IGHE and airway hyperresponsiveness: HCH decreased airway hyperresponsiveness, diminished OVA-induced TH2 responses, decreased the level of IL-4 in BALF and the level of IgE in serum, increased alveolar macrophage phagocytosis, decreased MDA level and increased SOD activity, inhibited OVA-induced NF-κB activation, activated Nrf2 and HO-1 expression