Research Progress on the Role and Mechanisms of Traditional Chinese Medicine in Preventing and Treating Radiation-induced Lung Injury via the TGF-β/Smad Signaling Pathway

Radiation-induced lung injury(RILI), a disease primarily characterized by radiation-induced pneumonitis(RP) and radiation-induced pulmonary fibrosis(RPF), is a common complication following thoracic radiotherapy, significantly impairing patients’ quality of life. The transforming growth factor-β(TGF-β)/Smad signaling pathway and its regulated cytokines play critical roles in the pathogenesis and progression of RILI. Multiple active components of Chinese herbal medicine have demonstrated therapeutic potential by modulating this pathway. They can inhibit inflammatory factor activation, suppress extracellular matrix(ECM) synthesis, and reduce collagen deposition, thereby alleviate pulmonary inflammatory infiltration and fibrosis, and improve lung function. Research has demonstrated that traditional Chinese medicine(TCM) exhibits immunomodulatory, antioxidant, metabolic regulatory, anti-inflammatory, and anti-fibrotic properties. While substantial studies have explored the pharmacological mechanisms of TCM in preventing and treating RILI, the precise bioactive components responsible for its therapeutic effects particularly in compound herbal formulations and their underlying mechanisms remain to be fully elucidated. Furthermore, the synergistic interplay among multiple pathways demands urgent attention. This review summarizes current advances in understanding how TCM modulates the TGF-β/Smad signaling pathway to mitigate RILI. It aims to provide a comprehensive reference for both clinical practice and fundamental research, establish a multidimensional theoretical framework to support the clinical translation of TCM, and facilitate mechanistic studies on RILI, ultimately contributing to the development of innovative treatment strategies.