Age dependent variation in the antioxidant status and oxidative stress in rats fed diet containing coconut oil and sunflower oil

Abstract

The aim of the study was to compare the effect of feeding coconut oil (CO) and sunflower oil (SO), fats customarily classified as saturated and polyunsaturated on oxidative stress in Sprague Dawley rats of different age groups. The rats were divided into six groups (I, II, III, IV, V&VI) based on their age (groups I & II-one month old, groups III & IV- 12 months old, groups V & VI-22 months old) and were provided with standard pellet diet along with 10% oil (groups I, III & V were fed with coconut oil, groups II, IV &VI were fed with sunflower oil). The concentration of lipid peroxidation products viz TBARS in the tissues and in RBC, hydroperoxides and conjugated dienes were found to be increased with age in rats fed SO compared to rats fed CO. The reduced glutathione content was found to decrease with respect to age, but rats fed CO showed higher glutathione content than rats fed SO in both the age groups. The activities of the antioxidant enzymes catalase, superoxide dismutase, were found to decrease with increasing age in rats fed SO. Glutathione peroxidase and Glutathione reductase decreased only in the aged rats. The in vitro LDL oxidation was also found to increase with age and depending on the nature of dietary fat. Thus we conclude that aging diminished total antioxidant capacity to an extent with both oil fed diets, but in a lower extent in rats fed coconut oil diet.