Modulation of carbon tetrachloride-induced oxidative stress by dietary fat in rats

Abstract

Oxidative stress is believed to be involved in the pathophysiology of a number of chronic diseases including atherosclerosis, diabetes, and cataracts and to accelerate the aging process. The aim of this study was to elucidate the role of various dietary fats in the in vivo modulation of CCl 4 induced oxidative stress using rat as a model. Rats were raised on diets enriched with saturated (Beef Tallow), n-9 (Sunola oil), n-6 (Safflower oil) or n-3 (Flaxseed oil) fatty acids and exposed to elevated oxidative stress by administration of CCl 4. Plasma concentration of 8-iso-PGF 2α, antioxidant micronutrients and antioxidant enzymes were measured to examine changes to oxidative stress subsequent to the administration of CCl 4. The fatty acid profiles of plasma and RBC membranes reflected the fats fed in the different diets. CCl 4 administration had no significant effect on fatty acid composition of plasma or RBC lipids. Plasma 8-iso-PGF 2α concentrations were elevated by CCl 4 administration regardless of the dietary fat fed. Within the induced oxidative groups the 8-iso-PGF 2α concentrations were highest in Safflower oil followed by Sunola oil, Tallow and finally Flaxseed oil. Induction of oxidative stress by CCl 4 administration was associated with a significant reduction in Vitamin A content reaching a significantly lower concentration (P <0.05) in the Tallow and Flaxseed oil groups. Vitamin E concentrations were significantly lower (p = 0.01) in the Safflower oil and the Flaxseed oil than in the Tallow diet group following CCl 4 administration. Superoxide Dismutase (SOD) and Glutathione Peroxidase (GSHPx) activities were not affected by dietary fat manipulation. The results of this study indicate that dietary fat can modulate lipid peroxidation and antioxidant defenses when exposed to a pro-oxidant challenge.