Effect of either gamma-tocotrienol or a tocotrienol mixture on the plasma lipid profile in hamsters

Ann Nutr Metab. 2002;46(1):17-23. doi: 10.1159/000046748.

Abstract

Background/aims: Tocotrienols has been shown to inhibit the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity; however, the published animal and human studies yield conflicting results. We investigated the effects of a 4-week dietary supplement of either gamma-tocotrienol (86% gamma-T3) or a mixture of tocotrienols (29.5% alpha-T3, 3.3% beta-T3, 41.4% gamma-T3, 0.1% delta-T3: mix-T3) on the plasma lipid profile in hamsters receiving a high fat diet.

Methods: The hamsters were randomized into 7 groups: no treatment, 16 mg/day/kg BW simvastatin, 23, 58, 263 mg/day/kg BW gamma-tocotrienol, and 39 or 263 mg/day/kg BW for the mixture of tocotrienols. Plasma lipid levels were measured after 2 and 4 weeks of treatment.

Results: In all groups treated with tocotrienol total cholesterol levels were decreased, ranging from 7 to 23% after 2 weeks of treatment and from 7 to 15% after 4 weeks. Low-density lipoprotein plasma levels changed accordingly: a decline of 6-37% after 2 weeks and of 12-32% at the end of the study was observed. After 4 weeks of treatment, total cholesterol and low-density lipoprotein plasma levels were significantly reduced in the 263 mg/day/kg BW mixed tocotrienols and the 58 mg/day/kg BW and 263 mg/day/kg BW gamma-tocotrienol groups when compared to the no treatment group. Plasma triglycerides and high-density lipoprotein levels did not change significantly.

Conclusion: This study provides further evidence that tocotrienols lower total cholesterol and low density lipoprotein plasma levels in hamsters and that gamma-tocotrienol is a more potent agent than a mixture of tocotrienols.

MeSH terms

  • Acyl Coenzyme A / antagonists & inhibitors
  • Animals
  • Anticholesteremic Agents / administration & dosage*
  • Anticholesteremic Agents / pharmacology
  • Antioxidants / administration & dosage*
  • Antioxidants / pharmacology
  • Cholesterol / blood
  • Chromans / administration & dosage*
  • Chromans / pharmacology
  • Cricetinae
  • Lipids / blood*
  • Lipoproteins, LDL / blood
  • Male
  • Mesocricetus
  • Random Allocation
  • Simvastatin / administration & dosage
  • Simvastatin / pharmacology
  • Tocotrienols / administration & dosage*
  • Tocotrienols / pharmacology
  • Vitamin E / administration & dosage*
  • Vitamin E / analogs & derivatives*
  • Vitamin E / pharmacology

Substances

  • Acyl Coenzyme A
  • Anticholesteremic Agents
  • Antioxidants
  • Chromans
  • Lipids
  • Lipoproteins, LDL
  • Tocotrienols
  • Vitamin E
  • 3-hydroxy-3-methylglutaryl-coenzyme A
  • plastochromanol 8
  • Cholesterol
  • Simvastatin