Inhibitory effect of Coptis chinensis on inflammation in LPS-induced endotoxemia

Abstract

Ethnopharmacological relevance: Rhizoma coptidis (RC) has been used as a remedy for inflammation-related diseases in traditional medicine. Although it is known to have anti-inflammatory activities, its mechanism of action on lipopolysaccharide (LPS)-induced inflammation has not yet been identified in detail. Aim of the study: This study was designed to assess the beneficial effects of pretreatment with RC in ameliorating LPS-induced liver inflammation. Materials and methods: Mice were orally administered RC (500, 1000 mg/kg) for three days in a row. 1 h after the last RC administration, the mice were intraperitoneally injected with LPS (35 mg/kg). After treatment, histological alterations and inflammatory factor levels in the liver and proinflammatory cytokines in the serum associated with inflammation were examined. Results: We found that pretreatment with RC (500 and 1000 mg/kg) exerted a significant protective effect by attenuating liver histopathological changes in endotoxemic mice. The results also demonstrated that RC suppressed secretion of LPS-stimulated pro-inflammatory cytokines, such as interleukin-6 (IL-6). Furthermore, RC inhibited LPS-mediated nuclear factor (NF)-kappa B activation via the prevention of I kappa B-alpha phosphorylation, as well as the phosphorylation of ERK1/2, JNK, and p38 MAPKs. These results were associated with decreases in the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (I-NOS). Conclusions: The results presented here dearly demonstrate that RC could significantly protect mice against LPS-induced acute liver injury. (C) 2013 Elsevier Ireland Ltd. All rights reserved.