Total Astragalus Saponins Modulate Ferroptosis Pathways in Cigarette Smoke and LPS-Induced Models of COPD: An in vitro and in vivo Investigation.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition characterized by persistent airflow limitation and chronic airway inflammation. Emerging evidence indicates that ferroptosis contributes to disease pathogenesis. The current therapeutic strategies cause adverse side effects and frequent exacerbations. Astragalus membranaceus (Fisch.) Bunge, a traditional Chinese herb with a long-standing history for treating pulmonary disorders, benefits patients with COPD. The primary active constituents are total astragalus saponins (AST); however, their application in COPD management remains underexplored. This study aimed to investigate the impact of AST on ferroptosis in COPD. METHODS: A COPD murine model was developed through exposure to cigarette smoke (CS) and lipopolysaccharide (LPS). We evaluated the impacts of AST on respiratory function, pulmonary index, lung pathology, and serum reactive oxygen species (ROS) and glutathione (GSH) levels in the COPD mice. Beas-2B cells were stimulated with cigarette smoke extract (CSE) to evaluate GSH, malondialdehyde (MDA), ROS, lipid peroxidation, Fe2⁺, and membrane integrity. The expression levels of ferroptosis-related genes and proteins were analyzed by quantitative polymerase chain reaction and Western blot in the COPD mice and CSE-induced cells. RESULTS: In COPD mice (n=8), AST treatment significantly improved respiratory function (Penh, TV, EF50, EF75), reduced tracheal wall thickening and inflammatory cell infiltration (p<0.001), decreased serum ROS and increased GSH (p<0.05), and regulated ferroptosis-related gene and protein expression (p<0.05). In CSE-stimulated Beas-2B cells, AST restored cell viability, increased GSH, decreased MDA and ROS production, reduced lipid peroxidation and intracellular Fe2⁺ accumulation, preserved membrane integrity, and upregulated GPX4 and FTH1 while downregulating ACSL4 and PTGS2 (p<0.05). CONCLUSION: Our findings suggest that AST exerts protective effects against CS and LPS-induced COPD in mice and CSE-induced injury in Beas-2B cells that are associated with modulation of ferroptosis-related markers. These results provide preliminary evidence supporting continued investigation of AST in preclinical COPD models and offer potential directions for future mechanistic research.