大豆异黄酮对先兆流产模型大鼠的保胎作用及机制研究

Study on the protective effect and mechanism of soybean isoflavones against threatened miscarriage model rats

目的 研究大豆异黄酮对先兆流产大鼠的保胎作用及可能机制。方法 取雌鼠促情,与雄鼠交配、妊娠后随机分为正常组(纯化水灌胃,n=10)、模型组(纯化水灌胃,n=9)、阳性对照药组(黄体酮4 mg/kg,肌内注射,n=9)和大豆异黄酮低、中、高剂量组(25、50、100 mg/kg灌胃,n=10)。除正常组外,其余各组大鼠均于孕8 d以米非司酮+米索前列醇灌胃建立先兆流产模型。各组大鼠分别于孕1~7 d、孕9~12 d给药/纯化水,每天1次。孕14 d时,计算各组大鼠的保胎率,检测大鼠血清中β-人绒毛膜促性腺激素(β-HCG)、孕酮(P)水平,观察大鼠胎盘与蜕膜组织病理形态学变化并检测其细胞凋亡指数,检测胎盘组织中凋亡相关因子(Fas)、凋亡相关因子配体(FasL)、增殖细胞核抗原(PCNA)和肝素结合表皮生长因子(HB-EGF) mRNA及其蛋白表达,检测蜕膜组织中Fas、PCNA和HB-EGF mRNA及其蛋白表达。结果 模型组大鼠胎盘组织充血扩张明显,血管较少且形态不规则,可见大量严重基质水肿、炎症细胞浸润和铁胆黄素沉积。与模型组比较,大豆异黄酮各剂量组大鼠的保胎率,血清β-HCG、P水平,胎盘与蜕膜组织中PCNA、HB-EGF mRNA及其蛋白表达水平均显著升高(P<0.05),病理学变化显著改善;胎盘与蜕膜组织细胞凋亡指数,胎盘组织中Fas、FasL mRNA及其蛋白表达水平,蜕膜组织中Fas mRNA及其蛋白表达水平均显著降低(P<0.05),且大豆异黄酮的上述作用呈剂量依赖性(P<0.05)。结论 大豆异黄酮对先兆流产模型大鼠有保胎作用;其作用机制可能与下调母-胎界面Fas、FasL mRNA及其蛋白表达,上调PCNA、HB-EGF mRNA及其蛋白表达有关。

OBJECTIVE To study the protective effect and possible mechanism of soybean isoflavones against threatened miscarriage rats.METHODS Female mice were selected to promote estrus and mate with male mice.After pregnancy,they were randomly divided into normal group(purified water,i.g.,n=10),model group(purified water,i.g.,n=9),positive control drug group(progesterone 4 mg/kg,i.m.,n=9),low-,medium-and high-dose soybean isoflavone groups(25,50 and 100 mg/kg,i.g.,n=10).Except for the normal group,the rest were given mifepristone+misoprostol on the 8th day of pregnancy to establish threatened miscarriage model,and then given purified water or drugs,once a day,on days 1-7 and 9-12 of pregnancy,respectively.At 14 days of pregnancy,the rates of fetal protection were counted.Serum levels of β-human chorionic gonadotrophin(β-HCG) and progesterone(P) in rats were detected.Pathological and morphological changes in rat placenta and decidua tissues were observed,and the apoptosis indexes of cells were detected;mRNA and protein expressions of factor of apoptosis related(Fas),factor of apoptosis related ligand(FasL),proliferating cell nuclear antigen(PCNA) and heparin binding epidermal growth factor(HB-EGF) were determined in placenta tissues,and mRNA and protein expressions of Fas,PCNA and HB-EGF in decidua tissues were detected.RESULTS In the model group,the placental tissues of rats were hyperemia and dilatation,with fewer and irregular blood vessels;severe stromal edema,inflammatory cell infiltration and iron-choledrin deposition were observed.Compared with model group,the fetal survival rates,serum levels of β-HCG and P,the expressions of PCNA and HB-EGF m RNA and proteins in the placenta and decidua tissue of soybean isoflavone groups increased significantly(P<0.05),while pathological changes were improved significantly;cell apoptosis index in the placenta and decidua tissue,the expressions of Fas,Fas L m RNA and proteins in the placenta and Fas m RNA and protein in the decidua tissue decreased significantly(P<0.05).The effect of soybean isoflavones was dose-dependent(P<0.05).CONCLUSIONS Soybean isoflavone has protective effect on threatened miscarriage,the mechanism of which is related to down-regulating the expressions of Fas and Fas L m RNA and protein at the maternal-fetal interface,and up-regulating the expressions of m RNA and protein of PCNA and HBEGF.