Reviewing preclinical evidence for potent anti-colitogenic effects of the "bee glue" propolis.

The incidence and disease burden of inflammatory bowel diseases including ulcerative colitis have risen significantly in recent years, and current treatment remains limited by adverse effects and insufficient long-term efficacy, creating demand for alternative or adjunct treatment options. The "bee glue" propolis, a natural compound with a long history of medicinal use, has attracted growing attention for its anti-oxidant, anti-inflammatory, and immune-modulatory properties. This review summarizes and critically evaluates research into anti-colitogenic effects of propolis and its bioactive molecules in experimental colitis animal models. Our structured literature search revealed 21 preclinical studies showing that application of propolis and derivatives resulted in clinical and histopathological improvement of colitis. Treated animals presented with reduced colonic inflammation, restored intestinal barrier integrity, and a more diverse commensal gut microbiota. Notably, the composition of propolis varied considerably between studies depending on geographical and botanical origins and extraction method of the compound, for instance. In conclusion, propolis and derivatives exert potent anti-colitogenic effects in vivo, and might constitute promising disease-alleviating treatment options in human intestinal inflammation, including ulcerative colitis that should be further unravelled in future clinical trials.