title: Effects of alpha-tocopherol and beta-carotene on hepatic lipid peroxidation and blood lipids in rats with dietary iron overload.
abstract: The ability of dietary antioxidants to reduce lipid peroxidation induced by iron overload was examined in weanling male Sprague-Dawley rats. Animals were fed ad libitum a modified AIN-76A diet (control) or control diet with 0.5% alpha-tocopherol acid succinate, 0.5% crystalline trans-beta-carotene, or 0.5% alpha-tocopherol acid succinate + 0.5% trans-beta-carotene for four weeks. In the following four-week period, the animals received the above diets with 10,000 micrograms Fe/g; a control group continued to receive 35 micrograms Fe/g, and a high-iron group received 10,000 micrograms Fe/g with no antioxidants. After four weeks of dietary supplementation with alpha-tocopherol. Beta-carotene or alpha-tocopherol + beta-carotene, liver concentrations of alpha-tocopherol and beta-carotene increased significantly (p < 0.001). Liver lipid peroxidation, measured by the lipid-conjugated diene assay, increased significantly from 0.012 mumol/mg of lipid in the controls to 0.021 mumol/mg of lipid in animals receiving the high-iron diet. However, lipid peroxidation was significantly reduced in all animals fed the antioxidants, with the group fed alpha-tocopherol + beta-carotene having a lower level than the high-iron group. Total serum cholesterol was elevated in animals fed a high-iron diet and in animals fed the high-iron diet with alpha-tocopherol. In contrast, total serum cholesterol levels in the two groups of animals receiving the diets containing high iron with beta-carotene alone or high iron with beta-carotene + alpha-tocopherol were significantly reduced to the level of the control group. High-density lipoprotein cholesterol also decreased to baseline in the animals receiving beta-carotene alone. Modulation of lipid peroxidation by alpha-tocopherol or beta-carotene may be an important mechanism for reducing oxidative stress.
authors.affiliation: Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Washington, DC 20204, USA.
authors.forename: P
authors.initials: P
authors.lastname: Whittaker
authors.forename: W G
authors.initials: WG
authors.lastname: Wamer
authors.forename: R F
authors.initials: RF
authors.lastname: Chanderbhan
authors.forename: V C
authors.initials: VC
authors.lastname: Dunkel
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002338:Carotenoids / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood; D004032:Diet; D007501:Iron / Q000008:administration & dosage / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008055:Lipids / Q000097:blood*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014810:Vitamin E / Q000494:pharmacology*; D014886:Weaning; D019207:beta Carotene
chemical_list: D000975:Antioxidants; D008055:Lipids; D019207:beta Carotene; D014810:Vitamin E; D002338:Carotenoids; D002784:Cholesterol; D007501:Iron