Xiebai San mediates the NCOA2-ESR1/2 signaling pathway to intervene in interstitial pneumonia

Background Interstitial pneumonia, particularly usual interstitial pneumonia (UIP) and idiopathic pulmonary fibrosis (IPF), is a disease with progressive and fatal disorder, and limited treatment options. Xiebai San (XBS), a classical Chinese herbal formula, has shown clinical promise but its mechanism of action remains unclear. Purpose To clarify the effects and mechanism of XBS on interstitial pneumonia. Methods The in vivo pharmacochemical analysis (UPLC-Q-Exactive-Orbitrap MS/MS), network pharmacology, and GEO database analysis (GSE10667) were applied to predict potential targets of XBS on interstitial pneumonia. BLM-induced mice received XBS (1.4, 2.8, 5.6 g/kg) or dexamethasone (0.5 mg/kg) for 21 days. Lung index, histopathology observation (H&E, Collagen-1 IHC), pulmonary function, and biomarkers of inflammation, oxidative stress and fibrosis were used to evaluated the efficacy of XBS. Reverse-phase protein microarray (RPPM), RT-qPCR, and Western blotting were integrated to clarify its mechanism. Results Thirty-seven components of XBS were identified in vivo , and they were associated with 237 potential targets for interstitial pneumonia. And GEO analysis confirmed the upregulation of key nodes (NCOA2, ESR1, and ESR2) in patients. XBS significantly attenuated BLM-induced lung damage, evidenced by reduced lung index, improved pulmonary function (Penh, EEP, PIF, PEF), decreased inflammatory infiltrates, collagen deposition, and alveolar destruction. XBS suppressed proinflammatory cytokines (TNF-α, IL-1β), oxidative stress (MDA, MPO), restored antioxidants (GSH, SOD), and inhibited fibrotic factors (TGF-β1, α-SMA, Collagen-1/3). Mechanistically, XBS downregulated the mRNA and protein expression of NCOA2 and ESR1/2, subsequently inhibiting glycolytic metabolic reprogramming (G6PC, PFKFB3, HIF-1α) and the TGF-β1/ERK1/2-Smad7 pro-fibrotic signaling pathway. Conclusion XBS alleviates BLM-induced interstitial pneumonia via NCOA2-ESR1/2-driven glycolytic metabolic reprogramming and TGF-β1/ERK1/2-Smad7 fibrotic signaling, offering a mechanistic rationale for interstitial pneumonia.