Tea catechins inhibit cholesterol oxidation accompanying oxidation of low density lipoprotein in vitro

Citation
K. Osada et al., Tea catechins inhibit cholesterol oxidation accompanying oxidation of low density lipoprotein in vitro, COMP BIOC C, 128(2), 2001, pp. 153-164
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Pharmacology & Toxicology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
ISSN journal
1532-0456 → ACNP
Volume
128
Issue
2
Year of publication
2001
Pages
153 - 164
Database
ISI
SICI code
1532-0456(200102)128:2<153:TCICOA>2.0.ZU;2-H
Abstract
Endogenous oxidized cholesterols are potent atherogenic agents. Therefore, the antioxidative effects of green tea catechins (GTC) against cholesterol oxidation were examined in an in vitro lipoprotein oxidation system. The an tioxidative potency of GTC against copper catalyzed LDL oxidation was in th e decreasing order(-)-epigalocatechin gallate (EGCG)= (-)-epicatechin galla te (ECG) > (-)-epicatechin (EC)=(+)-catechin (C) > (-)-epigallocatechin (EG C). Reflecting these activities, both EGCG (74%) and ECC (70%) inhibited th e formation of oxidized cholesterol, as well as the decrease of linoleic an d arachidonic acids, in copper catalyzed LDL oxidation. The formation of ox idized cholesterol in 2,2 '- azobis(2-amidinopropane) hydrochloride (AAPH)- mediated oxidation of rat plasma was also inhibited when the rats were give n diets containing 0.5% ECG or EGCG. In addition, EGCG and ECG highly inhib ited oxygen consumption and formation of conjugated dienes in AAPH-mediated linoleic acid peroxidative reaction. These two species of catechin also ma rkedly lowered the generation of hydroxyl radical and superoxide anion. Thu s, GTC, especially ECG and EGCG, seem to inhibit cholesterol oxidation in L DL by combination of interference with PUFA oxidation, the reduction and sc avenging of copper ion, hydroxyl radical generated from peroxidation of PUF A and superoxide anion. (C) 2001 Elsevier Science Inc. All rights reserved.