大豆苷元对去卵巢大鼠血脂及肝脏ERα和LDLR表达的影响

目的:探讨不同剂量大豆苷元对绝经后血脂的保护作用。方法:选用4月龄SD雌性大鼠66只,随机分为:假手术组(Sham)、去势组(OVX)、戊酸雌二醇组(E2)、大豆苷元高剂量(H-Dai,200mg/kg)组、中剂量(M-Dai,50mg/kg)组和低剂量(L-Dai,10mg/kg)组,每组11只。于去势术后4周开始分别给予相应的药物灌胃,3个月后处死大鼠,取血和肝脏,检测血清甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-c)、高密度脂蛋白胆固醇(HDL-c),以及肝脏ERα和LDLRmRNA的表达量。结果:与OVX组相比,大豆苷元可以降低血清LDL-c,且随着剂量的增加其作用更明显(P<0.01);大剂量可以降低血清TG(P<0.05)。大豆苷元还增加肝脏ERα和LDLRmRNA的表达量,且也有剂量依赖效应,低、中剂量组与高剂量组差异显著(P<0.01)。结论:大豆苷元对去势大鼠血脂有一定保护作用,其降低血清LDL-c的作用可能是通过ERα途径增加LDLR的表达而实现的。

Effects of different doses of daidzein on serum lipids and liver LDLR expression in ovariectomized rats

Objective: To explore the protective effect of daidzein with different dosage on serum lipids after menopause. Methods: Sixty-six Sprague-Dawley female rats aged 4 months were divided into six groups randomly (n=11). Four weeks later, Sham group and control OVX group were administreed with distilled water, whereas the other groups received valerate estriol (800 μg/kg) and different doses of daidzein (low dose, 10 mg/kg; medium dose, 50 mg/kg; high does, 200 mg/kg) by gavage for 3 months respectively. Serum TG, LDL-c, HDL-c and liver ERa, LDLR mRNA expression were measured after the sacrifice of the rats. Results: Compared with OVX group, daidzein could lower serum LDL-c(P<0.01), this effect in the high-dose group was more significant than that in the low-dose or medium-dose group, high-dose daidzein could lower serum TG (P<0.05). Daidzein increased ERa, LDLR mRNA expression in the liver, and the effect was more significant with the dose increased. Conclusion: Daidzein exerts some protective effects on serum lipids, the LDL-c-lowering effect may he attributed to the increase of LDLR expression, which may be realized through the ERα pathway.