Abstract: To investigate the immunomodulatory effect of icariin on asthmatic young mice and its related mechanism, an asthma model was established by ovalbumin sensitization combined with aerosol challenge in this study. The young mice were randomly divided into the control group (Con group), model group (Mod group), low-dose icariin group (Low-Ica group), high-dose icariin group (High-Ica group), and high-dose icariin + Janus kinase 2 (JAK2) activator coumermycin A1 (CA1) group (High-Ica+CA1 group), with 12 mice in each group. Airway reactivity and enhanced pause (Penh) value were detected by a pulmonary function detector. Morphological changes in lung tissue were observed by hematoxylin and eosin (HE) staining. Serum levels of immunoglobulin E (IgE), interleukin-4 (IL-4), IL-17, and interferon-γ (IFN-γ) were measured by enzyme-linked immunosorbent assay. The apoptosis level of eosinophil (EOS) in bronchoalveolar lavage fluid was detected by flow cytometry. The protein expression levels of JAK2, signal transducer and activator of transcription 3 (STAT3), and phosphorylated STAT3 (p-STAT3) in lung tissue were detected by Western blot (WB). The results showed that compared with the Con group, the Penh value increased (P<0.05), lung tissue injury was aggravated, and the levels of IgE, IL-4, IL-17, and the protein expression levels of JAK2 and p-STAT3 increased (P<0.05), while the level of IFN-γ and the apoptosis percentage of EOS decreased (P<0.05) in the Mod group; compared with the Mod group, the Penh value decreased (P<0.05), lung tissue injury was alleviated, and the levels of IgE, IL-4, IL-17, and the protein expression levels of JAK2 and p-STAT3 decreased (P<0.05), while the level of IFN-γ and the apoptosis percentage of EOS increased (P<0.05) in the Low-Ica group and High-Ica group; the JAK2 activator was found to reverse the aforementioned changes in the High-Ica group. The study indicates that icariin can alleviate lung tissue injury in asthmatic young mice, and its mechanism may be related to the inhibition of the JAK2/STAT3 signaling pathway, promotion of EOS apoptosis, and regulation of T helper 1 cell (Th1)/Th2 and Th17 immune imbalance.
Keywords: icariin; asthma; immunomodulation; Janus kinase 2; signal transducer and activator of transcription 3
（Acta Laser Biology Sinica, 2026, 35(4): 369-375）