Abstract
Background: Mucosal inflammation and ulcer play important roles in the pathogenesis of ulcerative colitis. As as traditional Chinese medicine compound composed of Periplaneta americana and Taraxacum mongolicum, Ento-PB is always prescribed for the treatment of ulcer and inflammatory diseases. As for the significant role of P. americana in terms of promoting mucosal healing, the compatibility of the anti-inflammatory drug T. mongolicum may enable Ento-PB to simultaneously play anti-inflammatory and promote mucosal healing effects on the treatment of UC. Therefore, this study aimed to evaluate the therapeutic potential and possible mechanism of Ento-PB for UC by establishing an acetic acid-induced colitis model in dogs.Methods: Preliminary identification to the chemical components of compound Ento-PB was carried out through high performance liquid chromatography. A cross-bred dogs model of acetic acid-induced ulcerative colitis was established to evaluate the efficacy of compound Ento-PB. The expression levels of inflammatory cytokines C-reactive protein (CRP), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-10 (IL-10) in plasma were measured by carrying out enzyme-linked immunosorbent assay (ELISA).Results: With the extension of treatment time, Ento-PB could effectively improve clinical symptoms of UC cross-bred dogs. Colonoscopy displayed that mucosal redness, swelling and congestion decreased gradually, and obviously repaired after mucosal injury. The intestinal texture was gradually clear, and the colonoscopy score gradually reduced. Histopathological examination revealed that the structure of colon was restored significantly, the infiltration of inflammatory cells was reduced, and the histological score was remarkably reduced. At the same time, the results of dynamic monitoring of inflammatory cytokines in plasma proved that Ento-PB can gradually down-regulate the activity of CRP, iNOS and COX-2, reduce the expression levels of inflammatory cytokines TNF-α and IL-1β, and gradually restore anti-inflammatory and the expression level of cytokine IL-10.Conclusions: Ento-PB reduces the level of pro-inflammatory cytokines in a dose- and time-dependent manner and inflammation, improves colon tissue lesions and the repair of intestinal mucosa after injury, and effectively increases acetic acid-induced colon inflammation in UC cross-bred dogs.
The new experimental ulcerative colitis model in rats induced by subserosal injection of acetic acid.
