Comparative immunopharmacology and toxicology of the bisbenzylisoquinoline alkaloids tetrandrine and berbamine.

Comparison of the bisbenzylisoquinolines tetrandrine and berbamine shows that both drugs are equipotent in terms of enhancement of antibody responses and suppression of delayed-type hypersensitivity (DTH) responses to sheep red blood cell antigens. Both compounds are also equally active when given to mice during the induction and expression phases of DTH. Using a model of experimental brucellosis in mice, it was found that both compounds did not affect antibody responses, while they caused equipotent suppression of DTH. By contrast, berbamine but not tetrandrine caused significant suppression of spleen weight. Also, berbamine caused a significantly greater enhancement of spleen colony counts of Brucella abortus than tetrandrine. Short-term toxicology studies showed no toxic effects at bioactive doses.