Linked Life Data

9393670

Source:http://linkedlifedata.com/resource/pubmed/id/9393670

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1997-12-17
pubmed:abstractText
Chronic inflammation has been implicated as the underlying factor in the pathogenesis of many disorders. In the past decade, inflammation-related endogenous production of reactive nitrogen species, similar to oxygen free radicals, has also been suggested as a risk factor for cancer, in addition to the well-studied exogenous nitroso compounds. Epidemiological, in vitro, and animal model studies have implicated green tea to be protective against nitroso compound-induced and inflammation-related cancer. Therefore, we investigated the effect of epigallocatechin-3-gallate (EGCG), one of the known biologically active catechins contained in green tea, on the production of nitric oxide (NO.). We have shown previously that EGCG reduces NO. production as measured by nitrite accumulation in the culture medium. Expanding on this finding, in this report we show that EGCG may do so by two mechanisms: reduction of inducible nitric oxide synthase (iNOS) gene expression and inhibition of enzyme activity. Addition of 1-10 microM EGCG to lipopolysaccharide- and interferon-gamma-activated mouse peritoneal cells reduced iNOS mRNA expression concentration dependently, to 82-14%, as measured by relative reverse transcription-polymerase chain reaction. Addition of 50-750 microM EGCG, in a concentration-dependent manner, inhibited the enzyme activity of iNOS, to 85-14%, and neuronal nitric oxide synthase (nNOS), to 93-56%, as measured by citrulline formation. EGCG competitively inhibited binding of arginine and tetrahydrobiopterin, and the gallate structure is important for this action.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1281-6
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Inhibition of inducible nitric oxide synthase gene expression and enzyme activity by epigallocatechin gallate, a natural product from green tea.
pubmed:affiliation
Department of Biomedical Sciences, Pennsylvania College of Podiatric Medicine, Philadelphia 19107-2496, USA. chan@biology.rutgers.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't