Objective To observe the effects of pycnogenol on contents of SOD and MDA,and the inhibition of superoxide anion and hydroxyl radical in 60Co γ-ray exposed mice organs.Methods The mice were randomly divided into 3 groups i.e.the normal control,irradiation control and pycnogenol experiment groups.The irradiation control and pycnogenol experiment groups were exposed to 60Co γ-ray,and the mice of pycnogenol experiment group were given pycnogenol for 7 days after radiation.The tissues were obtained after being sacrificed,in which the vitality of SOD,the content of MDA and the inhibition of superoxide anion and hydroxyl radical were detected.Results Results showed that after the mice were irradiated pycnogenol had no effect on SOD;however,the content of MDA could be reduced in organs.Pycnogenol could increase the inhibition of superoxide anion and hydroxyl radical in kidney,liver and testicular and could increase the inhibition of hydroxyl radical in spleen.Conclusions Pycnogenol shows certain anti-radiation effect through scavenging the superoxide anion and hydroxyl radical without increasing SOD content.

Objective To study the change and significance of DNA methylation pattern and DNA methyltransferase(DNMT1) protein in 60Co γ-ray irradiated mice tissues.Methods Twelve SPF C57BL/6J mice were randomly divided intocontrol group and radiation group.The radiation group were exposed to 4Gy-single whole body radiation.All mice were sacrificed 3 days after the radiation.The total number of peripheral white blood cells and the frequencies of micronucleated polychromatic erythocytes(fMNPCE) were measured.Methylated DNA immunoprecipitation-chip(MeDIP-chip) was adopted to investigate the differentially expressed CpG islands methylation profiles in mouse liver genome promoter.The immunohisto-chemical(SP method) and western blot method were used to check the expression of DNMT1 protein in tissues.Results Compared with the control group,the promoter methylation profiles of irradiated mice changed obviously,with 1300 genes methylated and 660 genes demethylated.With the improvement of the screening criteria,the obviously methylated genes were Trim71,Sema3f,Pcdh8,Sox4,1110034A24Rik,Limk1,Nefl,and Xpr1 and the demethylated genes were Sfrs18,Dr1,Ankrd42,Nae1,Sfi1,Accn1,Srd5a1,Nsun2,Eif1a,and Dusp5.Except in the lung,the expression of DNMT1 protein in liver,kidney,testicle,and brain tissues were all increased(P0.05).Conclusion There are methylation changes of gene promoter in ionizing radiation injury and the increased expression of DNMT1 may be the reason of gene promoter methylation.