EGCG铜离子络合物对结肠癌细胞内活性氧水平的影响(英文)

Effect of Epigallocatechin-3-gallate/Copper(Ⅱ)Complex on the Level of Intracellular Reactive Oxygen Species of Colorectal Cancer Cell

本文主要通过荧光探针结合流式细胞术，探讨了表没食子儿茶素没食子酸酯（EGCC）铜离子络合物（ECC）对结肠癌细胞（RKO细胞）内活性氧水平的影响，并进一步从分子水平阐述了其影响机制。结果表明，5-10mg／L的ECC能够显著增强胞内活性氧水平，并且随着ECC水平的增加，细胞周期主要阻止于G2／M期。另外，胞内黄嘌呤氧化酶活性呈降低趋势，并且超氧化物岐化酶-1活性并没有随着其基因水平的增强而显著增强；但过氧化氢酶虽然基因水平有了较大的提升，其在胞内的生物活性却呈现出显著性剂量依赖性降低。因此，胞内活性的提升可能主要归因于胞内活性氧（过氧化氢）未能及时被活性降低的过氧化氢酶清除所致。

The aim of this study was to investigate the effect of epigallocatechin-3-gaUate/copper （II） complex （ECC） on the level of reactive oxygen species （ROS） of RKO colorectal cancer cells. The fluorescence probe was used to meas- ure the intracellular ROS and Ca2 ＋ level with vanillin assay. The redox enzymes activities and their relative mRNA tran- scription level were determined by manufacture＇ s kits. The results showed that the concentration of ECC ranged from 5 to 10 mg/L in culture medium increased the intraeellular ROS level significantly. The cell cycle was mediated in G2/M phase, The xanthine oxidase （XOD） bioacfivities decreased with ECC in a dose-dependent manner, The superoxidase dismutase-1 （SOD1） activity varied irregularly except for higher corresponding gene transcription （relative to GAP- DH）. Although induced much more mRNA expression of eatalase （CAT） ,decreased activity of CAT in the intracellular RKO ceils was detected. Hence, the enhanced intracellular ROS level mainly attributed to the decrease CAT enzyme ac- tivity.