Radiation protective effect of an extract from Chelidonium majus.

We earlier reported that CM-AIa isolated from Chelidonium majus had mitogenic activity, generated lymphokine-activated killer cells, and increased the number of granulocyte-macrophage colony-forming cells (GM-CFC). In an extended effort to search for other immunostimulatory effects, we evaluated the protective effects of in vivo injected CM-AIa against irradiation. CM-AIa was found to increase the number of bone marrow cells, spleen cells, GM-CFC, and platelets in irradiated mice. In addition, this agent induced endogenous production of cytokines such as interleukin 1 and tumor necrosis factor alpha, which are required for hematopoietic recovery. We also demonstrated that CM-AIa treatment 24 hours before irradiation protected mice with 80% survival at lethal dose 100/15. These findings indicate that CM-AIa may be a useful agent for reducing the time needed for reconstitution of hematopoietic cells after irradiation treatment.