Swainsonine stimulates bone marrow cell proliferation and differentiation in different strains of inbred mice.

The immunomodulatory alkaloid swainsonine (8alphabeta-indolizidine-1alpha,2alpha,8beta-triol) has potential for overcoming the bone marrow suppressive effects of cancer chemotherapeutic drugs and radiation. The effect of swainsonine on bone marrow cellularity was evaluated in four different strains (C57BL/6; C3H-HEN; Balb/C and DBA-2 mice) of inbred mice subjected to multiple doses of the alkaloid. Swainsonine treatment stimulated bone marrow cell proliferation in all strains of mice. Examination of the peripheral blood did not reveal any increase in total leukocyte count. In vitro assessment of total colony-forming unit (CFU) capacity of bone marrow cells showed a two- to eight-fold increase in swainsonine treated mice of different strains compared to their corresponding controls given sham injections of physiological saline. Swainsonine induced increase in CFU capacity of bone marrow cells should find clinical application in cancer treatment with chemotherapeutic agents and radiation.