Chitooligosaccharide Effects On LPS-induced Oxidative Damage Of IPEC-J2 Cells

Objective:This study was designed to investigate the effect of Chitooligosaccharide (COS) on oxidative stress and used Lipopolysaccharide (LPS)-induced epithelial cells of pig jejunum (IPEC-J2) as an in vitro model of oxidative stress.Providing a theoretical basis for the clinical application of COS.Methods:1.Used MTT to detect the activity of cell proliferation. The cells were treated by different concentration of LPS(0、1.1、1、10μg/ml) and COS(0、50、100、200、400μg/ml),and divided into different acting time (12h、24h、48h).2.The researches were divided into control group, LPS group, COS group and LPS+COS group,and then detected the expression of Nrf2 and HO-1 by Western Blot.And detected by immunohistochemical of P38, JNK,8-OHDG protein expression in each group.Used thiobarbituric acid Colorimetric to detect the content of MDA, and ammonium molybdate Colorimetric to detect the of activity CAT,and xanthine oxidase colorimetric to detect the activity of SOD.3.The experimental data used statistical analysis software SPSS 19.0 t-test method for single-factor analysis of variance comparisons, with P<0.05 as the difference, results were expressed in mean ± standard error.Results:1.The optimum concentration of LPS and incubated time for model was 1μg/ml and 24h,the cell proliferation rate was 41.6%:COS promoted the proliferation of IPEC-J2. worked best when its concentration was 200μg/ml and incubated 24h. the cell proliferation rate was 126.3%2.Nrf2 and HO-1 protein expression was significantly higher in the LPS+COS group than in the control group (p<0.05); Nrf2 protein expression was significantly higher in the LPS+COS group than in the LPS group (p<0.05). there was an increasing trend in the HO-1 protein expression.3.The activity of SOD and CAT,and the contents of MDA were not significant different in LPS+COS group and the control group (p>0.05); The activity of SOD and CAT were increased significantly in the LPS+COS group than in the group of LPS(p<0.05),and the contents of MDA was decreased significantly in the LPS+COS group than in the group of LPS (p<0.05).4.The expression of P38 and 8-OHdG protein were increased significantly in LPS group than in the control group (p<0.05); The expression of P38 and 8-OHdG protein were decreased significantly in the LPS+COS group than in the LPS group(p<0.05); The expression of JNK protein in each group were not significant different(p>0.05).Conclusion:COS can reduce the expression of 8-OHdG and P38 protein, induce high expression of Nrf2 and HO-1, improve the activity of antioxidant enzymes, reduce the content of oxidative products, increase cellular resistance to oxidative stress, and play a protective role on IPEC-J2.