TY - JOUR
T1 - Inhibitory effects of conjugated epicatechin metabolites on peroxynitrite-mediated nitrotyrosine formation
AU - Natsume, Midori
AU - Osakabe, Naomi
AU - Yasuda, Akiko
AU - Osawa, Toshihiko
AU - Terao, Junji
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2008/1
Y1 - 2008/1
N2 - Previously, we identified four metabolites of (-)-epicatechin in blood and urine: (-)-epicatechin-3′-O-glucuronide (E3′G), 4′-O-methyl-(- )-epicatechin-3′-O-glucuronide (4′ME3′G), (-)-epicatechin-7-O- glucuronide (E7G), and 3′-O-methyl-(-)-epicatechin-7-O-glucuronide (3′ME7G) (Natsume et al. Free Radical Biol. Med. 34, 840-849, 2003). The aim of the current study was to compare the antioxidative activities of these metabolites with that of their parent compound. After oral administration of (-)-epicatechin, E3′G and 4′ME3′G were isolated from human urine, and E7G and 3′ME7G isolated from rat urine. We found that these compounds inhibited peroxynitrite-mediated tyrosine nitration, in the following order of potency: E3′G > (-)-epicatechin > E7G = 3′ME7G. = 4′ME3′G. These results demonstrate that the metabolites of (-)-epicatechin retain antioxidative activity on peroxynitrite-induced oxidative damages to some extent.
AB - Previously, we identified four metabolites of (-)-epicatechin in blood and urine: (-)-epicatechin-3′-O-glucuronide (E3′G), 4′-O-methyl-(- )-epicatechin-3′-O-glucuronide (4′ME3′G), (-)-epicatechin-7-O- glucuronide (E7G), and 3′-O-methyl-(-)-epicatechin-7-O-glucuronide (3′ME7G) (Natsume et al. Free Radical Biol. Med. 34, 840-849, 2003). The aim of the current study was to compare the antioxidative activities of these metabolites with that of their parent compound. After oral administration of (-)-epicatechin, E3′G and 4′ME3′G were isolated from human urine, and E7G and 3′ME7G isolated from rat urine. We found that these compounds inhibited peroxynitrite-mediated tyrosine nitration, in the following order of potency: E3′G > (-)-epicatechin > E7G = 3′ME7G. = 4′ME3′G. These results demonstrate that the metabolites of (-)-epicatechin retain antioxidative activity on peroxynitrite-induced oxidative damages to some extent.
KW - (-)-epicatechin
KW - Glucuronide
KW - Metabolites
KW - Nitrotyrosine
KW - Peroxynitrite
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U2 - 10.3164/jcbn.2008008
DO - 10.3164/jcbn.2008008
M3 - Article
C2 - 18231630
AN - SCOPUS:39149092347
VL - 42
SP - 50
EP - 53
JO - Journal of Clinical Biochemistry and Nutrition
JF - Journal of Clinical Biochemistry and Nutrition
SN - 0912-0009
IS - 1
ER -