Changtai granule, a traditional Chinese drug, protects hapten-induced colitis by attenuating inflammatory and immune dysfunctions

The study was aimed to investigate the effects and mechanism of action of Changtai granule (CT), a traditional compound Chinese medicinal formula, in rodent 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis. Rats with TNBS/ethanol-induced colitis were used. The colonic wet weight, myeloperoxidase (MPO) activity, macroscopic and histological colon injury was observed. Inflammation cytokines were determined by ELISA methods and semi-quantitative RT-PCR. When dosed orally once daily, CT markedly attenuated TNBS-induced colitis. CT significantly attenuated colonic wet weight, macroscopic and histological colon injury. CT decreased mucosal mRNA levels for several inflammatory mediators: inducible nitric oxide synthase, cyclooxygenase 2, and macrophage inflammatory protein 2. CT also decreased mucosal mRNA and protein levels of T effectors cytokines: tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2) and interferon-gamma (IFN-gamma). Systemic levels of these cytokines were also dramatically attenuated. CD3/CD28-mediated costimulation of T helper 1 effector cytokines release in lamina propria mononuclear cells (LPMC) was markedly inhibited by CT ex vivo and in vitro. Also CT prevented cytokines production by nuclear factor-kappaB (NF-kappaB). The potential anti-inflammatory and immunomodulatory effect of CT in TNBS colitis suggests that CT may be an effective treatment approach for inflammatory bowel disease.