The anti-rhinitis properties of Sparassis crispa were investigated in mice. To examine the immunomodulative activity of oral administration of S. crispa, splenocytes obtained from ovalbumin-sensitized BALB/ c mice fed S. crispa were restimulated in vitro with the same antigen. Oral administration of S. crispa induced IFN-γ, but inhibited IL-4 and IL-5 secretion, and suppressed ovalbumin-specific IgE secretion by ovalbumin-stimulated splenocytes. The effects of S. crispa were further investigated by using the allergic rhinitis model in BALB/c mice. Nasal symptoms, sneezing and nasal rubbing induced by ovalbumin challenges were inhibited by oral administration of S. crispa in a dose-dependent manner. Furthermore, ovalbumin-specific serum IgE levels were diminished in this model. These results demonstrated that S. crispa may be effective in suppressing symptoms of allergic rhinitis through its immunomodulating activities.Keywords: allergic rhinitis, cytokines, hanabiratake, ovalbumin-specific IgE, Sparassis crispa *To whom correspondence should be addressed. Email: takashi-kimura@unitika.co.jp IntroductionType I allergies, including pollinosis, allergic rhinitis, atopic dermatitis and asthma, are characterized by an elevated production of IgE and mast cell degranulation that result in release of histamine as well as other chemical mediators of allergy (Platts-Mills, 2001). The production of IgE from B cells is regulated by T-helper (Th) cells, which have been classified into Th1 and Th2 subtype (Mosmann et al., 1986). Th2 cells synthesize IL-4, which enhances the IgE production by B cells through inducing IgE isotype class switching and the proliferation of Th2 cells (Le et al., 1990;Swain et al., 1990). Th2 cells also synthesize IL-5 which enhances the IL-4-dependent IgE production (Pene et al., 1988). Therefore, Th2 cells and IL-4 are considered to be critical for IgE production. Conversely, IFN-γ produced by Th1 cells suppresses IgE production both by interfering with the IL-4-derived isotype class switching (Thyphronitis et al., 1989) and by inhibiting the proliferation of Th2 cells (Gajewski and Fitch, 1988). IL-12 produced by antigen-presenting cells, such as dendritic cells and macrophages, is known to stimulate both NK and Th1 cells to make them produce IFN-γ. These two Th1-type cytokines, IL-12 and IFN-γ, enhance the proliferation of Th1 cells (Belosevic et al., 1989;Hsieh et al., 1993). It is generally accepted that enhancement of Th2-mediated immunity causes IgE-dependent allergic diseases. Therefore, properly regulating the balance between Th1-and Th2-type immune responses to heterogeneous antigens is considered to be an important mechanism in the prevention and therapy of the diseases mentioned earlier. In fact, it has been indicated that oral administration of some lactobacillus can modulate the host Th1/Th2 balance and decrease serum IgE levels (Fujiwara et al., 2004;Kimoto et al., 2004). Furthermore, oral administration of the extract from Hatakeshimeji (Lyophyllum decastes) mushroom can modulate t...