Effects And Mechanism Of Enteromorpha Polysaccharide On Diquat-induced Oxidative Stress Mice

The body will produce a lot of free radicals through external stimulation(high temperature,high humidity,radiation and some chemical reagents),which will lead to oxidative stress,affect the animal production performance,improve morbidity and mortality,thus cause serious economic losses in the livestock industry.In this study,Diquat was used to establish a model of oxidative stress in mice.The anti-oxidation index,liver anti-oxidation and related factors,and expression of ileal inflammatory factors in serum were detected to identify the small amount of Diquat induced by EP.The protective effect and mechanism of the mouse oxidative stress model provide a reference for its production and application.40 clean-grade ICR female mice were randomly divided into four groups(n=10): normal control group,Diquat group,EP group,Diquat and EP group.All mice were fed with basal diet and free to eat and drink for 19 days.EP was dissolved in sterile water.Oxidative stress of mouse was induced by intraperitoneally injection of Diquat(600 mg/kg)on day 9 and 14,Control mice were given the same volume of saline.All mice were slaughtered on the nineteenth day of the experiment and their serum and tissues were collected.1.The mitigative effect of EP on oxidative stress induced by DiquatBy detecting serum antioxidant index and enzymes in the glutathione reduction system that related to investigate the effects of EP on growth performance,antioxidant index and serum glutathione reduction system of mice.The results demonstrate that EP added in drinking water could reduce the growth inhibition of mice caused by Diquat in a certain extent and the activity of antioxidant enzymes such as CAT,SOD and GSH-Px in the serum of mice.2.The mitigative effect of EP on liver injury caused by DiquatBy detecting pathological changes of hepatic tissues,factors related to oxidative stress,factors of glutathione reduction system,expression levels of inflammatory factors and the expression of genes related to STAT3 signal pathway to explore the effects of EP on hepatic oxidative stress of mice induced by Diquat.The results reveal that EP added in drinking water could inhibit the decreasing of antioxidant enzyme activity such as CAT,SOD,and GSH-Px,decrease the expression levels of IL-6,IL-1β and TNF-α but increase the expression level of IL-22 in liver.In addition,EP could alleviate the oxidative damage of liver caused by Diquat through regulating the expression of IL-22 gene to activate the STAT3 signal pathway and upregulating the expression levels of BCl-2 and BCl-XL.3.The mitigative effect of EP on intestinal injury caused by DiquatBy observing the ileal intestinal morphology,detecting the expression of tight junction protein in ileal epithelial cells,the expression of ileal inflammatory factors and the expression of NF-κB signaling pathway-related genes,the effects of EP on ileal oxidative stress induced by Diquat in mice were investigated.The results indicate that EP added in drinking water could reduce the injury to ileac epithelial villus height and crypt depth,repair the intestinal morphological injury,up-regulate the expression of ZO-1,Occludin and Claudin-1,and activate the NF-κB signal pathway to restore the abundances of IL-1β,TNF-α and IL-6 in ileum.Therefore,it is inferred from the above results that EP could protect the intestinal barrier by regulating the expression of tight junction proteins of intestinal epithelial cells and the secretion of inflammatory factors.