Tenuifolin mitigates allergic asthma by modulating M2 macrophage polarization via the STAT6 pathway 3388

Description Asthma affects approximately 300 million individuals globally, with a prevalence rate of about 10% in Taiwan. The increasing incidence, particularly among children, is associated with factors such as allergens, air pollution, and exposure to environmental chemicals, contributing to airway inflammation and immune system dysfunction. Tenuifolin (TEN), a bioactive compound derived from Polygala tenuifolia, a traditional Chinese herb used for insomnia, anxiety, and respiratory issues, has demonstrated neuroprotective and anti-inflammatory effects; however, its immunological mechanisms remain insufficiently characterized. Our studies revealed that TEN specifically inhibits M2 macrophage polarization without affecting M0 macrophage differentiation or apoptosis. Utilizing a murine ovalbumin-induced asthma model, we observed that TEN reduced eosinophils, lymphocytes, and alveolar macrophages infiltration, and suppressed type II immune cytokines in bronchoalveolar lavage fluid. Splenocytes re-stimulated with ovalbumin in vitro exhibited lower levels of IL-5, IL-13, and IL-10 in the TEN treatment group. Subsequent analysis of splenic cell subsets revealed that TEN decreased both the percentage and numbers of dendritic cells and macrophages, specifically CD206+ M2-like macrophages. Furthermore, TEN inhibited STAT6 phosphorylation during M2 macrophage polarization, underscoring its potential as a therapeutic agent for allergic asthma.