Abstract:

Objective To discuss the improvement effect of curcumin combined with fecal bacteria transplantation on the mice with dextran sulfate sodium （DSS）-induced ulcerative colitis （UC），and to clarify the related mechanism. Methods Fifty mice were randomly divided into control， model， curcumin， fecal bacteria transplantation， and combination groups. Except for the mice in control group （given distilled water），the mice in the other groups were given distilled water containing 2% DSS to establish the UC models. The mice in curcumin group were gavaged with 0.4 mL of 60 mg·kg^－1 curcumin solution once per day for 10 d； the mice in fecal bacteria transplantation group underwent enema with 0.2 mL of fecal bacteria suspension once per day for 10 d； the mice in combination group received the enema of 0.2 mL fecal bacteria suspension and gavaged with 0.4 mL of 60 mg·kg^－1 curcumin solution. At the end of the experiment， the disease activity index （DAI） and colon macroscopic damage index （CDMI） of the mice in various groups were calculated； the morphology of colon tissue of the mice in various groups was detected by HE staining；the levels of interleukin （IL）-1β， tumor necrosis factor-α（TNF-α）， IL-4， and IL-10 in colon tissue of the mice in various groups were detected by enzyme-linked immunosorbent assay （ELISA） method；the expression levels of occludin and zonula occludens-1 （ZO-1） mRNA and proteins in colon tissue of the mice in various groups were detected by real-time fluorescence quantitative（RT-qPCR） and Western blotting methods. Results The intestinal mucosal epithelial structure of the mice in control group was intact and continuous with regular glandular arrangement and without inflammatory cell infiltration or ulceration； the intestinal mucosal epithelial structure of the mice in model group exhibited loss of colonic mucosal epithelium， disordered glandular arrangement， reduced goblet cells， congestion and edema in mucosal and submucosal layers， and extensive infiltration of inflammatory cells with widespread small ulcers； the intestinal mucosal epithelial structure of the mice in curcumin， fecal bacteria transplantation， and combination groups exhibited relatively intact colonic mucosal epithelial structures with reduced inflammatory cell infiltration and ameliorated mucosal and submucosal congestion and edema. Compared with control group， the DAI and CDMI of the mice in model group were increased （P<0.05）， the levels of IL-1β and TNF-α were increased （P<0.05）， the levels of IL-4 and IL-10 were decreased （P<0.05），and the expression levels of occludin and ZO-1 mRNA and proteins were decreased （P<0.05）；compared with model group， the DAI and CDMI of the mice in curcumin， fecal bacteria transplantation， and combination groups were decreased （P<0.05），the levels of IL-1β and TNF-α were decreased （P<0.05）， the levels of IL-4 and IL-10 were increased （P<0.05）， and the expression levels of occludin and ZO-1 mRNA and proteins were increased （P<0.05）. Compared with curcumin group and fecal bacteria transplantation group，the DAI and CDMI of the mice in combination group were decreased （P<0.05），the levels of IL-1β and TNF-α were decreased （P<0.05）， the levels of IL-4 and IL-10 were increased （P<0.05）， and the expression levels of occludin and ZO-1 mRNA and proteins were increased （P<0.05）. Conclusion Curcumin combined with fecal bacteria transplantation can ameliorate the pathological damage in colonic tissue of the UC mice， inhibit the secretion of inflammatory factors， and promote the repaiment of intestin mucosa.

Key words: Ulcerative colitis, Inflammatory factor, Curcumin, Fecal bacteria transplantation, Dextran sulphate sodium