The effects and mechanisms of soybean isoflavone on osteoblast (OB) proliferation in vitro were investigated. Fifty female Wistar rats were randomly divided into five groups with 10 rats in each group. Rat OBs were separated and cultured. The first generation of OBs cultured for 48 hr at various concentrations of isoflavone were set as the experimental groups, the OBs exposed to estradiol (E2 ) culture were considered as positive control group. The biological characterization of OBs was investigated by phase contrast microscopy and alkaline phosphatase (ALP) histochemistry. The concentrations of interleukin (IL-1), osteoprotegerin (OPG), transforming growth factor (TGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) in isoflavone culture solutions were determined. Proliferation rate of OBs was increased in experimental group comparing that in the blank group. ALP activity in experimental group was higher than that in blank group. No significant differences of ALP activity were observed between E2 culture group and isoflavone group at concentrations of 10-5 and 10-7 mM (P > 0.05). Furthermore, in the experimental groups at low isoflavone concentrations, the concentrations of OPG, TGF, and VEGF were increased and positively correlated with OB proliferation. However, the concentrations of IL-1, GM-CSF were decreased at higher concentration of isoflavone and were negatively correlated with OB proliferation. Soybean isoflavone could promote the growth and proliferation of rat OB, it might act as the stimulator of OPG, TGF, and VEGF pathway, and the inhibitor of IL-1, GM-CSF pathway as well.

中文翻译：

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大豆异黄酮对体外大鼠成骨细胞代谢及细胞因子的影响

研究了大豆异黄酮对体外成骨细胞（OB）增殖的影响和机制。50只雌性Wistar大鼠随机分为5组，每组10只。分离培养大鼠OB。以不同浓度异黄酮培养48小时的第一代OB为实验组，以雌二醇(E2)培养的OB为阳性对照组。通过相差显微镜和碱性磷酸酶 (ALP) 组织化学研究 OB 的生物学特性。测定了异黄酮培养液中白细胞介素 (IL-1)、骨保护素 (OPG)、转化生长因子 (TGF)、粒细胞-巨噬细胞集落刺激因子 (GM-CSF) 和血管内皮生长因子 (VEGF) 的浓度。实验组OBs增殖率较空白组增加。实验组ALP活性高于空白组。E2培养组与异黄酮组在10-5和10-7 mM浓度下ALP活性无显着差异（P > 0.05）。此外，在低异黄酮浓度的实验组中，OPG、TGF和VEGF的浓度增加并且与OB增殖呈正相关。然而，IL-1、GM-CSF 的浓度在异黄酮浓度较高时降低，并且与 OB 增殖呈负相关。大豆异黄酮可促进大鼠OB的生长和增殖，可能作为OPG、TGF、VEGF通路的刺激剂，以及IL-1、GM-CSF通路的抑制剂。