Flower extract of Panax notoginseng attenuates lipopolysaccharide-induced inflammatory response via blocking of NF-κB signaling pathway in murine macrophages

Aim of the study: The root of Panax notoginseng (PN) is commonly used to treat chronic liver disease with its therapeutic abilities to stop haemorrhage in the circulation, while the PN flower (PN-F) is largely unknown in the biological activities on inflammation and mechanisms of its actions. In this study, the pharmacologic effects of PN-F methanol extract on inflammation were investigated to address potential therapeutic or toxic effects in LPS-stimulated mouse macrophage cells, RAW264.7 cells. Materials and methods: Production of NO, PGE(2) and pro-inflammatory cytokines (TNF-alpha and IL-1 beta) in supernatant. the expression of iNOS, COX-2 and cytokines, the phosphorylation of MAPK moleduces (ERK1/2, JNK and p38 MAPK), and the activation of NF-kappa B in PN-F extract were assayed in LPS-stimulated RAW264.7 cells. Results: PN-F extract significantly inhibited the productions of NO, PGE2, TNF-alpha and IL-1 beta on the LPS-stimulated RAW264.7 cells. In addition, PN-F extract suppressed the mRNA and protein expressions of iNOS, COX-2, TNF-alpha and IL-1 beta in LPS-stimulated RAW264.7 cells. The molecular mechanism of PN-F extract-mediated attenuation in RAW264.7 cells has close a relationship to suppressing the phosphorylation of MAPK molecules such as ERK1/2,JNK and p38 MAPK, and the translocation of NF-kappa B p65 subunit into nuclear. Conclusion: These results indicate that PN-F extract inhibits LPS-induced inflammatory response via the blocking of NF-KB signaling pathway in macrophages, and demonstrated that PN-F extract possesses anti-inflammatory properties in vitro. (C) 2008 Elsevier Ireland Ltd. All rights reserved.