Curcumin alleviated dextran sulfate sodium-induced colitis by recovering memory Th/Tfh subset balance

ARTICLE HIGHLIGHTS

Research background

Maintaining immune homeostasis by targeting memory immune cells is a crucial treatment strategy for autoimmune diseases. Discovering new drugs from natural plant medicine and traditional Chinese medicine to treat inflammatory bowel disease (IBD) is a research hotspot. Many researches had shown that curcumin (Cur) can effectively treat patients and animals with ulcerative colitis (UC). Although Cur can regulate the function of immune cells to alleviate UC in mice, whether Cur can regulate the memory T helper (mTh) cell- and memory follicular T helper (mTfh) cell-mediated homeostasis to treat IBD remains unknown.

Research motivation

To further widen the category of the immunopharmacological action of Cur and supply increasing scientific evidence for promoting the clinical application of Cur in IBD treatment.

Research objectives

To explore the potential mechanism underlying Cur-mediated alleviation of dextran sulfate sodium (DSS)-induced colonic pathological damage by observing changes in mTh and mTfh cells and their subsets and function.

Research methods

DSS was used to induce experimental colitis, and colitis was treated with Cur for 7 consecutive days. The therapeutic effect of Cur was evaluated through macroscopic and microscopic observations. The levels of mTh and mTfh cells and their subsets were detected through flow cytometry. SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels were measured through Western blotting.

Research results

Cur effectively alleviates DSS-induced colitis in mice, promotes the recovery of mouse weight and colonic length, and reduces colonic weight and the colonic weight index. Meanwhile, Cur inhibits ulcer formation and inflammatory cell infiltration in the colonic mucosa. The percentage of Th1, mTh1, Th7, mTh7, Th17, mTh17, Tfh1, mTfh1, Tfh7, mTfh7, Tfh17, and mTfh17 cells decreased after the mice with colitis were treated with Cur for 7 d, whereas the frequency of mTh10, Th10, mTfh10, and Tfh10 cells in the spleen of these mice increased. Additional studies revealed that the SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels significantly decreased in the colon tissue after Cur administration.

Research conclusions

Cur effectively alleviated DSS-induced colitis in mice by regulating mTh/Tfh cells, which was potentially realized by inhibiting the JAK1/STAT3/SOCS signaling pathway.

Research perspectives

Cur is a commonly used food additive and the main effective constituent of traditional Chinese medicine. Cur regulates the immune homeostasis mediated by memory T and B cells. This is a very promising and significant effect of Cur that can be used to develop the value of Cur as a healthcare product for preventing many chronic and recurrent diseases.