Activities of Antioxidant Enzymes and Lipid Metabolism in Rats Fed High Dose ofβ- Carotene, Canthaxanthin and Vitamin E in High Fat and Cholesterol Diets
英文摘要
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.
