TLR4expression.

关 键 词：表没食子儿茶素没食子酸酯 缺血再灌注 NF-κB P65 TLR4 BALB/C小鼠 

分 类 号：R392.11[医药卫生—免疫学]