Effects of Fucoidan on Survival and Hematopoietic Recovery in Irradiated Mice

Abstract

To evaluate the possible in vivo radioprotection conferred by fucoidan, the survival rate and hematopoietic changes in mice subjected to total body irradiation were investigated. BALB/c mice were administered 10, 50, or 100 mg of fucoidan/kg body wt i.p. before exposure to 9 Gy of gamma radiation, and then were monitored for 30 days. To see the effect of fucoidan on the radiation-induced damage to peripheral blood leukocytes, the number of blood leukocytes was counted in mice treated with fucoidan 4 h post-irradiation (6 Gy). The changes in bone marrow viability and the endogenous hematopoietic spleen colony formation after irradiation (6 Gy) were measured at 9 days in mice given fucoidan (10 and 100 mg/kg body wt, i.p.). The fucoidan pretreatment improved the survival rate of irradiated mice; 67% (6/9) of the mice treated with 100 mg/kg of fucoidan survived until day 30 after exposure to 9 Gy of gamma radiation, whereas most of the mice treated with less fucoidan died before day 15. This effect accompanied significant increases in peripheral blood leukocytes, endogenous spleen colonies, and bone marrow cells in irradiated mice pretreated with fucoidan, compared with control mice. Pretreatment with fucoidan before irradiation plays an important role in the survival of irradiated mice, possibly by protecting hematopoietic cells, including peripheral blood leukocytes, bone marrow cells, and endogenous spleen colonies. The molecular mechanism of the radioprotection conferred by fucoidan remains to be determined.