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.     

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.     

Spirodela polyrhiza (L.) Sch. ethanolic extract inhibits LPS-induced inflammation in RAW264.7 cells

Objective: Spirodela polyrhiza (L.) Sch. is widely used in Korean traditional medicine. No previous work has investigated in detail the anti-inflammatory activities of S. polyrhiza or assessed in vitro their potential underlying mechanism(s). We assessed the effects of S. polyrhiza ethanolic extract (SPEE) on the production of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and investigated some potential underlying mechanisms. Additionally, we performed simultaneous determination of seven flavonoids in S. polyrhiza by high-performance liquid chromatography (HPLC)-photodiode array (PDA).

Materials and methods: RAW264.7 cells were subjected to 5, 10, 20, and 50 μg/mL of SPEE for 1 h then treated with LPS for 24 h. Production of namely nitric oxide (NO), prostaglandin E₂ and cytokine levels were measured by the Griess reagent and ELISA, respectively. To investigate the underlying mechanisms of the anti-inflammatory activities of SPEE, expression of NO synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-κB) proteins were evaluated by western blot analysis. HPLC analysis was performed using a Gemini C₁₈ column at 40°C and PDA detection at 340 nm.

Results: SPEE treatment significantly inhibited the LPS-induced production of NO, prostaglandin E₂, interleukin-6, and tumor necrosis factor-α and inhibited the expression of iNOS and COX-2 via attenuation of NF-κB p65 expression. The contents of the seven flavonoids in S. polyrhiza range from 0.25 to 8.77 mg/g.

Conclusions: These results indicate that the anti-inflammatory activity of SPEE may be NF-κB p65 signaling. Also, the method will help to improve quality control of S. polyrhiza.     

Upregulation of heme oxygenase-1 via PI3K/Akt and Nrf-2 signaling pathways mediates the anti-inflammatory activity of Schisandrin in Porphyromonas gingivalis LPS-stimulated macrophages

The lipopolysaccharide (LPS) of Porphyromonas gingivalis is thought to induce periodontitis. In this study, we isolated Schisandrin from the dried fruits of Schisandra chinensis and examined the anti-inflammatory effect of Schisandrin in macrophages stimulated with LPS from P. gingivalis. First, Schisandrin inhibited LPS-induced pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. And Schisandrin suppressed the nuclear translocation and activity of NF-κB and phosphorylation of IκBα in LPS-stimulated RAW 264.7 cells. Next, the presence of a selective inhibitor of HO-1 (SnPP) and a siRNA specific for HO-1 inhibited Schisandrin-mediated anti-inflammatory activity. Furthermore, Schisandrin induced HO-1 expression of RAW 264.7 cells through Nrf-2, PI3K/Akt, and ERK activation. Therefore, these results suggest that the anti-inflammatory effects of Schisandrin on P. gingivalis LPS-stimulated RAW 264.7 cells may be due to a reduction of NF-κB activity and induction of the expression of HO-1, leading to TNF-α, IL-1β, and IL-6 down-regulation.     

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.     

Anti-inflammatory Effects of Ethanolic Extract from Sargassum horneri (Turner) C. Agardh on Lipopolysaccharide-Stimulated Macrophage Activation via NF-κB Pathway Regulation

Inflammation is major symptom of the innate immune response by infection of microbes. Macrophages, one of immune response related cells, play a role in inflammatory response. Recent studies reported that various natural products can regulate the activation of immune cells such as macrophage. Sargassum horneri (Turner) C. Agardh is one of brown algae. Recently, various seaweeds including brown algae have antioxidant and anti-inflammatory effects. However, anti-inflammatory effects of Sargassum horneri (Turner) C. Agardh are still unknown. In this study, we investigated anti-inflammatory effects of ethanolic extract of Sargassum horneri (Turner) C. Agardh (ESH) on RAW 264.7 murine macrophage cell line. The ESH was extracted from dried Sargassum horneri (Turner) C. Agardh with 70% ethanol and then lyophilized at ?40?°C. ESH was not cytotoxic to RAW 264.7, and nitric oxide (NO) production induced by LPS-stimulated macrophage activation was significantly decreased by the addition of 200?μg/mL of ESH. Moreover, ESH treatment reduced mRNA level of cytokines, including IL-1β, and pro-inflammatory genes such as iNOS and COX-2 in LPS-stimulated macrophage activation in a dose-dependent manner. ESH was found to elicit anti-inflammatory effects by inhibiting ERK, p-p38 and NF-κB phosphorylation. In addition, ESH inhibited the release of IL-1β in LPS-stimulated macrophages. These results suggest that ESH elicits anti-inflammatory effects on LPS-stimulated macrophage activation via the inhibition of ERK, p-p38, NF-κB, and pro-inflammatory gene expression.     

Anti-inflammatory effects of physalin E from Physalis angulata on lipopolysaccharide-stimulated RAW 264.7 cells through inhibition of NF-κB pathway

Physalin E is a naturally occurring seco-steroid isolated from the stems and aerial parts of Physalis angulata L. (Solanaceae). This study was aimed to explore the anti-inflammatory effects of physalin E on RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS) and the potential underlying mechanisms. The results showed that physalin E significantly inhibited LPS-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression and secretion in a dose-dependent manner. Unlike dexamethasone, these effects could not be blocked by miferstone (RU486). Meanwhile, physalin E reduced the degradation of I-kappa B protein in the cytoplasm and downregulated the nuclear factor-κB (NF-κB) p65 protein in the nuclear, which resulted in the inhibition of the NF-κB nuclear translocation. In conclusion, physalin E exerts its anti-inflammatory activities in LPS-induced macrophages. Physalin E can inhibit the production of inflammatory cytokines by targeting the NF-κB signaling pathway.     

7,8-Dihydroxyflavone exhibits anti-inflammatory properties by downregulating the NF-κB and MAPK signaling pathways in lipopolysaccharide-treated RAW264.7 cells

7,8-Dihydroxyflavone (7,8-DHF), a member of the flavonoid family, has received considerable attention as a selective tyrosine kinase receptor B agonist. Several studies have indicated that 7,8-DHF has neurotrophic and antioxidant activities. However, little is known about the cellular and molecular mechanisms underlying the anti-inflammatory activity of 7,8-DHF. Therefore, we investigated whether 7,8-DHF affects the expression of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Our results indicated that 7,8-DHF significantly attenuated secretion of LPS-induced inflammatory mediators nitric oxide (NO), prostaglandin E? (PGE?) and interleukin-1β (IL-1β) in RAW264.7 cells. Additionally, LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and IL-1β was decreased by pre-treatment with 7,8-DHF. Our results also showed that 7,8-DHF reduces LPS-induced nuclear factor-κB (NF-κB) activity via the suppression of the nuclear translocation of NF-κB p65 and the degradation of inhibitor κB (lκB). In addition, 7,8-DHF inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) such as extracellular-signal-related kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). These results suggest that the anti-inflammatory property of 7,8-DHF is related to the downregulation of iNOS, COX-2 and IL-1β, due to NF-κB inhibition as well as to the negative regulation of MAPK activation in RAW264.7 cells. Thus, 7,8-DHF may be a novel therapeutic agent for the prevention of various inflammatory diseases.     

Dichloromethane Fraction of Laminaria japonica Ethanolic Extract Inhibits Lipopolysaccharide-Induced Nitric Oxide Synthase and Cyclooxygenase-2 Expression in RAW 264.7 Cells via NF-κB Pathway

Strong anti-inflammatory activity has been found in Laminaria japonica dichloromethane fraction (LDF); however, the molecular mechanisms underlying its anti-inflammatory activity are not reported. Our results indicated that LDF inhibited LPS-induced nitric oxide and prostaglandin E(2) production in a dose-dependent manner and suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) in RAW 264.7 cells. Also, levels of pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were remarkably reduced by LDF in LPS-treated RAW 264.7 cells. LDF greatly inhibited promoter activity of nuclear factor-κB (NF-κB) and translocation of NF-κB subunits by prevention of the degradation of inhibitor κB-α in LPS-treated RAW 264.7 cells (p?相似文献   

Anti-inflammatory effects of galangin on lipopolysaccharide-activated macrophages via ERK and NF-κB pathway regulation

Inflammation is the major symptom of the innate immune response to microbial infection. Macrophages, immune response-related cells, play a role in the inflammatory response. Galangin is a member of the flavonols and is found in Alpinia officinarum, galangal root and propolis. Previous studies have demonstrated that galangin has antioxidant, anticancer, and antineoplastic activities. However, the anti-inflammatory effects of galangin are still unknown. In this study, we investigated the anti-inflammatory effects of galangin on RAW 264.7 murine macrophages. Galagin was not cytotoxic to RAW 264.7 cells, and nitric oxide (NO) production induced by lipopolysaccharide (LPS)-stimulated macrophages was significantly decreased by the addition of 50?μM galangin. Moreover, galangin treatment reduced mRNA levels of cytokines, including IL-1β and IL-6, and proinflammatory genes, such as iNOS in LPS-activated macrophages in a dose-dependent manner. Galangin treatment also decreased the protein expression levels of iNOS in activated macrophages. Galangin was found to elicit anti-inflammatory effects by inhibiting ERK and NF-κB-p65 phosphorylation. In addition, galangin-inhibited IL-1β production in LPS-activated macrophages. These results suggest that galangin elicits anti-inflammatory effects on LPS-activated macrophages via the inhibition of ERK, NF-κB-p65 and proinflammatory gene expression.     

Inhibition of LPS-induced inflammatory biomarkers by ethyl acetate fraction of Patrinia scabiosaefolia through suppression of NF-κB activation in RAW 264.7 cells

Patrinia scabiosaefolia (PS) has been used for curing various types of inflammatory-related disorders. However, the precise mechanism of the anti-inflammatory activity of PS remains unclear. Here, we investigated the anti-inflammatory effects of several fractions isolated from the PS in RAW 264.7 macrophages. The results indicated that the ethyl acetate fraction of PS (EAPS) concentration highly suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) and IL-6 productions without a cytotoxic effect on RAW 264.7 cells. EAPS inhibited the expressions of LPS-induced iNOS and COX-2 protein and their mRNA in a dose-dependent manner. Particularly, EAPS suppressed the level of nuclear factor-κB (NF-κB) activity, which was linked with the suppression of LPS-induced phosphorylation of p65 at serine 276 and p65 translocation into nuclei, but not MAPK signaling. In addition, treatment with EAPS inhibited the production of TNF-α in LPS-injected mice and suppressed the production of IL-6 and TNF-α in LPS-stimulated splenocytes from BALB/c mice. Therefore, we demonstrate here that Patrinia scabiosaefolia potentially inhibits the biomarkers related to inflammation through the blocking of NF-κB p65 activation, and it may be a potential therapeutic candidate for the treatment of inflammatory diseases.     

Gambogic acid protects from endotoxin shock by suppressing pro-inflammatory factors in vivo and in vitro

Objective

Gambogic acid (GBA) targeted Heat shock protein 90 (Hsp90) and prohibited TNF-α/NF-κB signaling pathway. It can be inferred that the anti-inflammatory activity of GBA results from inhibiting the cytokine production via NF-κB signaling pathway. We used the RAW264.7 cell line and the endotoxin shock mouse model to confirm the hypothesis that GBA protects mice from endotoxin shock by suppressing cytokine synthesis.

Method

RAW264.7 cells were cultured and the endotoxin shocked mice model was constructed. ELISA was employed to evaluate the change of cytokine secretion levels. The effects of GBA on the activation of NF-κB signaling pathway were also determined by western blot and immune-fluorescent analysis. Cell viability was determined by MTT assay, and the cell migration was tested by wound healing assay.

Result

Our results demonstrated that GBA significantly inhibited the LPS-induced release of pro-inflammatory factors both in cell lines and mice serum, thereby protecting mice from endotoxin shock. Furthermore, we observed that the reduction of inflammatory cytokines interleukin 1-beta, interleukin 6 and TNF-α resulted from the Hsp90’s client protein IKK degradation and the suppression of NF-κB pathway. Moreover, GBA suppressed the migration of LPS-induced RAW264.7 cells.

Conclusion

Our results indicate that GBA has a potential both as an antitumor and anti-inflammatory therapeutic agent.     

葫芦素E对脂多糖诱导RAW264.7巨噬细胞炎症反应的影响及作用机制

分析葫芦素E(CuE)对脂多糖(LPS)诱导的小鼠RAW264.7巨噬细胞炎症反应的影响,研究其抗炎作用的分子机制。采用改良MTT法检测RAW264.7细胞的增殖;以碘化丙锭染色检测CuE对细胞周期的影响;采用细胞内细胞因子染色法分析肿瘤坏死因子(TNF-α)的表达;免疫荧光染色分析胞内Actin的结构;应用免疫印迹法检测CuE对G-肌动蛋白(G-ac-tin)及核转录因子NF-κB核转位的影响。实验结果显示CuE对RAW264.7细胞的增殖具有剂量依赖性抑制作用,并降低细胞内G-actin的水平;CuE明显阻止LPS诱导的细胞伸展和伪足形成,使细胞周期阻滞于G2/M期。同时,CuE还明显抑制LPS活化的RAW264.7细胞表达促炎因子TNF-α,并显著降低LPS诱导的转录因子NF-κB的核转位作用。这些结果表明,CuE通过破坏RAW264.7巨噬细胞的肌动蛋白细胞骨架,引起细胞周期阻滞,并抑制LPS诱导的NF-κB核转位以及TNF-α的表达,从而发挥抗炎作用。     

β-sitosteryl-3-O-β-glucopyranoside isolated from the bark of Sorbus commixta ameliorates pro-inflammatory mediators in RAW 264.7 macrophages

The bark of Sorbus commixta has been used in Asian traditional medicine for treatment of cough, asthma, bronchial disorders, gastritis and dropsy. However, the anti-inflammatory effect of β-sitosteryl-3- O -β-glucopyranoside, a major compound of the bark of S. commixta, is poorly understood. In this study, we investigated the anti-inflammatory effect and the underlying molecular mechanisms of β-sitosteryl-3-O-β-glucopyranoside in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Prostaglandin E₂ (PGE₂) and cytokines released from cells were measured using EIA assay kit. The expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, Tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) was measured by real-time polymerase chain reaction (RT-PCR) and/or Western blot analysis. β-sitosteryl-3-O-β-glucopyranoside inhibited the production of nitric oxide (NO) and PGE₂ along with the expression of iNOS and COX-2 in LPS-stimulated RAW264.7 cells. In addition, β-sitosteryl-3-O-β-glucopyranoside reduced the release of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6. Moreover, β-sitosteryl-3-O-β-glucopyranoside inhibited the NF-κB activation induced by LPS, which was associated with the abrogation of IκBα degradation and subsequent decreases in nuclear p65 levels. The result suggested that the β-sitosteryl-3-O-β-glucopyranoside inhibited NO and pro-inflammatory productions by down-regulating the gene expression of pro-inflammatory mediators via the negative regulation of the NF-кB pathway in LPS-stimulated RAW 264.7 cells.     

Triphala herbal extract suppresses inflammatory responses in LPS-stimulated RAW 264.7 macrophages and adjuvant-induced arthritic rats via inhibition of NF-κB pathway

This study sought to explore the mechanism of anti-inflammatory effect of triphala in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and in adjuvant-induced arthritic rats. In stimulated RAW 264.7 cells, triphala (100–300 μg/ml) significantly suppressed production of inflammatory mediators (e.g. TNFα, IL-1β, IL-6, MCP-1, VEGF, NO, PGE₂), intracellular free radicals and release of lysosomal enzymes (e.g. acid phosphatase, β-galactosidase, N-acetyl glucosamindase and cathepsin D) in a dose-related manner. With triphala, mRNA levels of genes for pro-inflammatory TNFα, IL-1β, IL-6 and MCP-1, inflammatory iNOS and COX-2 enzymes and NF-κBp65 were down-regulated in the stimulated cells; in contrast, there was up-regulation of heme oxygenase-1 (HO-1) expression. Western blot analyses revealed that triphala suppressed the protein expression of NF-κB p65 and p-NF-κB p65 in the stimulated cells, which subsequently reduced over-expression of TNFα, IL-17, iNOS and COX-2 in a manner similar to that observed with BAY 11-7082, an IκB kinase inhibitor. Immunofluorescence analysis revealed inhibition of p-NF-κB p65 nuclear translocation and COX-2 protein expression caused by triphala. Consistent with these findings, the animal studies presented confirmed that triphala exhibited anti-inflammatory effects in a rat adjuvant-induced arthritis model by reducing of inflammatory mediator (e.g. IL-17, COX-2 and RANKL) expression via inhibition of NF-κB activation. Taken together, the results here demonstrated that triphala has potential anti-inflammatory applications that could be used for the treatment of inflammatory disorders, including rheumatoid arthritis.     

Anti-inflammatory properties of a triterpenoidal glycoside from Momordica cochinchinensis in LPS-stimulated macrophages

Two triterpenoidal saponins were isolated from the seeds of Momordica cochinchinensis Sprenger (Cucurbitaceae). Identification of chemical structures has been performed by ¹H- and ¹³C-NMR spectroscopy and gas chromatography (GC). One of the saponins is a new gypsogenin glycoside, named as gypsogenin 3-O-β-D-galactopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-D-glucuronopyranoside (compound 1), which is reported for the first time from natural resources. The other saponin is a quillaic acid glycoside (compound 2), which showed anti-inflammatory activities in RAW 264.7 cells. The mechanistic understanding of anti-inflammatory activities demonstrates that compound 2 inhibits lipopolysaccharide-induced expression of nitric oxide and IL-6 via NF-κB pathway.     

ox-LDL对巨噬细胞内皮脂肪酶表达的影响

目的: 探讨氧化低密度脂蛋白(ox-LDL)对鼠源RAW264.7巨噬细胞内皮脂肪酶(EL)表达的影响。方法: 用ox-LDL(0~100 mg/L)孵育RAW264.7细胞24 h使其活化,或者用PDTC (NF-κB抑制剂)预孵育RAW264.7细胞30 min再与ox-LDL(50 mg/L)共同孵育24 h;应用Western blotting 检测EL和NF-κB p65的表达。结果: ox-LDL孵育RAW264.7细胞明显增加EL表达(P<0.05);ox-LDL(50 mg/L)孵育RAW264.7细胞15~30 min可激活NF-κB,用NF-κB 抑制剂PDTC处理后则明显抑制ox-LDL诱导的EL表达增加(P<0.05)。结论: ox-LDL可明显增加RAW264.7细胞EL的表达,可能与NF-κB活化有关。     

Lipoxin A4 Inhibits NF-κB Activation and Cell Cycle Progression in RAW264.7 Cells

Lipoxins (LXs), including lipoxin A₄ (LXA₄), etc., have been approved for potent anti-inflammatory and immunomodulatory properties. Based on the important roles of macrophages in inflammation and immunomodulation, we investigate the effects of LXA₄ on lipopolysaccharide (LPS)-induced proliferation and the possible signal transduction pathways in RAW264.7 macrophages. RAW264.7 cells were treated in vitro with or without LPS in the absence or presence of LXA₄. [³H]-TdR incorporation assay and flow cytometry were used for detecting cell proliferation and cycle, respectively. Moreover, Western blot was applied to evaluate the protein expression levels of Cyclin E, IκBα, nuclear factor-κB (NF-κB), and IκB kinase (IKK). Our research showed that LXA₄ suppressed LPS-induced proliferation, increased the proportion of the G₀/G₁ phase, decreased the proportion of the S phase, and downregulated the expression of Cyclin E. Besides these, LXA₄ suppressed LPS-induced IκBα degradation, NF-κB translocation, and the expression of IKK. The data suggested that LXA₄ inhibited LPS-induced proliferation through the G₀/G₁ phase arrest in RAW264.7 macrophages, and the inhibitory effect might depend on NF-κB signaling transduction pathway.