Protective Effects of Curcumin-Regulated Intestinal Epithelial Autophagy on Inflammatory Bowel Disease in Mice

This study was aimed at exploring the ameliorating effect of curcumin (Cur) on inflammatory bowel disease (IBD) in mice induced by 3% dextran sodium sulfate (DSS) by regulating intestinal epithelial cell autophagy.

45 BALB/c mice were randomly divided into three groups: control group, DSS group, and Cur group, with 15 mice in each group. Expect for the control group, 3% DSS was freely drunk by the mice for 7 days to induce acute IBD, and the Cur group was given Cur gavage treatment. Hematoxylin-Eosin (HE) staining was performed to observe the pathological changes of mice colon tissue. The formation of autophagosomes in intestinal epithelial cells was detected by transmission electron microscopy (TEM). The protein expressions of LC3-II/LC3-I, p62, and Beclin1 were detected by Western blot.

Compared with that of the control group, body weight of mice in DSS group was significantly reduced, stool was not formed or presented with loose stools, there was occult blood or blood in the stool, hair color lost luster, disease activity index (DAI) score was significantly increased, and colonic mucosal epithelial cells showed colitis; LC3-II/LC3-I and Beclin1 expression were significantly decreased (P < 0.05), p62 was significantly increased, and autophagy was not obvious. In addition, compared with that of the DSS group, the diet of mice in the Cur group was improved, the decline of body weight was slowed down, the hair glossiness was restored, the blood in the stool gradually decreased or occulted, the DAI score was decreased, the colon tissue was significantly improved, the expressions of LC3-II/LC3-I and Beclin1 were significantly increased (P < 0.05), and the p62 was significantly decreased.

The effect of Cur on IBD mice was related to the regulation of the expression of autophagy pathway proteins LC3-II/LC3-I, Beclin1, and p62 in intestinal epithelial cells.