Linked Life Data

9530994

Source:http://linkedlifedata.com/resource/pubmed/id/9530994

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-5-12
pubmed:abstractText
Although the bioflavonoids, a large group of polyphenolic natural products, exert chemopreventive effects in cardiovascular disease and cancer, there is little information about the disposition of these dietary components in man. The objective of this study was to investigate the plasma-protein binding of the most abundant bioflavonoid, quercetin, using 14C-labelled quercetin. An ultracentrifugation assay (170,000 g for 16 h at 20 degrees C) was shown to sediment plasma proteins. Binding of quercetin to normal plasma was extensive (99.1+/-0.5%, mean +/- s.d., n = 5). The unbound fraction varied as much as 6-fold, 0.3-1.8%, between subjects. This high binding was independent of quercetin concentration over the range 1.5-15 microM (0.5-5 microg mL(-1)). Human serum albumin was the primary protein responsible for the binding of quercetin in plasma (99.4+/-0.1%). Binding by alpha1-acid glycoprotein (39.2+/-0.5%) and very-low-density lipoproteins (<0.5% of total quercetin) did not make substantial contributions to overall plasma binding. The equilibrium association constant for the binding of quercetin to serum albumin was 267+/-33 x 10(3) M(-1) (n = 15). Thermodynamic data for the binding of quercetin to serum albumin indicated spontaneous, endothermic association. Displacement studies suggested that in man the 'IIA' subdomain binding site of human serum albumin was the primary binding site for quercetin. Association of quercetin with erythrocytes was significantly (P < 0.001) reduced by plasma protein binding. These data indicate poor cellular availability of quercetin because of its extensive binding to plasma proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3573
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
243-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Extensive binding of the bioflavonoid quercetin to human plasma proteins.
pubmed:affiliation
Department of Cell & Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston 29425, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't