γ-tocotrienol as a hypocholesterolemic and antioxidant agent in rats fed atherogenic diets |
| |
Authors: | T Watkins P Lenz A Gapor M Struck A Tomeo M Bierenbaum |
| |
Affiliation: | (1) Fairleigh Dickinson University, 07940 Madison, New Jersey;(2) Kenneth L. Jordan Heart Fund, 48 Polymouth Street, 07042 Montclair, NJ |
| |
Abstract: | This study was designed to determine whether incorporation of γ-tocotrienol or α-tocopherol in an atherogenic diet would reduce
the concentration of plasma cholesterol, triglycerides and fatty acid peroxides, and attenuate platelet aggregability in rats.
For six weeks, male Wistar rats (n=90) were fed AIN76A semisynthetic test diets containing cholesterol (2% by weight), providing
fat as partially hydrogenated soybean oil (20% by weight), menhaden oil (20%) or corn oil (2%). Feeding the ration with menhaden
oil resulted in the highest concentrations of plasma cholesterol, low and very low density lipoprotein cholesterol, triglycerides,
thiobarbituric acid reactive substances and fatty acid hydroperoxides. Consumption of the ration containing γ-tocotrienol
(50 μ/kg) and α-tocopherol (500 mg/kg) for six weeks led to decreased plasma lipid concentrations. Plasma cholesterol, low
and very low density lipoprotein cholesterol, and triglycerides each decreased significantly (P<0.001). Plasma thiobarbituric acid reactive substances decreased significantly (P<0.01), as did the fatty acid hydroperoxides (P<0.05), when the diet contained both chromanols. Supplementation with γ-tocotrienol resulted in similar, though quantitatively
smaller, decrements in these plasma values. Plasma α-tocopherol concentrations were lowest in rats fed menhaden oil without
either chromanol. Though plasma α-tocopherol did not rise with γ-tocotrienol supplementation at 50 mg/kg, γ-tocotrienol at
100 mg/kg of ration spared plasma α-tocopherol, which rose from 0.60±0.2 to 1.34±0.4 mg/dL (P<0.05). The highest concentration of α-tocopherol was measured in plasma of animals fed a ration supplemented with α-tocopherol
at 500 mg/kg. In response to added collagen, the partially hydrogenated soybean oil diet without supplementary cholesterol
led to reduced platelet aggregation as compared with the cholesterol-supplemented diet. However, γ-tocotrienol at a level
of 50 mg/kg in the cholesterol-supplemented diet did not significantly reduce platelet aggregation. Platelets from animals
fed the menhaden oil diet released less adenosine triphosphate than the ones from any other diet group. The data suggest that
the combination of γ-tocotrienol and α-tocopherol, as present in palm oil distillates, deserves further evaluation as a potential
hypolipemic agent in hyperlipemic humans at atherogenic risk. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|