Natural polyphenols in ulcerative colitis: preclinical mechanisms of action and therapeutic potential

Ulcerative colitis is an idiopathic, chronic inflammatory disease affecting the mucosa of the rectum and colon to a variable extent. Current therapeutic strategies demonstrate only moderate efficacy, highlighting the unmet need to develop new therapies that induce and maintain remission. Encouraging results have been obtained from pre-clinical studies and a few clinical trials using natural polyphenols for ulcerative colitis treatment. In this review, we mainly examine the available evidence from both in vivo and limited clinical studies supporting the therapeutic potential of natural polyphenols on ulcerative colitis and discuss their possible mechanisms of action. Notably, the gut microbiota emerges as a particularly attractive target of natural polyphenols in ulcerative colitis therapy. In conclusion, natural polyphenols show promise as therapeutic candidates for ulcerative colitis through multiple mechanisms, including inhibition of inflammation and oxidative stress, modulation of intestinal microbiota, immune response, autophagy, and enhancement of intestinal barrier function.