Mechanism study of the effects of astragaloside IV and quercetin on idiopathic pulmonary fibrosis.

This study aimed to investigate the effects of astragaloside IV(AS-IV) and quercetin (QCT) on autophagic activity, pyroptosis, and epithelial-mesenchymal transdifferentiation (EMT) in the context of idiopathic pulmonary fibrosis (IPF), utilizing both in vivo and in vitro models. In the in vivo component of the research, C57BL/6 J mice were subjected to bleomycin (BLM) modeling, followed by AS-IV + QCT intervention at low, medium, and high doses for 14 and 28 days. Pathological changes in lung tissue were assessed through HE and Masson staining. Additionally, the expression levels of autophagy and pyroptosis-related proteins in serum and bronchoalveolar lavage fluid were examined via Western blot analysis. In the in vitro experiment, RAW264.7 macrophage cells were co-cultured with MLE-12 alveolar epithelial cells (3:1 ratio), implementing BLM and NLR family pyrin domain-containing protein (NLRP3) + BLM models to induce IPF. The effects of AS-IV and QCT on these cells were evaluated by electron microscopy to observe structural changes, while Western blot and ELISA were used to measure the expression of autophagy and pyroptosis-related proteins. Results showed that AS-IV and QCT significantly enhanced autophagic activity, evidenced by increased levels of LC3II and beclin-1 and decreased levels of P62. Additionally, both compounds reduced the expression of pyroptosis-related proteins (NLRP3, Caspase-1, IL-1β, and IL-18) and slowed the progression of EMT in alveolar epithelial cells. These findings propose that AS-IV and QCT inhibit the EMT process in IPF by activating autophagic mechanisms while suppressing pyroptosis, thereby underscoring their potential as innovative therapeutic strategies for IPF and highlighting the promising implications of herbal compounds in its prevention and treatment.