燕麥 β- 葡聚糖與多酚萃取物降血脂功能之比較研究   全文下載

Comparison of Protective Effects Between Oat β-Glucan and Phenol-Rich Extracts in Hyperlipidemic ICR Mice

燕麥中的β-葡聚糖（GE）已被廣泛認為是降低膽固醇的主要成分，然而燕麥中的多酚萃取物（PE）也被認為具抗高血脂潛能。本研究以餵食高脂飼料之ICR小鼠為實驗動物，比較和評估燕麥多酚萃取物和β-葡聚糖的降血脂功能。實驗共進行12週，結果多酚萃取物和β-葡聚糖均具顯著降膽固醇功能，能降低血清總膽固醇、血清低密度脂蛋白膽固醇及肝臟膽固醇。燕麥多酚萃取物能顯著降低肝臟三酸甘油酯，抑制肝臟HMG-CoA還原?活性，並且改善肝臟抗氧化防禦系統。燕麥β-葡聚糖則能顯著增加小鼠中性膽固醇和膽汁酸的排泄。本研究顯示燕麥β-葡聚糖和多酚萃取物均能預防小鼠高脂血症；膽固醇代謝和抗氧化防禦體系的研究，證明了燕麥中這兩種成分各有不同的降血脂機轉。

β-Glucan in oat is widely considered as the main ingredient for the anti-hypercholesterol effects; however, phenolic compounds in oat are also regarded to possess potential activities against dyslipidemia. In order to understand the underlying mechanisms thor-oughly, it is of great significance to evaluate and compare the hypolipidemic properties exerted by oat phenol-rich extract (PE) and β-glucan extract (GE) in hyperlipidemic ICR mice induced by high-fat diet. The study was conducted for 12 weeks. Both PE and GE showed a significant hypocholesterolemic action by reducing the concentration of serum total cholesterol (TC), low density lipopro-tein cholesterol and hepatic TC. Only PE reduced the hepatic triacylglycerol (TG), inhibited hepatic 3-hydroxy-3-methylglutary CoA reductase activities and improved the hepatic antioxidant defense system. However, GE significantly increased fecal excretion of neutral cholesterol and bile acids. This study demonstrated that not only β-glucan but also oat phenolic acids contributed to a preven-tive effect on hyperlipidemia. Based on the cholesterol metabolism and antioxidant defense system, the effects of the two functional components of oat were exerted in different ways.