Objective To investigate the protective effect of berberine on the injury of colon epithelial cells induced by dextran sulfate sodium(DSS).Methods NCM-460 cells were randomly divided into blank group(conventional culture),model group(40 mg·mL-1 DSS)and low-dose group(5 μmol·L-1 berberine),high-dose group(10 μmol·L-1 berberine),siRNA group(10 μmol·L-1 berberine+transfected siRNA plasmid),si-SelS group(10 μmol·L-1 berberine+transfected si-SelS plasmid).The expressions of selenioprotein S(SelS)were detected by Western blot;cell proliferation was detected by cell counting kit-8(CCK-8)and 5-ethynyl-2'-deoxyuridine(EdU)tests;trans epithellal electric resistance(TEER)levels were detected by Milli-cell ERS;superoxide dismutase(SOD)was detected by kit method;apoptosis was detected by flow cytometry.Results The relative expression levels of SelS protein in blank group,model group,high-dose group,siRNA group and si-SelS group were 1.02±0.13,0.42±0.05,0.90±0.08,0.89±0.10 and 0.30±0.03,respectively;the cell optical density at 48 h were 0.85±0.05,0.48±0.04,0.70±0.08,0.68±0.05 and 0.51±0.05,respectively;the EdU positive cell rates were(33.78±2.72)%,(11.90±2.00)%,(25.74±1.94)%,(24.29±1.96)%and(15.17±1.16)%,respectively;TEER values were(100.00±3.64)%,(43.47±4.19)%,(73.28±7.38)%,(76.25±7.68)%and(53.49±4.42)%,respectively;SOD activities were(13.32±0.73),(5.33±0.55),(9.63±1.13),(9.69±0.88)and(6.40±0.57)U·mL-1,respectively;the apoptosis rates were(3.21±0.02)%,(24.59±2.35)%,(10.90±1.09)%,(11.11±1.24)%and(16.73±1.56)%,respectively.The above indexes in the model group were compared with those in the blank group,and those in the high-dose group were compared with those in the model group.The above indexes of si-SelS group were statistically significant compared with those of siRNA group(all P<0.05).Conclusion Berberine can inhibit oxidative stress and improve DSS induced colon epithelial cell barrier damage by up-regulating SelS.