Chemiluminescence analysis of the prooxidant and antioxidant effects of epigallocatechin-3-gallate
(0) The aim of this study was to investigate the mechanism of antioxidant and prooxidant effects of epigallocatechin-3-gallate (EGCG) using chemiluminescence analysis. Results showed that EGCG scavenged superoxide radical and H2O2 in a dose dependent manner. EGCG scavenged 50％ of superoxide radical at 0.31 mM and scavenged 50％ of H2O2 at 0.09 mM, demonstrating that EGCG has a stronger reactive oxygen species (ROS) scavenging activity than ascorbic acid. Effects of EGCG on free radical-induced DNA oxidative damage were investigated. EGCG had protective effect on DNA at low concentrations (2-30 mM), but it enhanced the DNA oxidative damage at higher concentrations (＞60 mM), exhibiting a prooxidant effect on DNA. EGCG showed a greater reducing power on iron ions, reducing Fe3+ to Fe2+, which accelerates the generation of hydroxyl radical from the Fenton reaction. At low concentrations, ROS scavenging activity of EGCG might predominate over its reducing power and lead to its protective effect on DNA. However, relatively higher reducing power of EGCG at higher concentrations may gradually predominate over its ROS scavenging activity and result in the prooxidant effect of EGCG on DNA.
epigallocatechin-3-gallate chemiluminescence analysis prooxidant effect reactive oxygen species scavenging activity reducing power
Bing Tian Zongtao Sun Zhenjian Xu Yuejin Hua
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
国际会议
国际营养科学联盟第八届临床营养学大会暨第五届亚太临床营养学会大会
杭州
英文
153-157
2006-10-01（万方平台首次上网日期，不代表论文的发表时间）