Effects of cold‐pressed and vitamin E‐enriched flaxseed oils on lipid profile and antioxidant status in high‐fat fed rats

AbstractIn this study we evaluate whether cold‐pressed flaxseed oil (CFO), vitamin E‐enriched hot pressed and totally refined flaxseed oils (HRFOs) characterized by different qualities of micronutrients have beneficial effects on lipid profile and antioxidant status in high‐fat fed rats. Male Wistar rats were fed synthetic diets containing 10% of HRFO, CFO, low‐dose (100 mg/100 g oil) vitamin E‐enriched HRFO (L‐HRFO) or high‐dose (200 mg/100 g oil) vitamin E‐enriched HRFO (H‐HRFO), respectively for 4 wk. The results showed that plasma triglycerides (TG), total cholesterol (TC), and low‐density lipoprotein cholesterol levels in CFO group decreased by 12, 21, and 18% compared with HRFO group (p < 0.05), the total hepatic lipids, TC and TG levels in CFO group were also lower significantly than those in HRFO group, but no significant differences were observed in plasma and hepatic lipid profiles among HRFO, L‐HRFO, and H‐HRFO groups. T‐AOC levels significantly increased by 11, 12, and 22% in CFO, L‐HRFO and H‐HRFO groups compared with HRFO group, which was negatively correlated with the MDA levels and similar changes were observed for GSH and vitamin E levels in plasma. The CFO had a significantly higher cholesterol secretion than HRFO, L‐HRFO, and H‐HRFO. These results indicated that CFO had a more beneficial effect on improving lipid status and preventing oxidative stress than HRFO, and vitamin E‐enriched HRFO decreased the lipid peroxidation concentration though there was no significant effect on lipid profiles.Practical applications: The cold‐pressed and vitamin E‐enriched HRFOs characterized by different qualities of micronutrients reduced the risk factors of cardiovascular disease. This could provide a theoretical basis for the development of high value‐added functional food ingredients based on flaxseed oil or α‐linolenic acid.