Shin’iseihaito (Xinyiqingfeitang) extract ameliorates ovalbumin-induced murine allergic rhinitis by regulating cytokines

Shin’iseihaito (Xinyiqingfeitang) is a formula of traditional Japanese Kampo medicine and traditional Chinese medicine (TCM) and for chronic sinusitis. However, the precise action mechanism has been unknown. We examined the effect of shin’iseihaito extract (SSHT) on murine allergic rhinitis model using ovalbumin (OVA). We decocted the mixture of 9 crude drugs in water to prepare SSHT. SSHT (20 times amount of human dose) was orally administered to mice treated with OVA. After mice were sacrificed on day 28, immunoglobulin (Ig) E, interleukin (IL)-4, IL-13, interferon (IFN)-γ, and thymic stromal lymphopoietin (TSLP) levels in nasal lavage fluid samples were measured by enzyme-linked immunosorbent assay (ELISA). The pathological tissue sections from the nasal epithelial mucosa were histopathologically investigated by optical and scanning electron microscopies. We also investigated the effects of modified SSHTs prepared by removing one crude drug from shin'iseihaito to clarify the active ingredients. SSHT suppressed IgE, IL-4, IL-13, and TSLP levels, while increased the IFN-γ levels in OVA-induced allergic mice. Sensitization with OVA resulted in an increase in eosinophilia and goblet cells in murine nasal cavity tissue in comparison with those in untreated group, however, those were significantly reduced by the treatment with SSHT. The extracts of 8 crude drug's mixtures except for the removal of Gypsum fibrosum (GF) from shin'iseihaito counteracted on the suppressive effects of SSHT on IgE, IL-4, IL-13, and TSLP levels in nasal lavage fluid. Our result demonstrated that SSHT may contribute to inhibit the exacerbation of OVA-induced murine allergic rhinitis by regulating cytokines, and the components except for GF contributed anti-allergic effect of shin'iseihaito. Graphical abstract