Inhibitory effect of astragaloside I and IV on passive cutaneous anaphylaxis reaction and scratching behaviors in mice

To evaluate the antiallergic effect of the dried root of Astragalus membranaceus Bunge (AM) (Leguminosae), which inhibited the mouse passive cutaneous anaphylaxis (PCA) reaction in a preliminary experiment, its main constituents, astragalosides I and IV, were isolated and their antiallergic effects were investigated. Astragalosides I and IV inhibited the PCA reaction induced by the IgE-antigen complex, and the scratching behaviors induced by compound 48/80. These constituents reduced the protein expressions of TNF-α and IL-4 in IgE-induced RBL-2H3 cells. These findings suggest that astragalosides I and IV as well as AM can improve IgE-induced anaphylaxis and scratching behaviors.