Dietary polyphenols modulate intestinal barrier defects and inflammation in a murine model of colitis

Some polyphenols have been shown to promote the tight junction (TJ) barrier in intestinal cells. The present study investigated the ameliorative effects of polyphenols, curcumin, quercetin, naringenin or hesperetin, on experimental colitis with a particular focus on the TJ barrier in mice. Administration of dextran sulphate sodium (DSS) caused severe colon damage, indicated by body weight loss, clinical scores, and colon shortening, and TJ barrier impairment, indicated by FITC-dextran permeability. Supplemental feeding of polyphenols (0.3% (w/w)), curcumin, quercetin, naringenin or hesperetin, partially restored these symptoms although the levels of amelioration differed among the polyphenols tested. Feeding naringenin led to more effective restoration. The feeding of each polyphenol restored the expression of TJ proteins, such as zonula occludens-1, occludin, junctional adhesion molecule-A, and claudin-3, impaired by DSS administration. The colon barrier integrity correlated closely with the level of inflammation. Collectively, supplemental feeding of these polyphenols restores DSS-induced colitis, at least in part, through regulation of the colonic TJ barrier.