Wei Chen Chao, Ping Dai Qi, You Fan Tian, Qiang Chen Yong, Tao Che
Department of Orthopaedics and Traumatology, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of TCM, Shanghai 200071, China.
Mediators Inflamm. 2016;2016:9529630. doi: 10.1155/2016/9529630. Epub 2016 Apr 20.
Icariin (ICA) is an active compound extracted from Epimedium brevicornum Maxim. Previous reports have shown that icariin has a clinically significant therapeutic effect on rheumatoid arthritis. However, little is known about the mechanism by which icariin inhibits cartilage and bone degradation.
New Zealand rabbits were immunized with antigen-induced arthritis (AIA) and treated with icariin. Joint tissues from rabbits were studied by histological analysis, transmission electron microscopy (TEM), and micro-CT. The expression levels of receptor activator of nuclear factor-B ligand (RANKL) and osteoprotegerin (OPG) in joint tissues were determined using immunohistochemistry and real-time PCR analysis.
Histological analysis and TEM sections of cartilage in the ICA treated group showed a low level of chondrocyte destruction. Micro-CT analysis showed that the bone mineral density value and bone structural level in ICA treated rabbits were significantly higher compared with those in the AIA group. Immunohistochemistry and real-time PCR analysis showed that icariin treatment reduced RANKL expression and enhanced OPG expression levels, as compared to the AIA group.
These data indicate that ICA suppresses articular bone loss and prevents joint destruction. This study also determined that ICA regulated articular bone loss in part by regulating RANKL and OPG expression.
淫羊藿苷（ICA）是从短角淫羊藿中提取的一种活性化合物。先前的报道表明，淫羊藿苷对类风湿性关节炎具有临床上显著的治疗作用。然而，关于淫羊藿苷抑制软骨和骨降解的机制知之甚少。
用抗原诱导性关节炎（AIA）对新西兰兔进行免疫，并给予淫羊藿苷治疗。通过组织学分析、透射电子显微镜（TEM）和显微CT对兔的关节组织进行研究。使用免疫组织化学和实时PCR分析确定关节组织中核因子-κB受体活化因子配体（RANKL）和骨保护素（OPG）的表达水平。
ICA治疗组软骨的组织学分析和TEM切片显示软骨细胞破坏水平较低。显微CT分析表明，与AIA组相比，ICA治疗兔的骨密度值和骨结构水平显著更高。免疫组织化学和实时PCR分析表明，与AIA组相比，淫羊藿苷治疗降低了RANKL表达并提高了OPG表达水平。
这些数据表明ICA可抑制关节骨质流失并防止关节破坏。本研究还确定ICA部分通过调节RANKL和OPG表达来调节关节骨质流失。
