Involvement of multidrug resistance-associated proteins in regulating cellular levels of (-)-epigallocatechin-3-gallate and its methyl metabolites.

  title={Involvement of multidrug resistance-associated proteins in regulating cellular levels of (-)-epigallocatechin-3-gallate and its methyl metabolites.},
  author={Jungil Hong and Joshua D. Lambert and Sung Hack Lee and Patrick J. Sinko and Chung S. Yang},
  journal={Biochemical and biophysical research communications},
  volume={310 1},
Quercetin Increased the Antiproliferative Activity of Green Tea Polyphenol (-)-Epigallocatechin Gallate in Prostate Cancer Cells
In summary, quercetin combined with EGCG in vitro demonstrated enhanced inhibition of cell proliferation by increasing the intracellular concentration of E GCG and decreasing EGCGs methylation.
Effect of genistein on the bioavailability and intestinal cancer chemopreventive activity of (-)-epigallocatechin-3-gallate.
It is demonstrated that although genistein can enhance EGCG bioavailability and in vitro growth inhibitory activity, this combination enhances tumorigenesis in the APC(min/+) mouse, showing the need for careful cancer prevention studies in animal models and for caution when interpreting data from in vitro studies.
The results suggest that absorption of EGCG from the small intestine is largely via passive diffusion; however, at high concentrations, the small intestinal and colonic tissues become saturated.
Quercetin increased bioavailability and decreased methylation of green tea polyphenols in vitro and in vivo.
Combining quercetin with GT provides a promising approach to enhance the chemoprevention of GT and may vary by tissue depending on the intrinsic COMT and MRP activity.
Piperine enhances the bioavailability of the tea polyphenol (-)-epigallocatechin-3-gallate in mice.
It is reported that cotreatment with a second dietary component, piperine (from black pepper), enhanced the bioavailability of EGCG in mice and demonstrated the modulation of the E GCG bioavailablity by a second Dietary component and illustrates a mechanism for interactions between dietary chemicals.
Modulation of function of three ABC drug transporters, P-glycoprotein (ABCB1), mitoxantrone resistance protein (ABCG2) and multidrug resistance protein 1 (ABCC1) by tetrahydrocurcumin, a major metabolite of curcumin
This study clearly showed that THC inhibits the efflux function of P-gp, MXR and MRP1 and it is able to extend the MDR reversing activity of curcuminoids in vivo.
Green tea catechin, epigallocatechin-3-gallate, attenuates the cell viability of human non-small-cell lung cancer A549 cells via reducing Bcl-xL expression
Results indicated that the inhibition of cell proliferation by EGCg may be achieved via suppressing the expression of the cell death-inhibiting gene, Bcl-xL.


Enzymology of methylation of tea catechins and inhibition of catechol-O-methyltransferase by (-)-epigallocatechin gallate.
The present work provides basic information on the methylation of EGCG and suggests that E GCG may inhibit COMT-catalyzedmethylation of endogenous and exogenous compounds.
Effects of epigallocatechin-3-gallate on growth, epidermal growth factor receptor signaling pathways, gene expression, and chemosensitivity in human head and neck squamous cell carcinoma cell lines.
  • M. MasudaM. SuzuiI. Weinstein
  • Biology, Medicine
    Clinical cancer research : an official journal of the American Association for Cancer Research
  • 2001
These findings provide insights into molecular mechanisms of growth inhibition by EGCG and suggest that this naturally occurring compound may be useful, when used alone or in combination with other agents, in the chemoprevention and/or treatment of HNSCC.
Glucuronides of tea catechins: enzymology of biosynthesis and biological activities.
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 is characterized to provide foundations for understanding the biotransformation and biological activities of tea catechins.
Efflux of dietary flavonoid quercetin 4'-beta-glucoside across human intestinal Caco-2 cell monolayers by apical multidrug resistance-associated protein-2.
A role for MRP2 in the transport of a new class of agents, dietary glucosides, is suggested in the intestinal transcellular efflux of quercetin 4'-beta-glucoside.
Transport and Metabolism of the Tea Flavonoid (–)-Epicatechin by the Human Intestinal Cell Line Caco-2
An important role is suggested for the multispecific organic anion transporter MRP2 in the bioavailability of EC and possibly other tea flavonoids.
Pharmacokinetics of tea catechins after ingestion of green tea and (-)-epigallocatechin-3-gallate by humans: formation of different metabolites and individual variability.
  • Mao‐Jung LeeP. Maliakal Chung S. Yang
  • Biology
    Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology
  • 2002
The pharmacokinetic parameters of EGCG, EGC, and EC were analyzed after administration of a single oral dose of green tea or decaffeinated green tea to eight subjects and may be useful for designing the dose and dose frequency in intervention studies with tea and for development of biomarkers of tea consumption.