Comparative studies on the antiallergic effects of kampo medicines used for the therapy of respiratory diseases.

Eight kinds of kampo medicines mainly used for the treatment of asthma and other respiratory diseases, whose comparative effects were still unproven, were selected for comparison of their antiallergic activity in the present study. 1) In an experiment on 48-hr PCA reaction in rats passively sensitized with anti egg albumin IgE antisera, inhibitory effects were observed in those groups orally administered with the tested kampo medicines. Among the drugs tested, TJ-19 showed a potent inhibitory activity as effective as that of tranilast (TL). 2) In the study of extraction method, the effects of kampo drugs varied widely according to the extraction method by which they were prepared. This suggests that the routine methods for preparing these extracts should be reconsidered to achieve the optimal efficacy. 3) In the study of histamine release from rat peritoneal cells stimulated with compound 48/80, TJ-55, TJ-19 and TL exerted a strong inhibition, but TJ-119, TJ-29 and TJ-96 had a weak inhibition. 4) TJ-96, TJ-19 and TL exerted a strong inhibitory effect on LTC, release from rat peritoneal mast cells induced by calcium (Ca) ionophore A23187, but TJ-95, TJ-55 and TJ-119 exerted only a weak inhibition. To sum up of the results, any of these kampo medicines have unique pharmacological action and antiallergic effects. Besides, the method for extraction affects the efficacy of kampo medicine in vitro.