目的 观察淫羊藿水提取物对SD大鼠骨髓间充质干细胞（MSCs）骨向分化能力及转化生长因子β₁（TGF-β₁）、骨形态发生蛋白2（BMP-2）表达的影响，阐释其防治骨质疏松症的作用机制。方法 全骨髓贴壁法分离、纯化大鼠MSCs；以碱性磷酸酶（ALP）活性及ALP染色阳性率确定淫羊藿水提取物促MSCs骨向分化的最佳质量浓度，并以该质量浓度进行MSCs骨向分化实验。按是否添加经典成骨诱导液将大鼠分为对照组、成骨诱导剂组、淫羊藿水提取物（500 μg/mL）组、淫羊藿水提取物（500 μg/mL）＋成骨诱导剂组，每3～4 d各组更换含相应物质培养液1次，连续干预14 d。通过检测各组ALP、I型胶原（Col I）、骨钙素（BGP）和钙化结节等骨向分化指标的变化，以评价淫羊藿水提取物对MSCs骨向分化能力的影响；通过检测TGF-β₁、BMP-2的表达，研究淫羊藿水提取物促MSCs骨向分化的作用机制。结果 淫羊藿水提取物最佳促MSCs骨向分化的质量浓度为500 μg/mL；成骨诱导剂组、淫羊藿水提取物组及淫羊藿水提取物＋成骨诱导剂组均能促进MSCs骨向分化及上调TGF-β₁和BMP-2的表达。结论 淫羊藿促进MSCs骨向分化，上调TGF-β₁、BMP-2的表达可能是其作用机制之一。

Objective To investigate the effects of epimedium water extract (EWE) on the ability of osteogenic differentiation and the expression of TGF-β₁ and BMP-2 in inducing mesenchymal stem cells (MSCs) differenting into osteoblast and to further explain its mechanism. Methods MSCs were isolated and purified by differential time adherent method; the most effective concentration of EWE on the osteogenic differentiation of MSCs was confirmed by the activity of alkaline phosphatase (ALP) and positive rates of ALP staining; according to the differently induced condition, MSCs were divided into four groups: control, classic (induced by the classic osteoblast-induced system), EWE (induced by the most effective concentration of EWE on the osteogenic differentiation), and EWE + classic (induced by the combination of classic osteoblast-induced system and the most effective concentration of EWE on osteogenic differentiation) groups. ALP, type I collagen (Col I), bone gla protein (BGP), and calcium nodes in each group were detected and compared to indicate the osteogenic differentiation of each group. TGF-β₁ and BMP-2 in each group were detected by ELISA. Results The most effective concentration of the EWE on the osteogenic differentiation of MSCs was 500 μg/mL. The classic, EWE, and EWE + classic groups could promote the osteogenic differentiation of MSCs and increase the expression of TGF-β₁ and BMP-2. Conclusion The EWE could promote the osteogenic differentiation of MSCs. The increase of the expression of TGF-β₁ and BMP-2 in the induced groups of EWE may be the mechanism of improving the differentiation of MSCs into osteoblast.

国家自然科学基金资助项目（81173619）；广东省教育厅育苗工程项目（LYM10025）；广东省自然科学基金博士启动（S2012040007531）