Comet assay and antioxidant enzyme as blood biomarkers of low-dose radiation-induced adaptive response

This study investigated the ability of low doses to cause an in vivo radio-adaptive response (RAR) and examined the biological effects of acute low-dose total-body gamma irradiation in rats. Adult male rats were randomly divided into 8 groups. Acute gamma radiation doses of 0.25, 0.5, and 0.75 Gy for groups 2, 3, and 4, respectively, and a 2 Gy challenge dose for group 5 were administered 14 days later. then 0.25, 0.50, and 0.75 Gy, followed by 2 Gy to groups 6, 7, and 8. Twenty-four hours after irradiation, measurements were made of comet assay parameters and antioxidant indicators: Acute gamma exposure resulted in a significant rise in Comet Assay Score CAS (6-16%), Tail Length TL (4.7-7.45 μm), DNA in tail DNA% (11.82-17.76%), Tail Moment TM (1.17-3.78 μm), and Olive Tail Moment OTM (0.53-1.52 µmol/L), as well as dose-dependent increases in GSSG (4.6-9.58 µmol/L), and decrease in SOD (180.4-91.2 U/mL). These results demonstrate the rising detrimental consequences linked to higher acute gamma doses. Lower priming does encourage stronger adaptive responses, according to RAR analysis. The concentrations of GSSG, TL, OTM, and the ratio of Oxidized Glutathione/ Reduced Glutathione GSSG/GSH showed notable linear dose-response associations, indicating their potential as biomarkers for acute gamma radiation biodosimetry. These findings lay the groundwork for future research to verify these markers for dose evaluation and to examine the dynamics of RAR under various challenge doses and postirradiation circumstances.