放射线诱导的肺损伤（RILI）是胸部肿瘤放疗的常见副作用，包括早期放射线诱导的肺损伤（RP）和晚期放射线诱导的肺纤维化（RIPF）。目前，迫切需要阐明RILI的发病机制并寻找安全有效的RILI治疗方法。照射导致组织和细胞的DNA损伤和氧化应激，诱导细胞衰老，并促进RILI的发生和发展。近年来，654-2在急性肺损伤、急性肾损伤、衣原体性肺炎和COVID-19中显示出潜在的治疗价值。然而，目前尚无关于654-2介导的细胞衰老机制及其对RILI的预防和治疗效应的研究。本研究旨在研究654-2对X射线诱导的RILI的保护效应及其机制。体内实验采用18Gy X射线照射的小鼠RILI模型，小鼠分为对照组、模型组、药物组（对照+654-2）和治疗组（模型+654-2）。药物组和治疗组小鼠每隔一天腹腔注射5mg/kg654-2，直至第6周牺牲。体外实验利用受到16Gy辐射的MLE-12细胞，分为对照组、模型组和模型+654-2（2μM和10μM）组。进行各种实验评估肺组织形态学、纤维化、凋亡、细胞衰老、蛋白表达和抗氧化能力。654-2减轻了RILI小鼠和MLE-12细胞中的肺部病理损伤、炎症、DNA损伤、细胞衰老和凋亡。它恢复了上皮细胞的增殖能力并增强了抗氧化能力。此外，654-2激活了Nrf2/ARE途径，增加了Nrf2磷酸化，并上调了抗氧化基因的表达。抑制Nrf2逆转了654-2对ROS产生、抗氧化能力和细胞衰老的影响。654-2能够激活Nrf2/ARE途径，增强细胞的抗氧化能力，抑制细胞衰老，从而对RILI具有保护作用。版权所有© 2023。由Elsevier B.V.出版。

Radiation-induced lung injury (RILI) is a common side effect of thoracic tumor radiotherapy, including early-stage radiation-induced lung injury (RP) and late-stage radiation-induced pulmonary fibrosis (RIPF). Currently, it is urgently needed to clarify the pathogenesis of RILI and find safe and effective RILI treatment methods. Irradiation causes DNA damage and oxidative stress in tissues and cells, induces cellular senescence, and promotes the occurrence and development of RILI. In recent years, Anisodamine (654-2) has shown potential therapeutic value in acute lung injury, acute kidney injury, chlamydial pneumonia, and COVID-19. However, there is currently no research on the mechanism of 654-2-mediated cellular senescence and its preventive and therapeutic effects on RILI.This study aimed to investigate the protective effect and mechanism of 654-2 on X-ray-induced RILI.In vivo experiments involved a mouse RILI model with 18 Gy X-ray irradiation. Mice were divided into control, model, medication (control + 654-2), and treatment (model + 654-2) groups. And mice in medication and treatment groups were intraperitoneal injection of 5 mg/kg 654-2 every other day until being sacrificed at week 6. In vitro experiments used MLE-12 cells irradiated with 16 Gy and divided into control, model, and model + 654-2（2 μM and 10 μM） groups. Various assays were performed to evaluate lung tissue morphology, fibrosis, apoptosis, cytokine expression, cellular senescence, protein expression, and antioxidant capacity.654-2 mitigated pulmonary pathological damage, inflammation, DNA damage, cellular senescence, and apoptosis in RILI mice and MLE-12 cells. It restored epithelial cell proliferation ability and enhanced antioxidant capacity. Additionally, 654-2 activated the Nrf2/ARE pathway, increased Nrf2 phosphorylation, and upregulated antioxidant gene expression. Inhibition of Nrf2 reversed the effects of 654-2 on ROS production, antioxidant capacity, and cell senescence.654-2 can activate the Nrf2/ARE pathway, enhance cellular antioxidant capacity, and inhibit cellular senescence, thereby exerting a protective effect against RILI.Copyright © 2023. Published by Elsevier B.V.