Effects And Mechanisms Of Flavonoids Of Astragalus Complanatus Against Injuries Induced By Radiation

OBJECTIVE:To investigate the anti-irradiation effect and mechanism of flavonoids of Astragalus complanatus.METHODS:①The irradiation damage models of Kunming mice were established by 60Co gamma ray (6.0 Gy,at a dose rate of 1.00 Gy/min) in vivo. The protective effect of FAC against damage of irradiation were observed through survival rate of FAC - protected mice as well as the spleen,thymus indices and blood cell counts of FAC-protected mice; ConA-induced and LPS-induced splenocyte proliferation was determined by MTT assay;The protective effect of FAC against damage of irradiation was observed through staining of hematoxylin and eosin (HE).②Hemolysis of mice red blood cell (RBC) induced by H2O2 and the swelling of mice liver mitochondria induced by Fe2+ - Vit C were determined by spectrophotometric methods; The pyrogllol auto-oxidation was adopted to produce superoxide anion (O2·),the system H2O2/ Fe2+ was used to produce hydroxy radical (·OH) through Fenton reaction and spectrophotometry was used to detect the clearing functions of drugs with different concentrations against O2·,·OH and DPPH; SOD,MDA,GSH-px and T-AOC in mice with dose dependent manner were measured by tissue bomogenate;Furthermore the nuclear translacation of NF-κB p65 subunit and NF-κB inhibitor protein IκB-αwere observed by Western Blot.③The formation of micronuclei of chromosomes and quantity of marrow DNAin mice were measured by Giemsa staining method; Cytotoxia effect of BRL induced by H2O2 was analysed by single cell electrophoresis assay.RESULTS:①The 21-day survival rate of FAC-protected mice was 100% which was higher than mice of the control group; the spleen,thymus indexes and blood cell counts of FAC- protected mice were higher than those of the control group such as WBC,RBC,PLT,HGB and LY counts; ConA-induced and LPS-induced splenocyte proliferation in the group with FAC were higher than those of the control group . In the morphological study, compared with normal control group, as for the model control group, liver cell cords were disordered or disappeared; hepatic cells were swollen, some serious, hepatic cells appeared many necrotic areas, cellular nucleus concentrated, fragmentated, dissolved in necrotic areas, lymphocytes and neutrophils infiltrated in necrotic areas. While compared with model control group, in the treatment group, liver cell cords clear, liver antrum almost recovered to normal, hepatic cells developed slightly degeneration. The parenchymal hepatic cell necrosis and structure derangement of hepatic lobules in groups with FAC were lighter than in group without FAC.②The content of antioxidase of SOD and GSH-px in wice with FAC were heighten compared model without FAC.The lipid peroxidation was inhibited through decreaseing the amount of MDA in mice with dose dependent manner. T-AOC in mice was boosted by FAC. It is found that FAC has good scavenging effect on DPPH·,·OH and O2·that are above 60 %, especially scavenging effect on DPPH is above 90% ;The inhibition of mitochondrion swelling and erythrocyte hemolysis also be 50%; Furthermore the nuclear translacation of NF-κB p65 subunit were found decreasedly and NF-κB inhibitor protein IκB-αincreasely by western blot.③The micronuclear rates of marrow of FAC - protected mice was lower and quantity of marrow DNAwas higher than those of the control group; The leaking of DNAtails of FAC-treated cells was weaken.CONCLUSION:The result confirmed that FAC can alleviate irradiation damage induced by gamma-ray, which might be associated with ameliorating antioxidant level and protecting DNAin caryon.