Icariin Inhibits Intestinal Inflammation of DSS-Induced Colitis Mice Through Modulating Intestinal Flora Abundance and Modulating p-p65/p65 Molecule.

Abstract

Ulcerative colitis, as a kind of inflammatory bowel disease (IBD) is characterized by abdominal pain. This study aimed to investigate the effect of icariin (ICA) on the intestinal microflora of colitis mice. Fifteen female C57BL/6 mice were randomly divided into the Control group, dextran sodium sulfate (DSS)-induced colitis (DSS) group, and ICA treatment (DSS+ICA) group. The severity of inflammation in DSS-induced colitis mice was evaluated using disease activity scoring (considering weight-loss percentage, stool-shape change, and stool-bleeding scoring). Pathological changes of mice intestinal tract were evaluated using hematoxylin-eosin (HE) staining. Serum levels of TNF-α and IL-6 were detected with enzyme-linked immunosorbent assay. Expressions of p65 and p-p65 (p-p65/p65 ratio) were analyzed using Western blot assay. 16S rDNA sequencing was used to analyze the abundance and composition of intestinal microflora. Compared with DSS group, ICA significantly improved disease activity (P < .05) and reduced inflammatory damage of colon tissues (P < .05) in DSS-induced colitis mice. Compared with the DSS group, mice in the ICA group demonstrated significant weight and colon length (P < .05). ICA significantly inhibited expressions of IL-6 and TNF-α compared to the DSS group (P < .05). p-p65/ p65 ratio in the DSS + ICA group was remarkably enhanced compared to the DSS group (P < .05). ICA significantly reduced the proportion and activity of Bacteroides, Helicobacteraceae, Turicibacter, and significantly increased that of beneficial microflora (Lactobacillus, Lachnospiraceae, Akkermansia), so as improved damages of colon tissues. ICA can improve intestinal flora abundance and composition of DSS-induced colitis mice, and inhibit tissue damage and inflammatory response through modulating the p-p65/p65 expression.