Combined estrogenic effect of soybean food containing phytoestrogens and endocrine disruptor

异黄酮，如染料木黄酮和大豆黄酮，是植物雌激素存在于大豆食品中，并具有雌激素活性。在这项研究中，我们研究了含有人类摄入剂量水平的大豆酮（10 mg/kg/天）的大豆提取物（Nijiru）作为大豆食品和内分泌干扰物的联合雌激素效应。Nijiru粉末含有大豆苷、黄豆苷、染料木苷、大豆苷元、黄豆黄素和染料木黄素。Nijiru（1900-6600 mg/kg，相当于总剂量10 mg/kg）通过经口管饲法连续11天给予切除卵巢的ICR小鼠。然后将合成的内分泌活性激素己烯雌酚（DES）（0.05 mg/kg）与Nijiru共同经口给药，并再持续3天。Nijiru+DES治疗的相对子宫重量（占体重的%）略高于DES单独治疗。类似地，将合成内分泌活性化合物双酚A（BPA）（300 mg/kg）或杀虫剂甲氧滴滴涕（MX）（50 mg/kg）与Nijiru口服共同施用，并继续另外3天。虽然Nijiru+MX处理增加了相对子宫重量（与单独的MX相比），但Nijiru+BPA处理没有增加相对子宫重量（与单独的BPA相比）。

Isoflavones, such as genistein and daidzein, are phytoestrogens present in soybean foods and have estrogenic activity. In this study, we examined the combined estrogenic effect of soybean extract (Nijiru) containing human intake dose level of isoflavones (10 mg/kg/day) as soybean food and endocrine disruptor.Soybeans were boiled for 40 min at 120"C in water, and Nijiru was produced and was then freeze-dried to make a powder. Nijiru powder contained daidzin, glycitin, genistin, daidzein, glycitein, and genistein. Nijiru (1900-6600 mg/kg corresponding to dose of total isoflavone 10 mg/kg) was administered to ovariectomized ICR mice by oral gavage for 11 consecutive days. The synthetic endocrine-active hormone diethylstilbestrol (DES) (0.05 mg/kg) was then co-administered orally with Nijiru and continued for another 3 days. The relative uterine weight (% of body weight) of Nijiru+DES treatment was slightly higher than that of DES alone. Similarly, synthetic endocrine-active compound bisphenol A (BPA) (300 mg/kg) or pesticide methoxychlor (MX) (50 mg/kg) were co-administered orally with Nijiru and continued for another 3 days. Although Nijiru+MX treatment increased (vs. MX alone) the relative uterine weight, Nijiru+BPA treatment did not increase (vs. BPA alone) the relative uterine weight.