Radioprotective efficacy of tocopherol succinate is mediated through granulocyte-colony stimulating factor

► We have identified a novel radiation countermeasure, tocopherol succinate (TS). ► Resulting G-CSF from TS administration is responsible for radioprotection. ► TS protected mice against high doses of radiation-induced GI damage. ► Neutralizing antibody to G-CSF completely neutralized TS-induced G-CSF. ► Protection of GI was abrogated by administration of a G-CSF antibody.