文摘
Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but themolecular mechanisms of these effects have not been fully understood. Quantitative real-timepolymerase chain reaction (PCR) was used to investigate the relative expression levels and the effectsof 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 andoxidative 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, and60% 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. Thisstudy shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucoseuptake and insulin signaling pathway in rats fed a fructose-rich diet.