Fragrant rapeseed oil consumption prevents blood cholesterol accumulation via promoting fecal bile excretion and reducing oxidative stress in high cholesterol diet fed rats

Abstract

We investigated the compositional changes and effects of long-term supplementation on blood lipids in three rapeseed oils [refined (RO), roasted at 120 °C (FO-120) and roasted at 150 °C (FO-150)]. Sixty Sprague-Dawley rats were fed either a basal diet or one of five high-cholesterol diets comprising lard, lard with cholestyramine, or three rapeseed oils for 12 weeks. Results showed that FO-120 and FO-150 alleviated plasma total cholesterol and increased fecal bile acid excretion, but RO had no significant effect. In the liver, cholesterol synthesis and conversion mRNA expression were altered by FO-120 or FO-150 feeding, like the inhibition of Hmgcr and activation of Cyp7a1. Furthermore, FO-120 or FO-150 increased hepatic eicosapentaenoic and docosahexaenoic acid production and favorably improved hepatic redox status. Overall, the hypocholesterolemic effects may be attributed to their high levels of α-linolenic acid and polyphenols, linked closely to regulating cholesterol metabolism, promoting highly-unsaturated fatty acids synthesis, and reducing oxidative stress.

Keywords

• Rapeseed oil
• Roasting temperature
• Refining
• Cholesterol metabolism
• Antioxidant status