Citrus polymethoxylated flavones improve lipid and glucose homeostasis and modulate adipocytokines in fructose-induced insulin resistant hamsters

Life Sci. 2006 Jun 20;79(4):365-73. doi: 10.1016/j.lfs.2006.01.023. Epub 2006 Feb 21.

Abstract

The present study was undertaken to determine whether supplementation with polymethoxylated flavones (PMFs) could ameliorate the fructose-induced hypertriglyceridemia and other metabolic abnormalities associated with insulin resistance (IR) in hamsters. Following feeding with the fructose diet, hamsters were supplemented orally with PMF-L or PMF-H (62.5 and 125 mg/kg/day) for 4 weeks. Both PMF-treated groups showed a statistically significant (p<0.05) decrease in serum triglyceride (TG) and cholesterol levels compared to the fructose-fed control group. The fructose control group at the end of the study showed elevated serum insulin and impaired insulin sensitivity (glucose intolerance). On the other hand, PMF-supplemented groups showed a reversal in these metabolic defects, including a decrease in insulin level and an improvement in glucose tolerance. PMF supplementation also reduced TG contents in the liver and heart and was able to regulate adipocytokines by significantly suppressing TNF-alpha, INF-gamma, IL-1beta and IL-6 expression and increasing adiponectin in IR hamsters. The mechanism of PMF on the activation of peroxisome proliferator-activated receptors (PPAR) was also explored. PMF-H supplementation significantly increased PPARalpha and PPARgamma protein expression in the liver. This is the first report of positive effects of PMF on adipocytokine production and on PPAR expression in IR hamsters. This study suggests that PMF can ameliorate hypertriglyceridemia and its anti-diabetic effects may occur as a consequence of adipocytokine regulation and PPARalpha and PPARgamma activation.

Publication types

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

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Administration, Oral
  • Animals
  • Blood Glucose / drug effects
  • Cholesterol / blood
  • Citrus / chemistry*
  • Cricetinae
  • Cytokines / metabolism
  • Disease Models, Animal
  • Flavones / therapeutic use*
  • Fructose / administration & dosage
  • Fructose / pharmacology
  • Glucose Tolerance Test
  • Homeostasis / drug effects
  • Hypercholesterolemia / drug therapy*
  • Hypercholesterolemia / etiology
  • Hypolipidemic Agents / therapeutic use*
  • Insulin Resistance*
  • Lipids / blood
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Mesocricetus
  • PPAR gamma / drug effects
  • PPAR gamma / metabolism
  • Plant Extracts / therapeutic use
  • Triglycerides / blood

Substances

  • Blood Glucose
  • Cytokines
  • Flavones
  • Hypolipidemic Agents
  • Lipids
  • PPAR gamma
  • Plant Extracts
  • Triglycerides
  • Fructose
  • Cholesterol