Indirubin-3-monoxime exhibits anti-inflammatory properties by down-regulating NF-κB and JNK signaling pathways in lipopolysaccharide-treated RAW264.7 cells

Objective  

Indirubin-3-monoxime (I3M), an indirubin analogue that shows favorable inhibitory activity targeting cyclin-dependent kinase and glycogen synthase kinase, exhibits various biological properties, including chemopreventive, antiangiogenic, and neuropreventive activities. In the present study, we investigated the ability of I3M to regulate inflammatory reactions in macrophages.     

Chikusetsusaponin V inhibits inflammatory responses via NF-κB and MAPK signaling pathways in LPS-induced RAW 264.7 macrophages

Excessive activation of macrophages is implicated in various inflammation resulted injuries. Saponins from Panax japonicus (SPJ) have been shown to possess anti-inflammatory activities. However, whether Chikusetsusaponin V (CsV), the most abundant component of SPJ, can exert anti-inflammatory activities is unknown. The present study was aimed to investigate the anti-inflammatory effects of CsV in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells and the underlying mechanisms. Our data showed that CsV dose-dependently inhibited NO, iNOS, TNF-α and IL-1β expressions in LPS-stimulated RAW264.7 cells. Increased protein levels of nuclear NF-κB and elevated phosphorylation levels of ERK and JNK in LPS-stimulated RAW 264.7 cells were also found downregulated by CsV treatment. Furthermore, the increase of CD14 and TLR4 mRNA expression due to LPS stimulation were significantly reversed by CsV treatment. These results suggested that CsV attenuated LPS-induced inflammatory responses partly via TLR4/CD14-mediated NF-κB and MAPK pathways.     

Tat-biliverdin reductase A inhibits inflammatory response by regulation of MAPK and NF-κB pathways in Raw 264.7 cells and edema mouse model

Reactive oxygen species (ROS) accumulation induces oxidative stress and cell damage, which then activates several signaling pathways and triggers inflammatory response. Biliverdin is a natural product of heme metabolism which is converted to bilirubin by the enzyme biliverdin reductase A (BLVRA) which also plays a role in antioxidant activity via the ROS scavenging activity of bilirubin. In this study, we examined the anti-inflammatory and anti-apoptotic effects of Tat-BLVRA protein on lipopolysaccharide (LPS)-induced inflammation in Raw 264.7 macrophage cells. Transduction of Tat-BLVRA protein into Raw 264.7 cells and mice ear tissue was tested by Western blot analysis and immunohistochemical analysis. Tat-BLVRA protein was effective in inhibiting mitogen activated protein kinases (MAPKs), Akt and NF-κB activation, intracellular ROS production and DNA fragmentation. Also, Tat-BLVRA protein significantly inhibited the expression of cytokines, COX-2, and iNOS. In a 12-O-tetradecanoylphobol 13-acetate (TPA)-induced mouse model, mice ears treated with Tat-BLVRA protein showed decreased ear thickness and weight, as well as inhibited MAPKs activation and cytokine expression. Thus we suggested that Tat-BLVRA protein may provide an effective therapeutic agent for inflammatory skin diseases.     

Artemisinin inhibits inflammatory response via regulating NF-κB and MAPK signaling pathways

Artemisinin, isolated from the Chinese plant Artemisia annua, has been used for many years to treat different forms of malarial parasites. In this study, we explored the anti-inflammatory activity of artemisinin and the underlying mechanism of this action. We demonstrated that the anti-inflammatory effects of artemisinin in TPA-induced skin inflammation in mice. Then the artemisinin significantly inhibited the expression of NF-κB reporter gene induced by TNF-α in a dose-dependent manner. Artemisinin also inhibited TNF-α induced phosphorylation and degradation of IκBα, p65 nuclear translocation. Artemisinin also has an impact on upstream signaling of IKK through the inhibition of expression of adaptor proteins, TNF receptor-associated factor 2 (TRAF2) and receptor interacting protein 1 (RIP1). Furthermore, pretreatment of cells with artemisinin prevented the TNF-α-induced expression of NF-κB target genes, such as anti-apoptosis (c-IAP1, Bcl-2, and FLIP), proliferation (COX-2, cyclinD1), invasion (MMP-9), angiogenesis (VEGF), and major inflammatory cytokines (TNF-α, iNOS, and MCP1). We also proved that artemisinin potentiated TNF-α-induced apoptosis. Moreover, artemisinin significantly impaired the ROS production and phosphorylation of p38 and ERK, but did not affect the phosphorylation of JNK. Taken together, artemisinin may be a potentially useful therapeutic agent for inflammatory-related diseases.     

Stevioside Suppressed Inflammatory Cytokine Secretion by Downregulation of NF-κB and MAPK Signaling Pathways in LPS-Stimulated RAW264.7 Cells

Stevioside, a diterpene glycoside isolated from Stevia rebaudiana, has been reported to have anti-inflammatory properties. However, the underlying molecular mechanisms are not well understood. The objective of this study was to investigate the molecular mechanism of stevioside in modifying lipopolysaccharide (LPS)-induced signal pathways in RAW264.7 cells. RAW264.7 cells were stimulated with LPS in the presence or absence of stevioside. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα) protein, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) were determined by western blot. The results showed that stevioside dose-dependently inhibited the expression of tumor necrosis factor-α, interleukin-6, and interleukin-1β in LPS-stimulated RAW264.7 cells. Western blot analysis showed that stevioside suppressed LPS-induced NF-κB activation, IκBa degradation, phosphorylation of ERK, JNK, and P38. Our results suggest that stevioside exerts an anti-inflammatory property by inhibiting the activation of NF-κB and mitogen-activated protein kinase signaling and the release of proinflammatory cytokines. These findings suggest that stevioside may be a therapeutic agent against inflammatory diseases.     

Immune-enhancing effects of a polysaccharide PRG1-1 from Russula griseocarnosa on RAW264.7 macrophage cells via the MAPK and NF-κB signalling pathways

Polysaccharides are one of many bioactive compounds found in edible mushrooms. Edible mushrooms have become attractive as “health foods” and as source materials for immunomodulators. The aim of this project was to study the immunoregulatory effects of a purified polysaccharide derived from wild Russula griseocarnosa (PRG1-1) on macrophages. Our data showed that in RAW264.7 macrophage cells, PRG1-1 increased expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, PRG1-1 increased the production of nitric oxide (NO) and cytokines, including interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α). Western blotting demonstrated that the regulation of NO and cytokines was mediated through the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathways. Therefore, PRG1-1 has the capacity to activate macrophages via the NF-κB and MAPK pathways. These findings helped to elucidate the immune-modulatory properties of the polysaccharide from R. griseocarnosa.     

Imperatorin Attenuates LPS-Induced Inflammation by Suppressing NF-κB and MAPKs Activation in RAW 264.7 Macrophages

Imperatorin is a type of coumarin compound with antibacterial and antiviral activities. In the present study, we examined the anti-inflammatory effects of imperatorin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by investigating its impact on the production and expression of cytokines and the major signal-transduction pathways. We found that imperatorin downregulated LPS-induced levels of TNF-??, IL-1??, and IL-6 in RAW 264.7 macrophages in a concentration-dependent manner, and it significantly inhibited expression of TNF-?? and IL-6 (P?<?0.05 or P?<?0.01). The phosphorylation of mitogen-activated protein kinases and nuclear factor-kappaB (NF-??B) p65 protein were analyzed by western blotting. In RAW 264.7 macrophages treated with 1?mg/L of LPS, imperatorin significantly inhibited p38 and Jun N-terminal kinase phosphorylation protein expression. However, there was no significant change in p-ERK. Furthermore, imperatorin also inhibited NF-??B translocation into the nucleus through blockage of I??B?? phosphorylation and degradation.     

Cryptotanshinone Suppressed Inflammatory Cytokines Secretion in RAW264.7 Macrophages through Inhibition of the NF-κB and MAPK Signaling Pathways

Cryptotanshinone (CTS), a major constituent extracted from the medicinal herb Salvia miltiorrhiza Bunge, has well-documented antioxidative and anti-inflammatory effects. In the present study, the pharmacological effects and underlying molecular mechanisms of CTS on lipopolysaccharide (LPS)-induced inflammatory responses were investigated. By enzyme-linked immunosorbent assay, we observed that CTS reduced significantly the production of proinflammatory mediators (tumor necrosis factor-α and interleukin-6) induced by LPS in murine macrophage-like RAW264.7 cells. Mechanistically, CTS inhibited markedly the phosphorylation of mitogen-activated protein kinases (MAPKs), including ERK1/2, p38MAPK, and JNK, which are crucially involved in regulation of proinflammatory mediator secretion. Moreover, immunofluorescence and western blot analysis indicated that CTS abolished completely LPS-triggered nuclear factor-κB (NF-κB) activation. Taken together, these data implied that NF-κB and MAPKs might be the potential molecular targets for clarifying the protective effects of CTS on LPS-induced inflammatory cytokine production in macrophages.     

Peimine impairs pro-inflammatory cytokine secretion through the inhibition of the activation of NF-κB and MAPK in LPS-induced RAW264.7 macrophages

Abstract

In the previous study, we found that peimine has good anti-inflammatory effects in vivo. However, the anti-inflammatory mechanism of peimine remains unclear. We, therefore, assessed the effects of peimine on inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We found that peimine (0–25?mg/L) significantly inhibited tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and increased IL-10 production. Furthermore, peimine significantly inhibited the phosphorylation of p38, ERK and c-jun N-terminal kinase (JNK) as well as decreased p65 and IκB. The present results indicate that peimine inhibits the production of inflammatory cytokines induced by LPS through blocking MAPKs and NF-κB signaling pathways.     

Regulation of the polymeric immunoglobulin receptor by the classical and alternative NF-κB pathways in intestinal epithelial cells

The polymeric immunoglobulin receptor (pIgR) transports IgA antibodies across intestinal epithelial cells (IECs). Expression of pIgR is upregulated by proinflammatory signaling pathways via activation of nuclear factor-κB (NF-κB). Here, we examined the contributions of the RelA-dependent classical and RelB-dependent alternative pathways of NF-κB to pIgR regulation in the HT-29 human IEC line following stimulation with tumor necrosis factor (TNF), lipopolysaccharide (LPS; Toll-like receptor 4 (TLR4) ligand), and polyinosinic: polycytidylic acid (pIC; TLR3 ligand). Whereas induction of proinflammatory genes such as interleukin-8 (IL-8) required only RelA, pIgR expression was regulated by complex mechanisms that involved both RelA and RelB. Upregulation of pIgR expression by ligation of the lymphotoxin-β receptor suggested a direct role for the alternative NF-κB pathway. Inhibition of mitogen-activated protein kinases reduced the induction of IL-8, but enhanced the induction of pIgR by TNF and TLR signaling. Regulation of pIgR through unique signaling pathways could allow IECs to sustain high levels of IgA transport while limiting the proinflammatory responses.     

Inhibition of c-Jun N-terminal kinase and nuclear factor κ B pathways mediates fisetin-exerted anti-inflammatory activity in lipopolysccharide-treated RAW264.7 cells

Although fisetin, a natural flavonoid, was known to inhibit proliferation, carcinogenesis and inflammation, the underlying anti-inflammatory mechanism of fistein still remains unclear. Thus, in the present study, the anti-inflammatory mechanism of fisetin was investigated in association with mitogen-activated protein kinase (MAPK) and nuclear factor κ B (NF-κB) pathways in lipopolysaccharide (LPS)-stimulated RAW264.7 mouse macrophages. We found that fisetin significantly reduced the nitrate oxide (NO) production and also inhibited the expression of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) at protein and mRNA levels in LPS-stimulated cells. Consistently, fisetin significantly reduced the LPS-stimulated secretion of proinflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor α (TNF-α). Furthermore, fisetin suppressed the activation of nuclear factor κ B (NF-κB) and the phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal regulated kinase (ERK) and p38 MAPK in LPS-treated RAW264.7 cells. Overall, our findings demonstrate that fisetin exerted anti-inflammatory activity via inactivation of JNK and NF-κB in LPS-stimulated macrophage cells.     

Soybean glyceollins mitigate inducible nitric oxide synthase and cyclooxygenase-2 expression levels via suppression of the NF-κB signaling pathway in RAW 264.7 cells

Glyceollins, produced to induce disease resistance responses against specific species, such as an incompatible pathogen Phytophthora sojae in soybeans, have the potential to exhibit anti-inflammatory activity in RAW 264.7 cells. To investigate the anti-inflammatory effects of elicited glyceollins via a signaling pathway, we studied the glyceollin signaling pathway using several assays including RNA and protein expression levels. We found that soybean glyceollins significantly reduced LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the expression of inducible ΝΟ synthase (iNOS) and cyclooxygenase-2 (COX-2) via the suppression of NF-κB activation. Glyceollins also inhibited the phosphorylation of IκBα kinase (IKK), the degradation of IκBα, and the formation of NF-κB-DNA binding complex in a dose-dependent manner. Furthermore, they inhibited pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-18, but increased the generation of the anti-inflammatory cytokine IL-10. Collectively, the present data show that glyceollins elicit potential anti-inflammatory effects by suppressing the NF-κB signaling pathway in RAW 264.7 cells.     

Curcumin inhibits ox-LDL-induced MCP-1 expression by suppressing the p38MAPK and NF-κB pathways in rat vascular smooth muscle cells

Objective  

This study was designed to identify the inhibitory effect of curcumin on ox-LDL-induced monocyte chemoattractant protein-1 (MCP-1) production and investigated whether the effects are mediated by mitogen-activated protein kinase (MAPK) and NF-κB pathways in rat vascular smooth muscle cells (VSMCs).     

Benzoylaconine Modulates LPS-Induced Responses Through Inhibition of Toll-Like Receptor-Mediated NF-κB and MAPK Signaling in RAW264.7 Cells

Inflammation - Previous studies have shown that benzoylaconine (BAC), a representative monoester alkaloid, has a potential anti-inflammatory effect. This study investigated the underlying molecular...     

Sulglycotide ameliorates inflammation in lipopolysaccharide-stimulated mouse macrophage cells by blocking the NF-κB signaling pathway

Abstract

Objective: Several studies demonstrated that sulglycotide has anti-inflammatory and anti-cancer effects. However, the effect of sulglycotide is limited to gastric mucosal tissues and cells and underlying molecular mechanisms are not clear. This study estimated the effect of sulglycotide on lipopolysaccharide (LPS)-induced inflammatory responses in the macrophage cell line, RAW 264.7 and elucidated the molecular mechanisms.

Materials and methods: The inhibitory effect of sulglysotide on LPS-induced oxidative stress and inflammatory reactions were determined by Immunofluorescence staining, ELISA, Western blotting and RT-PCR.

Results: Our results show that sulglycotide has the ability to inhibit inflammatory mediators and cytokine production as well as reactive oxygen species (ROS) generation. This effect can be the result from regulating the activation of nuclear factor-kappa B (NF-κB) through blocking mitogen-activated protein kinase (MAPK) intracellular signaling pathways.

Conclusions: These results indicate that sulglycotide could be an anti-inflammatory and anti-oxidative compound that may be a useful candidate for treatment of inflammatory diseases.