Abstract
OBJECTIVE: To investigate whether traditional Chinese herbal formula Yupingfeng (YPF) powder has an anti-inflammatory effect on colonic inflammation, and to explore the mechanism involved. MATERIALS AND METHODS: YPF powder was orally administrated to trinitrobenzene sulfonic acid (TNBS)-induced colitis mice at the dose of 3, 6, and 12 g/kg/d for 7 consecutive days. Body weight, stool consistency, histopathological score, and myeloperoxidase (MPO) activity were tested to evaluate the effect of YPF powder on colonic inflammation while colonic enterochromaffin (EC) cell density and serotonin 5-hydroxytryptamine (5-HT) content were investigated to identify the effect of YPF powder on colonic 5-HT availability. RESULTS: The results showed that the body weight of colitis mice was markedly decreased by 10, 12, 14, and 17% at 1, 3, 5, and 7 days (P < 0.05), whereas stool consistency score (3.6 vs. 0.4, P < 0.05), histopathological score (3.6 vs. 0.3, P < 0.05), and MPO activity (2.7 vs. 0.1, P < 0.05) in colitis mice were significantly increased compared to that of the normal mice; YPF powder treatment dose-dependently increased the body weight (7-13% increase) and decreased the stool consistency score (0.4-1.4 decrease), histopathological score (0.2-0.7 decrease), and MPO activity (0.1-0.9 decrease) in colitis mice. Colonic EC cell density (70% increase) and 5-HT content (40% increase) were markedly increased in colitis mice (P < 0.05), YPF powder treatment dose-dependently reduced EC cell density (20-50% decrease), and 5-HT content (5-27% decrease) in colitis mice. CONCLUSION: The findings demonstrate that the anti-inflammatory effect of YPF powder on TNBS - induced colitis may be mediated via reducing EC cell hyperplasia and 5-HT content. The important role of YPF powder in regulating colonic EC cell number and 5-HT content may provide an alternative therapy for colonic inflammation.