柑橘類鮮果及果皮中含有豐富的機能性成分，具有抗氧化、抗癌、減少血液凝集、降低心臟血管疾病及增加免疫力等功效。國人腦血管及心血管疾病分居十大死因之第二及第三位，而動脈粥狀硬化(atherosclerosis)為導致心血管疾病 (cardiovascular disease)最主要之原因。動脈粥狀硬化導因於血液中膽固醇及低密度脂蛋白之高血脂水平，造成血管內皮損傷，最終形成動脈粥狀硬化病變。而低密度脂蛋白（ low density lipoprotein；LDL）的氧化修飾在早期的動脈粥狀硬化中扮演很重要的角色，藉由抗氧化的作用來抑制LDL 的氧化修飾，是一種有效預防動脈粥狀硬化發生的方法。本研究之目的為評估由柳丁的乙醇萃取物，其抗LDL 氧化，而進行體外抗氧化實驗。之後再以高脂飼料誘發倉鼠之高血脂動物模式進行具調節血脂功能潛力之評估驗證。
結果顯示，不同萃取條件之萃取物均具有很好的抗氧化能力(DPPH清除能力、抗LDL氧化作用) 。動物試驗由體重、肝臟與脂肪組織之觀察結果顯示，柳丁皮萃取物會延緩脂肪肝的形成以及減少脂肪的儲存。血液生化值的觀察結果顯示，飼料中添加75%乙醇柳丁皮萃取物(2%、1%、0.5%)可有效的降低由高脂飲食所引起的高血脂(膽固醇、低密度脂蛋白膽固醇、三酸甘油酯) 。 綜合以上結果顯示柳丁果皮萃取物有效抑制高脂肪飲食所引起的肥胖、高血脂及脂肪肝。
Citrus fruit and peel contain many functional ingredients that are involved in anti-oxidation, anticancer, improvement of cardiovascular function and immunity. In order to develop citrus as healthy food, we prepared ethanolic extract from orange peel and orange seed and tested their potential in hypolipidemic effect that could be used in prevention of atherosclerosis and cardiovascular disease. The oxidative modification of low density lipoprotein plays a key role in the pathogenesis of atherosclerosis. Anti-oxidative reagents, which can effectively inhibit LDL oxidation, may prevent atherosclerosis via reducing early atherogenesis , and slowing down the progression to advance stages. We first defined the production rate, composition and anti-oxidative activity of orange peel extract (OPE)
Furthermore, we examined the effect of OPE on the serum lipids in the high cholesterol and high fat-fed hamsters. The results showed that all of OPE showed strong anti-oxidative activity as demonstrated by DPPH depletion assay and thiobarbituric acid-reactive substances (TBARS) assay. The data of weight gain, liver and adipose tissue observation of animal study revealed that OPE was able to improve the phenomena of fatty liver and decrease the weight of adipose tissue. Serum sample analysis of serum cholesterol, TG, and LDL-cholesterol showed that the supplement of OPE (2%、1%、0.5%) in the chow could effectively lower the hyperlipidemia caused by high-fat diet. Based on these findings, orange peel extract at the tested concentrations could efficiently lower the serum lipid levels and prevent the development of fatty liver caused by high fat food.
