Radioprotective compounds are of importance in clinical
radiation therapy, because normal tissues should be protected against
radiation injury while using higher doses of radiation to obtain better
cancer control. We investigated the radioprotection of cellular
DNA in
cancer and in various cells and tissues, in a murine system following exposure to gamma-radiation and
tocopherol monoglucoside (TMG) administration. We used single-cell gel electrophoresis (comet assay) and studied the progression of murine
fibrosarcoma following radiation exposure and administration of TMG. The administration of TMG to
tumor-bearing mice protected the cellular
DNA against radiation-induced strand breaks as shown by the decrease in comet tail length, tail moment, and percentage of
DNA in the tails of the cells of normal tissues. The same parameters were not altered in the cells of
fibrosarcoma. Our results showed that the administration of TMG immediately after exposure to gamma-radiation can protect normal tissues against radiation damages in
tumor-bearing mice. Local gamma-radiation exposure (5 Gy) of the
tumor retarded the
tumor growth. Administration of TMG did not protect
cancer cells from radiation damage because the growth curves of
cancer cells treated with radiation alone and those treated with TMG after irradiation were not significantly different.