Effect of curcumin regulated memory Th7 cells in mice with DSS-induced colitis

Abnormal activation or dysfunction of memory helper T (mTh) cells is closely associated with the development of ulcerative colitis (UC). Curcumin (Cur), the main component of turmeric, plays a critical role in the treatment of UC due to its favorable anti-inflammatory and immunomodulatory bioactivities. However, whether Cur modulates mTh7 cells to alleviate UC is unknown. In the present study, dextran sulphate sodium (DSS) was administered to establish a colitis model in mice. Our current findings indicated that Cur effectively ameliorated the manifestations of colitis in mice, and had a significant effect in reducing disease activity index (DAI), as well as in the colonic weight and the proportion of colonic weight to colonic length. While Cur reduced the pathological injuries of the colon, restore the length of the colon, inhibited the secretion of IL-7 and IL-21, restored the secretion of IL-2, IL-4, and IL-10. Furthermore, Cur had a regulatory effect on mTh7 cells and their subpopulation status. The results of molecular docking simulations and Surface Plasmon Resonance (SPR) indicated that Cur demonstrates strong interaction capabilities with both IL-7 and IL-7R and reduced the expression levels of IL-7/IL-7R mRNA and protein. It is suggested that the alleviation of DSS-induced colitis by Cur may be achieved by reducing the level of mTh7 cells and inhibiting the activation of IL-7/IL-7R signaling.