Title: Enhancement in repair of radiation-induced DNA strand breaks in vivo by tocopherol monoglucoside

Authors: Veena Prakash Salvi, Dharmendra Kumar Maurya, Tsutomu V. Kagiya, Cherupally Krishnan Krishnan Nair

Addresses: Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India. ' Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India. ' Health Research Foundation, Kinki Invention Centre, Kyoto, Japan. ' Department of Radiation Biology, Amala Cancer Research Centre, Trichur, Kerala, and Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India

Abstract: Damage to cellular DNA and its repair in the peripheral blood leucocytes of mice exposed to 4 Gy whole-body gamma-radiation was studied by alkaline single cell gel electrophoresis or comet assay. The comet parameters of DNA, such as comet tail length, % of DNA in tail, tail moment and olive tail moment, were found increased in the leucocytes from irradiated animals due to radiation-induced DNA strand breaks. The strand breaks in cellular DNA were repaired in a time dependent manner as evidenced from the decrease in the comet parameters. Thus, 15 minutes after irradiation exposure, 15% of DNA strand breaks were repaired and at 90 minutes post-irradiation, 43% were repaired. When tocopherol monoglucoside was administered to mice following radiation, it was found that at 15 and 90 minutes post-irradiation, 64% and 67% DNA, respectively, were repaired. This would suggest that administration of tocopherol monoglucoside enhanced the repair of cellular DNA damage in whole-body irradiated mice. However, in vitro studies, either with humans or mice, peripheral blood leucocytes showed that the presence of tocopherol monoglucoside (0.5 mM) in post-irradiation incubation medium did not enhance the repair of DNA strand breaks.

Keywords: DNA damage; comet assay; radioprotector; tocopherol monoglucoside; DNA repair enhancement; gamma radiation; low radiation; gel electrophoresis; DNA strand breaks; irradiation exposure; peripheral blood leucocytes .

DOI: 10.1504/IJLR.2007.014488

International Journal of Low Radiation, 2007 Vol.4 No.1, pp.43 - 52

Available online: 11 Jul 2007 *

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