Epigallocatechin-3-gallate induced primary cultures of rat hippocampal neurons death linked to calcium overload and oxidative stress
Epigallocatechin-3-gallate induced primary cultures of rat hippocampal neurons death linked to calcium overload and oxidative stress
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DOI：
10.1007/s00210-009-0401-4
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
Shuting Yin;Ming-liang Tang;Hongmin Deng;Tairan Xing;Ju-tao Chen;Hui-Li Wang;D. Ruan
中科院分区：
文献类型：
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作者：
Shuting Yin;Ming-liang Tang;Hongmin Deng;Tairan Xing;Ju-tao Chen;Hui-Li Wang;D. Ruan
表没食子儿茶素-3-没食子酸酯（Epigallocatechin-3-gallate，EGCG）是一种儿茶素多酚类成分，是绿色茶提取物的主要成分。据报道，EGCG是一种有效的抗氧化剂，对氧化应激相关疾病有益，但其他人和我们以前的研究表明，EGCG在高浓度下具有促氧化作用。因此，在本研究中，我们试图研究在大鼠海马神经元培养中EGCG诱导细胞死亡的可能途径。结果表明，EGCG可引起细胞内游离钙浓度（[Ca ~（2+）]i）迅速升高，并呈剂量依赖性。暴露于EGCG剂量和时间依赖性地增加活性氧（ROS）的产生，降低线粒体膜电位（Δ Km）以及Bcl-2/Bax表达比率。重要的是，5，5 ′-二甲基-双（邻氨基苯氧基）乙烷-N，N，N′，N′-四乙酸的乙酰氧基甲酯、乙二醇-双-（2-氨乙基）-N，N，N′，N′-四乙酸和维生素E可以减弱EGCG诱导的细胞凋亡反应，包括ROS的产生和线粒体功能障碍，最终部分阻止EGCG诱导的细胞死亡。此外，用表没食子酸没食子酸酯（EGCG）处理海马神经元导致半胱氨酸蛋白酶（caspase）-3和半胱氨酸蛋白酶（caspase）-9活性升高，但没有明显伴随乳酸脱氢酶释放，这进一步证明细胞凋亡是表没食子酸没食子酸酯（EGCG）诱导海马神经元培养物中细胞死亡的主要方式。综上所述，这些发现表明，EGCG通过依赖于腺苷酸的途径诱导海马神经元死亡。
Epigallocatechin-3-gallate (EGCG), a catechin polyphenols component, is the main ingredient of green tea extract. It has been reported that EGCG is a potent antioxidant and beneficial in oxidative stress-related diseases, but others and our previous study showed that EGCG has pro-oxidant effects at high concentration. Thus, in this study, we tried to examine the possible pathway of EGCG-induced cell death in cultures of rat hippocampal neurons. Our results showed that EGCG caused a rapid elevation of intracellular free calcium levels ([Ca2+]i) in a dose-dependent way. Exposure to EGCG dose- and time-dependently increased the production of reactive oxygen species (ROS) and reduced mitochondrial membrane potential (Δψm) as well as the Bcl-2/Bax expression ratio. Importantly, acetoxymethyl ester of 5,5′-dimethyl-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, ethylene glycol-bis-(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, and vitamin E could attenuate EGCG-induced apoptotic responses, including ROS generation, mitochondrial dysfunction, and finally partially prevented EGCG-induced cell death. Furthermore, treatment of hippocampal neurons with EGCG resulted in an elevation of caspase-3 and caspase-9 activities with no significant accompaniment of lactate dehydrogenase release, which provided further evidence that apoptosis was the dominant mode of EGCG-induced cell death in cultures of hippocampal neurons. Taken together, these findings indicated that EGCG induced hippocampal neuron death through the mitochondrion-dependent pathway.