| 摘要: | 心血管疾病和癌症一直是西方國家常見疾病，且其具有高死亡率，癌症、腦血管
疾病和心血管疾病同時也是我國十大死因之第一、第二及第四位。而流行病學調
查發現新鮮蔬菜水果的攝取量和心血管疾病及癌症的發生率呈負相關，血中抗氧
化劑濃度低時，罹患心血管疾病的危險性增加，低密度脂蛋白過氧化情形也較嚴
重。類胡蘿蔔素和維生素E在蔬菜水果中含量很高，本研究主要以β-胡蘿蔔素、
乳化型β-胡蘿蔔素、乳化型canthaxanthin和維生素E當材料，進行研究。
本研究目的係在探討高油脂及高膽固醇的餵食條件下，高劑量β-胡蘿蔔素、
canthaxanthin和維生素E對大白鼠體內脂質代謝及抗氧化狀況的影響。實驗一 ：
將72隻Wistar品系大白鼠 ( 體重約252 g ) 隨機分成6組，採用AIN－76標準飼
料配方，每組飼料中油脂含量均為15﹪，各組分別餵予不添加膽固醇和膽酸；添
加1﹪膽固醇和0.1﹪膽酸；添加1﹪膽固醇和0.1﹪膽酸再分別添加0.2﹪β-胡蘿
蔔素、乳化型β-胡蘿蔔素、乳化型canthaxanthin和維生素E。實驗進行六週後，
分析血漿和肝臟中β-胡蘿蔔素、視網醇、canthaxanthin及維生素E濃度，分析紅
血球及肝臟中抗氧化酵素包括catalase、superoxide dismutase ( SOD )、
glutathione peroxidase ( GSH Px ) ，及glutathione reductase ( GSH Rd )、
glucose-6-phosphate dehydrogenase ( G-6-PDH )的活性，並分析血漿及肝臟中
過氧化指標產物malondialdehyde ( MDA ) ，及肝臟中conjugated diene含量。
實驗二 ： 將84隻Wistar品系雄性大白鼠 ( 體重約250 g ) 隨機分成6組，實驗
設計如同實驗一，實驗進行六週後，作肝組織切片、血漿及肝臟中總膽固醇 ( TC )
及三酸甘油酯 ( TG ) 濃度，並利用超高速離心法將血漿中極低密度脂蛋白
( VLDL ) 、低密度脂蛋白 ( LDL ) 、高密度脂蛋白 ( HDL )分離，分別分析其膽
固醇及三酸甘油酯濃度，此外並分析糞便中總中性固醇及總膽酸含量。
實驗一之結果顯示：血漿中β-胡蘿蔔素含量在給予乳化型β-胡蘿蔔素組較高，
顯示乳化型β-胡蘿蔔素的吸收率較β-胡蘿蔔素高。在視網醇方面，血漿視網醇並
不隨著β-胡蘿蔔素的補充而一直上升，肝臟視網醇濃度均為給予β-胡蘿蔔素組高
於未給予β-胡蘿蔔素組，而膽固醇的給予，會使視網醇下降。SOD及GSH Px的活性
均會因為膽固醇的給予而降低，但所添加的抗氧化劑β-胡蘿蔔素、canthaxanthin
和維生素E均能明顯提升其活性。在thiobarbituric acid ( TBA )實驗中，膽固醇
的添加會提升血清及肝臟中MDA量，及肝臟中conjugated diene量，血清中MDA含量
以維生素E組較低，肝臟中則因為抗氧化劑的補充，都能顯著的降低，維生素E也能
明顯的降低肝臟中conjugated diene。
在實驗二的肝臟組織切片中，膽固醇的給予造成輕微的發炎現象，而β-胡蘿蔔素的
給予對於細胞有較好的影響，canthaxanthin和維生素E的給予則使脂肪肝現象更為
嚴重。給予膽固醇後，會明顯提升血清中之總膽固醇濃度，降低了HDL膽固醇，
canthaxanthin和維生素E對膽固醇沒有影響，β-胡蘿蔔素則能顯著的降低血清中膽
固醇及LDL膽固醇，canthaxanthin和維生素E均會提升肝臟中總膽固醇含量。β-胡
蘿蔔素會提升血清三酸甘油酯，維生素E則可明顯降低血清中三酸甘油酯，
canthaxanthin和維生素E均會提升肝臟中總三酸甘油酯含量，其中以維生素E之影響
最明顯。而β-胡蘿蔔素可以增加糞便中性固醇和總膽酸。
總結: β-胡蘿蔔素、canthaxanthin和維生素E都可以降低因添加膽固醇所提升的
氧化壓力，以及能夠提升紅血球中GSH Px及肝臟中SOD的活性。β-胡蘿蔔素降低血漿
中總膽固醇及低密度脂蛋白膽固醇濃度，並且能夠增加糞便中固醇及總膽酸。
The purpose of this study was to investigate the effect of high
dose β-carotene, canthaxanthin vitamin E on the activities of
antioxidant enzymes and lipid metabolism in rats fed high fat and
cholesterol diet. Experiment I: Seventy-two male Wistar rats ( weight
about 252 g each ) were randomly divided into six group : two control
groups with or without adding 1 % cholesterol and 0.1 % cholic acid ,
the other groups fed 0.2 % β-carotene, beadlet β-carotene,
canthaxanthin or vitamin E with 1 % cholesterol and 0.1 % cholic acid,
all groups contained 15 % soybean oil. The rats of each group were
sacrificed at the end of six-week feeding period, then the artery blood,
liver and feces were collected. The levels of β-carotene, canthaxanthin,
retinol andα-tocopherol were analyzed by HPLC. Analytical items included
the activities of catalase, superoxide dismutase ( SOD ), glutathione
peroxidase ( GSH Px ), glutathione reductase ( GSH Rd ), Glucose-6-
phosphate dehydrogenase ( G-6-PD ), plasma and liver total cholesterol
( TC ), triglyceride ( TG ), thiobarbituric acid reactive substance
( TBARS ) test and liver conjugated diene. Experiment II: Eighty-four
male Wistar rats ( weight about 250 g each ) were randomly divided into
six groups. Experimental design was the same as experiment I. Analytical
items included pathological histology of liver tissue, plasma and liver
total cholesterol ( TC ) and triglyceride ( TG ), plasma cholesterol and
triglyceride level of very low density lipoprotein ( VLDL ), low density
lipoprotein ( LDL ), high density lipoprotein ( HDL ), feces neutral
steroids and total bile acids.
In experiment I, the result showed that plasma β-carotene
concentrations were higher in rats fed beadlet β-carotene, indicating
that beadlet β-carotene had higher absorption than normal β-carotene.
Rats fed cholesterol resulted in low plasma and liver retinol had lower
concentrations, whereas β-carotene feeding resulted in higher plasma and
liver retinol concentrations than the other groups fed cholesterol diets.
The activities of SOD and GSH Px were decreased by feeding cholesterol
diet,while β-carotene, canthaxanthin and vitamin E could increase those
enzyme activities ( P<0.05 ). The cholesterol diets would increase liver
TBARS, conjugated diene, plasma TBARS, and these items were decreased by
feeding antioxidants. Experiment II : Rats fed cholesterol diets groups
were induced series fatty liver, and rats fed β-carotene diets were
better cross to normal. Rats had cholesterol-feeding group had higher
plasma total cholesterol and LDL-C concentrations. Fed β-carotene diets
result in plasma total cholesterol and LDL-C decreased significantly
( P<0.05 ). Canthaxanthin and vitamin E fed groups had higher triglyceride
in liver. The feces neutral steroids and bile acids were increased in rats
fed β-carotene.
In conclusion, β-carotene, Canthaxanthin and vitamin E could decrease
the oxidative stress from dietary cholesterol. The activities of SOD and
GSH Px were decreased in rats fed cholesterol diet and β-carotene,
canthaxanthin and vitamin E could increase those activities. β-carotene-
fed decreased plasma total cholesterol and LDL-C. And β-carotene increased
the feces neutral steroids and total bile acids. |
