The Study Of The Selenium-enriched Houttuynia Cordata On Preventing And Treating Radiation-induced Lung Injury

Objective(1)To establish rats model of radiation-induced lung injury.(2)To explore the preventive and therapeutic effect of selenium-enriched Houttuynia cordata on radiation-induced lung injury.Methods(1)Thirty male SD rats were randomly divided into the model group(25 rats)and the blank control group(5 rats).The rats of model group were positioned under CT to determine the irradiation field and the right chest was irradiated 20 Gy at one time and the blank group received sham radiation.After 2,4,8 and 12 weeks of irradiation,the rats were sacrificed and lung tissues were taken,and HE staining and Masson staining were adapted to observe the inflammation and fibrosis of the lung tissues.(2)SD rats were randomly divided into 8 groups:selenium-enriched Houttuynia cordata prevention group,hormone prevention group,selenium-enriched Houttuynia cordata + hormone prevention group,selenium-enriched Houttuynia cordata treatment group,hormone treatment group,selenium-enriched Houttuynia cordata+ hormone treatment group,model group and blank control group.The blank control group received sham radiation and the other seven groups were positioned under CT to determine the irradiation field and the right chest was irradiated 20 Gy at one time.The preventive group was administered some drugs 1 week before the irradiation,the therapeutic group was administered some drugs 1 week after the irradiation,and the model group and the blank control group were administered the same amount of normal saline.After 2,4,8 and 12 weeks of irradiation,the rats were sacrificed and blood samples were collected and ELISA was adapted to mensurate the concentration of TGF-?1,TNF-?,SOD and GPX-1 in serum.Results(1)Four rats in the model group died after irradiation.The lung tissues of rats in the model group showed different degrees of inflammatory cell infiltration and fibrosis.Classification of pulmonary inflammation: 5 rats in the blank group were grade 1;In the model group,9 rats in grade 2,10 in grade 3,and 2 in grade 4.Classification of pulmonary fibrosis: 5 rats in the blank control group were grade 1;Inthe model group,2 rats in grade 1,4 in grade 2,9 in grade 3,and 6 in grade 4.(2)The lung coefficient,TGF-?1 concentration and TNF-? concentration in the model group were significantly higher than those in the blank control group and the drug treated groups(p<0.05),and the SOD concentration and GPX-1 concentration were significantly lower than those in the blank control group and the drug treated groups(p<0.05).There was no significant difference in lung coefficient and TGF-?1concentration between the preventive groups and the therapeutic groups(p>0.05).The concentrations of TNF-? in the rats in the preventive groups were significantly lower than those in the therapeutic groups(p<0.05).The SOD concentration of the rats in the Houttuynia cordata prevention group or combined with hormones was significantly higher than that in other drug treated groups(p<0.05).Using selenium-enriched Houttuynia cordata alone or combined with hormones could significantly increase the expression of GPX-1(p<0.05),but there was no significant difference in the concentration of GPX-1 between the preventive groups and the therapeutic groups.Conclusion(1)By means of CT localization,rat models of acute radiation-induced lung injury can be successfully constructed by 20 Gy irradiation on the right chest.(2)TGF-?1 and TNF-? significantly increase and SOD and GPX-1significantly decrease.TGF-?1?TNF-??SOD and GPX-1 have important effects on the pathological development of radiation-induced lung injury.(3)Selenium-enriched Houttuynia cordata can inhibit inflammatory response through reducing the expression of inflammatory substances and enhance the ability of removing ROS by up-regulating the expression of SOD and GPX-1,and it can delay or reduce the process of radiation-induced lung injury and play a preventive role.