Potential of Dragon’s Blood as a Space Radiation Protectant Especially on Brain-Liver Bystander Effect

During space manned missions,radiation is a serious health risk.Radiation can not only directly cause damage to target organs but also trigger side effects to affect nontarget organs.Dragon’s Blood(DB)is a traditional Chinese Dai medicine that has been proven to exhibit radioprotective effects in our lab previously.It can alleviate brain damage,hematopoietic dysfunction,and gastrointestinal damage caused by radiation in rats,but its mechanism of action is not clear yet.In order to study the effect of brain irradiation on the damage to the liver and the protective effects of Dragon’s Blood,herein,liquid chromatography coupled with a mass spectrometer was used to analyze the total differential protein expression in the rat liver after 30 Gy Co^(60)γ-ray whole-brain irradiation with/without administration of Dragon’s Blood for 10 days before irradiation.A total of 4557 proteins were identified in the rat liver.A total of 299 coexpressed differential proteins were screened in the RAD/CON group indicating that brain radiation significantly affected the liver’s metabolic system(such as drug and arachidonic acid metabolism),chemical carcinogenesis,and peroxisome process.A total of 85 differential proteins were screened in the DB/RAD group.Results indicated that Dragon’s Blood significantly regulated the expression of 26 proteins to normal levels(Msrb2,Txnrd2,Samm50,Pir,Pex11a,etc.)mainly through regulating the metabolism and redox homeostasis process.The results of molecular docking and network pharmacology found that the main effective radiation protection components in Dragon’s Blood are natural chalcones,flavan,and phenolic derivatives.