Linked Life Data

16330143

Source:http://linkedlifedata.com/resource/pubmed/id/16330143

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
2006-4-17
pubmed:abstractText
Recent reports have shown a decrease in blood pressure associated with the consumption of flavanol-containing foods. However, the mechanism behind this effect is not yet known. Previously we demonstrated that the flavanol epicatechin and its related oligomers, the procyanidins, inhibit angiotensin I converting enzyme (ACE) activity in vitro. In this study, we further characterized epicatechin monomer, dimer, tetramer and hexamer ACE inhibitory effect, by performing fluorescence quenching and kinetic assays, using angiotensin I as substrate. Assessment of ACE activity in cultured human umbilical vein endothelial cells (HUVEC) indicated that the tetramer was the most active inhibitor decreasing the formation of angiotensin II by 52% (P<0.001). When ACE activity was measured using isolated rabbit lung ACE, dimer, tetramer and hexamer inhibited angiotensin II production at IC(50) values of 97.0, 4.4, and 8.2 microM, respectively. The quenching of ACE tryptophan fluorescence was assayed to evaluate the molecular interaction between ACE and procyanidins. The hexamer was the most active quencher decreasing ACE fluorescence by 56%, followed by the tetramer and the dimer, decreasing ACE fluorescence by 37% and 36%, respectively. ACE activity was evaluated in the presence of different concentrations of the ACE activator chloride ion (Cl(-)). Increased Cl(-) concentrations reduced IC(50) values for the dimer and tetramer. Finally, ACE inhibition was determined in the presence of different albumin concentrations. The presence of albumin did not reverse the ACE inhibition by dimer and tetramer, but decreased hexamer inhibition by 65%. In summary, the inhibitory effect of procyanidins on ACE and the extent of this inhibition were largely dependent on procyanidin structure. ACE inhibition by procyanidins in vivo might provide a mechanism to explain the benefits of flavonoid consumption on cardiovascular diseases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-9084
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
359-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16330143-Angiotensin-Converting Enzyme Inhibitors, pubmed-meshheading:16330143-Animals, pubmed-meshheading:16330143-Biflavonoids, pubmed-meshheading:16330143-Catechin, pubmed-meshheading:16330143-Dose-Response Relationship, Drug, pubmed-meshheading:16330143-Endothelial Cells, pubmed-meshheading:16330143-Enzyme Activation, pubmed-meshheading:16330143-Humans, pubmed-meshheading:16330143-Hydrolysis, pubmed-meshheading:16330143-Kinetics, pubmed-meshheading:16330143-Peptidyl-Dipeptidase A, pubmed-meshheading:16330143-Proanthocyanidins, pubmed-meshheading:16330143-Rabbits, pubmed-meshheading:16330143-Serum Albumin, Bovine, pubmed-meshheading:16330143-Sodium Chloride, pubmed-meshheading:16330143-Spectrometry, Fluorescence, pubmed-meshheading:16330143-Structure-Activity Relationship
pubmed:articleTitle
Procyanidin structure defines the extent and specificity of angiotensin I converting enzyme inhibition.
pubmed:affiliation
Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.