[The effects of Cepharanthin on the recovery of hematopoietic stem cells after X-ray irradiation].

Administration of Cepharanthin (ceph) resulted in a significant acceleration of the recovery from leukopenia in 5-Gy X-ray irradiated mice. Then we examined the function of ceph on the recovery of hematopoietic stem cells after irradiation. The number of GM-CFU (granulocyte-macrophage committed stem cells) in the femur and spleen increased significantly in ceph compared to phosphate buffer solution administered groups. However, the time course of the recovery of GM-CFU did not differ between the two groups. These enhancing effects of ceph on GM-CFU were not observed when it was added to a bone marrow culture system. Therefore, the accelerating effects of the recovery from leukopenia after irradiation appears to be an indirect function of ceph.