Phytochemicals for the treatment of inflammatory bowel diseases

Inflammatory bowel diseases are a widespread problem of unclear aetiology in western as well as eastern societies. Even though there are established therapies to treat inflammatory bowel diseases, the clinical efficacy of these treatments is still not satisfactory. Plant derived compounds demonstrated promising results in pharmacological models of inflammation and few were also evaluated in early clinical trials. Classes of secondary metabolites with anti-inflammatory properties include isoprenoids, stilbenes, flavonoids, and alkaloids as well as structurally related compounds. Most of them affect nuclear factor kappa B activity, modulate enzymes and transcription factors, or reduce cytokine secretion. In addition to evaluating the anti-inflammatory abilities of natural products measured in vivo or in vitro models by immunological and enzymatic assays, some structure–activity-relationship studies were performed in order to find correlations between chemical features and anti-inflammatory activity for further optimization of chemical structures.