Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2003-3-18
pubmed:abstractText
(-)-Epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) are major green tea catechins with antioxidant and anticancer activities. In this study, we characterized the glucuronidation of EGCG and EGC in human, mouse, and rat microsomes and by nine different human UGT 1A and 2B isozymes expressed in insect cells. Six EGCG and EGC glucuronides were biosynthesized, and their structures were identified for the first time. (-)-EGCG-4"-O-glucuronide was the major EGCG glucuronide formed in all incubations. The catalytic efficiency (V(max)/K(m)) for (-)-EGCG-4"-O-glucuronide formation followed the order: mouse intestine > mouse liver > human liver > rat liver >> rat small intestine. The UGT-catalyzed glucuronidation of EGC was much lower than that of EGCG. The V(max)/K(m) for (-)-EGC-3'-O-glucuronide followed the following order: mouse liver > human liver > rat liver > rat and mouse small intestine. Human UGT1A1, 1A8, and 1A9 had high activities with EGCG. UGT1A8, an intestine-specific UGT, had the highest V(max)/K(m) for EGCG but low activity with EGC. Mice appeared to be more similar to humans than rats to humans in the glucuronidation of EGCG and EGC. Some of these catechin glucuronides retained the activities of their parent compounds in radical scavenging and in inhibiting the release of arachidonic acid from HT-29 human colon cancer cells. These results provide foundations for understanding the biotransformation and biological activities of tea catechins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0090-9556
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
452-61
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12642472-Animals, pubmed-meshheading:12642472-Arachidonic Acid, pubmed-meshheading:12642472-Catechin, pubmed-meshheading:12642472-Cells, Cultured, pubmed-meshheading:12642472-Chromatography, High Pressure Liquid, pubmed-meshheading:12642472-Colonic Neoplasms, pubmed-meshheading:12642472-Cytosol, pubmed-meshheading:12642472-Dose-Response Relationship, Drug, pubmed-meshheading:12642472-Female, pubmed-meshheading:12642472-Gas Chromatography-Mass Spectrometry, pubmed-meshheading:12642472-Glucuronides, pubmed-meshheading:12642472-Glucuronosyltransferase, pubmed-meshheading:12642472-Humans, pubmed-meshheading:12642472-Insects, pubmed-meshheading:12642472-Intestines, pubmed-meshheading:12642472-Kinetics, pubmed-meshheading:12642472-Liver, pubmed-meshheading:12642472-Male, pubmed-meshheading:12642472-Mice, pubmed-meshheading:12642472-Mice, Inbred Strains, pubmed-meshheading:12642472-Microsomes, pubmed-meshheading:12642472-Radiation-Protective Agents, pubmed-meshheading:12642472-Rats, pubmed-meshheading:12642472-Rats, Sprague-Dawley, pubmed-meshheading:12642472-Species Specificity
pubmed:year
2003
pubmed:articleTitle
Glucuronides of tea catechins: enzymology of biosynthesis and biological activities.
pubmed:affiliation
Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers the State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, U.S. Gov't, P.H.S.