Displaying publications 1 - 20 of 66 in total

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  1. Atrovirinone inhibits proinflammatory mediator synthesis through disruption of NF-kappaB nuclear translocation and MAPK phosphorylation in the murine monocytic macrophage RAW 264.7
    Israf DA, Tham CL, Syahida A, Lajis NH, Sulaiman MR, Mohamad AS, et al.
    Phytomedicine, 2010 Aug;17(10):732-9.
    PMID: 20378317 DOI: 10.1016/j.phymed.2010.02.006
    In a previous communication we showed that atrovirinone, a 1,4-benzoquinone isolated from the roots of Garcinia atroviridis, was able to inhibit several major proinflammatory mediators of inflammation. In this report we show that atrovirinone inhibits NO and PGE(2) synthesis through inhibition of iNOS and COX-2 expression. We also show that atrovirinone inhibits the secretion of IL-1beta and IL-6 in a dose dependent fashion whereas the secretion of IL-10, the anti-inflammatory cytokine, was enhanced. Subsequently we determined that the inhibition of proinflammatory cytokine synthesis and inducible enzyme expression was due to a dose-dependent inhibition of phosphorylation of p38 and ERK1/2. We also showed that atrovirinone prevented phosphorylation of I-kappaBalpha, which resulted in a reduction of p65NF-kappaB nuclear translocation as demonstrated by expression analysis. We conclude that atrovirinone is a potential anti-inflammatory drug lead that targets both the MAPK and NF-kappaB pathway.
    Matched MeSH terms: Macrophages/metabolism
  2. Caffeic acid phenethyl ester (CAPE): scavenger of peroxynitrite in vitro and in sepsis models
    Kassim M, Mansor M, Kamalden TA, Shariffuddin II, Hasan MS, Ong G, et al.
    Shock, 2014 Aug;42(2):154-60.
    PMID: 24667629 DOI: 10.1097/SHK.0000000000000179
    Excessive free radical production by immune cells has been linked to cell death and tissue injury during sepsis. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death that has been identified in several pathological conditions. Caffeic acid phenethyl ester (CAPE) is an active component of honeybee products and exhibits antioxidant, anti-inflammatory, and immunomodulatory activities. The present study examined the ability of CAPE to scavenge peroxynitrite in RAW 264.7 murine macrophages stimulated with lipopolysaccharide/interferon-γ that was used as an in vitro model. Conversion of 123-dihydrorhodamine to its oxidation product 123-rhodamine was used to measure peroxynitrite production. Two mouse models of sepsis (endotoxemia and cecal ligation and puncture) were used as in vivo models. The level of serum 3-nitrotyrosine was used as an in vivo marker of peroxynitrite. The results demonstrated that CAPE significantly improved the viability of lipopolysaccharide/interferon-γ-treated RAW 264.7 cells and significantly inhibited nitric oxide production, with effects similar to those observed with an inhibitor of inducible nitric oxide synthase (1400W). In addition, CAPE exclusively inhibited the synthesis of peroxynitrite from the artificial substrate SIN-1 and directly prevented the peroxynitrite-mediated conversion of dihydrorhodamine-123 to its fluorescent oxidation product rhodamine-123. In both sepsis models, CAPE inhibited cellular peroxynitrite synthesis, as evidenced by the absence of serum 3-nitrotyrosine, an in vivo marker of peroxynitrite. Thus, CAPE attenuates the inflammatory responses that lead to cell damage and, potentially, cell death through suppression of the production of cytotoxic molecules such as nitric oxide and peroxynitrite. These observations provide evidence of the therapeutic potential of CAPE treatment for a wide range of inflammatory disorders.
    Matched MeSH terms: Macrophages/metabolism
  3. Fulltext Gelam honey scavenges peroxynitrite during the immune response
    Kassim M, Mansor M, Suhaimi A, Ong G, Yusoff KM
    Int J Mol Sci, 2012;13(9):12113-29.
    PMID: 23109904 DOI: 10.3390/ijms130912113
    Monocytes and macrophages are part of the first-line defense against bacterial, fungal, and viral infections during host immune responses; they express high levels of proinflammatory cytokines and cytotoxic molecules, including nitric oxide, reactive oxygen species, and their reaction product peroxynitrite. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death. Honey, in addition to its well-known sweetening properties, is a natural antioxidant that has been used since ancient times in traditional medicine. We examined the ability of Gelam honey, derived from the Gelam tree (Melaleuca spp.), to scavenge peroxynitrite during immune responses mounted in the murine macrophage cell line RAW 264.7 when stimulated with lipopolysaccharide/interferon-γ (LPS/IFN-γ) and in LPS-treated rats. Gelam honey significantly improved the viability of LPS/IFN-γ-treated RAW 264.7 cells and inhibited nitric oxide production-similar to the effects observed with an inhibitor of inducible nitric oxide synthase (1400W). Furthermore, honey, but not 1400W, inhibited peroxynitrite production from the synthetic substrate 3-morpholinosydnonimine (SIN-1) and prevented the peroxynitrite-mediated conversion of dihydrorhodamine 123 to its fluorescent oxidation product rhodamine 123. Honey inhibited peroxynitrite synthesis in LPS-treated rats. Thus, honey may attenuate inflammatory responses that lead to cell damage and death, suggesting its therapeutic uses for several inflammatory disorders.
    Matched MeSH terms: Macrophages/metabolism*
  4. In vitro evaluation of the involvement of Nrf2 in maslinic acid-mediated anti-inflammatory effects in atheroma pathogenesis
    Ooi BK, Phang SW, Yong PVC, Chellappan DK, Dua K, Khaw KY, et al.
    Life Sci, 2021 Aug 01;278:119658.
    PMID: 34048809 DOI: 10.1016/j.lfs.2021.119658
    AIMS: Maslinic acid (MA) is a naturally occurring pentacyclic triterpene known to exert cardioprotective effects. This study aims to investigate the involvement of nuclear factor erythroid 2-related factor 2 (Nrf2) for MA-mediated anti-inflammatory effects in atheroma pathogenesis in vitro, including evaluation of tumor necrosis factor-alpha (TNF-α)-induced monocyte recruitment, oxidized low-density lipoprotein (oxLDL)-induced scavenger receptors expression, and nuclear factor-kappa B (NF-ĸB) activity in human umbilical vein endothelial cells (HUVECS) and human acute monocytic leukemia cell line (THP-1) macrophages.

    MATERIALS AND METHODS: An in vitro monocyte recruitment model utilizing THP-1 and HUVECs was developed to evaluate TNF-α-induced monocyte adhesion and trans-endothelial migration. To study the role of Nrf2 for MA-mediated anti-inflammatory effects, Nrf2 inhibitor ML385 was used as the pharmacological inhibitor. The expression of Nrf2, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 36 (CD36), and scavenger receptor type A (SR-A) in HUVECs and THP-1 macrophages were investigated using RT-qPCR and Western blotting. The NF-κB activity was determined using NF-κB (p65) Transcription Factor Assay Kit.

    KEY FINDINGS: The results showed opposing effects of MA on Nrf2 expression in HUVECs and THP-1 macrophages. MA suppressed TNF-α-induced Nrf2 expression in HUVECs, but enhanced its expression in THP-1 macrophages. Combined effects of MA and ML385 suppressed MCP-1, VCAM-1, and SR-A expressions. Intriguingly, at the protein level, ML385 selectively inhibited SR-A but enhanced CD36 expression. Meanwhile, ML385 further enhanced MA-mediated inhibition of NF-κB activity in HUVECs. This effect, however, was not observed in THP-1 macrophages.

    SIGNIFICANCE: MA attenuated foam cell formation by suppressing VCAM-1, MCP-1, and SR-A expression, as well as NF-κB activity, possibly through Nrf2 inhibition. The involvement of Nrf2 for MA-mediated anti-inflammatory effects however differs between HUVECs and macrophages. Future investigations are warranted for a detailed evaluation of the contributing roles of Nrf2 in foam cells formation.

    Matched MeSH terms: Macrophages/metabolism
  5. Increased SPRY1 expression activates NF-κB signaling and promotes pancreatic cancer progression by recruiting neutrophils and macrophages through CXCL12-CXCR4 axis
    Shi T, Li X, Zheng J, Duan Z, Ooi YY, Gao Y, et al.
    Cell Oncol (Dordr), 2023 Aug;46(4):969-985.
    PMID: 37014552 DOI: 10.1007/s13402-023-00791-z
    PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high mortality rate, in which about 90% of patients harbor somatic oncogenic point mutations in KRAS. SPRY family genes have been recognized as crucial negative regulators of Ras/Raf/ERK signaling. Here, we investigate the expression and role of SPRY proteins in PDAC.

    METHODS: Expression of SPRY genes in human and mice PDAC was analyzed using The Cancer Genome Atlas and Gene Expression Omnibus datasets, and by immunohistochemistry analysis. Gain-of-function, loss-of-function of Spry1 and orthotopic xenograft model were adopted to investigate the function of Spry1 in mice PDAC. Bioinformatics analysis, transwell and flowcytometry analysis were used to identify the effects of SPRY1 on immune cells. Co-immunoprecipitation and K-ras4B G12V overexpression were used to identify molecular mechanism.

    RESULTS: SPRY1 expression was remarkably increased in PDAC tissues and positively associated with poor prognosis of PDAC patients. SPRY1 knockdown suppressed tumor growth in mice. SPRY1 was found to promote CXCL12 expression and facilitate neutrophil and macrophage infiltration via CXCL12-CXCR4 axis. Pharmacological inhibition of CXCL12-CXCR4 largely abrogated the oncogenic functions of SPRY1 by suppressing neutrophil and macrophage infiltration. Mechanistically, SPRY1 interacted with ubiquitin carboxy-terminal hydrolase L1 to induce activation of nuclear factor κB signaling and ultimately increase CXCL12 expression. Moreover, SPRY1 transcription was dependent on KRAS mutation and was mediated by MAPK-ERK signaling.

    CONCLUSION: High expression of SPRY1 can function as an oncogene in PDAC by promoting cancer-associated inflammation. Targeting SPRY1 might be an important approach for designing new strategy of tumor therapy.

    Matched MeSH terms: Macrophages/metabolism
  6. In silico studies, nitric oxide, and cholinesterases inhibition activities of pyrazole and pyrazoline analogs of diarylpentanoids
    Mohd Faudzi SM, Leong SW, Auwal FA, Abas F, Wai LK, Ahmad S, et al.
    Arch Pharm (Weinheim), 2021 Jan;354(1):e2000161.
    PMID: 32886410 DOI: 10.1002/ardp.202000161
    A new series of pyrazole, phenylpyrazole, and pyrazoline analogs of diarylpentanoids (excluding compounds 3a, 4a, 5a, and 5b) was pan-assay interference compounds-filtered and synthesized via the reaction of diarylpentanoids with hydrazine monohydrate and phenylhydrazine. Each analog was evaluated for its anti-inflammatory ability via the suppression of nitric oxide (NO) on IFN-γ/LPS-activated RAW264.7 macrophage cells. The compounds were also investigated for their inhibitory capability toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), using a modification of Ellman's spectrophotometric method. The most potent NO inhibitor was found to be phenylpyrazole analog 4c, followed by 4e, when compared with curcumin. In contrast, pyrazole 3a and pyrazoline 5a were found to be the most selective and effective BChE inhibitors over AChE. The data collected from the single-crystal X-ray diffraction analysis of compound 5a were then applied in a docking simulation to determine the potential binding interactions that were responsible for the anti-BChE activity. The results obtained signify the potential of these pyrazole and pyrazoline scaffolds to be developed as therapeutic agents against inflammatory conditions and Alzheimer's disease.
    Matched MeSH terms: Macrophages/metabolism
  7. Fulltext Suppression of cell division-associated genes by Helicobacter pylori attenuates proliferation of RAW264.7 monocytic macrophage cells
    Tan GM, Looi CY, Fernandez KC, Vadivelu J, Loke MF, Wong WF
    Sci Rep, 2015;5:11046.
    PMID: 26078204 DOI: 10.1038/srep11046
    Helicobacter pylori at multiplicity of infection (MOI ≥ 50) have been shown to cause apoptosis in RAW264.7 monocytic macrophage cells. Because chronic gastric infection by H. pylori results in the persistence of macrophages in the host's gut, it is likely that H. pylori is present at low to moderate, rather than high numbers in the infected host. At present, the effect of low-MOI H. pylori infection on macrophage has not been fully elucidated. In this study, we investigated the genome-wide transcriptional regulation of H. pylori-infected RAW264.7 cells at MOI 1, 5 and 10 in the absence of cellular apoptosis. Microarray data revealed up- and down-regulation of 1341 and 1591 genes, respectively. The expression of genes encoding for DNA replication and cell cycle-associated molecules, including Aurora-B kinase (AurkB) were down-regulated. Immunoblot analysis verified the decreased expression of AurkB and downstream phosphorylation of Cdk1 caused by H. pylori infection. Consistently, we observed that H. pylori infection inhibited cell proliferation and progression through the G1/S and G2/M checkpoints. In summary, we suggest that H. pylori disrupts expression of cell cycle-associated genes, thereby impeding proliferation of RAW264.7 cells, and such disruption may be an immunoevasive strategy utilized by H. pylori.
    Matched MeSH terms: Macrophages/metabolism*
  8. Fulltext Single-cell RNA sequencing analysis of shrimp immune cells identifies macrophage-like phagocytes
    Yang P, Chen Y, Huang Z, Xia H, Cheng L, Wu H, et al.
    Elife, 2022 Oct 06;11.
    PMID: 36200862 DOI: 10.7554/eLife.80127
    Despite the importance of innate immunity in invertebrates, the diversity and function of innate immune cells in invertebrates are largely unknown. Using single-cell RNA-seq, we identified prohemocytes, monocytic hemocytes, and granulocytes as the three major cell-types in the white shrimp hemolymph. Our results identified a novel macrophage-like subset called monocytic hemocytes 2 (MH2) defined by the expression of certain marker genes, including Nlrp3 and Casp1. This subtype of shrimp hemocytes is phagocytic and expresses markers that indicate some conservation with mammalian macrophages. Combined, our work resolves the heterogenicity of hemocytes in a very economically important aquatic species and identifies a novel innate immune cell subset that is likely a critical player in the immune responses of shrimp to threatening infectious diseases affecting this industry.
    Matched MeSH terms: Macrophages/metabolism
  9. Fulltext Capgermacrenes A and B, Bioactive Secondary Metabolites from a Bornean Soft Coral, Capnella sp
    Phan CS, Ng SY, Kim EA, Jeon YJ, Palaniveloo K, Vairappan CS
    Mar Drugs, 2015 May;13(5):3103-15.
    PMID: 25996100 DOI: 10.3390/md13053103
    Two new bicyclogermacrenes, capgermacrenes A (1) and B (2), were isolated with two known compounds, palustrol (3) and litseagermacrane (4), from a population of Bornean soft coral Capnella sp. The structures of these metabolites were elucidated based on spectroscopic data. Compound 1 was found to inhibit the accumulation of the LPS-induced pro-inflammatory IL-1b and NO production by down-regulating the expression of iNOS protein in RAW 264.7 macrophages.
    Matched MeSH terms: Macrophages/metabolism
  10. Self-adjuvanting vaccine against group A streptococcus: application of fibrillized peptide and immunostimulatory lipid as adjuvant
    Azmi F, Ahmad Fuaad AA, Giddam AK, Batzloff MR, Good MF, Skwarczynski M, et al.
    Bioorg Med Chem, 2014 Nov 15;22(22):6401-8.
    PMID: 25438764 DOI: 10.1016/j.bmc.2014.09.042
    Peptides are of great interest to be used as vaccine antigens due to their safety, ease of manufacturing and specificity in generating immune response. There have been massive discoveries of peptide antigens over the past decade. However, peptides alone are poorly immunogenic, which demand co-administration with strong adjuvant to enhance their immunogenicity. Recently, fibril-forming peptides such as Q11 and lipoamino acid-based carrier have been identified to induce substantial immune responses when covalently linked to peptide epitope. In this study, we have incorporated either Q11 or lipoamino acids to a peptide epitope (J14) derived from M protein of group A streptococcus to develop self-adjuvanting vaccines. J14, Q11 and lipoamino acids were also conjugated together in a single vaccine construct in an attempt to evaluate the synergy effect of combining multiple adjuvants. Physicochemical characterization demonstrated that the vaccine constructs folded differently and self-assembled into nanoparticles. Significantly, only vaccine constructs containing double copies of lipoamino acids (regardless in conjugation with Q11 or not) were capable to induce significant dendritic cells uptake and subsequent J14-specific antibody responses in non-sizes dependent manners. Q11 had minimal impact in enhancing the immunogenicity of J14 even when it was used in combination with lipoamino acids. These findings highlight the impact of lipoamino acids moiety as a promising immunostimulant carrier and its number of attachment to peptide epitope was found to have a profound effect on the vaccine immunogenicity.
    Matched MeSH terms: Macrophages/metabolism
  11. Fulltext Effect of (R)-salbutamol on the switch of phenotype and metabolic pattern in LPS-induced macrophage cells
    Wang S, Liu F, Tan KS, Ser HL, Tan LT, Lee LH, et al.
    J Cell Mol Med, 2020 01;24(1):722-736.
    PMID: 31680470 DOI: 10.1111/jcmm.14780
    Evidence demonstrates that M1 macrophage polarization promotes inflammatory disease. Here, we discovered that (R)-salbutamol, a β2 receptor agonist, inhibits and reprograms the cellular metabolism of RAW264.7 macrophages. (R)-salbutamol significantly inhibited LPS-induced M1 macrophage polarization and downregulated expressions of typical M1 macrophage cytokines, including monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α). Also, (R)-salbutamol significantly decreased the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and reactive oxygen species (ROS), while increasing the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. In contrast, (S)-salbutamol increased the production of NO and ROS. Bioenergetic profiles showed that (R)-salbutamol significantly reduced aerobic glycolysis and enhanced mitochondrial respiration. Untargeted metabolomics analysis demonstrated that (R)-salbutamol modulated metabolic pathways, of which three metabolic pathways, namely, (a) phenylalanine metabolism, (b) the pentose phosphate pathway and (c) glycerophospholipid metabolism were the most noticeably impacted pathways. The effects of (R)-salbutamol on M1 polarization were inhibited by a specific β2 receptor antagonist, ICI-118551. These findings demonstrated that (R)-salbutamol inhibits the M1 phenotype by downregulating aerobic glycolysis and glycerophospholipid metabolism, which may propose (R)-salbutamol as the major pharmacologically active component of racemic salbutamol for the treatment of inflammatory diseases and highlight the medicinal value of (R)-salbutamol.
    Matched MeSH terms: Macrophages/metabolism*
  12. Fulltext Studies of synthetic chalcone derivatives as potential inhibitors of secretory phospholipase A2, cyclooxygenases, lipoxygenase and pro-inflammatory cytokines
    Jantan I, Bukhari SN, Adekoya OA, Sylte I
    Drug Des Devel Ther, 2014;8:1405-18.
    PMID: 25258510 DOI: 10.2147/DDDT.S67370
    Arachidonic acid metabolism leads to the generation of key lipid mediators which play a fundamental role during inflammation. The inhibition of enzymes involved in arachidonic acid metabolism has been considered as a synergistic anti-inflammatory effect with enhanced spectrum of activity. A series of 1,3-diphenyl-2-propen-1-one derivatives were investigated for anti-inflammatory related activities involving inhibition of secretory phospholipase A2, cyclooxygenases, soybean lipoxygenase, and lipopolysaccharides-induced secretion of interleukin-6 and tumor necrosis factor-alpha in mouse RAW264.7 macrophages. The results from the above mentioned assays exhibited that the synthesized compounds were effective inhibitors of pro-inflammatory enzymes and cytokines. The results also revealed that the chalcone derivatives with 4-methlyamino ethanol substitution seem to be significant for inhibition of enzymes and cytokines. Molecular docking experiments were carried out to elucidate the molecular aspects of the observed inhibitory activities of the investigated compounds. Present findings increase the possibility that these chalcone derivatives might serve as a beneficial starting point for the design and development of improved anti-inflammatory agents.
    Matched MeSH terms: Macrophages/metabolism
  13. Fulltext BDMC33, A curcumin derivative suppresses inflammatory responses in macrophage-like cellular system: role of inhibition in NF-κB and MAPK signaling pathways
    Lee KH, Chow YL, Sharmili V, Abas F, Alitheen NB, Shaari K, et al.
    Int J Mol Sci, 2012;13(3):2985-3008.
    PMID: 22489138 DOI: 10.3390/ijms13032985
    Our preliminary screening has shown that curcumin derivative BDMC33 [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] exerted promising nitric oxide inhibitory activity in activated macrophages. However, the molecular basis and mechanism for its pharmacological action is yet to be elucidated. The aim of this study was to investigate the anti-inflammatory properties of BDMC33 and elucidate its underlying mechanism action in macrophage cells. Our current study demonstrated that BDMC33 inhibits the secretion of major pro-inflammatory mediators in stimulated macrophages, and includes NO, TNF-α and IL-1β through interference in both nuclear factor kappaB (NF-κB) and mitogen activator protein kinase (MAPK) signaling cascade in IFN-γ/LPS-stimulated macrophages. Moreover, BDMC33 also interrupted LPS signaling through inhibiting the surface expression of CD-14 accessory molecules. In addition, the inhibitory action of BDMC33 not only restricted the macrophages cell (RAW264.7), but also inhibited the secretion of NO and TNF-α in IFN-γ/LPS-challenged microglial cells (BV-2). The experimental data suggests the inflammatory action of BDMC33 on activated macrophage-like cellular systems, which could be used as a future therapeutic agent in the management of chronic inflammatory diseases.
    Matched MeSH terms: Macrophages/metabolism*
  14. Evaluation of antioxidant and nitric oxide inhibitory activities of selected Malaysian medicinal plants
    Saha K, Lajis NH, Israf DA, Hamzah AS, Khozirah S, Khamis S, et al.
    J Ethnopharmacol, 2004 Jun;92(2-3):263-7.
    PMID: 15138010
    Methanol extracts of seven Malaysian medicinal plants were screened for antioxidant and nitric oxide inhibitory activities. Antioxidant activity was measured by using FTC, TBA and DPPH free radical scavenging methods and Griess assay was used for the measurement of nitric oxide inhibition in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated RAW 264.7 cells. All the extracts showed strong antioxidant activity comparable to or higher than that of alpha-tocopherol, BHT and quercetin in FTC and TBA methods. The extracts from Leea indica and Spermacoce articularis showed strong DPPH free radical scavenging activity comparable with quercetin, BHT and Vit C. Spermacoce exilis showed only moderate activity but other species were weak as compared to the standards. In the Griess assay Lasianthus oblongus, Chasalia chartacea, Hedyotis verticillata, Spermacoce articularis and Leea indica showed strong inhibitory activity on nitric oxide production in LPS and IFN-gamma-induced RAW 264.7 cells. Extracts from Psychotria rostrata and Spermacoce exilis also inhibited NO production but this was due to their cytotoxic effects upon cells during culture.
    Matched MeSH terms: Macrophages/metabolism*
  15. Nitric oxide production by a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans
    Sosroseno W, Barid I, Herminajeng E, Susilowati H
    Oral Microbiol. Immunol., 2002 Apr;17(2):72-8.
    PMID: 11929552
    The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could stimulate a murine macrophage cell line (RAW264.7 cells) to produce nitric oxide (NO). The cells were treated with LPS-A. actinomycetemcomitans or Escherichia coli LPS (LPS-Ec) for 24 h. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B and cytokines (IFN-gamma, TNF-alpha, IL-4 and IL-12) on the production of NO were also determined. The role of protein tyrosine kinase, protein kinase C and microtubulin organization on NO production were assessed by incubating RAW264.7 cells with genistein, bisindolylmaleide and colchicine prior to LPS-A. actinomycetemcomitans stimulation, respectively. NO levels from the culture supernatants were determined by the Griess reaction. The results showed that LPS-A. actinomycetemcomitans stimulated NO production by RAW264.7 cells in a dose-dependent manner, but was slightly less potent than LPS-Ec. NMMA and polymyxin B blocked the production of NO. IFN-gamma and IL-12 potentiated but IL-4 depressed NO production by LPS-A. actinomycetemcomitans-stimulated RAW264.7 cells. TNF-alpha had no effects on NO production. Genistein and bisindolylmalemaide, but not colchicine, reduced the production of NO in a dose-dependent mechanism. The results of the present study suggest that A. actinomycetemcomitans LPS, via the activation of protein tyrosine kinase and protein kinase C and the regulatory control of cytokines, stimulates NO production by murine macrophages.
    Matched MeSH terms: Macrophages/metabolism*
  16. Cardamonin, inhibits pro-inflammatory mediators in activated RAW 264.7 cells and whole blood
    Ahmad S, Israf DA, Lajis NH, Shaari K, Mohamed H, Wahab AA, et al.
    Eur J Pharmacol, 2006 May 24;538(1-3):188-94.
    PMID: 16650843
    Some chalcones, such as hydroxychalcones have been reported previously to inhibit major pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha) and reactive oxygen species production by suppressing inducible enzyme expression via inhibition of the mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of critical transcription factors. In this report, the effects of cardamonin (2',4'-dihydroxy-6'-methoxychalcone), a chalcone that we have previously isolated from Alpinia rafflesiana, was evaluated upon two cellular systems that are repeatedly used in the analysis of anti-inflammatory bioactive compounds namely RAW 264.7 cells and whole blood. Cardamonin inhibited NO and PGE(2) production from lipopolysaccharide- and interferon-gamma-induced RAW cells and whole blood with IC(50) values of 11.4 microM and 26.8 microM, respectively. Analysis of thromboxane B(2) (TxB(2)) secretion from whole blood either stimulated via the COX-1 or COX-2 pathway revealed that cardamonin inhibits the generation of TxB(2) via both pathways with IC(50) values of 2.9 and 1.1 microM, respectively. Analysis of IC(50) ratios determined that cardamonin was more COX-2 selective in its inhibition of TxB(2) with a ratio of 0.39. Cardamonin also inhibited the generation of intracellular reactive oxygen species and secretion of TNF-alpha from RAW 264.7 cells in a dose responsive manner with IC(50) values of 12.8 microM and 4.6 microM, respectively. However, cardamonin was a moderate inhibitor of lipoxygenase activity when tested in an enzymatic assay system, in which not a single concentration tested was able to cause an inhibition of more than 50%. Our results suggest that cardamonin acts upon major pro-inflammatory mediators in a similar fashion as described by previous work on other closely related synthetic hydroxychalcones and strengthens the conclusion of the importance of the methoxyl moiety substitution on the 4' or 6' locations of the A benzene ring.
    Matched MeSH terms: Macrophages/metabolism
  17. Fulltext Stimulatory effects of polysaccharide fraction from Solanum nigrum on RAW 264.7 murine macrophage cells
    Razali FN, Ismail A, Abidin NZ, Shuib AS
    PLoS One, 2014;9(10):e108988.
    PMID: 25299340 DOI: 10.1371/journal.pone.0108988
    The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth.
    Matched MeSH terms: Macrophages/metabolism
  18. Zinc Carnosine Inhibits Lipopolysaccharide-Induced Inflammatory Mediators by Suppressing NF-κb Activation in Raw 264.7 Macrophages, Independent of the MAPKs Signaling Pathway
    Ooi TC, Chan KM, Sharif R
    Biol Trace Elem Res, 2016 Aug;172(2):458-464.
    PMID: 26749414 DOI: 10.1007/s12011-015-0615-x
    This study aimed to investigate the role of the mitogen-activated protein kinases (MAPKs) signaling pathway in the anti-inflammatory effects of zinc carnosine (ZnC) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Cells were pretreated with ZnC (0-100 μM) for 2 h prior to the addition of LPS (1 μg/ml). Following 24 h of treatment, ZnC was found not to be cytotoxic to RAW 264.7 cells up to the concentration of 100 μM. Our current findings showed that ZnC did not protect RAW 264.7 cells from LPS-induced "respiratory burst". Significant increment in intracellular glutathione (GSH) level and reduction in thiobarbituric acid reactive substances (TBARS) concentration can only be observed in cell pretreated with high doses of ZnC only (50 and 100 μM for GSH and 100 μM only for TBARS). On the other hand, pretreatment of cells with ZnC was able to inhibit LPS-induced inducible nitric oxide synthase and cyclooxygenase-2 expression significantly. Furthermore, results from immunoblotting showed that ZnC was able to suppress nuclear factor-kappaB (NF-κB) activation, and highest suppression can be observed at 100 μM of ZnC pretreatment. However, pretreatment of ZnC did not inhibit the early activation of MAPKs. In conclusion, pretreatment with ZnC was able to inhibit the expression of inflammatory mediators in LPS-induced RAW 264.7 cells, mainly via suppression of NF-κB activation, and is independent of the MAPKs signaling pathway.
    Matched MeSH terms: Macrophages/metabolism
  19. Zinc L-carnosine suppresses inflammatory responses in lipopolysaccharide-induced RAW 264.7 murine macrophages cell line via activation of Nrf2/HO-1 signaling pathway
    Ooi TC, Chan KM, Sharif R
    Immunopharmacol Immunotoxicol, 2017 Oct;39(5):259-267.
    PMID: 28697633 DOI: 10.1080/08923973.2017.1344987
    CONTEXT: Zinc L-carnosine (ZnC) is a chelate of Zn and L-carnosine and is used clinically in the treatment of peptic ulcer.

    OBJECTIVE: In this study, we aim to investigate the involvement of heme oxygenase-1 (HO-1) in the anti-inflammatory effects of ZnC in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages.

    MATERIALS AND METHODS: We used immunoblotting analysis to evaluate the involvement of HO-1 in the anti-inflammatory effects of ZnC and the signaling pathway involved was measured using Dual luciferase reporter assay.

    RESULTS: Results from immunoblotting analysis demonstrated that pretreatment of cells with ZnC enhanced the expression of HO-1 in RAW 264.7 cells. Pretreatment of cells with HO-1 inhibitor (tin protoporphyrin IX dichloride) significantly attenuated the inhibitory effects of ZnC on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression and NF-κB activation in LPS-induced RAW 264.7 cells, suggesting that HO-1 play an important role in the suppression of inflammatory responses induced by ZnC. Furthermore, results from co-immunoprecipitation of Nrf2 and Keap1 and dual luciferase reporter assay showed that pretreatment of ZnC was able to activate the Nrf2 signaling pathway. Treatment of cells with p38 inhibitor (SB203580), c-Jun N-terminal kinase inhibitor (SP600125), and MEK 1/2 inhibitor (U0126) did not significantly suppress the induction of HO-1 by ZnC. Moreover, our present findings suggest that the effects of ZnC on NO production, HO-1 expression, and Nrf2 activation were attributed to its Zn subcomponent, but not l-carnosine.

    CONCLUSION: Pretreatment with ZnC was able to activate Nrf2/HO-1 signaling pathway, thus suppressing the expression of inflammatory mediators, such as NO and iNOS in LPS-induced RAW 264.7 cells.

    Matched MeSH terms: Macrophages/metabolism*
  20. Nitric oxide production by a murine macrophage cell line (RAW264.7 cells) stimulated with Aggregatibacter actinomycetemcomitans surface-associated material
    Sosroseno W, Bird PS, Seymour GJ
    Anaerobe, 2011 Oct;17(5):246-51.
    PMID: 21736946 DOI: 10.1016/j.anaerobe.2011.06.006
    Nitric oxide (NO) may play a crucial role in the pathogenesis of periodontal disease and, hence, the aim of the present study was to test the hypothesis that Aggregatibacter actinomycetemcomitans surface-associated material (SAM) stimulates inducible nitric oxide synthase (iNOS) activity and NO production by the murine macrophage cell line RAW264.7. Cells were stimulated with untreated or heat-treated A. actinomycetemcomitans SAM and with or without pre-treatment with L-N(6)-(1-Iminoethyl)-lysine (L-NIL) (an iNOS inhibitor), polymyxin B, interferon-gamma (IFN-γ) and Interleukin-4 (IL-4), IL-10, genistein [a protein tyrosine kinase (PTK) inhibitor], bisindolylmaleimide [a protein kinase C (PKC) inhibitor], bromophenacyl bromide (BPB) [a phospholipase A(2) (PLA2) inhibitor] or wortmannin [phosphatidylinositol 3-kinase (PI-3K) inhibitor]. The iNOS activity and nitrite production in the cell cultures were determined. Untreated but not heat-treated A. actinomycetemcomitans SAM-stimulated both iNOS activity and nitrite production in RAW264.7 cells. L-NIL, IL-4, IL-10, genistein, bisindolylmaleimide, or BPB, suppressed but IFN-γ enhanced both iNOS activity and nitrite production by A. actinomycetemcomitans SAM-stimulated cells. Wortmannin and polymyxin B failed to alter both iNOS activity or nitrite production by A. actinomycetemcomitans SAM treated cells. Therefore, the present study suggests that a heat-sensitive protein constituent(s) of A. actinomycetemcomitans SAM stimulates both iNOS activity and nitrite production by RAW264.7 cells in a cytokine, PTK, PKC, and PLA(2) but not PI-3K-dependent fashion.
    Matched MeSH terms: Macrophages/metabolism*
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