Echinacea purpurea (L.) Moench extract suppresses inflammation by inhibition of C3a/C3aR signaling pathway in TNBS-induced ulcerative colitis rats

Echinacea purpurea (L.) Moench (EP) is a perennial herbaceous flowering plant, commonly known as purple conical flower. It was widely used to treat skin inflammation and gastrointestinal diseases. Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease. Recent evidence shows that immune disorders are involved in the pathogenesis of UC. To evaluate the protective effect of Echinacea purpurea (L.) Moench exact (EE) on UC and explore the role of complement system in the treatment of UC. UC model was induced in rats by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and then rats were administered with EE for 10 days. Collect colon tissues for analysis of relevant mechanisms. EE could reduce the weight loss and diarrhea of UC rats. In addition, EE could improve the integrity of intestinal epithelial barrier in UC rats. EE inhibited the level of proinflammatory cytokines and promoted the antioxidation. Furthermore, EE suppressed the expression of C3aR, CFB, CD55, TLR4 and NLRP3. These results indicate that EE may achieve therapeutic effect by inhibiting C3a/C3aR signal pathway, suggesting that EE may be used as a medicinal plant to alleviate UC. [Display omitted] •EE could alleviated diarrhea of UC rats.•EE could improved the intestinal epithelial barrier integrity on UC rats.•EE suppressed the level of pro-inflammatory cytokines and contributed to the antioxidant effects.•EE suppressed the expression of C3aR, CFB, CD55, TLR4 and NLRP3, EE might achieve the therapeutic effect through inhibition of C3a/C3aR signaling pathway.