苜蓿皂苷对SD大鼠胆固醇代谢的影响及其分子机理的初步探讨  

Effect of alfalfa saponins on cholesterol metabolism and its molecular mechanisms

作　　者：袁德地[1] 史莹华[1] 王成章[1] 郭瑞[1] 王洁[1] 

机构地区：[1]河南农业大学牧医工程学院,河南郑州450002

出　　处：《草业学报》2013年第5期294-301,共8页Acta Prataculturae Sinica

基　　金：国家科技支撑计划项目(2011BAD17B04);现代农业产业技术体系项目(CARS-35)资助

摘　　要：研究了苜蓿皂苷对SD大鼠胆固醇代谢的影响,并初步探讨其分子机理。取雄性健康SD大鼠32只,随机分为4组,分别为:正常对照组、苜蓿皂苷组、高脂模型组和高脂皂苷组,每组8只。前4周为高脂模型建立期,后4周为灌胃期,正常对照组和苜蓿皂苷组饲喂基础饲粮,其余2组饲喂高脂饲粮,苜蓿皂苷组和高脂皂苷组从第5周开始灌胃240mg/kg苜蓿皂苷,灌胃4周。测定试验大鼠体重、肝脏系数、血脂水平、粪便和肝脏中的胆固醇、胆汁酸含量,并用实时荧光定量PCR技术检测大鼠肝脏胆固醇7α-羟化酶(CYP7a1)和三磷酸腺苷结合盒转运体G5/三磷酸腺苷结合盒转运体G8(ABCG5/ABCG8)mRNA的表达量。结果表明,1)苜蓿皂苷显著降低高脂大鼠体重、肝脏系数;降低血清中总胆固醇含量,加速胆固醇向肝脏的聚集;增加粪便中胆固醇和胆汁酸的排出;2)显著增加正常血脂水平大鼠粪便中胆固醇的含量,但对其体重、肝脏系数等影响不大;3)添加苜蓿皂苷后正常和高脂水平SD大鼠肝脏CYP7a1和ABCG5/ABCG8mRNA的表达量均成倍增加。提示苜蓿皂苷能够调节SD大鼠体内胆固醇的分布,具有良好的降血脂效应,其效应可能与增加CYP7a1和ABCG5/ABCG8mRNA表达量,加速体内胆固醇、胆汁酸排泄有关。To investigate the effects of alfalfa saponins on cholesterol metabolism and its molecular mechanism, 32 healthy male Sprague Dawley （SD） rats were randomly divided into four groups： normal control group, alfalfa saponins group, hyperlipidemia model group, hyperlipidemia model＋alfalfa saponins group. The first four weeks were the hyperlipidemia model establishment period： rats in the normal control group and in the alfalfa saponin group were fed with a basal diet while the other two groups were fed with a high fat diet. The last four weeks were the alfalfa saponins treatment period, alfalfa saponins （240 mg/kg） were administrated to both the alfalfa saponin group and to the hyperlipidemia model＋alfalfa saponins group by garage. The body weight, liver index, serum lipid level, total cholesterol and total bile acids in liver and faeces of the rats were measured. The mRNA expression of CYP7al and ABCG5/ABCG8 were measured by real-time PCR. Alfalfa saponins significantly reduced the body weight, liver index and the serum cholesterol level but increased the ac- cumulation of cholesterol in liver and the excretion of cholesterol and bile acids in faeces in hyperlipidemia rats and significantly increased the cholesterol excretion in faeces of normal rats. The mRNA expression of CYP7al and ABCGS/ABCG8 were multiplied in the alfalfa saponins treated groups. The results indicated that alfalfa saponins could adjust the distribution of cholesterol in rats and had a significant effect on the decrease of serum lipid. This effect could result from the increasing mRNA expression of CYP7al and ABCG5/ABCG8 in liver.

关 键 词：苜蓿皂苷 胆固醇代谢 分子机理 胆固醇7Α-羟化酶 三磷酸腺苷结合盒转运体G5 三磷酸腺苷结合盒转运体G8 

分 类 号：S541.9[农业科学—作物学]