[Augmentation of murine organ-associated natural immune responses by cepharanthin]

Oral administration of cepharanthin (bisbenzylisoquinoline alkaloid) to mice was effective in the organ-associated immune responses. Cepharanthin, as a biological response modifier (BRM), augmented natural killer (NK) activity of leukocytes isolated from the spleen, lymph node, lung, and liver. The degree of NK augmentation was almost the same in these organs without lymph node, and reached to the maximum levels 3 days after cepharanthin administration. In addition, adherent leukocytes (greater than 95% macrophages) isolated from the lung or liver following cepharanthin administration also exhibited an augmented macrophage-mediated cytotoxicity. These results suggest that such organ-associated immune responses may play an important role in the antitumor and/or antimetastatic effects mediated by cepharanthin.