Flavonoids and urate antioxidant interplay in plasma oxidative stress |
| |
Authors: | Filipe Paulo Lança Vasco Nuno Silva João Morlière Patrice Santus René Fernandes Afonso |
| |
Institution: | (1) Faculdade de Medicina de Lisboa, Centro de Metabolismo e Endocrinologia da, Av. Prof. Egas Moniz 1600, Lisboa, Portugal;(2) Disciplina de Mecanismos da Doença, Faculdade de Medicina de Lisboa, Av. Prof. Egas Moniz 1600, Lisboa, Portugal;(3) Laboratoire de Photobiologie, Museum National d'Histoire Naturelle, 43 rue Cuvier, 75231 Paris, France;(4) Institut de Recherce sur la Peau, INSERM U532, Hôpital Saint-Louis, 1 avenue Claude Vellefeuex, 75475 Paris, France |
| |
Abstract: | Flavonoids are naturally occurring plant compounds with antioxidant properties. Their consumption has been associated with the protective effects of certain diets against some of the complications of atherosclerosis. Lowdensity lipoprotein (LDL) oxidative modification is currently thought to be a significant event in the atherogenic process. Most of the experiments concerning the inhibition of LDL oxidation used isolated LDL. We used diluted human whole plasma to study the influence of flavonoids on lipid peroxidation (LPO) promoted by copper, and their interaction with uric acid, one of the most important plasma antioxidants. Lipid peroxidation was evaluated by the formation of thiobarbituric acid reactive substances (TBARS) and of free malondialdehyde (MDA). The comparative capability of the assayed flavonoids on copper (II) reduction was tested using the neocuproine colorimetric test. In our assay system, urate disappears and free MDA and TBARS formation increase during the incubation of plasma with copper. Most of the tested flavonoids inhibited copperinduced LPO. The inhibition of LPO by flavonoids correlated positively with their capability to reduce copper (II). The urate consumption during the incubation of plasma with copper was inhibited by myricetin, quercetin and kaempferol. The inhibition of urate degradation by flavonoids correlated positively with the inhibition of LPO. Urate inhibited the copperinduced LPO in a concentrationdependent mode. Luteolin, rutin, catechin, quercetin had an antioxidant synergy with urate. Our results show that some flavonoids could protect endogenous urate from oxidative degradation, and demonstrate an antioxidant synergy between urate and some of the flavonoids. |
| |
Keywords: | flavonoids urate lipid peroxidation copper (II) plasma antioxidants free radicals |
本文献已被 PubMed SpringerLink 等数据库收录! |
|