Zhi-Chuan-Ling alleviates OVA-induced allergic asthma by suppressing M2 macrophage polarization via the PI3K/AKT/mTOR/STAT6 pathway.

Abstract

BACKGROUND: Allergic asthma, predominantly driven by Th2 immune responses, is a chronic respiratory disease that poses a significant threat to human health. Zhi-Chuan-Ling (ZCL), a traditional Chinese medicine widely used for the treatment of asthma and wheezy bronchitis, has been shown to relieve airway constriction and suppress airway inflammation. However, its mechanisms in regulating macrophage polarization, a key Th2-driven inflammatory process, remain unclear. PURPOSE: This study aimed to assess the therapeutic effects of ZCL on allergic asthma and to investigate its molecular mechanisms in modulating macrophage polarization. METHODS: The chemical profile of ZCL was characterized by high-performance liquid chromatography (HPLC). An ovalbumin (OVA)-induced mouse model of allergic asthma was established to assess the anti-asthmatic effects of ZCL. Mechanistic studies included hematoxylin-eosin (H&E) and Masson's trichrome (MT) staining, immunofluorescence (IF), ELISA, flow cytometry (FCM), transcriptomic profiling, Western blotting (WB), and in silico molecular docking to predict binding interactions of key ZCL compounds with target proteins involved in M2 macrophage polarization and airway inflammation. RESULTS: ZCL treatment significantly alleviated asthma symptoms and reduced airway inflammation in vivo. Mechanistically, ZCL inhibited M2 macrophage polarization by modulating the PI3K/AKT/mTOR/STAT6 signaling pathway. Molecular docking analysis revealed favorable binding of major ZCL compounds to PI3K, AKT, mTOR, and STAT6, supporting their potential role in modulating these signaling molecules. CONCLUSION: ZCL protects against allergic asthma by suppressing M2 macrophage polarization through the PI3K/AKT/mTOR/STAT6 axis and by directly interacting with key pathway proteins, thereby attenuating airway inflammation and remodeling. These findings provide both functional and molecular evidence for the therapeutic potential of ZCL in allergic asthma.