The present study aims to investigate the strong neuro and radio-protective activity of chelating agents through inhibition of metal catalyzed Fenton reaction and aims to explore the potential of PCR-RFLP as biomarkers. Polymorphisms of rat brain angiotensin II subtype 2 receptor gene (AT2RG) were investigated as a biomarker for the effect of 6 Gy irradiation with or without prior carnosine and dimer­captosuccinic acid (DMSA) injection alone or in combination. AT2RG was separated into purified form (≈2950 bp) using PCR magnification followed by digestion of AT2RG with restriction endonucleases which gave different polymorphism profiles which illustrated the following, strong antioxidant activity of carnosine alone and moderate antioxidant activity of DMSA. Maximum protection was achieved by the dual action of both carnosine and DMSA. Antioxidants prevented oxidative stress induced mutations of AT2RG that confer stability to its function such as neuroprotection and blood pressure osmoregulation. PCR-RFLP analysis explored the possibility of using of AT2RG polymorphisms restricted by XbaI, Acc65I restriction endonucleases as characteristic of new biomarkers for non radiation exposed individuals.