Linked Life Data

15288573

Source:http://linkedlifedata.com/resource/pubmed/id/15288573

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2004-8-3
pubmed:abstractText
Quercetin is one of the most ubiquitous bioflavonoids in foods of plant origin. Although quercetin is generally considered to provide protection against oxidative injury and inflammation, recent studies have demonstrated that its cytoprotective effects occur within a narrow concentration range. We attempted to examine the concentration-dependent effect on proliferation and inflammation in the primary culture of rat aortic smooth muscle cells. We demonstrate that quercetin inhibited [3H]thymidine incorporation into rat aortic smooth muscle cells only at concentrations < or =50 microM in a concentration-dependent manner. Nevertheless, quercetin, at concentrations > or =100 microM, reduced cell viability; this was further characterized as being due to apoptosis, which occurred through the proteolytic activation of pro-caspase-3. Additionally, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK) substantially increased in rat aortic smooth muscle cells exposed to 100 microM quercetin, results which differ from observations by others and ourselves of cells exposed to < or =50 microM quercetin. Unlike P-JNK and P-p38, the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/ERK2) was not significantly affected by the concentration-dependent effects of quercetin. Surprisingly, the adverse effects of higher concentrations of quercetin could be ameliorated by adding the antioxidants, catalase, and N-acetylcysteine (NAC). Furthermore, the electrophoretic mobility shift assay (EMSA) showed that rat aortic smooth muscle cells exposed to quercetin at concentrations of < or =50 microM caused concentration-dependent inhibition of nuclear factor kappa B (NF-kappaB) activity, whereas concentrations of > or =100 microM resulted in increased NF-kappaB binding activity. We demonstrate for the first time that quercetin at low concentrations has antiproliferative and antiinflammatory effects, but at concentrations of > or =100 microM, is likely to induce the opposite effects on rat aortic smooth muscle cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
496
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
41-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Concentration-dependent differential effects of quercetin on rat aortic smooth muscle cells.
pubmed:affiliation
The Section of Cardiology, Department of Medicine, Taipei Medical University Hospital, 250 Wu-Hsing Street, Taipei 110, Taiwan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't