Comparison of the Radioprotective Properties of Riboxin (Inosine) and Indralin with Prophylactic Administration at Dosages of 100 mg/кg According to the Survival Criterion of Irradiated Mice

Relevance: Due to the high chemical toxicity of all known effective radioprotectors, studies of the radioprotective properties of safer drugs are very relevant. A sufficient number of works are devoted to the radioprotective properties of ribonucleoside riboxin (inosine). However, studies comparing the direct radioprotective properties of riboxin and a recognized radioprotector, for example, indralin, using a survival test in irradiated animals have not yet been carried out.

Purpose: Conduct a comparative assessment of the radioprotective properties of riboxin and indralin using a survival test in mice exposed to external X-ray radiation.

Material and methods: The experiment was carried out on 200 male ICR (CD-1) mice of the SPF category in duplicate. In each experiment, the animals were divided into the following groups, separated by body weight, 10 animals each: vivar control, not exposed to drugs and radiation, radiation control, with preliminary intraperitoneal administration of sterile water and exposed to external X-ray radiation in doses of 6.0, 6.5 and 6.75 Gy, experimental groups exposed to irradiation in the indicated doses with preliminary intraperitoneal administration of riboxin at a dosage of 100 ml/kg body weight or indralin at a dosage of 100 ml/kg. Survival was assessed for 30 days after irradiation. The dose change factor was determined using probit analysis as the ratio of the radiation dose causing the death of half of the irradiated animals that received the drug to the radiation dose causing the death of half of the irradiated animals without administration of the drug.

Results: The use of indralin before X-ray irradiation in doses of 6.0 Gy, 6.5 Gy and 6.75 Gy led to a statistically significant increase in the survival of animals compared to the group receiving Riboxin and control irradiation (р<0,05, log-rank test). Using equations derived from Phinney probit analysis, LD₅₀ doses were calculated for indralin and riboxin, from which dose change factors were calculated to be 1.8 and 1.07, respectively.

Conclusion: Since riboxin has not demonstrated radioprotective properties, its preventive use with intraperitoneal administration under the conditions described in this paper, for leveling the effects of radiation can be considered ineffective.