期刊名称:Journal of Clinical Biochemistry and Nutrition
印刷版ISSN:0912-0009
电子版ISSN:1880-5086
出版年度:2002
卷号:32
页码:55-68
DOI:10.3164/jcbn.32.55
出版社:The Society for Free Radical Research Japan
摘要:We investigated the effects of catechins and ground green tea drinking on the susceptibilities of human low density lipoprotein (LDL) and plasma to the oxidation by CuSO4 in vitro and ex vivo. The effects of (-)epicatechin (EC) and (-)epigallocatechin gallate (EGCg) on LDL oxidation in vitro were estimated by measuring the lag time of conjugated diene formation, lipid hydroperoxide and agarose gel electrophoretic mobility. EC and EGCg had antioxidant activities for LDL oxidation, and the antioxidant activity of EGCg to LDL oxidation was stronger than that of EC in vitro . In an ex vivo study, we investigated the effects of ground green tea drinking on LDL and plasma oxidation after the consumption of a cup of green tea (5g). Plasma total catechin contents were increased at 1 and 3h after the oral ingestion, and we detected (-)epigallocatechin (EGC), EC, EGCg and (+)catechin (CA) in plasma. The lag time of conjugated diene formation of plasma was increased in all subjects after consumption of green tea ( p <0.028), but the susceptibility of LDL oxidation ex vivo was different among individual subjects. Although the β-carotene, α-tocopherol and uric acid contents in plasma did not change after green tea consumption, ascorbic acid contents in plasma increased at 3h after green tea ingestion. These findings suggest that catechins suppressed the susceptibilities of human LDL to oxidation by CuSO4 in vitro and plasma oxidation ex vivo after ground green tea ingestion.