Alkaloids as Emerging Therapeutics against Pulmonary Fibrosis: Classification, Mechanisms, and Translational Potential

Pulmonary fibrosis (PF) is a chronic and progressive lung disease characterized by an unclear etiology and poor prognosis. Currently, the therapeutic drugs available for PF are limited and insufficient to meet the clinical demands. In recent years, the anti‐PF potential of natural products has garnered increasing attention, with alkaloids showing particularly promising prospects. Alkaloids can intervene PF through multiple signaling pathways. Alkaloids exert anti‐inflammatory, antioxidant, and antiapoptotic effects, which contribute to the inhibition of extracellular matrix (ECM) deposition, the protection of alveolar epithelial cells, and the suppression of lung fibroblast activation and proliferation involved in PF. However, a comprehensive and systematic synthesis of the existing research remains lacking. This review emphasizes the summary of the mechanisms by which alkaloids prevent and treat PF, including experimental research methodologies and clinical research findings. In addition, it highlights the existing challenges and outlines potential directions for future research, with the goal of providing new insights into the development of novel therapeutic agents for PF prevention and treatment.