Enhancement of fibrinolytic activity of bovine aortic endothelial cells by ginsenoside Rb_2  

人参皂苷Rb_2促进牛主动脉内皮细胞纤溶活性

作　　者：刘建文[1] 魏东芝[1] 杜长斌 钟建江[1] 

机构地区：[1]华东理工大学生物化学研究所生物反应器国家重点实验室

出　　处：《Acta Pharmacologica Sinica》2003年第2期102-108,共7页中国药理学报（英文版）

基　　金：Shanghai Key Discipline

摘　　要：AIM: The effect of ginsenoside Rb_2 purified from Panax ginseng on fibrinolytic activity of bovine aortic endothelial cells (BAEC) was investigated. METHODS: Cellular plasminogen activator (PA) level of the lysates was measured by the chromogenic substrate S-2403. Fibrin underlay technique was carried out to observe fibrinolysis by growing endothelial cells in the culture medium. Cell viability was then determined by measurement of the activity of mitochondrial dehydrogenase. The ability of Rb_2 of potentiating cellular PA activity was investigated by measuring the amounts of PA and PA inhibitor-1 (PAI-1) in the culture medium using zymography and reverse zymography. Changes in the expression of urokinase-type PA (uPA), uPA receptor, and PAI-1 mRNA in BAEC after treatment with Rb_2 were analyzed by Northern blot. RESULTS: Rb_2 enhanced cellular PA activity in a concentration-and timedependent manner. Treatment of BAEC with Rb_2 10 mg/L for 9 h resulted in a 3.5-fold increase of PA activity without a marked cytotoxic effect, as shown by LDH levels in culture. Increased PA levels caused the increase in surface plasmin levels as observed by fibrin underlay technique. Rb_2 greatly or moderately increased the amount of urokinase-type PA (uPA) or its inhibitor (PAI-1), present in the culture medium, whereas saponin did not influence mRNA levels of uPA, its surface receptor, and PAI-1, suggesting that Rb2 may stimulate the secretion of uPA without enhancing its gene expression. The enhancement of PA levels by retinoic acid alone, a stimulator of PA synthesis, was potentiated by the simultaneous addition of ginsenoside Rb_2 1 mg/L. Therefore, Rb_2 might exert a strong synergism in the synthesis of cellular PA in BAEC. CONCLUSION: Ginsenoside Rb_2 enhanced the PA activity levels in BAEC as well as the surface plasmin activity of BAEC. Rb_2 may stimulate the secretion of uPA without enhancing the gene expression of uPA, uPA receptor (uPAR), and PAI-1.目的:研究分离纯化的人参皂苷Rb_2对牛主动脉内皮细胞(BAEC)纤维蛋白溶酶活性的作用。方法:使用底物发光试剂S-2403测定细胞内PA的溶解产物。血管内皮细胞表面纤溶酶活性的测定采用BAEC纤维蛋白的载体技术。用酶谱分析和还原酶谱分析法通过培养液来分析细胞产生的纤溶酶原激活物(PA)和纤溶酶原激活物抑制剂(PAI-1)。用Northernblot分析uPA,uPA receptor和PAI-1的mRNA表达。结果:Rb_2对于血管内皮细胞产生的PA活性的促进作用表现出剂量、时间依赖性。Rb_2 10mg/L对内皮细胞处理9小时后,血管内皮细胞的PA活性提高了2.5倍。培养液中LDH检测表明Rb_2未表现出明显细胞毒性。纤维蛋白测定表明,PA水平的增加进而提高了纤维蛋白溶酶的水平。Rb_2能够显著增加培养液中尿激酶型PA(uPA)和其拮抗物(PAI-1)的水平,但Rb_2对于uPA,其表面受体(uPAR)和PAI-1的mRNA水平无影响,同时添加Rb_2 1mg/L能够显著增强维甲酸(RA 0.001-1μmol/L)对PA合成的刺激作用。结论:Rb_2能增加血管内皮细胞表面纤溶酶的活性,是通过促进血管内皮细胞纤溶活性因子的分泌而不是通过增强其基因表达起作用的。

关 键 词：vascular endothelium Panax ginseng SAPONINS plasminogen activators FIBRINOLYSIS TRETINOIN 

分 类 号：R285[医药卫生—中药学]