Cytokines In RAW264 Research Articles

Atheroprotective effect of novel peptides from Porphyridium purpureum in RAW 264.7 macrophage cell line and its molecular docking study.

To explore the atherogenic foam cell prevention efficiency of two dipeptides purified from Porphyridium purpureum on RAW 264.7 cell line and to study its molecular interaction through molecular docking. P. purpureum consists of 29.9% protein and 2.98% phycoerythrin on a dry weight basis. The two dipeptides namely of Histidine-Glutamic acid (HE) and Glycine-Proline (GP) isolated from the total protein and purified phycoerythrin of P. purpureum respectively, were evaluated for atherogenic foam cell prevention capacity in RAW 264.7 cell line. The IC5O values of peptides were found to be 91.2 ± 1.81µg/ml (GP), 103.3 ± 4.8µg/ml(HE) in MTT assay. The two peptides reduce the foam cell formation, intracellular lipid accumulation (cholesterol and triglycerides) and the secretion of TNF-α and IL-6 which are inflammatory cytokines in RAW 264.7 cell line at non-cytotoxic concentrations. A molecular interaction study proposed the binding pose for GP and HE peptides targeting the scavenging receptors CD36, SRA1, and Map Kinase p38 (a protein mediator). The cell line and molecular docking study indicated that among the two dipeptides, peptide GP has the highest atherogenic foam cell prevention efficiency.

In vitro and in vivo antiseptic activities of caffeoylquinic acid

Purpose: To evaluate the antiseptic effect of caffeoylquinic acid (CA) in in vivo and in vitro models.Methods: In vivo sepsis was produced in rats via cecal ligation and puncture (CLP) method. Four groups of rats were used: control group, untreated CLP group, and two CA groups treated with caffeoylquinic acid (50 and 100 mg/kg, p.o.) for 30 days before the induction of sepsis. Following the induction of sepsis, histological assessment of lung tissue was carried out using hematoxylin and eosin, and isolectin B4 staining. In addition, in vitro tests were performed on RAW264.7 cells in which inflammation and oxidative stress were induced by lipopolysaccharide (LPS).Results: Treatment with CA significantly (p < 0.05) enhanced the survival of lung cells, relative to the CLP group. Lung histopathology revealed that pretreatment with CA did not attenuate the increased infiltration of macrophages in the alveoli. Results from in vitro studies showed that CA attenuated LPS-induced nitric oxide (NO) levels, but had no significant effect on the level of LPS-induced pro-inflammatory cytokines in RAW264.7 cells (p < 0.05).Conclusion: These results reveal that CA attenuates NO and TNF-α levels in LPS-stimulated macrophages, thereby decreasing inflammation-associated sepsis. Thus, CA may have beneficial effects on lung injury as a result of its antioxidant and anti-inflammatory activities.Keywords: Caffeoylquinic acid, Sepsis, Oxidative stress, Cytokines, Cecalligation, Puncture

Identification of active compound combination contributing to anti-inflammatory activity of Xiao-Cheng-Qi Decoction via human intestinal bacterial metabolism

Human intestinal bacteria play an important role in the metabolism of herbal medicines, leading to the variations in their pharmacological profile. The present study aimed to investigate the metabolism of Xiao-Cheng-Qi decoction (XCQD) by human intestinal bacteria and to discover active component combination (ACC) contributing to the anti-inflammatory activity of XCQD. The water extract of XCQD was anaerobically incubated with human intestinal bacteria suspensions for 48 h at 37 °C. A liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) method was performed for identification of the metabolites. In addition, the anti-inflammatory effects of XCQD and biotransformed XCQD (XCQD-BT) were evaluated in vitro with cytokines in RAW264.7 cells induced by lipopolysaccharide (LPS). A total of 51 compounds were identified in XCQD and XCQD-BT. Among them, 20 metabolites were proven to be transformed by human intestinal bacteria. Significantly, a combination of 14 compounds was identified as ACC from XCQD-BT, which was as effective as XCQD in cell models of inflammation. In conclusion, this study provided an applicable method, based on intestinal bacterial metabolism, for identifying combinatory compounds responsible for a certain pharmacological activity of herbal medicines.

Interference of Quercetin on Astragalus Polysaccharide-Induced Macrophage Activation.

Polysaccharides, which exert immunoregulatory effects, are becoming more and more popular as food supplements; however, certain components of ordinary foods could be reducing the polysaccharides beneficial effects. Quercetin, a flavonoid found in common fruits and vegetables, is one such component. This study investigated the effects of quercetin on Astragalus polysaccharide RAP induced-macrophage activation. The results show quercetin decreases the NO production and iNOS gene expression in RAW264.7 cells, and it inhibits the production of cytokines in RAW264.7 cells and peritoneal macrophages. Western blot analysis results suggest that quercetin inhibits the phosphorylation of Akt/mTORC1, MAPKs, and TBK1, but has no effect on NF-κB in RAP-induced RAW264.7 cells. Taken together, the results show that quercetin partly inhibits macrophage activation by the Astragalus polysaccharide RAP. This study demonstrates that quercetin-containing foods may interfere with the immune-enhancing effects of Astragalus polysaccharide RAP to a certain extent.

Antioxidant activity in HepG2 cells, immunomodulatory effects in RAW 264.7 cells and absorption characteristics in Caco‐2 cells of the peptide fraction isolated from Dendrobium aphyllum

SummaryDA‐P, fraction of peptides with a molecular weight &lt;1 kDa isolated from Dendrobium aphyllum, was analysed in three types of cell lines to verify its bioactivity and absorptivity. The cellular antioxidant activity of DA‐P in HepG2 cells was used and results revealed an EC50 of 2.88 ± 0.143 mg mL−1 and a CAA unit of 63.46 ± 2.11 μm QE/100 g peptides. DA‐P treatment enhanced the secretion of cytokines in RAW 264.7 cells. After demonstrating the presence of tight junctions in Caco‐2 monolayers, the absorption was 25.57% ± 0.016% and 19.7% ± 0.012% from different sides. The relatively high absorption indicated that the antioxidant‐relevant immune functions of DA‐P had a greater possibility to be absorbed by Caco‐2 cells. Free amino acids and LC‐MS/MS analysis indicated the degradation and expulsion of components after the absorption of DA‐P, and Ser‐Ser‐Arg was able to come across the monolayers.

Influence of iRoot SP and mineral trioxide aggregate on the activation and polarization of macrophages induced by lipopolysaccharide

BackgroundBiomaterials could affect the inflammation reaction and wound healing via the activation and polarization of macrophages. However, the influence of iRoot SP and mineral trioxide aggregate (MTA) on macrophage polarization under inflammatory conditions was not reported although these two root filling materials have been applied extensively in patients undergoing endodontic treatment. Therefore, the present study aimed to explore the mechanism how iRoot SP and MTA affect the cell behavior of RAW 264.7 macrophages when stimulated by lipopolysaccharide (LPS) in vitro.MethodsThe gene expression of three main related pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) was examined by quantitative real-time polymerase chain reaction (qRT-PCR) in RAW 264.7 macrophages when stimulated by iRoot SP and MTA in the presence of LPS. The protein expression of the M1 and M2 phenotype specific markers, CD11c and CD206, was assessed by immunofluorescence and flow cytometry in RAW 264.7 macrophages.ResultsLPS promoted the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to the control group. Both iRoot SP and MTA were significantly able to enhance the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to LPS group. LPS could increase the expression of CD11c as compared to the control group while iRoot SP and MTA were able to enhance the expression of both CD11c and CD206 as compared to LPS group.ConclusionsiRoot SP and MTA could potentially promote the release of pro-inflammatory cytokines in RAW 264.7 macrophages and induce into M1/M2 phenotype when cultured with LPS.

Melanoma exosomes promote mixed M1 and M2 macrophage polarization

Macrophages are key participants in melanoma growth and survival. In general, macrophages can be classified as M1 or M2 activation phenotypes. Increasing evidence demonstrates that melanoma exosomes also facilitate tumor survival and metastasis. However, the role of melanoma exosomes in directly influencing macrophage function is poorly understood. Herein, we investigated the hypothesis that natural melanoma exosomes might directly influence macrophage polarization. To explore this hypothesis, ELISA, RT-qPCR, and macrophage functional studies were performed in vitro using an established source of melanoma exosomes (B16-F10). ELISA results for melanoma exosome induction of common M1 and M2 cytokines in RAW 264.7 macrophages, revealed that melanoma exosomes do not polarize macrophages exclusively in the M1 or M2 direction. Melanoma exosomes induced the M1 and M2 representative cytokines TNF-α and IL-10 respectively. Further assessment, using an RT-qPCR array with RAW 264.7 and primary macrophages, confirmed and extended the ELISA findings. Upregulation of markers common to both M1 and M2 polarization phenotypes included CCL22, IL-12B, IL-1β, IL-6, i-NOS, and TNF-α. The M2 cytokine TGF-β was upregulated in primary but not RAW 264.7 macrophages. Pro-tumor functions have been attributed to each of these markers. Macrophage functional assays demonstrated a trend toward increased i-NOS (M1) to arginase (M2) activity. Collectively, the results provide the first evidence that melanoma exosomes can induce a mixed M1 and M2 pro-tumor macrophage activation phenotype.

Wide-range screening of anti-inflammatory compounds in tomato using LC-MS and elucidating the mechanism of their functions.

Obesity-induced chronic inflammation is a key factor in type 2 diabetes. A vicious cycle involving pro-inflammatory mediators between adipocytes and macrophages is a common cause of chronic inflammation in the adipose tissue. Tomato is one of the most popular vegetables and is associated with a reduced risk of diabetes. However, the molecular mechanism underlying the effect of tomato on diabetes is unclear. In this study, we focused on anti-inflammatory compounds in tomato. We found that the extract of tomato reduced plasma glucose and inflammatory markers in mice. We screened anti-inflammatory fractions in tomato using lipopolysaccharide-stimulated RAW264.7 macrophages, and active compounds were estimated by liquid chromatography-mass spectrometry over a wide range. Surprisingly, a large number of compounds including oxylipin and coumarin derivatives were estimated as anti-inflammatory compounds. Especially, 9-oxo-octadecadienoic acid and daphnetin suppressed pro-inflammatory cytokines in RAW264.7 macrophages inhibiting mitogen-activated protein kinase phosphorylation and inhibitor of kappa B α protein degradation. These findings suggest that tomato containing diverse anti-inflammatory compounds ameliorates chronic inflammation in obese adipose tissue.

Effects of a novel microtubule-depolymerizer on pro-inflammatory signaling in RAW264.7 macrophages

The Nuclear Factor-kappa B (NF-κB) pathway is vital for immune system regulation and pro-inflammatory signaling. Many inflammatory disorders and diseases, including cancer, are linked to dysregulation of NF-κB signaling. When macrophages recognize the presence of a pathogen, the signaling pathway is activated, resulting in the nuclear translocation of the transcription factor, NF-κB, to turn on pro-inflammatory genes. Here, we demonstrate the effects of a novel microtubule depolymerizer, NT-07-16, a polysubstituted pyrrole compound, on this process. Treatment with NT-07-16 decreased the production of pro-inflammatory cytokines in RAW264.7 mouse macrophages. It appears that the reduction in pro-inflammatory mediators produced by the macrophages after exposure to NT-07-16 may be due to activities upstream of the translocation of NF-κB into the nucleus. NF-κB translocation occurs after its inhibitory protein, IκB-α is phosphorylated which signals for its degradation releasing NF-κB so it is free to move into the nucleus. Previous studies from other laboratories indicate that these processes are associated with the microtubule network. Our results show that exposure to the microtubule-depolymerizer, NT-07-16 reduces the phosphorylation of IκB-α and also decreases the association of NF-κB with tubulin which may affect the ability of NF-κB to translocate into the nucleus. Therefore, the anti-inflammatory activity of NT-07-16 may be explained, at least in part, by alterations in these steps in the NF-κB signaling pathway leading to less NF-κB entering the nucleus and reducing the production of pro-inflammatory mediators by the activated macrophages.

Design, Synthesis, and Biological Activity of Tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine Derivatives as Anti-Inflammatory Agents.

We designed and synthesized 26 prototype compounds and studied their anti-inflammatory activity and underlying molecular mechanisms. The inhibitory effects of the compounds on the production of nitric oxide (NO), cytokines, inflammatory-related proteins, and mRNAs in lipopolysaccharide (LPS)-stimulated macrophages were determined by the Griess assay, Enzyme linked immunosorbent assay (ELISA), Western blot analysis, and Reverse transcription-Polymerase Chain Reaction (RT-PCR), respectively. Our results indicated that treatment with A2, A6 and B7 significantly inhibited the secretion of NO and inflammatory cytokines in RAW264.7 cells without demonstrable cytotoxicity. It was also found that A2, A6 and B7 strongly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase enzyme COX-2, and prevented nuclear translocation of nuclear factor κB (NF-κB) p65 by inhibiting the degradation of p50 and IκBα. Furthermore, the phosphorylation of mitogen-activated protein kinase (MAPKs) in LPS-stimulated RAW264.7 cells was significantly inhibited by A2, A6 and B7. These findings suggest that A2, A6 and B7 may operate as an effective anti-inflammatory agent through inhibiting the activation of NF-κB and MAPK signaling pathways in macrophages. Moreover, rat paw swelling experiments showed that these compounds possess anti-inflammatory activity in vivo, with compound A6 exhibiting similar activities to the reference drug Indomethacin.

Antioxidant and anti-inflammatory properties of chicken egg vitelline membrane hydrolysates

Vitelline membrane (VM) is a multilayered structure that surrounds the egg yolk serving to separate the yolk and the white. Due to its poor solubility in aqueous-based media, VM proteins and their biological properties have not been fully defined. In the current study, VM was hydrolyzed using different enzymes under the optimum hydrolysis conditions. Antioxidant and anti-inflammatory properties were evaluated in chemical and cellular models. Flavourzyme- and trypsin-treated samples showed the highest radical scavenging and ferric ion reducing effect (31% and 20 μM of Trolox equivalents/mg, respectively). In cellular studies, all VM hydrolysates were cyto-compatible and inhibited nitric oxide production by RAW264.7 macrophage cells significantly. Lipopolysaccharide-stimulated up-regulation of pro-inflammatory cytokines in RAW264.7 cells was suppressed by flavourzyme-treated VM. These results revealed that enzymatic hydrolysis of VM is a promising approach to produce peptides with several bioactivities (free radical scavenging, metal chelation, and anti-inflammatory) as valuable ingredients for cosmeceuticals and nutraceuticals.

Eicosapentaenoic Acid (EPA) Induced Macrophages Activation through GPR120-Mediated Raf-ERK1/2-IKKβ-NF-κB p65 Signaling Pathways.

Objectives: To investigate the immunomodulatory effect and molecular mechanisms of Eicosapentaenoic acid (EPA, a typical kind of n-3PUFAs) on RAW264.7 cells. Methods: A variety of research methods, including the RAW264.7 cells culture, cell proliferation assays, morphologic observations, measurements of NO production, cytokine assays, nuclear protein extractions, western blot analyses and NF-κB p65 immunofluorescence assays were used in this study. Results: The results showed that EPA could increase the proliferation index and enhance the release of nitric oxide (NO) and cytokines in RAW264.7 cells. Western blotting results revealed that the protein level of GPR120 increased significantly in RAW264.7 cells after EPA treatment. Meanwhile, EPA elevated the phosphorylation status of Raf, which may act as an upstream regulator of EPA-induced phosphorylated ERK1/2. In addition, the phosphorylated ERK1/2 may then promote IKKβ in endochylema and translocate the NF-κB p65 subunit into the nucleus, thus regulating the production of inducible nitric oxide synthase (iNOS) and cytokines. Conclusions: EPA (0.6–3.0 μmol) activates RAW264.7 cells through GPR120-mediated Raf-ERK1/2-IKKβ-NF-κB p65 signaling pathways.

Achillea asiatica extract and its active compounds induce cutaneous wound healing

Ethnopharmacological relevanceAchillea asiatica Serg. is a perennial herb belonging to the Asteraceae family that has long been traditionally used to treat acute intestinal and stomach inflammation, persistent fever, ulcers, wounds, and rheumatism. Aim of the studyWe investigated the effect of A. asiatica extract (AAE) on cutaneous wound healing. Materials and methodsTo assess the effect of AAE on wounds, an incisional Sprague-Dawley (SD) rat model was topically treated with AAE for 2 weeks. HaCaT keratinocytes, Hs68 dermal fibroblasts, and RAW 264.7 macrophages were used for in vitro experiments. After treatment with AAE, cell viability, cell migration, and production of nitric oxide (NO) and prostaglandin E2 (PGE2) were investigated. mRNA expression of collagen type I and III and inflammatory cytokines was measured by RT-PCR. The effect of AAE on activation of β-catenin and other markers was determined by Western blot analysis. ResultsAAE treatment significantly increased epithelialization and accelerated wound healing in SD rats. Meanwhile, AAE and its active compounds reduced NO and PGE2 release and mRNA expression of inflammatory cytokines in RAW 264.7 macrophages, reflecting anti-inflammatory activity. Furthermore, AAE and its constituents stimulated collagen expression in Hs68 fibroblasts by activating transforming growth factor-β and stimulated keratinocyte differentiation and motility by inducing β-catenin, Akt, and keratinocyte differentiation markers. ConclusionsAAE improves skin wounds in SD rats and supports keratinocyte development.

Cleavable conjugation of CpG oligodeoxynucleotides onto microparticles for facile release and cytokine induction in macrophages

The development of biomaterials for efficient intracellular delivery of the nucleic acid-based immune-stimulating molecule, CpG oligodeoxynucleotides (CpG), is crucial for their biological activity. In this study, we successfully fabricated polydopamine-coated porous poly(lactic-co-glycolic acid) microparticles (PPM) for the delivery of CpGs. After conjugation of CpGs to PPMs via cleavable disulfide linkages, CpGs were readily released from CpG-conjugated PPM (PPM-s–s-CpGs) in reductive conditions. Released CpGs exhibited significantly enhanced induction of two cytokines, TNF-α and IL-6, in RAW264.7 cells. GpC-conjugated PPMs showed negligible cytokine induction, whereas CpG-conjugated PPMs exhibited strong induction of the two cytokines in RAW264.7 cells. The PPM-s–s-CpGs can serve as immune-stimulating adjuvants to enhance the immune responses of vaccines.

Anti-Inflammatory Effects, SAR, and Action Mechanism of Monoterpenoids from Radix Paeoniae Alba on LPS-Stimulated RAW 264.7 Cells.

Nine monoterpenoids from Radix Paeoniae Alba, including paeoniflorin derivatives, paeoniflorin (PF), 4-O-methylpaeoniflorin (MPF), 4-O-methylbenzoylpaeoniflorin (MBPF); paeonidanin derivatives, paeonidanin (PD), paeonidanin A (PDA), albiflorin derivatives, albiflorin (AF), benzoylalbiflorin (BAF), galloylalbiflorin (GAF), and debenzoylalbiflorin (DAF), were obtained in our previous phytochemistry investigations. Their anti-inflammatory effects were determined in the present study. The expression and production of pro-inflammatory cytokines in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells were measured using an Elisa assay and nitric oxide (NO) release was determined using the Griess method. The results demonstrated that the most of the monoterpenoids suppressed the LPS-induced production of NO, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α). The anti-inflammatory activities of these monoterpenoids were closely related to their structural characteristics. Paeoniflorins and paeonidanins presented stronger anti-inflammatory activities than those of albiflorin derivatives. Furthermore, the action mechanisms of MBPF, having a strong anti-inflammatory effect, were investigated using quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot methods. The results indicated that MBPF could down-regulate the mRNA and protein expression level of inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW 264.7 cells. The mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/AKT and nuclear factor κB (NF-κB) signaling pathways are involved in mediating the role of MBPF in suppressing the expression and production of pro-inflammatory cytokines in RAW 264.7 cells.

Essential oil of Artemisia argyi suppresses inflammatory responses by inhibiting JAK/STATs activation

Ethnopharmacological relevanceArtemisia argyi is a herbal medicine traditionally used in Asia for the treatment of bronchitis, dermatitis and arthritis. Recent studies revealed the anti-inflammatory effect of essential oil in this plant. However, the mechanisms underlying the therapeutic potential have not been well elucidated. The present study is aimed to verify its anti-inflammatory effect and investigate the probable mechanisms. Materials and methodsThe essential oil from Artemisia argyi (AAEO) was initially tested against LPS-induced production of inflammatory mediators and cytokines in RAW264.7 macrophages. Protein and mRNA expressions of iNOS and COX-2 were determined by Western blotting and RT-PCR analysis, respectively. The effects on the activation of MAPK/NF-κB/AP-1 and JAK/STATs pathway were also investigated by western blot. Meanwhile, in vivo anti-inflammatory effect was examined by histologic and immunohistochemical analysis in TPA-induced mouse ear edema model. ResultsThe results of in vitro experiments showed that AAEO dose-dependently suppressed the release of pro-inflammatory mediators (NO, PGE2 and ROS) and cytokines (TNF-α, IL-6, IFN-β and MCP-1) in LPS-induced RAW264.7 macrophages. It down-regulated iNOS and COX-2 protein and mRNA expression but did not affect the activity of these two enzymes. AAEO significantly inhibited the phosphorylation of JAK2 and STAT1/3, but not the activation of MAPK and NF-κB cascades. In animal model, oral administration of AAEO significantly attenuated TPA-induced mouse ear edema and decreased the protein level of COX-2. ConclusionAAEO suppresses inflammatory responses via down-regulation of the JAK/STATs signaling and ROS scavenging, which could contribute, at least in part, to the anti-inflammatory effect of AAEO.

Evaluation of immunomodulatory effects of zearalenone in mice

Zearalenone (ZEA) is a non-steroidal estrogenic mycotoxin produced by Fusarium species. The toxicity of ZEA has been evaluated for reproductive and developmental effects; however, there is little evidence about its acute toxicity or general immunotoxicity. In the present study, immune regulatory functions were investigated in mice that had been exposed to ZEA (5 or 20 mg/kg BW) daily for 14 days. Results showed that sub-populations of CD4+, CD8+ and CD11c+ cells in the spleen and CD4+, CD8+ and F4/80+ cells in the mesenteric lymph nodes (MLN) of ZEA (20 mg/kg)-exposed hosts were decreased compared to those in the control mice. However, CD19+ and CD11c+ cells were increased in the MLN of the ZEA mice and CD4+CD25+Foxp3+ cells were decreased in the spleen and MLN. There were differential changes in the immune cell populations of the small intestine of the ZEA mice as well, depending on small intestine location. In ex vivo experiments, ZEA treatments resulted in increased proliferative capacities of mitogen-induced splenocytes and MLN cells; such changes were paralleled by significant increases in interferon (IFN)-γ production. With regard to serum isotypes, IgM levels were decreased and IgE levels were increased in the 20 mg/kg ZEA-treated mice. Mucosal IgA levels were decreased in the duodenum and vagina of these hosts. Serum analyzes also revealed that tumor necrosis factor (TNF)-α levels were decreased and interleukin (IL)-6 levels increased as a result of ZEA exposures. ZEA treatment also led to increased apoptosis in the spleen and Peyer’s patches; these changes were associated with changes in the ratios of Bax:Bcl-2. Following priming with different TLR ligands, ZEA exposure led to differentially modulated TLR signaling and variable production of pro- and anti-inflammatory cytokines in RAW 264.7 macrophage cells. Taken together, these results indicated that ZEA could alter the normal expression/function of different immune system components and this would likely lead to immunomodulation in situ.

Docosapentaenoic Acid (22:5n-3) Downregulates mRNA Expression of Pro-inflammatory Factors in LPS-activated Murine Macrophage Like RAW264.7 Cells.

Docosapentaenoic acid (22:5n-3, n-3 DPA) is a n-3 polyunsaturated fatty acid (PUFA) found in fish oil, and has been reported to have health benefits. This study investigated conversion of n-3 DPA, and examined the anti-inflammatory effects of n-3 DPA on activated macrophages. Murine macrophage-like RAW264.7 cells were incubated in culture media containing n-3 DPA for 72 h. The level of n-3 DPA in the fatty acid composition of the total lipid fraction increased in a dose-dependent manner. Furthermore, the levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were higher in treated cells than in control cells. In RAW264.7 cells stimulated by lipopolysaccharide (LPS), n-3 DPA significantly down-regulated mRNA expression of pro-inflammatory factors such as IL-6, IL-1β, iNOS and COX-2. Production of IL-6 was also reduced by n-3 DPA in a dose-dependent manner. We found that n-3 DPA treatment resulted in greater IL-6 mRNA down-regulation than that achieved with EPA treatment, and was similar to that of DHA treatment. Furthermore, expression levels of IL-6 and IL-1β mRNAs were measured in the presence of the delta-6 desaturase inhibitor SC26196 in the culture medium to inhibit the conversion of n-3 DPA to DHA. There was no significant difference in the down-regulation in the mRNA expression of pro-inflammatory cytokines in RAW264.7 cells by n-3 DPA with or without presence of SC26196. These results demonstrate that n-3 DPA exhibits anti-inflammatory effects in activated RAW264.7 cells, which are independent of DHA conversion.

Solanesol induces the expression of heme oxygenase-1 via p38 and Akt and suppresses the production of proinflammatory cytokines in RAW264.7 cells.

The aim of the present study was to examine the anti-inflammatory effect of solanesol and to elucidate the underlying mechanisms. Heme oxygenase-1 (HO-1) plays an important role in cytoprotection against oxidative stress and inflammation. Solanesol induced HO-1 expression both at the level of mRNA and proteins, resulting in increased HO-1 activity. Solanesol treatment enhanced the level of the phosphorylated form, nuclear translocation, ARE-binding, and transcriptional activity of Nrf2. p38 and Akt contributed to ARE-driven HO-1 expression. Solanesol activated both p38 and Akt, and treatments with SB203580 (a p38 kinase inhibitor), LY294002 (an Akt inhibitor), specific p38 siRNA and Akt siRNA suppressed the solanesol-induced activation of Nrf2, resulting in a decrease in HO-1 expression. Solanesol also elevated the autophagic protein LC3B-II level. SnPP (a HO-1 inhibitor) and HO-1 siRNA markedly abolished the anti-inflammatory effect of solanesol against LPS-induced cell damage. Likewise, SB203580, LY294002, 3-MA and Baf-A1 inhibited the solanesol-induced anti-inflammatory effect. These studies demonstrate that solanesol attenuates inflammation by HO-1 induction via p38 and Akt signaling. Thus, it is quite plausible that HO-1 induction by solanesol could trigger anti-inflammatory pathways including limiting LPS-stimulated cytokine production through autophagic signaling via p38 and Akt.

Toxic proteins from Crotontiglium L. exert a proinflammatory effect by inducing release of proinflammatory cytokines and activating the p38-MAPK signaling pathway.

The aim of the present study was to determine the toxic targets of proteins from Croton tiglium L. and to investigate the potential mechanism of their toxicity. The toxic targets were determined by oral medication and intraperitoneal injection. The median lethal dose of oral medication in mice was calculated using Bliss software (2,752.8–3,407.5 mg/kg), and that of intraperitoneal injection was 195.8–272.69 mg/kg. The results of histopathological examination demonstrated that the kidney was primarily impaired by intraperitoneal injection, with slight degeneration of renal tubular epithelial cells. As to oral medication, the digestive tract was primarily injured, which manifested as congestion, bleeding, serious edema and other symptoms. Oral administration of the proteins caused gastrointestinal edema by increasing the intestinal permeability. Severe edema was associated with the inflammatory response, therefore the association between the toxicity of the proteins and inflammation was investigated. The proinflammatory effects of the crude proteins on the release of inflammatory mediator prostaglandin E2 (PGE2) were evaluated through intraperitoneal injection and the production of proinflammatory cytokines in RAW264.7 macrophages. Maximum PGE2 was released in the mice in vivo following intraperitoneal injection with 400 mg crude protein/kg body weight. Proinflammatory cytokines in macrophages, including tumor necrosis factor-α and interleukin-1β, were produced in dose- and time-dependent manners in vitro. furthermore, the expressions of cell signaling molecules were detected by western blotting. The inflammatory response induced by crude protein in macrophages was associated with the mitogen-activated protein kinase (MAPK) signaling pathway mainly including p38-MAPK, extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase 1/2/3 and the activated p38-MAPK signaling pathway. However, extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinases 1–3 exhibited no significant response.