Dietary flavonoid quercetin stimulates vasorelaxation in aortic vessels

Nicholas K H Khoo, C. Roger White, Lucas Pozzo-Miller, Fen Zhou, Chad Constance, Takafumi Inoue, Rakesh P. Patel, Dale A. Parks

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    69 Citations (Scopus)


    Considerable epidemiological evidence indicates that dietary consumption of moderate levels of polyphenols decreases both the incidence of cardiovascular disease and the mortality associated with myocardial infarction. Molecular mechanisms of this cardiovascular protection remain uncertain but can involve changes in rates of nitric oxide (NO) generation by endothelial nitric oxide synthase (eNOS). We examined the vascular responses to quercetin using a combination of biochemical and vessel function criteria. Quercetin treatment for 30min enhanced relaxation of rat aortic ring segments. Moreover, the addition of L-NAME (100μM) or charybdotoxin (ChTx) blocked quercetin-mediated vasorelaxation thus demonstrating the effect was partially dependent on NOS and endothelium-derived hyperpolarizing factor (EDHF). Additionally, bovine aortic endothelial cells (BAEC) treated with quercetin showed a rapid increase of intracellular Ca2+ concentrations as well as a dose- and time-dependent stimulation of eNOS phosphorylation with a concomitant increase in NO production. These results demonstrate that quercetin-mediated stimulation of eNOS phosphorylation increases NO bioavailability in endothelial cells and can thus play a role in the vascular protective effects associated with improved endothelial cell function.

    Original languageEnglish
    Pages (from-to)339-347
    Number of pages9
    JournalFree Radical Biology and Medicine
    Issue number3
    Publication statusPublished - 2010 Aug



    • Aortic ring segments
    • Cardioprotection
    • Catalase
    • Endothelium
    • Endothelium-derived hyperpolarizing factor
    • ENOS
    • Fura-2
    • HO
    • Heart
    • Mircofluorometric Ca imaging
    • Nitric oxide synthase
    • Phosphorylation

    ASJC Scopus subject areas

    • Biochemistry
    • Physiology (medical)

    Cite this

    Khoo, N. K. H., White, C. R., Pozzo-Miller, L., Zhou, F., Constance, C., Inoue, T., Patel, R. P., & Parks, D. A. (2010). Dietary flavonoid quercetin stimulates vasorelaxation in aortic vessels. Free Radical Biology and Medicine, 49(3), 339-347.