Green tea leaf extract improves lipid and glucose homeostasis in a fructose-fed insulin-resistant hamster model

J Ethnopharmacol. 2006 Mar 8;104(1-2):24-31. doi: 10.1016/j.jep.2005.08.045. Epub 2005 Oct 3.

Abstract

The present study evaluated the effect of green tea (Camellia sinensis L.) leaf extract on triglyceride and glucose homeostasis in a fructose-fed hypertriglyceridemic, insulin-resistant hamster model. There was a significant decrease in plasma triglyceride levels following supplementation of the green tea epigallocatechin gallate-enriched extract (42% at 150 mg/(kg day) to 62% at 300 mg/(kg day) for 4 weeks). Compared to baseline, the fructose control group at the end of the study showed elevated serum insulin and apolipoprotein B levels, and decreased serum adiponectin levels. The fructose/green tea extract group showed a reversal in all of these metabolic defects, including an improvement in glucose levels during a glucose tolerance test. Triglyceride content was also examined in various tissues and compared to the control fructose group; supplementation of the green tea extract (300 mg/kg) reduced triglyceride content in liver and heart tissues. There was molecular evidence of improved lipid and glucose homeostasis based on peroxisome proliferator-activated receptor (PPAR) protein expression. Compared to the control fructose group, supplementation of the green tea extract (300 mg/kg) significantly increased PPARalpha and PPARgamma protein expression. In summary, the data suggest that intake of the green tea extract ameliorated the fructose-induced hypertriglyceridemia and the insulin-resistant state in part through PPAR.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / drug effects*
  • Blood Glucose / metabolism
  • Cricetinae
  • Disease Models, Animal*
  • Fructose / administration & dosage*
  • Homeostasis / drug effects
  • Homeostasis / physiology
  • Insulin Resistance / physiology*
  • Lipids / blood*
  • Male
  • Mesocricetus
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology
  • Plant Leaves
  • Tea*

Substances

  • Blood Glucose
  • Lipids
  • Plant Extracts
  • Tea
  • Fructose