决明子蒽醌在细胞内胆固醇合成中的作用(英文)

Effects of anthraquinones from Cassia obtusifolia L. on cholesterol biosynthesis in cells

背景:有关决明子降脂的有效化学成分及作用途径作者进行资料查询时尚未找到明确报道。目的:观察决明子蒽醌类化合物对实验性高脂血症大鼠血脂水平及细胞内源性总胆固醇合成的影响,推断决明子降脂的有效成分及作用途径。设计、时间及地点:随机对照动物实验,于2003-09/2004-05在华南师范大学生命科学学院完成动物饲养及实验,在生物技术研究所完成尾静脉取血、血脂测定、细胞培养及存活率测定。材料:选用SD雄性成年大鼠45只,均灌胃脂肪乳剂建立高脂血症动物模型。决明子购于广州药房,由华南植物研究所鉴定;蒽醌由华南师范大学生物技术研究所制备。方法:将45只SD雄性大鼠按随机数字表法分为3组(n=15):即对照组、决明子蒽醌80mg/kg组和决明子蒽醌20mg/kg组。造模2d后各组动物每天上午继续灌胃脂肪乳剂1次;下午按实验分组灌胃相应剂量的药物,对照组灌胃相同剂量的生理盐水,1次/d,连续20d。主要观察指标:应用两性霉素B细胞模型法检测决明子蒽醌在中国仓鼠卵细胞内源性胆固醇合成中的作用。应用酶终点法测定各组大鼠血清总胆固醇、三酰甘油、高密度脂蛋白胆固醇及低密度脂蛋白胆固醇水平;采用四甲基偶氮唑蓝法以分光光度测定中国仓鼠卵细胞的存活率(A570)。结果:①决明子蒽醌能明显降低高脂血症大鼠血清总胆固醇、三酰甘油及低密度脂蛋白胆固醇水平,提高高密度脂蛋白胆固醇水平,呈明显的量-效关系。②决明子蒽醌能提高中国仓鼠卵细胞的存活率。结论:决明子蒽醌具有降血脂作用,是决明子降脂的主要有效部位;抑制细胞内胆固醇的合成可能是决明子蒽醌降脂的作用途径之一。

BACKGROUND： The effective chemical constituents and the precise action mechanism of Cassia obtusifolia L. seed to rats with hypercholesterolemia are not clear. OBJECTIVE： To investigate effects of anthraquinones from Cassia obtusifolia L. on hypolipidemic activity and endogenous cholesterol biosynthesis in rats with experimental hyperlipoidemia, and to explore the effective compound and the mechanism of Cassia obtusifolia L. seed on hypolipidemic action. DESIGN, TIME AND SETTING： The randomized controlled animal experiment was performed from September 2003 to May 2004. All rats were raised and tested at the College of Life Sciences, South China Normal University. Blood sample was collected from the tail vein at the Institute of Biotechnology to detect blood lipid, survival rate, and to culture cells. MATERIALS： Forty-five male Sprague Dawley （SD） rats were used to establish animal models of hyperlipoidemia by intragastrically with fat emulsion. Cassia obtusifolia L. seed was purchased from Guangzhou Dispensary, China, and further identified by South China Plant Institute. Anthraquinones were extracted from Cassia obtusifolia L. by the Institute of Biotechnology of South China Normal University. METHODS： Forty-five male SD rats were randomly divided into three groups （n=15）： a control group, 80 mg/kg and 20 mg/kg anthraquinones groups. Rat models in each group were given fat emulsion in the morning and afternoon 2 days after model induction, once in morning. Rat modes were treated with corresponding doses of drugs in the two experimental groups. Rat models were administrated with the same volume of saline in the control group, once a day, for 20 days. MAIN OUTCOME MEASURES： Effect of anthraquinones on endogenous cholesterin in Chinese hamster oocytes was measured by amphotericin B cell models. The levels of serum total cholesterol, triglyceride, low-density lipoprotein-cholesterol （LDL-C） and high-density lipoprotein-cholesterol （HDL-C） were detected by enzyme endpoint method. Survival rate of Chinese hamster oocytes （A570） was tested by methyl thiazolyl tetrazolium （MTT） with spectrophotometric determination. RESULTS： Anthraquinones significantly reduced total cholesterol, triglyceride, LDL-C levels and increased HDL-C levels in hyperlipidemic rats in a dose-dependant pattern. Anthraquinones elevated the survival rate of Chinese hamster oocytes. CONCLUSION： Anthraquinones can decrease blood lipid levels. Inhibition of cholesterol synthesis of anthraquinones may be one of the underlying mechanism involved in decreasing blood lipid.