Xanthii fructus inhibits inflammatory responses in LPS-stimulated RAW 264.7 macrophages through suppressing NF-κB and JNK/p38 MAPK.

Xanthii fructus (XF) has long been used to treat a variety of inflammatory conditions in Korean traditional medicine, but the underlying mechanisms that could explain the anti-inflammatory actions of XF remain largely unknown. This study aimed to elucidate the anti-inflammatory effects of X. fructus (XF) and to examine its underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The effect of XF on LPS-induced mRNA and protein expressions of inflammatory mediators and cytokines were determined. Moreover, the activation of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and the expression of heme oxygenase-1 (HO-1) were explored to elucidate the anti-inflammatory mechanisms. XF significantly inhibited LPS-induced production of inflammatory mediators, interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2), without any cytotoxicity. However, it did not affect tissue necrosis factor (TNF)-α or IL-1β production in LPS-stimulated RAW 264.7 cells. Expression levels of inducible nitric oxide synthase (iNOS) mRNA and protein were inhibited dose-dependently by XF in LPS-stimulated RAW 264.7 cells, but there were no changes in cyclooxygenase-2 (COX-2) mRNA and protein. XF significantly attenuated LPS-induced phosphorylation and degradation of inhibitory kappa Bα (IκBα) and consequently reduced the nuclear translocation of p65 NF-κB. Pretreatment with XF also strongly inhibited the LPS-induced phosphorylation of p38 kinase and JNK, whereas the phosphorylation of ERK1/2 was not affected. In addition, XF led to an increase in HO-1 expression. Taken together, our findings support that XF inhibits LPS-induced inflammatory responses by blocking NF-κB activation, inhibiting JNK/p38 MAPK phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that it could be an attractive therapeutic candidate for various inflammatory diseases.

Yeom M ，Kim JH ，Min JH ，Hwang MK ，Jung HS ，Sohn Y ... -  《-》

Cnidilide, an alkylphthalide isolated from the roots of Cnidium officinale, suppresses LPS-induced NO, PGE(2), IL-1β, IL-6 and TNF-α production by AP-1 and NF-κB inactivation in RAW 264.7 macrophages.

Cnidilide, an alkyl phthalide isolated from the rhizome of Cnidium officinale, has been reported to possess antispasmodic and sedative effects. However, the anti-inflammatory capacity and molecular mechanism of cnidilide have not been studied to date. In the present study, we investigated the inhibitory effects of cnidilide on LPS-induced pro-inflammatory mediators and the underlying molecular mechanisms in RAW 264.7 macrophages. Our results indicated that cnidilide potently inhibits inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression at the protein and mRNA levels and their promoter activities, causing attendant decreases in the production of nitric oxide (NO) and prostaglandin E2 (PGE2). In addition, cnidilide reduced LPS-induced production and mRNA expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. Molecular data revealed that cnidilide inhibited LPS-induced transcriptional activity of activator protein-1 (AP-1) by reducing the phosphorylation and nuclear translocation of c-Fos and c-Jun. In addition, cnidilide attenuated LPS-induced transcriptional activity of nuclear factor-κB (NF-κB), and this reduction was accompanied by parallel reduction in the phosphorylation, but not in the translocation of p65 NF-κB. In addition, cnidilide inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and mitogen- and stress-activated protein kinase 1(MSK-1), a downstream kinase. Moreover, the phosphorylation of c-Jun N-terminal kinase (JNK) was suppressed by cnidilide in a concentration-dependent manner, whereas it did not inhibit the extracellular signal-regulated kinase (ERK) phosphorylation in LPS-stimulated RAW 264.7 macrophages. Taken together, our findings suggest that cnidilide has anti-inflammatory properties by inhibiting p38 MAPK, JNK, AP-1, and the NF-κB pathway in LPS-stimulated RAW 264.7 macrophages.

Lee WS ，Shin JS ，Jang DS ，Lee KT ... -  《-》

Euscaphic acid isolated from roots of Rosa rugosa inhibits LPS-induced inflammatory responses via TLR4-mediated NF-κB inactivation in RAW 264.7 macrophages.

As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we have evaluated the anti-inflammatory effects of euscaphic acid (19α-hydroxyursane-type triterpenoids, EA) isolated from roots of Rosa rugosa and its underlying molecular mechanisms in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. EA concentration-dependently reduced the production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) induced by LPS in RAW 264.7 macgophages. Consistent with these data, expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and iNOS, COX-2, TNF-α, and IL-1β mRNA were inhibited by EA in a concentration-dependent manner. In addition, EA attenuated LPS-induced DNA binding and transcriptional activity of nuclear factor-kappa B (NF-κB), which was accompanied by a parallel reduction of degradation and phosphorylation of inhibitory kappa Bα (IκBα) and consequently by decreased nuclear translocation of p65 subunit of NF-κB. Pretreatment with EA significantly inhibited the LPS-induced phosphorylation of IκB kinase β (IKKβ), p38, and JNK, whereas the phosphorylation of ERK1/2 was unaffected. Furthermore, EA interfered with the LPS-induced clustering of TNF receptor-associated factor 6 (TRAF6) with interleukin receptor associated kinase 1 (IRAK1) and transforming growth factor-β-activated kinase 1 (TAK1). Taken together, these results suggest that EA inhibits LPS-induced inflammatory responses by interference with the clustering of TRAF6 with IRAK1 and TAK1, resulting in blocking the activation of IKK and MAPKs signal transduction to downregulate NF-κB activations.

Kim IT ，Ryu S ，Shin JS ，Choi JH ，Park HJ ，Lee KT ... -  《-》

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

Jung HW ，Seo UK ，Kim JH ，Leem KH ，Park YK ... -  《-》

Chrysanthemum indicum Linné extract inhibits the inflammatory response by suppressing NF-kappaB and MAPKs activation in lipopolysaccharide-induced RAW 264.7 macrophages.

Cheon MS ，Yoon T ，Lee DY ，Choi G ，Moon BC ，Lee AY ，Choo BK ，Kim HK ... -  《-》