Anti-inflammatory effects of Huangqin tang extract in mice on ulcerative colitis

Abstract

Ethnopharmacological relevance: HuangqinTang (HQT) is a traditional Chinese formula which is composed of Scutellaria baicalensis Georgi, Paeonia lactiflora Pall, Glycyrrhiza uralensis Fisch, and Ziziphus jujube Mill. HQT has been used in China for a wide range of disorders, especially in gastrointestinal inflammation with symptoms of nausea, vomiting, diarrhea, abdominal cramps and so on.

Aim of the study: To investigate the protective effects of HQT extract on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) induced colitis in mice.

Materials and methods: Different doses of HQT extract (1, 2 and 4 g/kg/day) and salicylazosulfapyridine (SASP, 500 mg/kg/day) were administered by gavage for 7 days after the induction of colitis with TNBS. The effects were studied by macroscopic score, histological analysis, immunohistochemical study of Cyclo-oxygenase-2 protein expression, as well as by determination of inflammation markers such as myeloperoxidase (MPO) and mRNA expression levels of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6.

Results: In TNBS induced group, mice body weight decreased gradually and did not recover at the end of the experiment, as compared with that of control group (p<0.01). Edema and redness were also discovered in the colons profoundly and scores representing inflammation were all high in this group (p<0.01). The level of colonic MPO activity and the tissue levels of TNF-α, IL-1β and IL-6 were markedly increased (p<0.01). The mice treated with HQT extract and SASP recovered significantly compared with the TNBS group (p<0.01).

Conclusion: Our results suggested that the efficacy of HQT extract, especially at the higher dose, was analogous to that of SASP, which implicated its potential application as a natural alternative medicine in colitis treatment.

Keywords: Cyclo-oxygenase-2; Huangqin Tang extract; Interleukin-1β; Myeloperoxidase; Tumor necrosis factor-α; Ulcerative colitis.