Studies on the potential for polyphenols as a complementary therapy for IBD have shown that the anti-inflammatory and immunomodulatory effects of tea flavonoids observed in liver tissue and endothelial cells—inhibition of COX-2, decreased NO production, NF-κB suppression—are also observed in the intestinal mucosa, resulting in overall amelioration of the inflammatory state of IBD [127,143,145]. This evidence concerns the gene NFKB1 and inflammatory bowel disease.