Propolis Flavonoids: Current Evidence in Animal Models and Future Promise for the Treatment of Ulcerative Colitis

Ulcerative colitis is a chronic, immune-mediated inflammatory bowel disease with a rising global incidence and a considerable economic burden. Conventional treatments, such as steroidal anti-inflammatory drugs and immunosuppressants, are often associated with adverse effects and high costs. In this context, flavonoids—such as those identified in the chemical composition of propolis—are emerging as highly promising therapeutic alternatives. This review highlights how diverse classes of flavonoids, including flavones, flavonols, flavanones, isoflavones, and flavan-3-ols, mitigate colitis through multiple interconnected mechanisms. Their main actions include reducing inflammation by decreasing the levels of proinflammatory cytokines and modulating key signaling pathways; exerting potent antioxidant activity; and improving intestinal barrier integrity by increasing tight junction proteins and mucin production. Numerous studies reporting significant improvements in clinical parameters such as body weight, colon length, and the disease activity index are discussed. Innovation in formulations, for example, the use of nanoparticles, is crucial to improve the solubility, stability, and bioavailability of flavonoids, allowing for their targeted delivery to the inflamed colon. In summary, flavonoids are promising candidates for the development of complementary or alternative treatments for ulcerative colitis. Although further clinical evidence is needed to establish their safety and conditions for use in humans, the available preclinical results are promising.