60Coγ induction improves the protective effect of Acetobacter pasteurianus against ionizing radiation in mice.

Exposure to ionizing radiation (IR) tends to cause serious health concerns. Thus, radioprotective agents are vital for the population exposed to radiation. As microorganisms have the advantages of fast reproduction and no geographical restrictions, direct microbe-based and environmental induction compounds are thriving radioprotectants resources. Oxidative system and oxidase in Acetobacter pasteurianus are unique and intriguing, the radioprotective effect of the cell-free extract from A. pasteurianus (APE) and 60Coγ-treated extract (IRE) were comparatively investigated in the present study. The survival rate of A. pasteurianus with IRE addition was 149.1% in H2O2 damage test, while that with APE was only 10.4%. The viability of 60Coγ-treated AML-12 cells was increased by 18.8% with IRE addition, yet APE showed no significant radioprotective effect. Moreover, in 60Coγ-treated mice, IRE could significantly protect the white blood cell, improve the liver index, and attenuate the injuries of immune organs in mice. Administration of IRE significantly raised the activities of superoxide dismutase (SOD) and reduced the products of lipid peroxidation. These results clarified that gavage with APE and IRE presented notable antioxidant and radioprotective efficacy. A. pasteurianus showed appealing potential to be novel radioprotective bioagents and 60Coγ treatment on microbe could be a new method for the development of better radioprotectant. KEY POINTS: • 60Coγ induction could improve the radioprotective effect of APE. • IRE protected white blood cell in mice under IR. • IRE products have broad application prospects in radioprotection based on microbes.