[Effect of mao-bushi-saishin-to (MBST), a formula of Chinese medicines, on 48 hr homologous passive cutaneous anaphylaxis in rats].

We studied the effect of oral administration of the extracts from MBST and its component chinese plants, and 1-ephedrine on 48 hr homologous passive cutaneous anaphylaxis (PCA), and histamine- or serotonin-induced skin reaction in rats. Administration (100-1,000 mg/kg) of MBST 1 hr before antigen challenge dose-dependently inhibited PCA. Skin reaction induced by histamine was also inhibited by this formula at 1,000 mg/kg 1 hr prior to the provocation in some degree. The inhibitory component of MBST of PCA was found to be Mao. Further examinations revealed that 1-ephedrine, which is contained in Mao in a large amount, did not substantially inhibit histamine- or serotonin-induced skin reaction. These results indicate that MBST has a significantly inhibitory activity on PCA, to which 1-ephedrine from Mao in the formula almost totally contributes, through the inhibition of chemical mediator release. Since MBST showed some inhibition of histamine-induced skin reaction, on which 1-ephedrine did not affect, it is suggested that some ingredient of MBST responsible for inhibition of PCA may be involved in addition to 1-ephedrine.