The inhibition of the oxidation of low density lipoprotein by (+)-catechin, a naturally occurring flavonoid.
(+)-Catechin inhibited the copper-catalysed oxidation of human low density lipoprotein (LDL) in a dose-dependent manner with complete inhibition at 20 micrograms/mL. The flavonoid at a concentration of 50 micrograms/mL also inhibited oxidation of LDL induced by the mouse transformed macrophage J774, human monocyte-derived macrophages and vascular endothelial cells isolated from human umbilical cords. LDL modified by copper-catalysed or cell-induced oxidation was endocytosed and degraded by human macrophages at a much greater rate than native LDL. LDL reisolated from copper or cell incubations in the presence of (+)-catechin was endocytosed and degraded at rates similar to native LDL. (+)-Catechin appeared to inhibit the uptake and degradation by macrophages of cell-modified LDL. The actions of (+)-catechin on cell-induced oxidation of LDL are consistent with the ability of flavonoids of similar structure to inhibit lipoxygenases and with a role for lipoxygenases in cell-induced modification of LDL in vivo.
Mangiapane
H
H
Department of Biochemistry, Nottingham University Medical School, Queen's Medical Centre, U.K.
Thomson
J
J
Salter
A
A
Brown
S
S
Bell
G D
GD
White
D A
DA
D000818:Animals; D002392:Catechin / Q000494:pharmacology*; D002461:Cell Line, Transformed / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D016166:Free Radical Scavengers; D006801:Humans; D008074:Lipoproteins / Q000302:isolation & purification; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects
D005419:Flavonoids; D016166:Free Radical Scavengers; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D002392:Catechin