Epigallocatechin gallate supplementation alleviates diabetes in rodents.
As the prevalence of type 2 diabetes mellitus is increasing at an alarming rate, effective nutritional and exercise strategies for the prevention of this disease are required. Specific dietary components with antidiabetic efficacy could be one aspect of these strategies. This study investigated the antidiabetic effects of the most abundant green tea catechin, epigallocatechin gallate (EGCG, TEAVIGO), in rodent models of type 2 diabetes mellitus and H4IIE rat hepatoma cells. We assessed glucose and insulin tolerance in db/db mice and ZDF rats after they ingested EGCG. Using gene microarray and real-time quantitative RT-PCR we investigated the effect of EGCG on gene expression in H4IIE rat hepatoma cells as well as in liver and adipose tissue of db/db mice. EGCG improved oral glucose tolerance and blood glucose in food-deprived rats in a dose-dependent manner. Plasma concentrations of triacylglycerol were reduced and glucose-stimulated insulin secretion was enhanced. In H4IIE cells, EGCG downregulated genes involved in gluconeogenesis and the synthesis of fatty acids, triacylgycerol, and cholesterol. EGCG decreased the mRNA expression of phosphoenolpyruvate carboxykinase in H4IIE cells as well as in liver and adipose tissue of db/db mice. Glucokinase mRNA expression was upregulated in the liver of db/db mice in a dose-dependent manner. This study shows that EGCG beneficially modifies glucose and lipid metabolism in H4IIE cells and markedly enhances glucose tolerance in diabetic rodents. Dietary supplementation with EGCG could potentially contribute to nutritional strategies for the prevention and treatment of type 2 diabetes mellitus.
Wolfram
Swen
S
DSM Nutritional Products Ltd, Department of Human Nutrition and Health, CH-4002 Basel, Switzerland. swen.wolfram@dsm.com
Raederstorff
Daniel
D
Preller
Mareike
M
Wang
Ying
Y
Teixeira
Sandra R
SR
Riegger
Christoph
C
Weber
Peter
P
D042962:Acyl-CoA Oxidase / Q000235:genetics; D000273:Adipose Tissue / Q000201:enzymology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D045744:Cell Line, Tumor; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000517:prevention & control*; D019587:Dietary Supplements; D015870:Gene Expression / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D005941:Glucokinase / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D005951:Glucose Tolerance Test; D050356:Lipid Metabolism / Q000235:genetics; D008099:Liver / Q000201:enzymology; D008114:Liver Neoplasms, Experimental; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020411:Oligonucleotide Array Sequence Analysis; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics; D012333:RNA, Messenger; D051381:Rats; D017207:Rats, Sprague-Dawley
D001786:Blood Glucose; D012333:RNA, Messenger; D002392:Catechin; C045651:epigallocatechin gallate; D042962:Acyl-CoA Oxidase; D002334:Carnitine O-Palmitoyltransferase; D005941:Glucokinase; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D005947:Glucose