表儿茶素对牛磺酸脱氧胆酸诱导Huh7细胞凋亡的作用  

Epicatechin abolished TDCA-induced apoptosis in Huh7 cell by inhibiting Bax,p38 MAPK and ROS production

作　　者：余晶[1] Vladimir Khaoustov 徐玉敏 Boils Yoffe 

机构地区：[1]广西中医学院第一附属医院肝病内科,广西南宁530023 [2]贝勒医学院医学系迈克尔德贝基退伍军人医疗中心,美国德克萨斯州休斯敦77030

出　　处：《中国中药杂志》2009年第10期1272-1275,共4页China Journal of Chinese Materia Medica

基　　金：广西教育厅广西财政资助出国留学项目[桂教国交(2005)86]

摘　　要：目的:探索表儿茶素对牛磺酸脱氧胆酸诱导Huh7细胞凋亡的抑制作用及其作用机制。方法:对牛磺酸脱氧胆酸(TDCA)400μmol.L-1和表儿茶素干预培养48 h的Huh7细胞,应用MTT法检测细胞活力,荧光探针测定细胞内活性氧(ROS)生成量,荧光caspase-3/7分析法探测细胞凋亡,免疫蛋白印迹测定促凋亡蛋白Bax,细胞色素C和磷酸化p38蛋白激酶含量。结果:TDCA孵育可诱导Huh7细胞凋亡,存活率下降(54.24±2.20)%,细胞经表儿茶素与TDCA共孵育后,细胞存活率提高到(85.64±0.84)%;表儿茶素能显著抑制TDCA引起的Huh7细胞ROS生成,caspase-3/7蛋白酶活性升高。ROS生成下降54.2%,caspase-3/7活性下降52.3%(P<0.01)。表儿茶素抑制TDCA诱导Huh7细胞凋亡随剂量增加抑制作用加强。表儿茶素抑制TDCA诱导促凋亡蛋白Bax表达,细胞色素C释放及p38蛋白激酶磷酸化。结论:表儿茶素抑制TDCA诱导Huh7细胞线粒体损伤而导致的细胞凋亡。其作用机制是通过减少细胞内活性氧和促凋亡蛋白Bax生成,抑制细胞色素C释放及p38蛋白激酶磷酸化。Objective： To investigate the molecular mechanisms involved in anti-apoptotic effects of epicathechin in liver cells. Method： Human hepatoma cell line （Huh7） was treated with 400 μmol ·L^-1 taurodeoxycholic acid （TDCA） for 48 hours to induce apoptosis. Intracellular generation of reactive oxygen species （ROS） was detected with DCFH-DA assay. Caspase-3/7 activity was analyzed with EnzoLyte Homogeneous AMC kit. Cell proliferation was measured by MTT assay. The expression of Bax, Phospho-p38 MAPK and the levels of cytochrome C were assessed by Western-blot analysis. Result： TDCA-dependent intracellular ROS production was 8-fold higher as compared to untreated cells, consequently resulting in 45% reduction of cell viability. Interestingly, pretreatment of cells with epicatechin resulted in a dose-dependent inhibition of TDCA-induced ROS generation and reduced cell apoptosis by three- fold as compared to TDCA treatment alone. In addition epicatechin reduced Bax expression with consequential inhibition of cytochrome C release from mitochondria, inhibition of caspase 3/7 activation and p38 MAPK phosphorylation. Conclusion： Epicatechin protects Huh7 cells from oxidative stress and mitochondria-induced apoptosis. The molecular mechanisms of anti-apoptotic effects of epicatechin were associated with inhibition of p38 MAPK phosphorylation and Bax expression, and reduction of ROS production. These findings implicate epicathechin might have potential as protective agent against a variety of oxidative stress-mediated liver conditions.

关 键 词：表儿茶素 牛磺酸脱氧胆酸 活性氧 凋亡 

分 类 号：R285.5[医药卫生—中药学]