Protective effects of 2-aminoethylthiosulfuric acid and structurally analogous organosulfur compounds against ionizing radiation

• Published in: Journal of Clinical Biochemistry and Nutrition Vol. 72; no. 2; pp. 117 - 125
• Main Authors: Takeshita, Keizo, Ueno, Megumi, Fujii-Aikawa, Kaori, Okazaki, Shoko, Ohta, Yuhei, Ozawa, Toshihiko
• Format: Journal Article
• Language: English
• Published: Japan SOCIETY FOR FREE RADICAL RESEARCH JAPAN 01-01-2023; Japan Science and Technology Agency; the Society for Free Radical Research Japan
• Subjects: Aqueous solutions; Body weight; Bone marrow; Cysteamine; Damage; Energy technology; Erythrocytes; Ionizing radiation; Irradiation; Leukocytes (neutrophilic); Nuclear weapons; Organosulfur compounds; Original; Protected species; Radiation; radiation protective agent; radical scavenger; reactive oxygen species; Scavenging; Spleen; sulfuric compound; thiosulfate ester; Toxic hazards; Toxicity; X ray irradiation; radical scavenger; radiation protective agent; thiosulfate ester; sulfuric compound; reactive oxygen species
• ISSN: 0912-0009; 1880-5086
• DOI: 10.3164/jcbn.22-88

High efficacy and minimal toxicity radioprotectors are desirable options for the hazards posed by nuclear medical and energy technologies and the dangers presented by nuclear weapons in an unstable global situation. Although cysteamine is an effective radioprotector, it has considerable toxicity. In this study, the protective effects of the less toxic organosulfur compounds 2-‍aminoethylthiosulfate (AETS), thiotaurine (TTAU), and hypotaurine (HTAU) against X-ray damage in mice were compared with that of cysteamine. Intraperitoneal injection of either AETS or cysteamine (2.2 mmol/kg body weight) 30 min before X-ray irradiation (7.0 Gy) provided 100% survival for 30 days, limited the decrease in erythrocytes and neutrophils over 9 days, and reduced damage to bone marrow and spleen over 9 days. Neither TTAU nor HTAU provided any protection. In mice, 30 min after AETS administration, non-protein thiol content increased in the spleen, indicating cysteamine generation by AETS hydrolysis, the active protective species of AETS. All examined compounds scavenged •OH under diffusion control in aqueous solution, which is inconsistent with the difference in the protective effects among the compounds. The results indicate that AETS protects animals from ionizing radiation by several mechanisms, including scavenging •OH as cysteamine.