The Antagonistic Effects Of Two Common Natural Antioxidants Curcumin And Vitamin E On Spleen Damage In Mice Induced By Dibutyl Phthalate (DBP)

Objective:Antioxidants curcumin(Cur)and vitamin E(Vit E)can clean up some reactive oxygen species like oxygen free radicalsin vivo,which arouse oxidative injury by a variety of signaling pathways.Dibutyl phthalate(DBP)is environmental oxidative stress,is also a ubiquitous environmental contaminant at levels which can be deleterious to human health.Spleen is the largest lymphoid organ of the body and plays an important role in the immune system.The purpose of this study was to explore the antagonistic effects of Vit E and Cur on DBP-induced spleen injury.Methods:54 male BALB/c mice were randomly divided into 6 groups(n=9):Saline group(Saline,gavage),DBP group(50 mg/kg/d DBP,gavage),Vit E group(50 mg/kg/d VitE,gavage),DBP+Vit E group(50 mg/kg/d DBP+50 mg/kg/d Vit E),Cur group(2.5 mg/kg/d Cur,intraperitoneal injection)and DBP+Cur group(50mg/kg/d DBP+2.5 mg/kg/d Cur).After consecutive 21 days of treatment,the changes of oxidative stress,inflammation and apoptosis in spleen of mice were reflected by measuring the contents of reactive oxygen species(ROS)and glutathione(GSH),the levels of interleukin-1β(IL-1β),cytochrome C(Cyt C),(Cysteine aspartic acid protease-9,Caspase-9),and(Cysteine aspartic acid protease-3,Caspase-3)in spleen homogenate.The histopathological changes of spleen were observed by H&E and toluidine blue staining,the phosphorylation of nuclear factor-κB(NF-κB)and the expression of CD3~+and CD8~+in T lymphocyte subsets were analyzed by immunohistochemistry.Results:The results of pathological observation showed that the interface between red pulp(RP)and white pulp(WP)in normal control group was clear,while in DBP group,the junction between RP and WP was blurred,the arrangement was sparse,and the number of lymphocytes was relatively decreased.The number of mast cells in WP increased significantly.Compared with the Saline group,the levels of ROS,IL-1β,Cyt C,Caspase-9,Caspase-3,NF-κB p65 in spleen tissue of DBP group were increased,while the levels of GSH and CD8~+were decreased(P<0.05).After treated with Vit E and Cur respectively,compared with DBP group,the levels of ROS,IL-1β,Cyt C,Caspase-9,Caspase-3,NF-κB p65 in spleen tissue of DBP group were decreased,while the levels of GSH and CD8~+were increased(P<0.05).Conclusion:(1)Exposure of 50 mg/kg DBP could alter spleen injury in the tested mice,which may lead to disorder of CD3~+and CD8~+expression in spleen;(2)The immune injury of DBP may be related to oxidative stress in spleen;(3)DBP could alter the changes of the inflammatory and apoptotic factors associated with oxidative stress in spleen;(4)Both Vit E and Cur could antagonize the oxidative stress of spleen induced by DBP,and improve the levels of spleen inflammation and apoptosis after DBP exposure to a certain extent,so that the morphology of spleen tissue tended to be normal.The above findings will be helpful to expand our understanding of antioxidant effects of Vit E、Cur and its possible mechanism,and suggest that Vit E and Cur can improve DBP-induced spleen injury and the DBP-associated decline of immune function.