为了减轻骨质流失，目前大多数药物都针对破骨细胞。 Saikosaponin A (Ssa) 是一种从柴胡 (Bupleurum falcatum) 中提取的三萜皂苷，具有免疫调节、神经调节、抗病毒、抗癌、抗惊厥、抗炎和抗增殖作用。最近，骨稳态的调节被证明涉及铁死亡。在此，我们的目的是确定Ssa对破骨细胞生成和分化的抑制作用、是否涉及铁死亡及其潜在机制。进行抗酒石酸酸性磷酸酶 (TRAP) 染色、F-肌动蛋白染色和凹坑形成测定，以证实 Ssa 介导的体外 RANKL 诱导的破骨细胞生成抑制。通过铁定量、FerroOrange 染色、二氯二氢荧光素二乙酸酯、MitoSOX、丙二醛、谷胱甘肽和硼二吡咯亚甲基 581/591 C11 测定来测量，Ssa 可以通过促进脂质过氧化来促进破骨细胞铁死亡并增加线粒体损伤。通路分析显示Ssa可通过抑制Nrf2/SCL7A11/GPX4轴促进破骨细胞铁死亡。值得注意的是，我们发现铁死亡抑制剂ferrostatin-1和Nrf2激活剂叔丁基氢醌逆转了Ssa对RANKL诱导的破骨细胞生成的抑制作用。在体内，微型计算机断层扫描、苏木精和伊红染色、TRAP染色、酶联免疫吸附测定和免疫荧光证实，在脂多糖诱导的牙周炎大鼠中，Ssa治疗可剂量依赖性地减少牙槽骨吸收。结果表明 Ssa 是一种很有前景的治疗溶骨性疾病的药物。版权所有 © 2024 Li、Liu、Feng、Bai、Wang、Zhang 和 Wang。

To alleviate bone loss, most current drugs target osteoclasts. Saikosaponin A (Ssa), a triterpene saponin derived from Bupleurum falcatum (also known as Radix bupleuri), has immunoregulatory, neuromodulatory, antiviral, anticancer, anti-convulsant, anti-inflammatory, and anti-proliferative effects. Recently, modulation of bone homeostasis was shown to involve ferroptosis. Herein, we aimed to determine Ssa's inhibitory effects on osteoclastogenesis and differentiation, whether ferroptosis is involved, and the underlying mechanisms. Tartrate-resistant acid phosphatase (TRAP) staining, F-actin staining, and pit formation assays were conducted to confirm Ssa-mediated inhibition of RANKL-induced osteoclastogenesis in vitro. Ssa could promote osteoclast ferroptosis and increase mitochondrial damage by promoting lipid peroxidation, as measured by iron quantification, FerroOrange staining, Dichloro-dihydro-fluorescein diacetate, MitoSOX, malondialdehyde, glutathione, and boron-dipyrromethene 581/591 C11 assays. Pathway analysis showed that Ssa can promote osteoclasts ferroptosis by inhibiting the Nrf2/SCL7A11/GPX4 axis. Notably, we found that the ferroptosis inhibitor ferrostatin-1 and the Nrf2 activator tert-Butylhydroquinone reversed the inhibitory effects of Ssa on RANKL-induced osteoclastogenesis. In vivo, micro-computed tomography, hematoxylin and eosin staining, TRAP staining, enzyme-linked immunosorbent assays, and immunofluorescence confirmed that in rats with periodontitis induced by lipopolysaccharide, treatment with Ssa reduced alveolar bone resorption dose-dependently. The results suggested Ssa as a promising drug to treat osteolytic diseases.Copyright © 2024 Li, Liu, Feng, Bai, Wang, Zhang and Wang.