骨质疏松属代谢性骨病，促进骨形成是其治疗的最佳途径之一。目前促进骨形成活性评价常用的大鼠等体内模型存在实验周期长、样品用量大、检测成本高等问题，成骨/破骨细胞等体外模型无法体现样品的在体综合效应。而斑马鱼模型具有样品用量少、高效、灵敏、可视等优点。牛膝属于传统的补肾壮骨类中药，我们前期从牛膝中垂钓出促进骨形成的有效部位及果聚糖，并初步验证斑马鱼可用于其活性筛选。本项目将首次以斑马鱼在体荧光成像模型为切入点，快速评价果聚糖促进骨形成的活性；并在此活性指导下继续分离果聚糖，利用一系列化学反应结合多种谱学方法明确其结构；进而根据果聚糖对斑马鱼、大鼠、成骨细胞、Wnt通路的作用结果，从动物-细胞-分子水平全面阐释牛膝促进骨形成的机理。本项目将揭示牛膝促进骨形成的物质基础及作用机制；为抗骨质疏松中药的药效评价和机制研究提供在体化、微板化、可视化、高通量的模型；为拓展糖聚合物的药用新领域提供科学依据。

Osteoporosis (OP) is a metabolic bone disease, and one of the most effective treatments for OP is increasing bone formation. In addition to the long experiment cycle and high cost, the ovariectomized (OVX) rat model also requires a large amount of samples. Besides, cell-based assays were not able to reflect the overall effects of animal studies. In contrast, zebrafish models as a whole-organism has numerous qualities that are well-suited to study bone formation in OP: a small amount of samples, high efficiency, high sensitivity, and accessibility for visual observation. Although Achyranthes bidentata Blume has been used effectively in the treatment of OP, its active constituents and possible mechanisms of action remain unclear. We previously isolated active fractions and fructan that stimulate bone formation in OVX rats from A.bidentata, and found that zebrafish models can be used in high-throughput screening of anti-osteoporosis drugs. By using in vivo fluorescent imaging of zebrafish, the present study will evaluate the effects of fructan on bone formation and isolate new fructan by bioassay guided isolation. The chemical structure of newly isolated fructan will be identified by a series of chemical reactions and spectrums. The mechanism of fructan from A.bidentata in promoting bone formation will be explored by using zabrafish, rats and osteoblasts focusing on Wnt signaling pathway. This project aims to reveal the active constituents of A.bidentata and possible mechanisms of action on bone formation, and evaluate the possibility of using a high-throughout microplate-based in vivo model (zebrafish) monitored by fluorescent imaging for study on the efficacy and mechanism of actions of traditional Chinese medicines for treating OP, and provide the pharmacological basis for the medicinal use of fructan in treating OP.