Studies on the radioprotective effect of seaweed sulfated polysaccharide and its mechanism

Seaweed sulfated polysaccharide (SP) is a natural sulfated polysaccharide isolated from seaweed and has various pharmacological activities. However, previous studies on the radioprotective effect of SP were limited to in vivo whole-body studies. In the present study, SP was examined for radioprotective effect and its mechanism by MTT assay and the electron spin resonance (ESR). The items studied were as follows: (1) Different doses of SP were given to 60Co γ-ray irradiated KM mice, and their influence on the peripheral blood recovery and 30 d survival rate of the irradiated mice were observed. (2) The radioprotective mechanism of SP on hematopoietic cells was studied in two hematopoietic growth factor-dependent cell lines (NFS-60 to G-CSF, TF-1 to GM-CSF) by MTT assay. (3) The irradiated 5'-TMP was used as a model for estimating the amount of DNA to observe the protective activity of SP on the radiation injury of DNA by using ESR. The results found that SP could promote the recovery of peripheral blood and proliferation of the hematopoietic cells in irradiated mice, increase their 30 d survival rate, and scavenge the free radicals