J Radiat Res. 2013 Nov 1;54(6):973-88. Epub 2013 May 8.Singh VK1, Beattie LA, Seed TM.Author information1Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA.AbstractDespite the potential devastating health consequences of intense total-body irradiation, and the decades of research, there still remains a dearth of safe and effective radiation countermeasures for emergency, radiological/nuclear contingencies that have been fully approved and sanctioned for use by the US FDA. Vitamin E is a well-known antioxidant, effective in scavenging free radicals generated by radiation exposure. Vitamin E analogs, collectively known as tocols, have been subject to active investigation for a long time as radioprotectors in patients undergoing radiotherapy and in the context of possible radiation accidents or terrorism scenarios. Eight major isoforms comprise the tocol group: four tocopherols and four tocotrienols.
A number of these agents and their derivatives are being investigated actively as radiation countermeasures using animal models, and several appear promising. Although the tocols are well recognized as potent antioxidants and are generally thought to mediate radioprotection through 'free radical quenching', recent studies have suggested several alternative mechanisms: most notably, an 'indirect effect' of tocols in eliciting specific species of radioprotective growth factors/cytokines such as granulocyte colony-stimulating factor (G-CSF). The radioprotective efficacy of at least two tocols has been abrogated using a neutralizing antibody of G-CSF. Based on encouraging results of radioprotective efficacy, laboratory testing of γ-tocotrienol has moved from a small rodent model to a large nonhuman primate model for preclinical evaluation. In this brief review we identify and discuss selected tocols and their derivatives currently under development as radiation countermeasures, and attempt to describe in some detail their in vivo efficacy.
vitamin EPMID: 23658414 PMCID: PMC3823775 DOI: 10.1093/jrr/rrt048 [Indexed for MEDLINE] Free PMC ArticlePublication typesResearch Support, U.S. Gov't, Non-P.H.S.ReviewMeSH termsAcute Radiation Syndrome/physiopathology*Acute Radiation Syndrome/prevention & control*AnimalsCritical Care/methods*HumansRadiation Protection/methods*Radiation-Protective Agents/therapeutic use*Tocopherols/therapeutic useTocotrienols/therapeutic useTreatment OutcomeVitamin E/therapeutic use*SubstancesRadiation-Protective AgentsTocotrienolsVitamin ETocopherolsFull Text SourcesSilverchair Information SystemsEurope PubMed CentralPubMed CentralPubMed Central CanadaMedicalCritical Care - MedlinePlus Health InformationVitamin E - MedlinePlus Health Information, , , , , , , , , , , and . (2017) Succinate ester derivative of δ-tocopherol enhances the protective effects against 60Co γ-ray-induced hematopoietic injury through granulocyte colony-stimulating factor induction in mice. Online publication date: 1-Feb-2017. CrossRef , , , , , , , and .
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