Protective Effect Of Cyanidin-3-O-glucoside On Radiation-induced Damage In Mice And Its Mechanism

With the development of nuclear industry,the application of radiation technology in medical diagnosis and treatment is becoming more and more extensive,and the relationship between radiation and people is getting closer.However radiation caused great harm to the hematopoietic system,the immune system,and the nervous system.As non-toxic and harmless radiation protection agents,the natural products have great prospects.The purpose of this study was to investigate the protective effect of cyanidin-3-O-β-glucoside(C3G),a predominant anthocyanin from blue honeysuckle,on radiation-induced damage and its mechanism.(1)Separation and purification of C3G: Using polyamide resin chromatography and high performance liquid preparative chromatography to separate and purify the anthocyanin complex components from the blue pod,a single C3 G component was obtained.The purity of the prepared sample was determined to be 95.74% by HPLC.(2)C3G scavenging free radical activity in vitro: In vitro free radical scavenging activity experiments were performed to compare the scavenging activities of the blueberry anthocyanin complex component,C3 G and the positive control-ascorbic acid ABTS free radical,DPPH free radical,hydroxyl radical and superoxide anion free radical.The above four free radical scavenging activities of C3 G were higher than those of the blue pod anthocyanin complex component.Among them,C3 G has a higher scavenging activity on ABTS radicals and hydroxyl radicals than ascorbic acid.Studies have shown that C3 G is a good natural antioxidant and free radical scavenger.(3)Protective effects of C3 G on radiation-induced oxidative stress injury in mice: The 60Coγ radiation damage models in mice were established as normal control group,radiation control group,positive control group,low dose C3G(50mg/kg bw)group and high dose C3G(150 mg/kg bw)group.Amifostine(200mg/kg)was injected intraperitoneally before radiation as a positive control group.Through the study of mouse body weight,organ index,peripheral blood leukocyte count,bone marrow cell micronucleus number,liver tissue morphological change analysis,T-SOD activity,CAT activity,GSH level and MDA content determination in serum,we have studied the protective effects of C3 G on radiation-induced oxidative damage in mice.The results showed that C3 G can effectively increase the index of immune organs in irradiated mice,improve the morphological changes of liver in mice,increase the number ofperipheral blood leukocytes in mice and reduce the micronucleus rate of bone marrow cells.C3 G inhibited radiation-induced oxidative stress on cells and tissues damage significantly by increasing T-SOD and CAT activities and GSH level and decreasing the content of MDA in serum of mice.(4)The mechanism of C3 G radiation protection in mice: Realtime quantitative PCR and Western blot were used to study the expression of related RNA and proteins in liver tissue of mice.The mechanism of C3 G radiation protection in mice was explored.Studies have found that radiation led to decreased expression of Nrf2 and downstream proteins of HO-1,GST,and NQO1 in mice.Compared with the irradiation group,the expression of both total Nrf2 and Nrf2 in nucleus of the C3 G intervention group significantly increased,and the expression of HO-1,GST,and NQO1 also increased significantly.The results showed that C3 G upregulated the expression of Nrf2,promoted nuclear transport of Nrf2,activated the expression of downstream antioxidant proteins HO-1,GST and NQO1,and activated Nrf2 pathway.Thus C3 G inhibits radiation-induced oxidative stress damage in mice.