黑米和红米抗动脉硬化和抗氧化作用初步研究

THE ANTIATHEROSCLEROTIC AND ANTIOXIDATIVE EFFECTS OF BLACK AND RED RICE SUPPLEMENTATION IN RABBITS FED CHOLESTEROL RICH DIET

目的 : 研究黑米和红米抗动脉粥样硬化 ( AS)和抗氧化作用。方法 : 2 4只雄性新西兰兔随机分为三组 ,饲含胆固醇 5 g/kg,猪油 35 g/kg,米粉 (分别为白米 ,黑米及红米 ) 30 0 g/kg的混合饲料。 1 0 w后处死 ,测主动脉脂质斑块面积 ;肝匀浆活性氧 ( ROS) ;血清和肝总抗氧化能力 ( TAC) ;红细胞和肝超氧化物歧化酶 ( SOD)活性 ;全血和肝谷胱甘肽过氧化物酶 ( GSH- Px)活性 ;血清和肝丙二醛 ( MDA)、一氧化氮 ( NO)含量及一氧化氮合成酶 ( NOS)活性。结果 : 与白米组相比较 ,黑、红米二组的主动脉脂质斑块面积和肝 ROS显著降低 ( P<0 .0 5 ) ;而血清和肝 TAC均显著增高 ( P<0 .0 5 ) ;红细胞 SOD活性也显著增高 ( P<0 .0 5 )。但三组间肝 SOD活性没有显著性差异 ( P<0 .0 5 ) ,而且血和肝 GSH- Px、NOS活性以及 MDA、NO含量的差异也不显著 ( P>0 .0 5 )。结论 : 黑、红米可降低高脂高胆固醇饲实验兔的主动脉脂质斑块面积 ,其抗 AS作用机制可能是通过降低体内 ROS水平 ,提高机体抗氧化能力 。

Objective: to observe the antiatherosclerotic effects of black and red rice and to find out their effective mechanism against atherosclerosis in rabbits. Methods: A total of 24 New Zealand white male rabbits were randomized into three groups(white rice, black rice and red rice groups).The rabbits were fed cholesterol rich diet(cholesterol content 5g/kg;lard 35g/kg)containing 300g/kg white, black and red rice powders respectively. After 10 weeks, the rabbits were killed. The aorta was dissected and the plaque area and total area of the intimal surface of aorta were measured by automatic image analyzer. Reactive oxygen species(ROS) in the liver were measured by fluorescence spectrophotometer method. Total antioxidative capacity(TAC), level of malonyldialdehyde(MDA), concentration of nitric oxide(NO) and activities of nitric oxide synthase(NOS) in serum and liver were measured. The activities of superoxide dismutase(SOD) in red blood cells and liver were determined. In addition, activities of glutathione peroxidase(GSH Px) in the whole blood and liver were measured. Results: The plaque area (% of total surface) and the level of liver ROS were significantly lower in the red and black rice groups than in the white rice group(P<0.05).Serum and liver TAC and the activity of SOD in red blood cells were significantly higher in the red and black rice groups than in the white rice group. We found no significant differences among the three groups in the activity of SOD in liver, activities of GSH Px in blood and liver, contents of MDA in serum and liver, levels of NO and activities of NOS in serum and liver. Conclusion: The black and red rice supplementation can reduce atherosclerotic plaque on the aorta of rabbits fed cholesterol rich diet. The mechanism might be due to decreased levels of ROS and increased antioxidative capacity.