Mulberry extract inhibits the development of atherosclerosis in cholesterol-fed rabbits

生科四甲91240253

吳威儀

脂質的過氧化及低密度脂蛋白的氧化被證實是動脈粥狀硬化發生過程的致病因子。利用抗氧化劑預防低密度脂蛋白的氧化反應可能使是一種有效的抑制動脈粥狀硬化發生過程的方法。利用桑椹豐富的天然抗氧化色素成分，我們期待桑椹可抑制低密度脂蛋白氧化而達到預防動脈粥狀硬化的發生。此外，並以高膽固醇飲食混合桑椹萃取物餵食之動物實驗模式，觀察動物血脂變化及血管的病理變化，最終以科學證據驗證桑椹具有抑制預防動脈粥狀硬化發生的效果。

Abstract

名詞解釋 MWE→mulberry water extract HCD→High cholesterol diet Atherosclerosis→ 動脈粥狀硬化 Anthocyanin→ 花色素 ( 抗氧化物質 ) Foam cell→ 泡沫細胞 Intima→ 動脈血管內膜

低密度脂蛋白 (LDL) LDL 富含膽固醇，人體總血清中約有 65% 的膽固

醇由 LDL 攜帶傳送至周圍組織，因此 LDL 的吸收與膽固醇的代謝息息相關。若 LDL 無法有效的被細胞組織吸收，而在血液循環系統中存在過多的 LDL會增加罹患心血管循環系統疾病的風險。

低密度脂蛋白 80% 可由肝吸收，另 20% 則由周圍組織吸收，吸收方式是經由 LDL receptor 攝取，藉由 receptor-mediated 途徑與 nonspecific endocytosis 方式進入細胞及肝臟中。

Introduction

Atherosclerosis

病程的中期 macrophage 會與 intima 中 T cell 作用而產生成 cytokines

Materials and methods

Preparation of MWE 桑椹果實 (100g)+ 飲用水 (200cc) 果汁機

濾網過濾去渣

離心機離心去渣 (3000rpm,15mins)

-80c 冷凍； 12 小時

真空冷凍乾燥 Concentrations of anthocyanins in MWE >MWE contains about 2.5% anthocyanins

Animals and diets

Group1 rabbits were fed with standard chow. Group2 rabbits were fed with standard chow wi

th 1% MWE in the daily diet. Group3 rabbits were fed with HCD diet(containi

ng 3% lard oil and 1.3% cholesterol). Group4 treated with HCD plus 0.5% MWE. Group5 treated with HCD plus 1% MWE.

Growth and diet intake

No significant difference in body weights was observedduring the experimental period.

Result and Discussion

This may indicate a specific inhibitory effect of MWE on fatty acid synthesis, especially triglycerides.

Effect of MWE on serum lipid levels

Effect of MWE on plasma cholesterol levels in 10 week-period HCD-fed rabbits.

動物動脈組織切片之病理分析

The arrow( ) is shown for foam cell and ( ) for smooth muscle cell migration. Calcification core is shown as arrow ( ) in (c);

Pathological analysis

Calcification 是指 foam cell apoptosis 後，細胞所流出的膽固醇和脂質聚集而促使 Gruel 的形成。 Gruel唯一種糜粥狀的油脂聚合物，也是形成動脈粥狀硬化斑的主因。

動物動脈脂肪斑 (fatty streak)染色

脂肪的堆積情形

主動脈損害程度

MWE 餵食下肝、腎之生化毒性分析

此表顯示 MWE添加於飲食中並不會有生化毒性

Conclusion In this study, MWE was shown to decrease cholesterol and triglyceride and attenuate the development of atherosclerosis in HCD-fed rabbits. Additionally, MWE had no toxic effects on the liver or renal functions during the experimental period. Taken together, these data suggest a promising application of MWE in cardioprotection. MWE was shown to lower the serum cholesterol and triglycer

ide and repress progression of atherosclerosis in HCD-fed rabbit

s. This outcome might be attributed to the preventative effect of antho

cyanins against LDL-oxidation in the arterial wall and supports the use of MWE for lowering the incidence of atherosclerosisand coronary heart disease.