<p>Astaxanthin, a carotenoid pigment, is believed to be effective in the repair of</p><p>DNA damage. Our study evaluates the effect of astaxanthin on DNA damage in</p><p>rats exposed to whole-body</p><p>radiotherapy using the comet assay. Thirty-two</p><p>male</p><p>rats were randomly divided into four groups (control, ionizing radiation, astaxanthin,</p><p>and radiation+astaxanthin). The radiation and radiation+astaxanthin</p><p>groups were exposed to X-rays</p><p>at a dose of 8 gray (0.62 gray/min). Astaxanthin</p><p>was administered at 4 mg/kg by gavage for 7 days starting from irradiation. The</p><p>%TailDNA parameter was chosen as an indicator of DNA damage and the results</p><p>were compared using one-way</p><p>ANOVA. %TailDNA was 3.24 ± 3.12 in the control</p><p>group, 2.85 ± 2.73 in the astaxanthin group, 4.11 ± 7.90 in the radiation group, and</p><p>3.59 ± 4.05 in the radiation+astaxanthin group. There was a significant increase</p><p>in DNA damage in the radiation group, compared with the control and astaxanthin</p><p>groups (p &lt; .001). DNA damage was reduced in the radiation+astaxanthin</p><p>group compared with the radiation group (p &lt; .05). Although this decrease did</p><p>not reduce damage to the level of the control group, it was significant. The decrease</p><p>in radiation-induced</p><p>DNA damage by astaxanthin administration in our</p><p>study supports the hypothesis that astaxanthin is a promising agent for against/</p><p>reducing DNA damage.</p>