As a result, PC inhibited airway eosinophil accumulation, the influx of inflammatory cells, airway hyperresponsiveness (AHR), production of Th2 cytokines (IL-4, IL-5 and IL-13) and tumor necrosis factor-α (TNF-α) in the bronchoalveolar lavage fluid and/or lung, as well as OVA-specific immunoglobulin E (IgE) in the serum. Here, IL4 is linked to airway hyperresponsiveness.