Quercetin is recovered in human plasma as conjugated derivatives which retain antioxidant properties

FEBS Letters

Régérat, Françoise¹  Texier, Odile¹  Manach, Claudine²  Rémésy, Christian²  Crespy, Vanessa²  Morand, Christine²  Demigné, Christian² 

[1] Laboratoire de Pharmacognosie et Biotechnologies, Faculté de Pharmacie, 63001 Clermont-Ferrand, France;Unité des Maladies Métaboliques et Micronutriments, I.N.R.A. de Clermont-Ferrand/Theix, 63122 St Genès-Champanelle, France

关键词: Quercetin;    Flavonoid;    Conjugated metabolite;    Dietary antioxidant;    Low density lipoprotein oxidation;    Human;   

DOI  :  10.1016/S0014-5793(98)00367-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Quercetin is one of the most abundant flavonoids in the human diet. This study aimed to determine the plasma concentrations of quercetin in 10 healthy volunteers after the consumption of a complex meal rich in plant products. Quercetin was determined in plasma (2 h before, and 3, 7 and 20 h after the meal), and in a duplicated portion of the meal by HPLC analysis with an electrochemical detection. The amount of ingested quercetin was estimated to be 87 mg. Before the meal, quercetin concentration in hydrolyzed plasmas ranged from 28 to 142 nM. A marked increase was observed 3 h after the meal in all subjects, with a mean concentration of 373 nM (S.E.M.=61). After 7 h, quercetin concentration in hydrolyzed plasmas decreased and after 20 h basal levels were found again. The antioxidant capacities of quercetin, 3′-O-methylquercetin, and of some of their conjugated derivatives were compared by the measurement of the conjugated dienes resulting from the Cu²⁺-induced oxidation of human LDL. 3′-O-Methylquercetin and conjugated derivatives of quercetin significantly prolonged the lag phase, but the magnitude of their effect was about half that of the aglycone.

【 授权许可】

Unknown