Prevention of Gamma Radiation-Induced Mortality in Mice by the Isoflavone Genistein

摘要

There is a need to develop medical countermeasures to protect first- responders and remediation workers from the biomedical effects of ionizing radiation. Agents that can protect against ionizing radiation and that can be administered before radiation would permit rescue workers to perform needed operations. The ideal radioprotector would be nontoxic and would not degrade performance. Soy phytoestrogens have strong antioxidant activity and have been reported to have many beneficial health effects, including a reduction in bone loss and the incidence of some types of cancer. The most plentiful isoflavone from soybeans is genistein (4', 5, 7- trihydroxy-flavone). In the present study, the radioprotective and behavioral effects of an acute administration of the isoflavone genistein were investigated in adult CD2F1 male mice. They were administered a single subcutaneous dose of genistein, either 24 hr or 1 hr before a lethal dose of gamma radiation (9.5 Gy cobalt-60 at 0.6 Gy/min). The mice received vehicle or genistein at 3.12, 6.25, 12.5, 25, 50, 100, 200, or 400 mg/kg. For mice treated 24 hr before irradiation, there was a significant increase in 30-day survival for animals receiving genistein doses of 25 to 400 mg/kg.