Protective effect of the methanol extract from Cryptotaenia japonica Hassk. against lipopolysaccharide-induced inflammation in vitro and in vivo

BACKGROUND: In folk medicine, the aerial part of Crytotaenia japonica Hassk. (CJ), is applied for treatment of the common cold, cough, urinary problems, pneumonia, and skin rashes. In this paper, the in vitro and in vivo anti-inflammatory activity of CJ methanol extract was tested using lipopolysaccharide (LPS)-induced inflammatory models. METHODS: We measured nitric oxide (NO), inducible NO synthase (iNOS), and inflammatory cytokine levels from LPS-stimulated mouse peritoneal macrophages. Also, several cellular signaling molecules which regulate the expressions of these inflammatory markers were examined. Finally, we tested whether oral administration of CJ methanol extract might affect the serum cytokine levels in LPS-injected mice. RESULTS: CJ methanol extract reduced NO release via iNOS protein inhibition. The extract was also shown to decrease the secretions of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-12. Analysis of signaling molecules showed that CJ inhibited the phosphorylation of STAT1, p38, JNK and ERK1/2 as well as IκBα degradation. Finally, CJ decreased the serum levels of TNF-α and IL-6 in LPS-injected mice. CONCLUSIONS: Our results demonstrated the anti-inflammatory activity of CJ methanol extract and its possible underlying mechanisms that involve modulation of IκBα, MAPK, and STAT1 activities.