Impact of Orally Administered Royal Jelly on the Dynamic Metabolism of ¹³⁷Cs, ¹³¹I and ⁸⁵Sr in Mice

Abstract

The Fukushima nuclear accident released various radionuclides, including ¹³⁷Cs, ¹³¹I and ⁹⁰Sr, into the environment. At present, there is public concern about internal exposure to these radionuclides via contaminated foodstuffs, and therefore there is an urgent need for an effective and easily obtainable radioprotective agent. It has been reported that royal jelly (RJ) functions as an antioxidant for protection against DNA oxidation. We therefore postulated that administration of RJ would reduce internal exposure to radiation and/or promote the metabolic turnover of radionuclides. In this study, we evaluated whether or not RJ would act as a radioprotective agent. We analyzed the biodistribution of ¹³⁷Cs, ¹³¹I and ⁸⁵Sr in mice administered RJ orally for 1 week. Accumulation of these radionuclides was significantly decreased in the RJ-treated mice, and the radionuclides were mainly excreted into the urine. RJ decreased the accumulation of ¹³¹I in the thyroid gland particularly. In addition, we succeeded in visualizing the effect of RJ non-invasively by gamma-ray emission imaging (GREI) , which is a multiple nuclide imaging modality.