Luteolin ameliorates experimental colitis in mice through ERK-mediated suppression of inflammation, apoptosis and autophagy.

Ulcerative colitis (UC) is a chronic inflammatory disease with increasing incidence and prevalence worldwide. Currently used treatments of UC are unsatisfactory, while natural bioactive compounds are considered to be emerging therapeutic agents. Luteolin (Lut) is a natural compound with beneficial effects in a variety of diseases, however, its effect in UC has been poorly studied. In this study we investigated the effect of Lut in posttreatment and cotreatment of dextran sulfate sodium (DSS)-induced experimental colitis in mice. In addition, the role of extracellular signal-regulated kinases 1/2 (ERK1/2) in the mechanism of action of Lut in experimental colitis was investigated using the ERK inhibitor PD0325901. Lut attenuated symptoms of DSS-induced colitis in mice, ameliorated colon tissue damage and reduced inflammation, apoptosis and autophagy. The effect was more pronounced if Lut was administered simultaneously with DSS. The administration of ERK inhibitor exacerbated DSS-induced colitis symptoms and prevented the protective effects of Lut. The results provide new mechanistic details underlying the anti-inflammatory, anti-apoptotic and anti-autophagic effects of Lut through the activation of the ERK signaling pathway. This suggested that Lut can be used as a novel therapeutic candidate in the treatment of UC or could be used as a supplement to existing therapy.