Radioprotective activity of betalains from red beets in mice exposed to gamma irradiation

We investigated the radioprotective activity of betalains from red beets in mice irradiated by a 60Co gamma (γ) ray (6.0 Gy, at a dose of 1.5 Gy min− 1). Mice were randomly divided into five groups, namely the control group and four experimental groups which were given one of four concentrations of betalains from red beets (0, 5, 20 and 80 mg/kg, equivalent to betanin) for 30 days. The four experimental groups of mice were then exposed to the 60Co γ-rays and were given betalains from red beets for a further 3 days. The number of white blood cells, karyota of the femur and the number of micronuclei in polychromatophilic erythrocytes of bone marrow in mice were determined. The activity of superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, spleen index and thymus index were also determined. The results indicate that the administration of betalains from red beets is radioprotective in mice irradiated by 60Co in vivo. The underlying mechanism remains unclear but appears to be mediated by the antioxidant activity of the betalains from red beets and modulation of the immune system.