Green tea polyphenols inhibit the sodium-dependent glucose transporter of intestinal epithelial cells by a competitive mechanism.
Intestinal glucose uptake is mainly performed by the sodium-dependent glucose transporter, SGLT1. The transport activity of SGLT1 was markedly inhibited by green tea polyphenols, this inhibitory activity being most pronounced in polyphenols having galloyl residues such as epicatechin gallate (ECg) and epigallocatechin gallate (EGCg). Experiments using brush-border membrane vesicles obtained from the rabbit small intestine demonstrated that ECg inhibited SGLT1 in a competitive manner, although ECg itself was not transported via SGLT1. The present results suggest that tea polyphenols such as ECg interact with SGLT1 as antagonist-like molecules, possibly playing a role in controlling the dietary glucose uptake in the intestinal tract.
Kobayashi
Y
Y
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Suzuki
M
M
Satsu
H
H
Arai
S
S
Hara
Y
Y
Suzuki
K
K
Miyamoto
Y
Y
Shimizu
M
M
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000502:physiology*; D007583:Jejunum; D007700:Kinetics; D008297:Male; D008871:Microvilli / Q000187:drug effects / Q000502:physiology; D009004:Monosaccharide Transport Proteins / Q000037:antagonists & inhibitors*; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011108:Polymers / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013662:Tea / Q000737:chemistry*
D005419:Flavonoids; D009004:Monosaccharide Transport Proteins; D010636:Phenols; D011108:Polymers; D013662:Tea; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; C057580:gallocatechol; D005947:Glucose