α‐Tocopherol acetate supplementation enhances rat hepatic cytochrome PROD activity in the presence of phenobarbital induction
| Autor: | Chong-Kuei Lii, Wei‐Che Sung, Haw-Wen Chen, Yuh‐Jane Ko |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Male
Cancer Research medicine.medical_specialty alpha-Tocopherol Tocopherols Medicine (miscellaneous) Weanling Antioxidants Rats Sprague-Dawley chemistry.chemical_compound Biotransformation Internal medicine medicine Animals Vitamin E Tocopherol Enzyme inducer chemistry.chemical_classification Nutrition and Dietetics biology food and beverages Cytochrome P450 Glutathione Rats Endocrinology Enzyme Liver Oncology chemistry Enzyme Induction Phenobarbital Cytochrome P-450 CYP2B1 Dietary Supplements biology.protein Steroid 11-beta-Hydroxylase Lipid Peroxidation Xenobiotic medicine.drug |
| Zdroj: | Nutrition and Cancer. 32:37-42 |
| ISSN: | 1532-7914 0163-5581 |
| Popis: | Hepatic cytochrome P-450 enzymes play important roles in bioactivation of chemical carcinogens, biotransformation of many endogenous compounds, and detoxification of numerous xenobiotics. These enzyme activities have been shown to be regulated by various dietary factors. In our previous study, hepatic cytochrome pentoxyresorufin O-dealkylase (PROD) activity was decreased in rats fed an alpha-tocopherol acetate-deficient diet compared with rats fed alpha-tocopherol acetate-adequate or -supplemented diets. The objective of the present study was to investigate whether the modulatory effect of dietary alpha-tocopherol acetate on hepatic cytochrome PROD activity is influenced by the presence of phenobarbital. Weanling male Sprague-Dawley rats were fed the AIN-76 diet for four days, fasted for two days, then fed semipurified diets that were alpha-tocopherol acetate deficient, adequate, or supplemented with 5 and 15 g/kg alpha-tocopherol acetate for four days. Liver and plasma alpha-tocopherol concentrations were dose dependently regulated by dietary alpha-tocopherol acetate level. Inhibition of lipid peroxidation by dietary alpha-tocopherol acetate was dose dependent. Hepatic total cytochrome P-450 content was significantly greater in rats fed diets supplemented with 5 and 15 g/kg alpha-tocopherol acetate than in rats fed an alpha-tocopherol-adequate diet (p0.05). Hepatic cytochrome PROD activity was significantly greater in rats fed diets supplemented with 5 and 15 g/kg alpha-tocopherol acetate than in rats fed alpha-tocopherol acetate-deficient and -adequate diets (p0.05). These results suggest that, in the presence of phenobarbital, dietary alpha-tocopherol acetate efficiently affects tissue alpha-tocopherol levels and inhibits lipid peroxidation and that diets supplemented with 5 or 15 g/kg alpha-tocopherol acetate enhance hepatic cytochrome PROD activity compared with alpha-tocopherol acetate-deficient or -adequate diets. |
| Databáze: | OpenAIRE |
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