TY - JOUR
T1 - Dose-dependent levels of epigallocatechin-3-gallate in human colon cancer cells and mouse plasma and tissues
AU - Lambert, Joshua D.
AU - Lee, Mao Jung
AU - Diamond, Lauren
AU - Ju, Jihyeung
AU - Hong, Jungil
AU - Bose, Mousumi
AU - Newmark, Harold L.
AU - Yang, Chung S.
PY - 2006/1
Y1 - 2006/1
N2 - Epigallocatechin-3-gallate (EGCG; molecular formula: C22H 18011) is the most abundant catechin in green tea (Camellia sinensis Theaceae). Both EGCG and green tea have been shown to have cancer-preventive activity in a number of animal models, and numerous mechanisms have been proposed based on studies with human cell lines. EGCG has been shown to undergo extensive biotransformation to yield methylated and glucuronidated metabolites in mice, rats, and humans. In the present study, we determined the concentration-dependent uptake of EGCG by HT-29 human colon cancer cells (20-600 μM) and the dose dependence of EGCG plasma and tissue levels after a single dose of EGCG (50-2000 mg/kg i.g.) to male CF-1 mice. The cytosolic levels of EGCG were linear with respect to extracellular concentration of EGCG after treatment of HT-29 cells for 2 h (915.3-6851.6 μg/g). In vivo, EGCG exhibited a linear dose relationship in the plasma (0.03-4.17 μg/ml), prostate (0.01-0.91 μg/g), and liver (0.09- 18.3 μg/g). In the small intestine and colon, however, the levels of EGCG plateaued between 500 and 2000 mg/kg i.g. These 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. The levels of 4″-O-methyl-EGCG and 4′,4″-di-O-methyl-EGCG parallel those of EGCG with respect to dose. The present study provides information with respect to what concentrations of EGCG are achievable in mice and may guide dose selection for future cancer chemoprevention studies with EGCG.
AB - Epigallocatechin-3-gallate (EGCG; molecular formula: C22H 18011) is the most abundant catechin in green tea (Camellia sinensis Theaceae). Both EGCG and green tea have been shown to have cancer-preventive activity in a number of animal models, and numerous mechanisms have been proposed based on studies with human cell lines. EGCG has been shown to undergo extensive biotransformation to yield methylated and glucuronidated metabolites in mice, rats, and humans. In the present study, we determined the concentration-dependent uptake of EGCG by HT-29 human colon cancer cells (20-600 μM) and the dose dependence of EGCG plasma and tissue levels after a single dose of EGCG (50-2000 mg/kg i.g.) to male CF-1 mice. The cytosolic levels of EGCG were linear with respect to extracellular concentration of EGCG after treatment of HT-29 cells for 2 h (915.3-6851.6 μg/g). In vivo, EGCG exhibited a linear dose relationship in the plasma (0.03-4.17 μg/ml), prostate (0.01-0.91 μg/g), and liver (0.09- 18.3 μg/g). In the small intestine and colon, however, the levels of EGCG plateaued between 500 and 2000 mg/kg i.g. These 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. The levels of 4″-O-methyl-EGCG and 4′,4″-di-O-methyl-EGCG parallel those of EGCG with respect to dose. The present study provides information with respect to what concentrations of EGCG are achievable in mice and may guide dose selection for future cancer chemoprevention studies with EGCG.
UR - http://www.scopus.com/inward/record.url?scp=29944437798&partnerID=8YFLogxK
U2 - 10.1124/dmd.104.003434
DO - 10.1124/dmd.104.003434
M3 - Article
C2 - 16204466
AN - SCOPUS:29944437798
SN - 0090-9556
VL - 34
SP - 8
EP - 11
JO - Drug Metabolism and Disposition
JF - Drug Metabolism and Disposition
IS - 1
ER -