Reduction of Development of Late Allergic Eosinophilic Rhinitis by Kurozu Moromi Powder in BALB/c Mice

The preventive effect of the development of the late allergic eosinophilic rhinitis (LAER), a T helper (Th)2 type immune response, in BALB/c mice by kurozu moromi powder (kmp) was examined. Mice were pre-treated with or without (control) kmp intragastrically for 30 days (50mg/kg/day) and then LAER was induced by ovalbumin. Compared to the control group, kmp treatment resulted in reduction of the number of eosinophils, but not lymphocytes, in the blood. The kmp treatment significantly decreased concentration of interleukin (IL)-4, the Th2 cytokine, compared to the control in nasal cavity fluid (NF). However, no difference or increase in concentration of interferon-γ, a Th1 cytokine, in NF was observed in the two groups. The control group showed slight to moderate rhinitis, such as hyperplasia of respiratory epithelium and goblet cells with prominent mucous secretion and infiltration of eosinophils and lymphocytes in nasal mucosa. These changes were significantly reduced in mice treated with the kmp. The inhibitory effect of the kmp on the development of LAER may be due to decreased local Th2 cell activity promoting eosinophil infiltration, which is separate from the mutual Th1/Th2 inhibitory effect. In addition, the present study suggests that the kmp may be a useful food for prevention of the development of LAER in humans.