白桦脂醇的选择性雌激素受体调节作用实验研究

目的对白桦脂醇的选择性雌激素受体调节作用进行研究,探讨其植物雌激素活性。方法将40只性未成熟雌性小鼠采用随机数字表法分为空白组,雌激素组,白桦脂醇低、高剂量组4组,每组10只,分别给予生理盐水及17β-雌二醇(17β-E₂)、白桦脂醇混悬液灌胃7 d。灌胃结束后,通过酶联免疫吸附测定(ELISA)法检测小鼠血清雌二醇(E₂)、黄体生成素(LH)、卵泡刺激素(FSH)水平;剖取子宫称重,计算子宫增重率和子宫指数;通过Western bolt法检测小鼠子宫组织中雌激素受体(ER)α、ERβ和雌激素膜受体G蛋白偶联受体30(GPR30)蛋白的表达;通过细胞增殖实验观察白桦脂醇对人乳腺癌细胞(MCF-7)的促增殖作用;通过细胞增殖拮抗实验观察ER阻断剂ICI182 780、ERα阻断剂MPP、ERβ阻断剂THC、雌激素膜受体GPR30阻断剂G15等4种阻断剂对白桦脂醇促MCF-7细胞增殖作用的影响。结果白桦脂醇能明显升高性未成熟雌性小鼠的子宫增重率、子宫指数,血清E₂、FSH水平,以及子宫组织中ERα、GPR30蛋白的表达水平(...

Experimental study on selective estrogen receptor regulatory action of betulin

Objective To study on selective estrogen receptor regulatory action of betulin and to explore its phytoestrogen activity.Methods Forty immature female mice were divided into four groups according to random number table method,including blank group,estrogen group,betulin low and high dose group,with 10 mice in each.They were given normal saline,17β-estradiol(17β-E2)and betulin suspension by gavage for 7 days.After gavage,serum levels of estradiol(E2),luteinizing hormone(LH)and follicle stimulating hormone(FSH)were detected by ELISA method;the uterus was dissected and weighed,and the uterine weight gain rate and uterine index were calculated;the protein expressions of estrogen receptor(ER)α,ERβand estrogen membrane receptor G-protein-coupled receptor 30(GPR30)in mouse uterine tissues were detected by Western bolt method;the effect of betulin on promoting proliferation of Michigan Cancer Foundation-7(MCF-7)was observed by cell proliferation experiment;the effects of ER blocking agent ICI18780,ERαblocking agent MPP,ERβblocking agent THC and estrogen membrane receptor GPR30 blocking agent G15 on betulin promoting MCF-7 cells proliferation were observed by cell proliferation antagonism experiment.Results Betulin significantly increased the uterine weight gain rate,uterine index,serum levels of E2 and FSH,and the protein expression levels of ERαand GPR30 in uterine tissues of immature female mice(P<0.05 or P<0.01),and promoted the proliferation of MCF-7 cells(P<0.01),moreover,its promoting effect on the MCF-7 cells proliferation was antagonized by ICI182780,MPP and G15(P<0.01).Conclusion Betulin has estrogenic activity,which is mediated by ERαand GPR30.