Protective effects of soybean isoflavone against gamma-irradiation induced damages in mice.

In the present work, we investigated the radioprotective efficacy of soybean isoflavone (SI) in mitigating gamma-irradiation-induced oxidative damage to the livers and blood systems of adult Swiss albino mice. We administered various doses of SI (50 mg/kg b.wt, 100 mg/kg b.wt, and 400 mg/kg b.wt) to the mice for seven consecutive days before exposing them to a single dose of 4.56 Gy 60Co-gamma whole-body irradiation. The irradiated mice continued to receive SI for two or seven days before sacrifice. The SI treatments significantly elevated liver catalase (CAT) and glutathione peroxidase (GPx) enzyme activities and mRNA abundances, and decreased the malonaldehyde (MDA) levels. The SI treatments also accelerated the recovery of circulating white blood cells (WBCs) and reticulocytes (RETs) seven days following irradiation. These effects were dose-dependent, and the strongest effect on most biomarkers (but not on histopathology) was seen with an intermediate dose. Our results provide useful information for future investigations, and strongly implicate a clinical application for SI.