These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of physiological quercetin metabolites on interleukin-1β-induced inducible NOS expression.
    Author: Cho JM, Chang SY, Kim DB, Needs PW, Jo YH, Kim MJ.
    Journal: J Nutr Biochem; 2012 Nov; 23(11):1394-402. PubMed ID: 22221676.
    Abstract:
    Cytokines released by inflammatory cells around the pancreatic islets are implicated in the pathogenesis of diabetes mellitus. Specifically, interleukin-1β (IL-1β) is known to be involved in islet β-cell damage by activation of nuclear factor-κB (NF-κB)-mediated inducible nitric oxide synthase (iNOS) gene expression. Though most flavonoids are shown to have various beneficial effects, little is known about the anti-inflammatory effects of their metabolites. Therefore, we investigated the effects of quercetin and its metabolites quercetin 3'-sulfate, quercetin 3-glucuronide and isorhamnetin 3-glucuronide on IL-1β-stimulated iNOS gene expression in RINm5F β-cells. The nitrite level, iNOS protein and its mRNA expression levels and iNOS promoter activity were measured. In addition, IκBα protein phosphorylation, nuclear translocation of nuclear factor-κB (NF-κB) and NF-κB DNA binding activity were determined. Adenosine 5'-triphosphate disodium salt-induced insulin release was also measured. Quercetin significantly reduced IL-1β-induced nitrite production, iNOS protein and its mRNA expression levels, and it also inhibited IL-1β-induced IκBα phosphorylation, NF-κB activation and iNOS promoter activity. Additionally, quercetin significantly restored the inhibition of insulin secretion by IL-1β. Meanwhile, quercetin metabolites did not show any effect on IL-1β-induced iNOS gene expression and also on insulin secretion. Therefore, in terms of iNOS expression mechanism, dietary ingestion of quercetin is unlikely to show anti-inflammatory effects in rat islet β-cells exposed to IL-1β.
    [Abstract] [Full Text] [Related] [New Search]