Myeloperoxidase/nitrite-mediated lipid peroxidation of low-density lipoprotein as modulated by flavonoids.
Date Published: Thursday, February 27, 2003
FEBS Lett 2003, 537 (1-3), 146-50.
Authors: Kostyuk, V. A.; Kraemer, T.; Sies, H.; Schewe, T.
In the presence of a H(2)O(2)-generating system, myeloperoxidase (MPO) caused conjugated diene formation in low-density lipoprotein (LDL), indicating lipid peroxidation which was dependent on nitrite but not on chloride. The oxidation of LDL was inhibited by micromolar concentrations of flavonoidssuch as (-)-epicatechin, quercetin, rutin, taxifolin and luteolin, presumably via scavenging of the MPO-derived NO(2) radical. The flavonoids served as substrates of MPO leading to products with distinct absorbance spectra. The MPO-catalyzed oxidation of flavonoids was accelerated in the presence of nitrite.