摘要目的：研究壳寡糖对脂多糖（LPS）诱导肠上皮细胞炎症的影响。方法肠上皮细胞Caco?2分为5组：正常对照组、模型组、壳寡糖高、中、低浓度组。以1μg/L LPS刺激细胞48h建立炎症模型。药物干预组于LPS刺激前2 h，分别以0.25，0.5和1.0 g/L壳寡糖预处理细胞。MTT法检测细胞活力。以ELISA法检测培养上清中炎症相关因子肿瘤坏死因子（TNF）?α，白介素（IL）?8和前列腺素（PG）E2水平。以Western印迹法检测细胞Toll样受体（TLR）4、核因子κB（NF?κB）及环氧酶（COX）2的表达变化。结果壳寡糖和/或LPS处理后Caco?2细胞存活率不受影响。与模型组相比，壳寡糖在0.25，0.5和1.0 g/L剂量下呈浓度依赖性地降低Caco?2细胞TNF?α（352.5±21.6，298.4±25.1，203.4±20.0 vs 436.8±38.7μg/L）和PGE2的释放（632.2±35.6，522.6±26.7，402.4±30.2 vs 822.3±23.5μg/L）（P<0.05；P<0.01），0.5和1.0 g/L壳寡糖可降低细胞COX?2表达水平（P<0.05；P<0.01）。壳寡糖中、高浓度组TLR4表达明显低于模型组（P<0.05），壳寡糖各剂量组NF?κB的表达水平显著降低（P<0.05；P<0.01）。结论壳寡糖可对抗LPS诱导的肠上皮细胞炎症，对炎性肠病具潜在保护作用。作用机理可能与TLR4\NF?κB信号通路抑制有关。

abstractsObjective To investigate the protective effect of oligochitosan on lipopolysaccharide (LPS)induced inflammation of the intestinal epithelial cells. Methods intestinal epithelial cells Caco?2 were divided into five groups:normal control group,model group,high?,medium? and low?level oligochitosan groups. In the oligochitosan groups,the cells were pre?treated with 0.25,0.5 and 1.0 g/L oligochitosan,respectively,at 2 h before LPS stimulation. MTT method was used for cell viability assay. ELISA was used to measure the levels of inflammation related cytokines,such as tumor necrotizing factor?related factor alpha (TNF?α),interleukin?8 (IL?8) and prostaglandin E2 (PGE2),in the cell culture supernatant. Western blotting was used to detect the changes in expression of Toll?like receptor 4(TLR4), nuclear factor κB(NF?κB)and cyclooxygenase 2(COX?2). Results The Caco?2 cell viability was not affected by treatment with oligochitosan and/or LPS. Compared with the model group,0.25,0.5 and 1.0 g/L oligochitosan reduced the production of TNF?α(352.5±21.6,298.4±25.1,203.4 ±20.0 vs 436.8±38.7μg/L, P<0.05)and PGE2(632.2±35.6,522.6±26.7,402.4±30.2 vs 822.3±23.5μg/L,P<0.01)in Caco?2 cells in a dose dependent manner;0.5 and 1.0 g/L oligochitosan reduced COX 2 expression(P<0.05 and P<0.01);medium?and high?level oligochitosan was significantly associated with lowered expression of TLR 4 compared with the model group (P<0.05);the expression of NF?κB in each group of oligochitosan dosage was&nbsp;significantly lowered (P<0.05;P<0.01). Conclusion Oligochitosan may reverse LPS ? induced inflammation of the intestinal epithelial cells and therefore may be potentially protective against inflammatory bowel diseases. The underlysing mechanism of this action may be related to inhibition of TLR4/NF?κB signaling pathway.