Department of Spine Surgery, Changzhou TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Changzhou, 213000, People's Republic of China.
Department of Orthopedics, Yunnan Province Hospital of Traditional Chinese Medicine, Kunming, 650000, People's Republic of China.
Mol Med. 2024 Aug 16;30(1):125. doi: 10.1186/s10020-024-00893-w.
Epimedin A (EA) has been shown to suppress extensive osteoclastogenesis and bone resorption, but the effects of EA remain incompletely understood. The aim of our study was to investigate the effects of EA on osteoclastogenesis and bone resorption to explore the corresponding signalling pathways.
Rats were randomly assigned to the sham operation or ovariectomy group, and alendronate was used for the positive control group. The therapeutic effect of EA on osteoporosis was systematically analysed by measuring bone mineral density and bone biomechanical properties. In vitro, RAW264.7 cells were treated with receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) to induce osteoclast differentiation. Cell viability assays, tartrate-resistant acid phosphatase (TRAP) staining, and immunofluorescence were used to elucidate the effects of EA on osteoclastogenesis. In addition, the expression of bone differentiation-related proteins or genes was evaluated using Western blot analysis or quantitative polymerase chain reaction (PCR), respectively.
After 3 months of oral EA intervention, ovariectomized rats exhibited increased bone density, relative bone volume, trabecular thickness, and trabecular number, as well as reduced trabecular separation. EA dose-dependently normalized bone density and trabecular microarchitecture in the ovariectomized rats. Additionally, EA inhibited the expression of TRAP and NFATc1 in the ovariectomized rats. Moreover, the in vitro results indicated that EA inhibits osteoclast differentiation by suppressing the TRAF6/PI3K/AKT/NF-κB pathway. Further studies revealed that the effect on osteoclast differentiation, which was originally inhibited by EA, was reversed when the TRAF6 gene was overexpressed.
The findings indicated that EA can negatively regulate osteoclastogenesis by inhibiting the TRAF6/PI3K/AKT/NF-κB axis and that ameliorating ovariectomy-induced osteoporosis in rats with EA may be a promising potential therapeutic strategy for the treatment of osteoporosis.
已证实淫羊藿素（EA）可抑制破骨细胞的广泛生成和骨吸收，但 EA 的作用仍不完全清楚。本研究旨在探讨 EA 对破骨细胞生成和骨吸收的影响，以探索相应的信号通路。
将大鼠随机分为假手术或卵巢切除组，并使用阿仑膦酸钠作为阳性对照组。通过测量骨矿物质密度和骨生物力学特性，系统分析 EA 治疗骨质疏松症的疗效。在体外，用核因子κB 受体激活剂配体（RANKL）和巨噬细胞集落刺激因子（M-CSF）处理 RAW264.7 细胞诱导破骨细胞分化。细胞活力测定、抗酒石酸酸性磷酸酶（TRAP）染色和免疫荧光法用于阐明 EA 对破骨细胞生成的影响。此外，分别通过 Western blot 分析和定量聚合酶链反应（PCR）评估骨分化相关蛋白或基因的表达。
经过 3 个月的 EA 口服干预，卵巢切除大鼠的骨密度、相对骨量、小梁厚度和数量增加，小梁分离减少。EA 呈剂量依赖性使卵巢切除大鼠的骨密度和小梁微结构正常化。此外，EA 抑制了卵巢切除大鼠中 TRAP 和 NFATc1 的表达。此外，体外结果表明，EA 通过抑制 TRAF6/PI3K/AKT/NF-κB 通路抑制破骨细胞分化。进一步的研究表明，最初被 EA 抑制的破骨细胞分化作用，在 TRAF6 基因过表达时被逆转。
这些发现表明，EA 可通过抑制 TRAF6/PI3K/AKT/NF-κB 轴负调控破骨细胞生成，EA 改善卵巢切除大鼠的骨质疏松症可能是治疗骨质疏松症的一种有前途的潜在治疗策略。
