Differential effect of high dietary iron on alpha-tocopherol and retinol levels in the liver and serum of mice fed olive oil- and corn oil-enriched diets.
The influence of dietary fats on cellular alpha-tocopherol and retinol uptake in iron overload is poorly understood. The aim of this study was to investigate the effect of a high-iron diet on the retinol and alpha-tocopherol levels in mice fed olive oil- and corn oil-enriched diets. Mice were fed for 3 weeks a standard mouse chow (the control group) and diets enriched with 5% by weight of corn oil or olive oil. Diets of the mice fed corn oil and olive oil were additionally supplemented with 1% by weight carbonyl iron. Both dietary oils and iron increased the liver iron uptake. High-iron feeding induced oxidative stress in mice liver, measured as a thiobarbituric acid-reactive substance level. Both fats and iron induced changes in the liver fatty acid composition. Liver retinol and alpha-tocopherol stores increased with iron supplementation in the olive oil-enriched diet, with a simultaneous decrease in serum. The results suggest that the influx of alpha-tocopherol and retinol from serum to the liver is induced by high dietary iron. This redistribution appears to be stronger for retinol than for alpha-tocopherol and is also higher in mice fed olive oil than in mice fed corn oil, suggesting that the composition of dietary lipids is important in the treatment of high-iron tissue conditions. In conclusion, the results of this study suggest that the increase of hepatic alpha-tocopherol and retinol levels in the olive oil-based diet is a dietary-dependent responsive mechanism that probably is not primarily related to an increased risk of oxidative damage induced by high-iron intake.
Domitrović
Robert
R
Department of Chemistry and Biochemistry, School of Medicine, University of Rijeka, 51000 Rijeka, Croatia. robertd@medri.hr
Tota
Marin
M
Milin
Cedomila
C
D000818:Animals; D003314:Corn Oil / Q000008:administration & dosage; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D019266:Iron, Dietary / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D000069463:Olive Oil; D018384:Oxidative Stress / Q000187:drug effects; D010938:Plant Oils / Q000008:administration & dosage; D011897:Random Allocation; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014801:Vitamin A / Q000097:blood / Q000378:metabolism*; D024502:alpha-Tocopherol / Q000097:blood / Q000378:metabolism*
D005227:Fatty Acids; D019266:Iron, Dietary; D000069463:Olive Oil; D010938:Plant Oils; D017392:Thiobarbituric Acid Reactive Substances; D014801:Vitamin A; D003314:Corn Oil; D024502:alpha-Tocopherol