Effect of beta-carotene Supplementation on Lipid Peroxides and Antioxidative Enzyme Activities in Hyperlipidemic Rats

ABSTRACT

This study was performed to investigate the effect of dietary beta-carotene supplementation on lipid metabolism and antioxidant enzyme activities in hyperlipidemic rats. Fifty Sprague-Dawley male rats aging 7 weeks were fed the control diet (CD, 5% corn oil) and the high fat diet (HFD, 15% beef tallow + 1% cholesterol) for 4 weeks and then 0.02% beta-carotene was supplemented to CD and HFD group for 8 more weeks. Serum lipid compositions, lipid peroxides and antioxidative enzymes in liver were analyzed at 4, 8 and 12week of the experiment. Serum levels of total lipid, total cholesterol, triglyceride, LDL-cholesterol, VLDL-cholesterol were higher in HFD groups than in CD groups (p < 0.001). Serum levels of HDL-cholesterol were higher in CD groups than in HFD groups (p < 0.01). The effect of beta-carotene supplementation was not significant in all groups but tended to be lower in total lipid, total cholesterol and triglyceride. Thiobarbituric acid reactive substances (TBARS) levels in plasma and liver were showed significantly higher in HFD groups (p < 0.001, p < 0.05). The effects of beta-carotene supplementation on the level of plasma and liver TBARS were not found except HFD groups at 12 week. Liver conjugated diene levels in HFD groups were higher than in CD groups (p < 0.01), but the effect of beta-carotene supplementation did not show any differences. Liver lipofuscin levels were not significantly different among all groups. The activities of superoxide dismutase (SOD) and catalase were significantly lower in HFD groups at 8 week (p < 0.001) but were not significantly different at 4 and 12week. The activity of SOD in beta-carotene supplemented HFD group was significantly higher at 8 week (p < 0.01). Glutathione peroxidase (GSHPx) activity was significantly lower in HFD groups (p < 0.01) and was significantly increased in groups supplemented beta-carotene (p < 0.05). It is suggested that beta-carotene supplementation partly decreases the serum lipid and lipid peroxide levels and increases the activities of antioxidant enzymes in hyperlipidemic rats.