The effect of dietary fats and supplements on markers of oxidative stress in rats

Oxidative stress assessed by TEARS, lipid hydroperoxides and protein carbonyls were investigated in male Sprague-Dawley rats. The present study reports the results of three experiments. In the first experiment, rats (n=20) were divided into four groups, a control, exercised, supplemented, and exercised plus supplemented group. The supplement given was a combination of choline, carnitine and caffeine. The supplement significantly increased TEARS and protein carbonyl concentrations in serum. Exercise significantly increased TEARS concentrations in serum but reduced them.in testes. Protein carbonyl concentrations were decreased in skeletal muscle and brain due to exercise. In the second experiment, rats (n=24) were fed a diet containing fish oil, com oil, safflower oil or palm oil as the dietary source of fat. In the animals fed unsaturated fatty acids, the concentration of lipid peroxidation was higher than for the animals fed a saturated diet. Protein carbonyl concentrations were increased with the saturated diet. In the third experiment, rats (n=24) were fed two different diets with predominantly trans or cis fatty acids. Half the animals in each group were killed 2 hours after an acute dose of ethanol. Trans fatty acids reduced oxidative stress measured by the three markers; the acute dose of ethanol had no significant effect. Lipid hydroperoxide concentrations were the least affected by any of the treatments. In conclusion, the effects of different treatments on oxidative stress depend not only on the marker but are also tissue specific.