Effects of Baicalin on barrier dysfunction of intestinal epithelial cells induced by hypoxia reoxygenation

Objective To investigate the effects of Baicalin on barrier dysfunction of intestinal epithelial cells induced by hypoxia reoxygenation injury. Methods Hypoxia reoxygenation injury models of rat's intestinal epithelial cell-6(IEC-6) were established.Optional Baicalin concentration was chosen by detecting cell proliferation by using methylthiazolyl tetrazolium(MTT) assay.IEC-6 cells were randomly divided into 5 groups: normal control group, hypoxia reoxygenation group, hypoxia reoxygenation+ 5.0×10-3 mol/L Baicalin group, hypoxia reoxygenation+ 1.0×10-3 mol/L Baicalin group, and hypoxia reoxygenation+ 0.2×10-3 mol/L Baicalin group.Supernatants were collected for the determination of malondialdehyde(MDA) and superoxide dismutase(SOD). Expressions of tight junction proteins [Occludin and Zonula Occludens 1(ZO-1)] and NF-κB protein were detected by using Western blot, and the expressions of occludin and ZO-1 mRNA were detected by using real-time fluorescence quantification-PCR. Results Baicalin had inhibition effects on cell proliferation induced by hypoxia reoxygenation injury(the normal control group absorbance value: 0.442±0.015, hypoxia reoxygenation group: 0.256±0.007, hypoxia reoxygenation+ 5.0×10-3 mol/L Baicalin group: 0.407±0.008; F=66.904, P<0.05). Compared with normal control group, the MDA protein level of hypoxia reoxygenation group in culture medium was increased[the normal control group: (3.502±0.231) mol/L, the hypoxia reoxygenation group: (5.541±0.143) mol/L]and SOD protein level was decreased[the normal control group: (20.073±0.493)×103 U/L, hypoxia reoxygenation group: (13.324±0.081)×103 U/L], Occludin and ZO-1 expressions were decreased, and NF-κB(p65)expression was increased(all P<0.05). Compared with the hypoxia reoxygenation group, along with Baicalin concentration increasing, MDA protein levels in the Baicalin groups were decreased[hypoxia reoxygenation+ 5.0×10-3 mol/L Baicalin group: (4.320±0.106) mol/L, hypoxia reoxygenation+ 1.0×10-3 mol/L Baicalin group: (4.578±0.080)mol/L, hypoxia reoxygenation+ 0.2×10-3 mol/L Baicalin group: (4.928±0.118)mol/L] and SOD levels were increased[hypoxia reoxygenation+ 5.0×10-3 mol/L Baicalin group: (18.462±0.284)×103 U/L, hypoxia reoxygenation+ 1.0×10-3 mol/L Baicalin group: (16.624±0.364)×103 U/L, hypoxia reoxygenation+ 0.2×10-3 mol/L Baicalin group: (14.023±0.140)×103 U/L], while protein and mRNA levels of Occludin and ZO-1 were increased, and NF-κB(P65)expression was decreased(all P<0.05). Conclusion Through NF-κB signaling pathways, Baicalin can alleviate intestinal epithelial cells barrier dysfunction induced by hypoxia reoxygenation. Key words: Baicalin; Gut barrier; Ischemia-reperfusion injury, hypoxia reoxygenation; Tight junction protein