Therapeutic effect of curcumin on experimental colitis mediated by inhibiting CD8⁺CD11c⁺ cells

To verify whether curcumin (Cur) can treat inflammatory bowel disease by regulating CD8⁺CD11c⁺ cells.

We evaluated the suppressive effect of Cur on CD8⁺CD11c⁺ cells in spleen and Peyer's patches (PPs) in colitis induced by trinitrobenzene sulfonic acid. Mice with colitis were treated by 200 mg/kg Cur for 7 d. On day 8, the therapeutic effect of Cur was evaluated by visual assessment and histological examination, while co-stimulatory molecules of CD8⁺CD11c⁺ cells in the spleen and PPs were measured by flow cytometry. The levels of interleukin (IL)-10, interferon (IFN)-γ and transforming growth factor (TGF)-β1 in spleen and colonic mucosa were determined by ELISA.

The disease activity index, colon weight, weight index of colon and histological score of experimental colitis were obviously decreased after Cur treatment, while the body weight and colon length recovered. After treatment with Cur, CD8⁺CD11c⁺ cells were decreased in the spleen and PPs, and the expression of major histocompatibility complex II, CD205, CD40, CD40L and intercellular adhesion molecule-1 was inhibited. IL-10, IFN-γ and TGF-β1 levels were increased compared with those in mice with untreated colitis.

Cur can effectively treat experimental colitis, which is realized by inhibiting CD8⁺CD11c⁺ cells.