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


CONCLUSIONS
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.
Raederstorff
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D
Department of Vitamin and Nutrition Research, Roche Vitamins Ltd., CH-4070 Basel, Switzerland. daniel.raederstorff@roche.com
Elste
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Aebischer
C
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Weber
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D000214:Acyl Coenzyme A / Q000037:antagonists & inhibitors; D000818:Animals; D000924:Anticholesteremic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D000975:Antioxidants / Q000008:administration & dosage* / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood; D002839:Chromans / Q000008:administration & dosage* / Q000494:pharmacology; D006224:Cricetinae; D008055:Lipids / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008647:Mesocricetus; D011897:Random Allocation; D019821:Simvastatin / Q000008:administration & dosage / Q000494:pharmacology; D024508:Tocotrienols / Q000008:administration & dosage* / Q000494:pharmacology; D014810:Vitamin E / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000494:pharmacology
D000214:Acyl Coenzyme A; D000924:Anticholesteremic Agents; D000975:Antioxidants; D002839:Chromans; D008055:Lipids; D008077:Lipoproteins, LDL; D024508:Tocotrienols; D014810:Vitamin E; C008047:3-hydroxy-3-methylglutaryl-coenzyme A; C013649:plastochromanol 8; D002784:Cholesterol; D019821:Simvastatin