探讨淫羊藿素对鼻咽癌(NPC)细胞的放射增敏作用及其机制。采用MTT法和克隆形成实验评价淫羊藿素对人鼻咽癌HONE1和HNE1细胞增殖的影响。使用流式细胞术评估淫羊藿素治疗、γ射线辐射或两者对鼻咽癌细胞的活性氧（ROS）产生、细胞周期分布和凋亡的影响。采用Western blotting检测DNA损伤标志物γ-H2AX、周期相关蛋白CDC25C、p-CDC25C和细胞周期蛋白B1以及铁死亡标志物ACSL4和GXP4的表达。采用皮下HONE1细胞异种移植裸鼠模型，观察淫羊藿素和放射线对肿瘤生长的影响。淫羊藿素剂量依赖性地抑制鼻咽癌细胞的活力，并增强放射线对细胞增殖的抑制作用。流式细胞术和Western blotting显示，放疗前淫羊藿素处理显着促进NPC细胞中ROS的产生和γ-H2AX的表达（P<0.001）。与单独放疗相比，联合治疗导致细胞周期阻滞于G2期，细胞内CDC25C和cyclin B1表达下调，p-CDC25C表达上调（P<0.01），细胞凋亡增加。铁死亡蛋白ACSL4表达增强，GXP4表达降低（P<0.001）。在荷瘤小鼠中，与单独放疗相比，淫羊藿素治疗显着降低了肿瘤生长速度并降低了肿瘤重量（P<0.001）。淫羊藿素可以通过增强ROS产生来增强体外和裸鼠中的NPC细胞的放射敏感性。促进细胞的铁死亡。

To explore the radiosensitizing effect of icaritin on nasopharyngeal carcinoma (NPC) cells and the underlying mechanism.MTT assay and clonal formation assay were used to evaluate the effect of icaritin on proliferation of human NPC HONE1 and HNE1 cells. The effects of icaritin treatment, γ-ray radiation, or both on production of reactive oxygen species (ROS), cell cycle distribution and apoptosis of the NPC cells were assessed using flow cytometry. The expressions of DNA damage markers γ-H2AX, cycle-related proteins CDC25C, p-CDC25C and cyclin B1, and ferroptosis markers ACSL4 and GXP4 were detected using Western blotting. A nude mouse model bearing subcutaneous HONE1 cell xenograft was used to observe the effect of icaritin and radiation on tumor growth.Icaritin dose-dependently inhibited the viability of the NPC cells and enhanced the inhibitory effect of radiation on cell proliferation. Flow cytometry and Western blotting showed that icaritin treatment prior to radiation significantly promoted ROS production and γ-H2AX expression in the NPC cells (P<0.001). Compared with radiation exposure alone, the combined treatment caused cell cycle arrest in G2 phase, down-regulated CDC25C and cyclin B1 expression, and up-regulated p-CDC25C expression in the cells (P<0.01), resulting also in increased cell apoptosis, enhanced expression of ferroptosis protein ACSL4 and lowered expression of GXP4 (P<0.001). In the tumor-bearing mice, icaritin treatment, compared with radiation alone, significantly reduced the tumor growth rate and decreased tumor weight (P<0.001).Icaritin can enhance radiosensitivity of NPC cells both in vitro and in nude mice possibly by enhancing ROS production to promote iron death of the cells.