Genistein treatment protects mice from ionizing radiation injury

The radioprotective and behavioral effects of an acute administration of the isoavone genistein (4′,5,7‐trihydroxyavone) were investigated in adult CD2F1 male mice. Mice were administered a single subcutaneous (s.c.) dose of genistein either 24 h or 1 h before a lethal dose of gamma radiation (9.5‐Gy of cobalt‐60 at 0.6 Gy min −1 ). Mice received saline, PEG‐400 vehicle or genistein at 3.125, 6.25, 12.5, 25, 50, 100, 200, or 400 mg kg −1 body weight. For mice treated 24 h before irradiation there was a signicant increase in 30‐day survival for animals receiving genistein doses of 25 to 400 mg kg −1 ( p < 0.001). In contrast, the 30‐day survival rates of mice treated with genistein 1 h before irradiation were not signicantly different from those of the vehicle control group. Additionally, the acute toxicity of genistein was evaluated in non‐irradiated male mice administered a single s.c. injection of saline, vehicle, or genistein at 100, 200 or 400 mg kg −1 . At these genistein doses there were no adverse effects, compared with controls, on locomotor activity, grip strength, motor coordination, body weight, testes weight, or histopathology. These results demonstrate that a single s.c. administration of the avonoid genistein at non‐toxic doses provides protection against acute radiation injury. Published in 2003 by John Wiley & Sons, Ltd.