Yang Ziyin, Jie Guoliang, Dong Fang, Xu Yi, Watanabe Naoharu, Tu Youying
Department of Tea Science, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, China.
Toxicol In Vitro. 2008 Aug;22(5):1250-6. doi: 10.1016/j.tiv.2008.04.007. Epub 2008 Apr 18.
The antioxidant properties of theaflavins and their gallate esters, namely theaflavin (TF1), theaflavin-3(3')-gallate (TF2) and theaflavin-3,3'-digallate (TF3) were investigated by comparing with epigallocatechin gallate (EGCG). The order of hydroxyl radicals-scavenging ability was TF3>TF2>TF1>EGCG. The order of 2,2-diphenyl-1-picrylhydrazyl scavenging ability was TF3>TF2>EGCG>TF1. TF1, TF2, and TF3 showed more effective effects than EGCG in protection against H2O2-mediated damage in HPF-1 cells. TF2 was the most potent accelerant of HPF-1 cell proliferation. TF1, TF2 and TF3 suppressed the accumulation of intracellular reactive species in H2O2-mediated damage HPF-1 cells. Pre-treated for 2h and eliminated from the cells, TF1 and TF3 still showed protective effects against H2O2-mediated damage in HPF-1 cells. This suggests that the protective effects of TF1 and TF3 on oxidative damage HPF-1 cells may be responsible for other mechanisms, rather than only scavenging the already formed reactive species. It remains to be determined whether TF1 and TF3 improved the normal HPF-1 cell resistive abilities toward radical-damage in pre-treatment. Further studies of the effects of theaflavins on some enzymes or signal transduction in the normal HPF-1 cells are underway.
通过与表没食子儿茶素没食子酸酯（EGCG）比较，研究了茶黄素及其没食子酸酯，即茶黄素（TF1）、茶黄素-3(3')-没食子酸酯（TF2）和茶黄素-3,3'-二没食子酸酯（TF3）的抗氧化性能。清除羟基自由基能力的顺序为TF3>TF2>TF1>EGCG。清除2,2-二苯基-1-苦基肼自由基能力的顺序为TF3>TF2>EGCG>TF1。在保护HPF-1细胞免受过氧化氢介导的损伤方面，TF1、TF2和TF3比EGCG表现出更有效的作用。TF2是HPF-1细胞增殖最有效的促进剂。TF1、TF2和TF3抑制了过氧化氢介导损伤的HPF-1细胞内活性物质的积累。预处理2小时并从细胞中去除后，TF1和TF3对HPF-1细胞中过氧化氢介导的损伤仍具有保护作用。这表明TF1和TF3对HPF-1细胞氧化损伤的保护作用可能是由其他机制引起的，而不仅仅是清除已经形成的活性物质。TF1和TF3在预处理时是否提高了正常HPF-1细胞对自由基损伤的抵抗能力还有待确定。目前正在进一步研究茶黄素对正常HPF-1细胞中某些酶或信号转导的影响。
