Cinnamon extract prevents the insulin resistance induced by a high-fructose diet

Horm Metab Res. 2004 Feb;36(2):119-25. doi: 10.1055/s-2004-814223.


The aim of this study was to determine whether cinnamon extract (CE) would improve the glucose utilization in normal male Wistar rats fed a high-fructose diet (HFD) for three weeks with or without CE added to the drinking water (300 mg/kg/day). In vivo glucose utilization was measured by the euglycemic clamp technique. Further analyses on the possible changes in insulin signaling occurring in skeletal muscle were performed afterwards by Western blotting. At 3 mU/kg/min insulin infusions, the decreased glucose infusion rate (GIR) in HFD-fed rats (60 % of controls, p < 0.01) was improved by CE administration to the same level of controls (normal chow diet) and the improving effect of CE on the GIR of HFD-fed rats was blocked by approximately 50 % by N-monometyl-L-arginine. The same tendency was found during the 30 mU/kg/min insulin infusions. There were no differences in skeletal muscle insulin receptor (IR)-beta, IR substrate (IRS)-1, or phosphatidylinositol (PI) 3-kinase protein content in any groups. However, the muscular insulin-stimulated IR-beta and IRS-1 tyrosine phosphorylation levels and IRS-1 associated with PI 3-kinase in HFD-fed rats were only 70 +/- 9 %, 76 +/- 5 %, and 72 +/- 6 % of controls (p < 0.05), respectively, and these decreases were significantly improved by CE treatment. These results suggest that early CE administration to HFD-fed rats would prevent the development of insulin resistance at least in part by enhancing insulin signaling and possibly via the NO pathway in skeletal muscle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / analysis
  • Body Weight
  • Cinnamomum zeylanicum / chemistry*
  • Diet
  • Dose-Response Relationship, Drug
  • Eating
  • Fatty Acids, Nonesterified / blood
  • Fructose / administration & dosage*
  • Glucose / administration & dosage
  • Glucose / metabolism
  • Glucose Clamp Technique
  • Insulin / blood
  • Insulin Receptor Substrate Proteins
  • Insulin Resistance*
  • Male
  • Phosphoproteins
  • Phosphorylation / drug effects
  • Plant Extracts / pharmacology*
  • Rats
  • Rats, Wistar
  • Receptor, Insulin / metabolism
  • Tyrosine / metabolism


  • Blood Glucose
  • Fatty Acids, Nonesterified
  • Insulin
  • Insulin Receptor Substrate Proteins
  • Irs1 protein, rat
  • Phosphoproteins
  • Plant Extracts
  • Fructose
  • Tyrosine
  • Receptor, Insulin
  • Glucose