[Mode of the anti-allergic action of cepharanthine on an experimental model of allergic rhinitis].

Cepharanthine, a biscouclaurine alkaloid of Stephania cepharantha, has been used for various clinical purposes. Cepharanthine was known to inhibit histamine release from mast cells obtained from sensitized animals. In vitro studies suggested that the mechanism of action of cepharanthine may be ascribed to the membrane stabilizing action. The membrane stabilization may be attained by reducing the elasticity of the membrane. However, in vivo mechanisms of the anti-allergic action of cepharanthine have not been examined. In the present in vivo study, the anti-allergic action of cepharanthine was examined using experimental allergic rhinitis in rats. The locally administered cepharanthine solution (0.1 mg/ml), by perfusing the nasal cavity, inhibited the dye leakage and an increase in lysosomal enzyme activity due to antigen stimulation. This is the reason for the membrane stabilization by cepharanthine. In the metyrapone (20 mg/kg, s.c., 5 days) pretreated rats of the rhinitis models, the anti-allergic action of cepharanthine was weaker. On the other hand, the effect of ketotifen was not altered by such an effect. The experimental results suggest that the anti-allergic mechanism of cepharanthine might be exerted by its membrane stabilizing action and by stimulation of the pituitary-adrenotropic function.