title: Inhibition of starch digestion by the green tea polyphenol, (-)-epigallocatechin-3-gallate.
abstract: METHODS
  Green tea has been shown to ameliorate symptoms of metabolic syndrome in vivo. The effects could be due, in part, to modulation of postprandial blood glucose levels.
  
  
  RESULTS
  We examined the effect of coadministration of (-)-epigallocatechin-3-gallate (EGCG, 100 mg/kg, i.g.) on blood glucose levels following oral administration of common corn starch (CCS), maltose, sucrose, or glucose to fasted CF-1 mice. We found that cotreatment with EGCG significantly reduced postprandial blood glucose levels after administration of CCS compared to control mice (50 and 20% reduction in peak blood glucose levels and blood glucose area under the curve, respectively). EGCG had no effect on postprandial blood glucose following administration of maltose or glucose, suggesting that EGCG may modulate amylase-mediated starch digestion. In vitro, EGCG noncompetitively inhibited pancreatic amylase activity by 34% at 20 μM. No significant change was induced in the expression of two small intestinal glucose transporters (GLUT2 and SGLT1).
  
  
  CONCLUSIONS
  Our results suggest that EGCG acutely reduces postprandial blood glucose levels in mice when coadministered with CCS and this may be due in part to inhibition of α-amylase. The relatively low effective dose of EGCG makes a compelling case for studies in human subjects.
authors.affiliation: Center of Excellence for Plant and Mushroom Foods for Health, Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Forester
authors.forename: Yeyi
authors.initials: Y
authors.lastname: Gu
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Lambert
mesh_terms: D000284:Administration, Oral; D000681:Amylases / Q000378:metabolism; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D055292:Pancreatic alpha-Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019518:Postprandial Period; D051269:Sodium-Glucose Transporter 1 / Q000378:metabolism; D013213:Starch / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D013662:Tea / Q000737:chemistry
chemical_list: D001786:Blood Glucose; D051273:Glucose Transporter Type 2; C495682:Slc2a2 protein, mouse; C495675:Slc5a1 protein, mouse; D051269:Sodium-Glucose Transporter 1; D013662:Tea; D002392:Catechin; D013213:Starch; C045651:epigallocatechin gallate; D000681:Amylases; D055292:Pancreatic alpha-Amylases