Inhibition of radical reaction of apolipoprotein B-100 and alpha-tocopherol in human plasma by green tea catechins.
(-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), and Trolox inhibited the decreases of apolipoprotein B-100 (apoB) and alpha-tocopherol in a radical reaction of human plasma initiated by Cu(2+). The concentrations of EC, EGC, ECg, EGCg, and Trolox for 50% inhibition (IC50) of apoB fragmentation were 39.1, 42.2, 14.6, 21.3, and 36.2 microM, respectively. Similar IC50 values were observed for alpha-tocopherol consumption, indicating the close relationship between apoB fragmentation and alpha-tocopherol consumption. These results demonstrate that tea catechins serve as an effective antioxidant in plasma and that the gallate group has a strong antioxidative activity.
Hashimoto
R
R
Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506 Japan.
Yaita
M
M
Tanaka
K
K
Hara
Y
Y
Kojo
S
S
D000975:Antioxidants; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000037:antagonists & inhibitors* / Q000097:blood; D001161:Arteriosclerosis / Q000517:prevention & control; D002392:Catechin / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D010084:Oxidation-Reduction; D013662:Tea; D014810:Vitamin E / Q000037:antagonists & inhibitors* / Q000097:blood
D000975:Antioxidants; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D013662:Tea; D014810:Vitamin E; D002392:Catechin