Suppressive effects of Hochu-ekki-to, a traditional Chinese medicine, on IgE production and histamine release in mice immunized with ovalbumin

We examined the effects of Bu-Zhong-Yi-Qi-Tang (Japanese name: Hochu-ekid-t o, HET), a traditional Chinese medicine, on IgE production and histamine re lease in mice immunized intraperitoneally with a mixture of ovalbumin (OA) and aluminum hydroxide (alum adjuvant). Three groups of mice were orally ad ministered 0, 1.7 or 17 mg of RET on day 13 after the first immunization wi th a mixture of 1 mu g OA and 1 mg alum adjuvant. They were again immunized with the same dose of OA pins alum adjuvant on day 14. The immunological c hanges in mice treated with OA alone or OA plus HET were examined, and the following findings were obtained. In the MET-treated mice, the elevation of anti-GA IgE in serum, and histamine release from basophils in blood, were significantly suppressed. A significant suppression of interleukin-4 (IL-Lb ) secretion and proliferation of splenic lymphocytes in primary culture was also observed. A tendency to suppress the elevation of anti-GA IgG1 in ser um and interleukin-2 (IL-2) secretion from splenic lymphocytes was observed in the HET-treated mice. These findings suggest that oral administration o f HET suppresses IgE antibody production and histamine release in type I al lergic reaction in mice immunized with OA plus alum adjuvant; this shows th e efficacy of HET in treating type I allergic diseases, such as asthma.