Green Tea Polyphenol Extract Regulates the Expression of Genes Involved in Glucose Uptake and Insulin Signaling in Rats Fed a High Fructose Diet
- 1 July 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 55 (15), 6372-6378
- https://doi.org/10.1021/jf070695o
Abstract
Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but the molecular mechanisms of these effects have not been fully understood. Quantitative real-time polymerase chain reaction (PCR) was used to investigate the relative expression levels and the effects of green tea (1 and 2 g solid extract/kg diet) on the expression of glucose transporter family genes (Glut1/Slc2a1, Glut2/Slc2a2, Glut3/Slc2a3, and Glut4/Slc2a4) and insulin signaling pathway genes (Ins1, Ins2, Insr, Irs1, Irs2, Akt1, Grb2, Igf1, Igf2, Igf1r, Igf2r, Gsk3b, Gys1, Pik3cb, Pik3r1, Shc1, and Sos1) in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance and oxidative stress. Glut2 and Glut4 were the major Glut mRNAs in rat liver and muscle, respectively. Green tea extract (1 g) increased Glut1, Glut4, Gsk3b, and Irs2 mRNA levels by 110, 160, 30, and 60% in the liver, respectively, and increased Irs1 by 80% in the muscle. Green tea extract (2 g) increased Glut4, Gsk3b, and Pik3cb mRNA levels by 90, 30, and 30% but decreased Shc1 by 60% in the liver and increased Glut2, Glut4, Shc1, and Sos1 by 80, 40, 60, and 50% in the muscle. This study shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucose uptake and insulin signaling pathway in rats fed a fructose-rich diet. Keywords: Diabetes; fructose-rich diet; green tea; glucose transporter; insulin signaling pathway; obesity; polyphenol extract, ratKeywords
This publication has 28 references indexed in Scilit:
- Inflammation and metabolic disordersNature, 2006
- Epigallocatechin gallate (EGCG) mimics insulin action on the transcription factor FOXO1a and elicits cellular responses in the presence and absence of insulinCellular Signalling, 2006
- Anti‐obesity effects of green tea: From bedside to benchMolecular Nutrition & Food Research, 2006
- Occurrence and biological significance of proanthocyanidins in the American dietPhytochemistry, 2005
- Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological ActivityJournal of Agricultural and Food Chemistry, 2003
- Insulin and dexamethasone induce GLUT4 gene expression in foetal brown adipocytes: synergistic effect through CCAAT/enhancer-binding protein alphaBiochemical Journal, 2003
- Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT MethodMethods, 2001
- Decreased Sensitivity of Tristetraprolin-deficient Cells to p38 Inhibitors Suggests the Involvement of Tristetraprolin in the p38 Signaling PathwayJournal of Biological Chemistry, 2001
- Feedback Inhibition of Macrophage Tumor Necrosis Factor-α Production by TristetraprolinScience, 1998
- Pretranslational suppression of a glucose transporter protein causes insulin resistance in adipocytes from patients with non-insulin-dependent diabetes mellitus and obesity.JCI Insight, 1991