Src/NF-κB-targeted inhibition of LPS-induced macrophage activation and dextran sodium sulphate-induced colitis by Archidendron clypearia methanol extract

Traditional Herbal Medicine Pithecellobium clypearia (Jack) Benth: Research progress in chemical constituents and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Pithecellobium clypearia, a traditional herbal medicine, has garnered widespread attention for its significant anti-infective benefits. However, there is currently a lack of comprehensive reviews examining the chemical constituents and pharmacological activities of P. clypearia.

AIMS OF THE STUDY

This review aims to investigate the chemical constituents and pharmacological effects of P. clypearia, and to explore its potential for wider medical applications through the synthesis of these findings.

MATERIALS AND METHODS

The Web of Science, PubMed, CNKI, Google Scholar, and WanFang databases were searched for Pithecellobium clypearia, Using "Pithecellobium clypearia", "Archidendron clypearia", "pharmacology", "chemical composition" and "biological activity", as the keywords, we summarized the main chemical compositions and pathological mechanisms of P. clypearia.

RESULTS

A total of 129 compounds were isolated from P. clypearia, the primary active components identified include flavonoids, polysaccharides, lignins, triterpenoids, steroids, and phenolic acids. These compounds contribute to the medicinal plant's diverse pharmacological effects, which include antiviral, antibacterial, anti-inflammatory, antioxidant, and neuroprotective properties. P. clypearia presents great potential, especially in its antiviral and anti-inflammatory effects, indicating its valuable role in future therapeutic strategies.

CONCLUSION

P. clypearia has demonstrated effectiveness and safety in treating various respiratory and gastrointestinal diseases. It shows good monotherapy efficacy and significantly enhances overall treatment outcomes when used in combination therapy. P. clypearia is a valuable treatment option for patients of different age groups and provides a safe and effective alternative in various clinical settings.

Evaluation of the Mechanism of Sinomenii Caulis in Treating Ulcerative Colitis based on Network Pharmacology and Molecular Docking

BACKGROUND

Studies have indicated that Sinomenii Caulis (SC) has several physiological activities, such as anti-inflammatory, anti-cancer, immunosuppression, and so on. SC is currently widely used in the treatment of rheumatoid arthritis, skin disease, and other diseases. However, the mechanism of SC in the treatment of ulcerative colitis (UC) remains unclear.

AIMS

To predict the active components of SC and determine the mechanism of SC on UC.

METHODS

Active components and targets of SC were screened and obtained by TCMSP, PharmMapper, and CTD databases. The target genes of UC were searched from GEO (GSE9452), and DisGeNET databases. Based on the String database, Cytoscape 3.7.2 software, and David 6.7 database, we analyzed the relationship between SC active components and UC potential targets or pathways. Finally, identification of SC targets in anti-UC by molecular docking. GROMACS software was used to perform molecular dynamics simulations of protein and compound complexes and to perform free energy calculations.

RESULTS

Six main active components, 61 potential anti-UC gene targets, and the top 5 targets with degree value are IL6, TNF, IL1β, CASP3, and SRC. According to GO enrichment analysis, the vascular endothelial growth factor receptor and vascular endothelial growth factor stimulus may be relevant biological processes implicated in the treatment of UC by SC. The KEGG pathway analysis result was mainly associated with the IL-17, AGE-RAGE, and TNF signaling pathways. Based on molecular docking results, beta-sitosterol, 16-epi-Isositsirikine, Sinomenine, and Stepholidine are strongly bound to the main targets. Molecular dynamics simulation results showed that IL1B/beta-sitosterol and TNF/16-epi-Isositsirikine binding was more stable.

CONCLUSION

SC can play a therapeutic role in UC through multiple components, targets, and pathways. The specific mechanism of action needs to be further explored.

Minocycline synergizes with corticosteroids in reducing colitis severity in mice via the modulation of pro-inflammatory molecules

Background: A few studies have highlighted the anti-inflammatory properties of minocycline in reducing colitis severity in mice, but its molecular mechanism is not fully understood. The aim of this study was to determine the anti-inflammatory properties of minocycline and the expression/activity profiles of molecules involved in pro-inflammatory signaling cascades, cytokines, and molecules involved in the apoptotic machinery. The synergistic effect between minocycline and corticosteroids was also evaluated. Methods: The effects of various treatment approaches were determined in mice using the dextran sulfate sodium (DSS) colitis model at gross and microscopic levels. The expression/activity profiles of various pro- or anti-inflammatory molecules were determined using Western blotting and polymerase chain reaction (PCR). Results: Minocycline treatment significantly reduced colitis severity using prophylactic and treatment approaches and produced a synergistic effect with budesonide and methylprednisolone in reducing the active state of colitis. This was mediated in part through reduced colonic expression/activity of pro-inflammatory molecules, cytokines, proteins involved in the apoptotic machinery, and increased expression of the anti-inflammatory cytokine IL-10. Conclusion: Minocycline synergizes with corticosteroids to reduce colitis severity, which could reduce their dose-dependent side effects and treatment cost. The reduction in colitis severity was achieved by modulating the expression/activity profiles of various pro- and anti-inflammatory signaling molecules, cytokines, and molecules involved in the apoptotic machinery.

Phillygenin Attenuated Colon Inflammation and Improved Intestinal Mucosal Barrier in DSS-induced Colitis Mice via TLR4/Src Mediated MAPK and NF-κB Signaling Pathways

Ulcerative colitis (UC) is a chronic, relapsing, and nonspecific inflammatory bowel disease (IBD). Phillygenin (PHI), a natural bioactive ingredient, isolated from Forsythiae Fructus, exhibits anti-inflammatory, anti-oxidative, and hepatoprotective activities. However, few reports provide direct evidence on the efficacy of PHI in improving colitis mice. The present study elucidated that the symptoms of DSS-induced colitis mice were alleviated after PHI administration, including body weight loss, the disease activity index, colon length shortening, colonic pathological damage, splenomegaly, and hepatomegaly. PHI treatment improved the intestinal mucosal barrier by protecting goblet cells, promoting gene expressions of Clca1, Slc26a3, and Aqp8, increasing tight junction proteins (TJs), and reducing epithelial cell apoptosis. In addition, the levels of oxidative stress (MPO, SOD, and MDA) and inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10) were reversed by PHI in colitis mice. According to transcriptome and network pharmacology analysis, inflammatory pathway might be an important mechanism for PHI to improve colitis. Western blotting displayed that the PHI inhibited the activation of tyrosine kinase Src mediated by TLR4, and then reduced the phosphorylation of downstream proteins p38, JNK, and NF-κB in colitis mice. In summary, our results suggested that PHI might be an appropriate and effective drug candidate to protect colitis.

Anti-Inflammatory Functions of Methanol Extract from Malus baccata (L.) Borkh. Leaves and Shoots by Targeting the NF-κB Pathway

Malus baccata (L.) Borkh. is a widely used medical plant in Asia. Since the anti-inflammatory mechanism of this plant is not fully understood, the aim of this study was to explore the anti-inflammatory function and mechanism of Malus baccata (L.) Borkh. methanol extract (Mb-ME). For in vitro experiments, nitric oxide production assay, PCR, overexpression strategy, immunoblotting, luciferase reporter assay, and immunoprecipitation were employed to explore the molecular mechanism and the target proteins of Mb-ME. For in vivo experiments, an HCl/EtOH-induced gastritis mouse model was used to confirm the anti-inflammatory function. Mb-ME showed a strong ability to inhibit the production of nitric oxide and the expression of inflammatory genes. Mb-ME decreased NF-κB luciferase activity mediated by MyD88 and TRIF. Moreover, Mb-ME blocked the activation of Src, Syk, p85, Akt, p50, p60, IKKα/β, and IκBα in LPS-induced RAW264.7 cells. Overexpression and immunoprecipitation analyses suggested Syk and Src as the target enzymes of Mb-ME. In vitro results showed that Mb-ME could alleviate gastritis and relieve the protein expression of p-Src, p-Syk, and COX-2, as well as the gene expression of COX-2 and TNF-α. In summary, this study implied that Mb-ME performs an anti-inflammatory role by suppressing Syk and Src in the NF-κB signaling pathway, both in vivo and in vitro.

Identifying Hub Genes, Key Pathways and Immune Cell Infiltration Characteristics in Pediatric and Adult Ulcerative Colitis by Integrated Bioinformatic Analysis

BACKGROUND AND AIMS

In the present study, we investigated the differentially expressed genes (DEGs), pathways and immune cell infiltration characteristics of pediatric and adult ulcerative colitis (UC).

METHODS

We conducted DEG analysis using the microarray dataset GSE87473 containing 19 pediatric and 87 adult UC samples downloaded from the Gene Expression Omnibus. Gene ontology and pathway enrichment analyses were conducted using Metascape. We constructed the protein-protein interaction (PPI) network and the drug-target interaction network of DEGs and identified hub modules and genes using Cytoscape and analyzed immune cell infiltration in pediatric and adult UC using CIBERSORT.

RESULTS

In total, 1700 DEGs were screened from the dataset. These genes were enriched mainly in inter-cellular items relating to cell junctions, cell adhesion, actin cytoskeleton and transmembrane receptor signaling pathways and intra-cellular items relating to the splicing, metabolism and localization of RNA. CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC were identified as hub DEGs. Immune cell infiltration analysis revealed higher proportions of naive B cells, resting memory T helper cells, regulatory T cells, monocytes, M0 macrophages and activated mast cells in pediatric UC, along with lower proportions of memory B cells, follicular helper T cells, γδ T cells, M2 macrophages, and activated dendritic cells.

CONCLUSIONS

Our study suggested that hub genes CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC and immune cells including B cells, T cells, monocytes, macrophages and mast cells play vital roles in the pathological differences between pediatric and adult UC and may serve as potential biomarkers in the diagnosis and treatment of UC.

Molecular Biology of Atherosclerotic Ischemic Strokes

Among the causes of global death and disability, ischemic stroke (also known as cerebral ischemia) plays a pivotal role, by determining the highest number of worldwide mortality, behind cardiomyopathies, affecting 30 million people. The etiopathogenetic burden of a cerebrovascular accident could be brain ischemia (~80%) or intracranial hemorrhage (~20%). The most common site when ischemia occurs is the one is perfused by middle cerebral arteries. Worse prognosis and disablement consequent to brain damage occur in elderly patients or affected by neurological impairment, hypertension, dyslipidemia, and diabetes. Since, in the coming years, estimates predict an exponential increase of people who have diabetes, the disease mentioned above constitutes together with stroke a severe social and economic burden. In diabetic patients after an ischemic stroke, an exorbitant activation of inflammatory molecular pathways and ongoing inflammation is responsible for more severe brain injury and impairment, promoting the advancement of ischemic stroke and diabetes. Considering that the ominous prognosis of ischemic brain damage could by partially clarified by way of already known risk factors the auspice would be modifying poor outcome in the post-stroke phase detecting novel biomolecules associated with poor prognosis and targeting them for revolutionary therapeutic strategies.

Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

Background

Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer’s disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model.

Methods

Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention.

Results

Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction.

Conclusion

Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

Gastroprotective effects of the nonsaponin fraction of Korean Red Ginseng through cyclooxygenase-1 upregulation

Background

Korean Red Ginseng is known to exhibit immune-enhancing and anti-inflammatory properties. The immune-enhancing effects of the nonsaponin fraction (NSF) of Korean Red Ginseng have been studied in many reports. However, the gastroprotective effect of this fraction is not fully understood. In this study, we demonstrate the activities of NSF for gastrointestinal protection and its related critical factor.

Methods

The in vitro and in vivo regulatory functions of NSF on cyclooxygenase-1 (COX-1) messenger RNA and protein levels were examined by reverse transcription polymerase chain reaction and immunoblotting analyses. Gastroprotective effects of NSF were investigated by histological score, gastric juice pH, and myeloperoxidase activity on indomethacin-induced, cold stress-induced, and acetylsalicylic acid-induced gastritis and dextran sulfate sodium-induced colitis in in vivo mouse models.

Results

NSF did not show cytotoxicity, and it increased COX-1 messenger RNA expression and protein levels in RAW264.7 cells. This upregulation was also observed in colitis and gastritis in vivo models. In addition, NSF treatment in mice ameliorated the symptoms of gastrointestinal inflammation, including histological score, colon length, gastric juice pH, gastric wall thickness, and myeloperoxidase activity.

Conclusion

These results suggest that NSF has gastroprotective effects on gastritis and colitis in in vivo mouse models through COX-1 upregulation.

Anti-Inflammatory Effects of Licania macrocarpa Cuatrec Methanol Extract Target Src- and TAK1-Mediated Pathways

In this study, we investigated the anti-inflammatory effects of Licania macrocarpa Cuatrec methanol extract (Lm-ME) in vitro and in vivo and found pharmacological target proteins of Lm-ME in TLR4-mediated inflammatory signaling. This extract reduced NO production and mRNA expression of inflammatory cytokines such as iNOS, COX-2, IL-6, and IL-1β. In the NF-κB- and AP-1-mediated luciferase reporter gene assay, transcription factor activities decreased under cotransfection with MyD88 or TRIF. Phosphorylated protein levels of Src, PI3K, IKKα/β, and IκBα as well as p50 and p65 in the NF-κB signal pathway were downregulated, and phosphorylation of TAK1, MEK1/2, MKK4/7, and MKK3/6 as well as ERK, JNK, and p38 was decreased in the AP-1 signal pathway. Through overexpression of HA-Src and HA-TAK1, respectively, Lm-ME inhibited autophosphorylation of overexpressed proteins and thereby activated fewer downstream signaling molecules. Lm-ME also attenuated stomach ulcers in an HCl/EtOH-induced acute gastritis model mice, and COX-2 mRNA expression and phosphorylated TAK1 levels in gastric tissues were diminished. The flavonoids kaempferol and quercetin were identified in the HPLC analysis of Lm-ME; both are actively anti-inflammatory. Therefore, these results suggest that Lm-ME can be used for anti-inflammatory remedy by targeting Src and TAK1.

Syk: a new target for attenuation of Helicobacter pylori-induced gastric mucosal inflammatory responses

The magnitude of gastric mucosal inflammatory response to H. pylori relies primarily on the extent of its key endotoxin, LPS, engagement of Toll-like receptor-4 (TLR4) and the initiation of signal transduction events converging on mitogen-activated protein kinase (MAPK) and IκB complex (IKK) cascades. These cascades, in turn, exert their control over the assembly of transcription factors, NFκB and AP1, implicated in the induction of the expression of iNOS and COX-2 proinflammatory genes. The LPS-induced TLR4 activation and the ensuing phosphorylation of its intracellular tyrosine domain by Src-family kinases not only leads to recruitment to the cytoplasmic domain of TLR4 of adaptor molecules directly involved in propagation of the signaling cascades converging on MAPK and IKK, but also provides a propitious docking site for a non-receptor tyrosine kinase, spleen tyrosine kinase (Syk), the activation of which apparently leads to upregulation in the expression of proinflammatory genes. Here, we review the pathways engaged by H. pylori in the recruitment and interaction of Syk with TLR4 in gastric mucosa, and discuss the cascades involved in Syk-mediated amplification in proinflammatory signaling. We focus, moreover, on the potential role of drugs targeting Syk and TLR4 in the treatment of H. pylori-related gastric disease.

Spleen tyrosine kinase from Nile tilapia (Oreochromis niloticus): Molecular characterization, expression pattern upon bacterial infection and the potential role in BCR signaling and inflammatory response

Spleen tyrosine kinase (SYK), a member of non-receptor tyrosine kinase family, plays an important role in immune responses against pathogen infection, which is capable of activating B cells signaling pathway and regulating inflammatory response. In this study, Nile tilapia (Oreochromis niloticus) ortholog (OnSYK) was identified and characterized at expression pattern against bacterial infection, function in B cells activation pathway and inflammatory response. The cDNA of OnSYK ORF contained 1851 bp of nucleotide sequence encoding polypeptides of 616 amino acids. The deduced OnSYK protein was highly homologous to other species SYK, containing two SH2 domains and a TyrKc domain. Spatial mRNA expression analysis revealed that OnSYK had wide tissue distribution and was highly expressed in the liver. After challenge of Streptococcus agalactiae (S. agalactiae) in vivo, mRNA expression of OnSYK was significantly up-regulated in the head kidney, spleen and liver. The up-regulation of OnSYK transcript was also displayed in the head kidney and spleen leukocytes stimulation with S. agalactiae and LPS in vitro, which was confirmed at protein level in the head kidney leukocytes by FACS analysis. In addition, after induction with mouse anti-OnIgM monoclonal antibody in vitro, the expressions of OnSYK and its downstream molecules (OnLYN, OnBLNK and OnAP-1) were significantly up-regulated in the head kidney leukocytes, and pharmacological inhibition of SYK activity with inhibitor (P505-15) significantly attenuated the expressions of OnLYN, OnBLNK and OnAP-1. Moreover, upon LPS challenge, the expressions of OnSYK, OnTNF-α, OnIL-6 and OnAP-1 were also up-regulated in the head kidney monocytes/macrophages. After treatment with SYK inhibitor (BAY 61-3606), the expressions of OnTNF-α, OnIL-6 and OnAP-1 were inhibited in the LPS-challenged head kidney monocytes/macrophages. Taken together, the results of this study indicated that OnSYK, playing potential roles in BCR signaling and inflammatory response, was likely to get involved in host defense against bacterial infection in Nile tilapia.

Xanthine oxidase inhibitors from Archidendron clypearia (Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants

OBJECTIVE

To screen Vietnamese medicinal plants for xanthine oxidase (XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant.

METHODS

The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR.

RESULTS

Three hundreds and eleven methanol extracts (CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/mL with inhibition rates of over 50%. The extracts of Archidendron clypearia (A. clypearia), Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC₅₀ values below 30 μg/mL. Chemical study performed on the extract of A. clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and (-)-7-O-galloyltricetiflavan. The compound (-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC₅₀ value of 25.5 μmol/L.

CONCLUSIONS

From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC₅₀ values of the methanol extracts below 30 μg/mL. Compound (-)-7-O- galloyltricetiflavan was identified as an XO inhibitor from A. clypearia with IC₅₀ value of 25.5 μmol/L.

The therapeutic effects of Periploca forrestii Schltr. Stem extracts on collagen-induced arthritis by inhibiting the activation of Src/NF-κB signaling pathway in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Periploca forrestii Schltr. is a classical traditional Chinese medicine (TCM) called Heilonggu (HLG) in China. According to the theory of TCM, it possesses the efficacy of eliminating wind and removing dampness. In clinical practice, it is commonly used for the treatment of rheumatoid arthritis. The present work aimed to evaluate the anti-rheumatism activity of HLG ethanol extract and reveal the underlying molecular mechanism by employing an animal model of collagen-induced rheumatoid arthritis (CIA) in rats.

MATERIALS AND METHODS

The CIA was induced in male Sprague-Dawley rats by intradermal injection of bovine collagen-II in complete Freund's adjuvant (CFA) at the base of tail. The rats received oral administration of HLG (200 and 400mg/kg) from day 1, with the treatment lasting for 28 days. A variety of indicators were measured for evaluation of anti-rheumatism effect, including paw swelling, arthritis scores, and histopathological changes. Furthermore, the serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and prostaglandin E2 (PGE2), as well as cyclooxygenase-2 (COX-2), nuclear factor NF-κB p65 and Src kinase in joint synovial tissues were detected to explore the possible mechanisms.

RESULTS

The administration of HLG significantly restored type II collagen-induced arthritis in rats as evidenced by decrease in paw swelling and inflammatory factors in serum. Meanwhile, this treatment also notably reduced NF-κB p65 and COX-2 expression. Surprisingly, the activity of Src kinase was also inhibited demonstrated by downregulation of phosphorylated Src.

CONCLUSION

Our results revealed that HLG possessed observable therapeutic action on collagen-induced arthritis by inhibiting the activation of Src and nuclear translocation of NF-κB in rats. HLG may serve as a potential candidate for the management of patients with RA.

Pyrrole-Derivative of Chalcone, (E)-3-Phenyl-1-(2-Pyrrolyl)-2-Propenone, Inhibits Inflammatory Responses via Inhibition of Src, Syk, and TAK1 Kinase Activities

(E)-3-Phenyl-1-(2-pyrrolyl)-2-propenone (PPP) is a pyrrole derivative of chalcone, in which the B-ring of chalcone linked to β-carbon is replaced by pyrrole group. While pyrrole has been studied for possible Src inhibition activity, chalcone, especially the substituents on the B-ring, has shown pharmaceutical, anti-inflammatory, and anti-oxidant properties via inhibition of NF-κB activity. Our study is aimed to investigate whether this novel synthetic compound retains or enhances the pharmaceutically beneficial activities from the both structures. For this purpose, inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 cells were analyzed. Nitric oxide (NO) production, inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α) mRNA expression, and the intracellular inflammatory signaling cascade were measured. Interestingly, PPP strongly inhibited NO release in a dose-dependent manner. To further investigate this anti-inflammatory activity, we identified molecular pathways by immunoblot analyses of nuclear fractions and whole cell lysates prepared from LPS-stimulated RAW264.7 cells with or without PPP pretreatment. The nuclear levels of p50, c-Jun, and c-Fos were significantly inhibited when cells were exposed to PPP. Moreover, according to the luciferase reporter gene assay after cotransfection with either TRIF or MyD88 in HEK293 cells, NF-κB-mediated luciferase activity dose-dependently diminished. Additionally, it was confirmed that PPP dampens the upstream signaling cascade of NF-κB and AP-1 activation. Thus, PPP inhibited Syk, Src, and TAK1 activities induced by LPS or induced by overexpression of these genes. Therefore, our results suggest that PPP displays anti-inflammatory activity via inhibition of Syk, Src, and TAK1 activity, which may be developed as a novel anti-inflammatory drug.

Identification, characterization, kinetics, and molecular docking of flavonoid constituents from Archidendron clypearia (Jack.) Nielsen leaves and twigs

In our search for natural soluble epoxide hydrolase (sEH) inhibitors from plants, we found that the methanolic extract of the leaves and twigs of Archidendron clypearia (Jack.) Nielsen (Fabaceae) significantly inhibits sEH in vitro. In a phytochemical investigation of the water layer of A. clypearia, we isolated two new chalcones, clypesides A-B (1-2), 13 flavonoid derivatives (3-15) and established their structures based on an extensive 1D and 2D NMR, CD data, and MS analysis. All of the flavonoid derivatives inhibited sEH enzymatic activity in a dose-dependent manner, with IC50 values ranging from 10.0±0.4 to 30.1±2.1μM. A kinetic analysis of compounds 4, 8-10, 12, 13, and 15 revealed that the compounds 8-10 were non-competitive, 4, 13, and 15 were mixed-type, and 12 was competitive inhibitors. Additionally, molecular docking increased our understanding of their receptor-ligand binding. These results demonstrated that flavonoid derivatives from A. clypearia are potential sEH inhibitors.

1-(2,3-Dibenzimidazol-2-ylpropyl)-2-methoxybenzene Is a Syk Inhibitor with Anti-Inflammatory Properties

Inflammation is the protective action of our bodies against external pathogens by recognition of pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs). Proper regulation of inflammatory responses is required to maintain our body’s homeostasis, as well as there are demands to develop proper acute or chronic inflammation. In this study, we elucidated the regulatory mechanism of NF-κB-mediated inflammatory responses by a novel compound, 1-(2,3-dibenzimidazol-2-ylpropyl)-2-methoxybenzene (DBMB). We found that DBMB suppressed inflammatory mediators, nitric oxide (NO) and prostaglandin E₂ (PGE₂), reacted to exposure to a number of toll like receptor (TLR) ligands. Such observations occurred following to decreased mRNA expression of several pro-inflammatory mediators, and such diminished mRNA levels were caused by inhibited transcriptional factor nuclear factor (NF)-κB, as evaluated by luciferase reporter assay and molecular biological approaches. To find the potential targets of DBMB, we screened phosphorylated forms of NF-κB signal molecules: inhibitor of κBα (IκBα), IκB kinase (IKK)α/β, Akt, 3-phosphoinositide dependent protein kinase-1 (PDK1), p85, and spleen tyrosine kinase (Syk). We found that DBMB treatment could suppress signal transduction through these molecules. Additionally, we conducted in vitro kinase assays using immunoprecipitated Syk and its substrate, p85. Consequently, we could say that DBMB clearly suppressed the kinase activity of Syk kinase activity. Together, our results demonstrate that synthetic DBMB has an effect on the inflammatory NF-κB signaling pathway and suggest the potential for clinical use in the treatment of inflammatory diseases.

(E)-3-(3-methoxyphenyl)-1-(2-pyrrolyl)-2-propenone displays suppression of inflammatory responses via inhibition of Src, Syk, and NF-κB

(E)-3-(3-methoxyphenyl)-1-(2-pyrrolyl)-2-propenone (MPP) is an aldol condensation product resulting from pyrrole-2-carbaldehyde and m- and p- substituted acetophenones. However, its biological activity has not yet been evaluated. Since it has been reported that some propenone-type compounds display anti-inflammatory activity, we investigated whether MPP could negatively modulate inflammatory responses. To do this, we employed lipopolysaccharide (LPS)-stimulated macrophage-like RAW264.7 cells and examined the inhibitory levels of nitric oxide (NO) production and transcriptional activation, as well as the target proteins involved in the inflammatory signaling cascade. Interestingly, MPP was found to reduce the production of NO in LPS-treated RAW264.7 cells, without causing cytotoxicity. Moreover, this compound suppressed the mRNA levels of inflammatory genes, such as inducible NO synthase (iNOS) and tumor necrosis factor (TNF)-α. Using luciferase reporter gene assays performed in HEK293 cells and immunoblotting analysis with nuclear protein fractions, we determined that MPP reduced the transcriptional activation of nuclear factor (NF)-κB. Furthermore, the activation of a series of upstream signals for NF-κB activation, composed of Src, Syk, Akt, and IκBα, were also blocked by this compound. It was confirmed that MPP was able to suppress autophosphorylation of overexpressed Src and Syk in HEK293 cells. Therefore, these results suggest that MPP can function as an anti-inflammatory drug with NF-κB inhibitory properties via the suppression of Src and Syk.

4-Isopropyl-2,6-bis(1-phenylethyl)aniline 1, an Analogue of KTH-13 Isolated from Cordyceps bassiana, Inhibits the NF-κB-Mediated Inflammatory Response

The Cordyceps species has been a good source of compounds with anticancer and anti-inflammatory activities. Recently, we reported a novel compound (4-isopropyl-2,6-bis(1-phenylethyl)phenol, KTH-13) with anticancer activity isolated from Cordyceps bassiana and created several derivatives to increase its pharmacological activity. In this study, we tested one of the KTH-013 derivatives, 4-isopropyl-2,6-bis(1-phenylethyl)aniline 1 (KTH-13-AD1), with regard to anti-inflammatory activity under macrophage-mediated inflammatory conditions. KTH-13-AD1 clearly suppressed the production of nitric oxide (NO) and reactive oxygen species (ROS) in lipopolysaccharide (LPS) and sodium nitroprusside- (SNP-) treated macrophage-like cells (RAW264.7 cells). Similarly, this compound also reduced mRNA expression of inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α), as analyzed by RT-PCR and real-time PCR. Interestingly, KTH-13-AD1 strongly diminished NF-κB-mediated luciferase activities and nuclear translocation of NF-κB family proteins. In accordance, KTH-13-AD1 suppressed the upstream signaling pathway of NF-κB activation, including IκBα, IKKα/β, AKT, p85/PI3K, and Src in a time- and dose-dependent manner. The autophosphorylation of Src and NF-κB observed during the overexpression of Src was also suppressed by KTH-13-AD1. These results strongly suggest that KTH-13-AD1 has strong anti-inflammatory features mediated by suppression of the Src/NF-κB regulatory loop.

Salvianolic Acid B Down-regulates Matrix Metalloproteinase-9 Activity and Expression in Tumor Necrosis Factor-α-induced Human Coronary Artery Endothelial Cells

BACKGROUND

Salvianolic acid B (Sal B) is a bioactive water-soluble compound of Salviae miltiorrhizae, a traditional herbal medicine that has been used clinically for the treatment of cardiovascular diseases. This study sought to evaluate the effect of Sal B on matrix metalloproteinase-9 (MMP-9) and on the underlying mechanisms in tumor necrosis factor-α± (TNF-α±)-activated human coronary artery endothelial cells (HCAECs), a cell model of Kawasaki disease.

METHODS

HCAECs were pretreated with 1-10 αμmol/L of Sal B, and then stimulated by TNF-α± at different time points. The protein expression and activity of MMP-9 were determined by Western blot assay and gelatin zymogram assay, respectively. Nuclear factor-κB (NF-κB) activation was detected with immunofluorescence, electrophoretic mobility shift assay, and Western blot assay. Protein expression levels of mitogen-activated protein kinase (c-Jun N-terminal kinase [JNK], extra-cellular signal-regulated kinase [ERK], and p38) were determined by Western blot assay.

RESULTS

After HCAECs were exposed to TNF-α±, 1-10 αμmol/L Sal B significantly inhibited TNF-α±-induced MMP-9 expression and activity. Furthermore, Sal B significantly decreased IκBα± phosphorylation and p65 nuclear translocation in HCAECs stimulated with TNF-α± for 30 min. In addition, Sal B decreased the phosphorylation of JNK and ERK1/2 proteins in cells treated with TNF-α± for 10 min.

CONCLUSIONS

The data suggested that Sal B suppressed TNF-α±-induced MMP-9 expression and activity by blocking the activation of NF-κB, JNK, and ERK1/2 signaling pathways.

A direct protein kinase B-targeted anti-inflammatory activity of cordycepin from artificially cultured fruit body of Cordyceps militaris

Background:

Cordyceps militaris is one of well-known medicinal mushrooms with anti-inflammatory, anti-cancer, anti-diabetic, and anti-obesity activities.

Objective:

The objective of the following study is to isolate chemical components from the ethanol extract (Cm-EE) from Cordyceps militaris and to evaluate their anti-inflammatory activities.

Materials and Methods:

Column chromatographic separation was performed and anti-inflammatory roles of these compounds were also examined by using NO production and protein kinase B (AKT) activity assays.

Results:

From Cm-EE, 13 constituents, including trehalose (1), cordycepin (2), 6-hydroxyethyladenosine (3), nicotinic amide (4), butyric acid (5), β-dimorphecolic acid (6), α-dimorphecolic acid (7), palmitic acid (8), linoleic acid (9), cordycepeptide A (10), 4-(2-hydroxy-3-((9E,12E)-octadeca-9,12-dienoyloxy)propoxy)-2-(trimethylammonio)butanoate (11), 4-(2-hydroxy-3-(palmitoyloxy)propoxy)-2-(trimethylammonio)butanoate (12), and linoleic acid methyl ester (13) were isolated. Of these components, compound 2 displayed a significant inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. Furthermore, this compound strongly and directly suppressed the kinase activity of AKT, an essential signalling enzyme in LPS-induced NO production, by interacting with its ATP binding site.

Conclusion:

C. militaris could have anti-inflammatory activity mediated by cordycepin-induced suppression of AKT.

AP-1-Targeted Anti-Inflammatory Activities of the Nanostructured, Self-Assembling S5 Peptide

Peptide-based therapeutics have received increasing attention in medical research. However, the local delivery of such therapeutics poses unique challenges. Self-assembling peptides that use decorated nanofibers are one approach by which these therapeutics may be delivered. We previously found that the self-assembling K5 peptide affects the anti-inflammatory response. The aim of the present study was to investigate another self-assembling peptide, S5. Unlike the K5 peptide which has a positive charge, the S5 peptide has a free hydroxyl (-OH) group. We first examined whether the S5 peptide regulates the inflammatory response in primary cells and found that the S5 peptide reduced the production of prostaglandin E₂ (PGE₂) and tumor necrosis factor (TNF)-α in lipopolysaccharide- (LPS-) treated bone marrow-derived macrophages. Moreover, the S5 peptide significantly downregulated cyclooxygenase- (COX-) 2, TNF-α, and interleukin- (IL-) 1β expression by blocking the nuclear translocation of c-Jun. Consistent with this finding, the S5 peptide diminished the activation of inflammatory signaling enzymes related to p38. The S5 peptide also inhibited the formation of the p38/c-Jun signaling complex in RAW264.7 cells. Similarly, p38 and MKK3/6 were inhibited by the S5 peptide in LPS-activated peritoneal macrophages. Taken together, these results strongly suggest that the S5 peptide could exert anti-inflammatory effects by inhibiting the c-Jun/p38 signaling pathway.

In vivo and in vitro anti-inflammatory activities of Persicaria chinensis methanolic extract targeting Src/Syk/NF-κB

ETHNOPHARMACOLOGIC RELEVANCE

Persicaria chinensis L. (Polygonaceae) [also synonym as Polygonum chimnense L.] has been used as Chinese traditional medicine to treat ulcer, eczema, stomach ache, and various inflammatory skin diseases. Due to no molecular pharmacological evidence of this anti-inflammatory herbal plant, we investigated the inhibitory mechanisms and target proteins contributing to the anti-inflammatory responses of the plant by using its methanolic extract (Pc-ME).

MATERIALS AND METHODS

We used lipopolysaccharide (LPS)-treated macrophages and a murine HCl/EtOH-induced gastritis model to evaluate the anti-inflammatory activity of Pc-ME. HPLC analysis was employed to identify potential active components of this extract. Molecular approaches including kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes were used to confirm target enzymes.

RESULTS

Pc-ME inhibited LPS-induced nitric oxide and prostaglandin E2 release by RAW264.7 macrophages and ameliorated HCl/EtOH-induced gastric ulcers in mice. The nuclear translocation of NF-κB (p65 and p50) was suppressed by Pc-ME. Phosphorylation of Src and Syk, their kinase activities, and formation of the signaling complex of these proteins were repressed by Pc-ME. Phosphorylation of p85 and Akt induced by Src or Syk overexpression was blocked by Pc-ME. In the mouse gastritis model, orally administered Pc-ME suppressed the increased phosphorylation of IκBα, Αkt, Src, and Syk. Caffeic acid, kaempferol, and quercetin, identified as major anti-inflammatory components of Pc-ME by HPLC, displayed strong nitric oxide inhibitory activity in LPS-treated macrophages.

CONCLUSION

Pc-ME might play a pivotal ethnopharmacologic role as an anti-inflammatory herbal medicine by targeting Syk and Src kinases and their downstream transcription factor NF-κB.

Effects of baicalin in CD4 + CD29 + T cell subsets of ulcerative colitis patients

AIM

To evaluate the role of baicalin in ulcerative colitis (UC) with regard to the CD4(+)CD29(+) T helper cell, its surface markers and serum inflammatory cytokines.

METHODS

Flow cytometry was used to detect the percentage of CD4(+)CD29(+) cells in patients with UC. Real time polymerase chain reaction was used to detect expression of GATA-3, forkhead box P3, T-box expressed in T cells (T-bet), and retinoic acid-related orphan nuclear hormone receptor C (RORC). Western blotting was used to analyze expression of nuclear factor-κB (NF-κB) p65, phosphorylation of NF-κB (p-NF-κB) p65, STAT4, p-STAT4, STAT6 and p-STAT6. The concentrations of interferon-γ (IFN-γ), interleukin (IL)-4, IL-5, IL-6, IL-10 and TGF-β in serum were determined by ELISA assay.

RESULTS

The percentages of CD4(+)CD29(+) T cells were lower in treatment with 40 and 20 μmol/L baicalin than in the treatment of no baicalin. Treatment with 40 or 20 μmol/L baicalin significantly upregulated expression of IL-4, TGF-β1 and IL-10, increased p-STAT6/STAT6 ratio, but downregulated expression of IFN-γ, IL-5, IL-6, RORC, Foxp3 and T-bet, and decreased ratios of T-bet/GATA-3, p-STAT4/STAT4 and p-NF-κB/NF-κB compared to the treatment of no baicalin.

CONCLUSION

The results indicate that baicalin regulates immune balance and relieves the ulcerative colitis-induced inflammation reaction by promoting proliferation of CD4(+)CD29(+) cells and modulating immunosuppressive pathways.

Functional roles of Syk in macrophage-mediated inflammatory responses

Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases.

Syk and Src are major pharmacological targets of a Cerbera manghas methanol extract with kaempferol-based anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Cerbera manghas L. (Apocynaceae), a semi-mangrove medicinal plant distributed throughout tropical and subtropical countries, is traditionally known to possess analgesic, anti-inflammatory, anti-convulsant, cardiotonic, and hypotensive activity. In vitro and in vivo anti-inflammatory activities of a methanol extract of the leaves of Cerbera manghas and the underlying molecular mechanisms were investigated to validate the ethnopharmacological use of this plant.

MATERIALS AND METHODS

The effect of Cerbera manghas methanol extract (Cm-ME) on the production of inflammatory mediators and the induction of HCl/EtOH-treated gastritis was explored using macrophages, HEK293 cells, and ICR mice. The molecular targets of this extract and potential active components in Cm-ME were also investigated.

RESULTS

Cm-ME inhibited the production of nitric oxide (NO) in lipopolysaccharide (LPS)-treated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. This extract also suppressed the expression of NO synthase (iNOS) and cyclooxygenase (COX)-2. NF-κB-mediated enhancement of luciferase activity, nuclear translocation of p50 and p65, and phosphorylation of IκBα were markedly reduced by Cm-ME treatment. Direct enzyme assays, reporter gene assays, and immunoprecipitation analysis of kinases revealed Syk and Src as immunopharmacological targets of Cm-ME. Moreover, this extract strongly ameliorated the gastric symptoms induced by HCl/EtOH treatment of mice. Finally, HPLC analysis and pharmacological tests identified kaempferol as an active component of the extract with Src/Syk inhibitory activities.

CONCLUSION

Inhibition of Syk/Src and the NF-κB pathway by kaempferol could play a key role in the anti-inflammatory pharmacological action of Cerbera manghas.

In Vitro Inhibitory Effects of Moringa oleifera Leaf Extract and Its Major Components on Chemiluminescence and Chemotactic Activity of Phagocytes

The ethanol extract of Moringa oleifera Lam. leaves and its major constituents, crypto-chlorogenic acid, quercetin 3- O-glucoside and kaempferol 3- O-glucoside, were investigated on the respiratory burst of human whole blood and isolated human polymorphonuclear leukocytes (PMNs) using a luminol-based chemiluminescence assay. The chemotactic migration of PMNs was also investigated using the Boyden chamber technique. The ethanol extract demonstrated inhibitory activities on the oxidative burst and the chemotactic migration of PMNs. Quercetin 3- O-glucoside, crypto-chlorogenic acid, and kaempferol 3- O-glucoside, isolated from the extract, expressed relatively strong inhibitory activity on the oxidative burst of PMNs with IC50 values of 4.1, 6.7 and 7.0 μM, respectively, comparable with that of aspirin. They also demonstrated strong inhibition of chemotatic migration of PMNs with IC50 values of 9.5, 15.9 and 18.2 μM, respectively. The results suggest that M. oleifera leaves could modulate the immune response of human phagocytes, linking to its ethnopharmacological use as an anti-inflammatory agent. The immunomodulating activity of the plant was mainly due to its major components.

Methanol extract of Evodia lepta displays Syk/Src-targeted anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Evodia lepta (Spreng.) Merr., in the Rutaceae family, is a medicinal plant traditionally used to treat inflammatory symptoms such as in meningitis and hepatitis. However, no study has systematically investigated its anti-inflammatory activities including its molecular mechanism.

MATERIALS AND METHODS

The effects of a methanol extract from the roots Evodia lepta (El-ME) were evaluated using lipopolysaccharide (LPS)-treated RAW264.7 cells producing nitric oxide (NO) and prostaglandin E2 (PGE2), and an HCl/ethanol-induced mouse gastritis model. Target molecules were identified by analyzing the activation of transcription factors and their upstream kinases.

RESULTS

El-ME reduced the production of NO and PGE2 from LPS-activated RAW264.7 cells in a dose-dependent manner. El-ME also ameliorated the gastritis symptoms of EtOH/HCl-treated mice. The extract suppressed production of mRNA for the inducible NO synthase (iNOS) and cyclooxygenase (COX)-2; the nuclear translocation of nuclear factor (NF)-κB; the phosphorylation of upstream kinases that activate NF-κB; and the kinase activities of Syk and Src.

CONCLUSION

The anti-inflammatory effects of El-ME might be due to its suppression of Syk/Src and NF-κB. Considering the in vitro and in vivo efficacy of El-ME, Evodia lepta could be developed into an anti-inflammatory herbal remedy.

Ethanol Extract of Antrodia camphorata Grown on Germinated Brown Rice Suppresses Inflammatory Responses in Mice with Acute DSS-Induced Colitis

The anti-inflammatory activity of Antrodia camphorata (AC) grown on germinated brown rice (CBR) extract was evaluated in vitro and in vivo. CBR suppressed the release of nitric oxide (NO) and prostaglandin (PG) E2 from lipopolysaccharide-(LPS-)stimulated RAW264.7 cells. CBR inhibited the level of inducible nitric oxide synthase (iNOS) and cyclooxygenase-(COX-)2 proteins, and it activated p38-MAPK, extracellular signal-related kinases (ERK), and NF-κB in LPS-stimulated RAW264.7 macrophages. LPS-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) mRNA expression was reduced in CBR-treated RAW264.7 cells. In concert with in vitro data, CBR suppressed the levels of dextran-sulfate-sodium-(DSS-)induced iNOS and COX-2 proteins in the colon tissue. CBR treatment inhibited activated p38-MAPK, ERK, and NF-κB proteins in the colon tissue of DSS-induced mice. TNF-α and IL-6 mRNA expression was reduced in DSS+CBR-treated mice. The disease activity index and histological scores were significantly lower in CBR-treated mice (500 mg/kg/day) than in DSS-treated mice (P < 0.05 versus DSS). This is the first report of anti-inflammatory activity of CBR in DSS-induced acute colitis. These results suggest that CBR is a promising, potential agent for preventing acute colitis through the inhibition of NF-κB signaling and its upstream signaling molecules, including MAPKs.

Fuyuan Decoction inhibits nitric oxide production via inactivation of nuclear factor-κB in SW1353 chondrosarcoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Fuyuan Decoction (FYD) is an empirical formula of treating Bi Zheng in traditional Chinese medicine (TCM). Despite the fact that the efficiency of FYD on treating osteoarthritis has been verified in clinic, the underlying mechanisms are not totally understood. This study was to investigate the effects and mechanisms of FYD on nitric oxide (NO) production and nuclear factor (NF)-κB activation in interleukin (IL)-1β-stimulated chondrocytes.

MATERIALS AND METHODS

SW1353 human chondrosarcoma cells were pretreated with various concentrations of FYD-containing serum (FYD-CS), and then were stimulated by IL-1β. Amounts of NO were determined by Griess reaction assay. Inducible NO synthase (iNOS) expression, inhibitor-κBα (IκBα) degradation and nuclear translocation of p65 protein were determined by Western blot assay. DNA binding activity of NF-κB was determined by ELISA assay using Trans AM(™) kit for p65.

RESULTS

10% and 20% (v/v) FYD-CS significantly decreased NO production in a concentration-dependent manner (p<0.05 or p<0.01) as compared to control in IL-1β-induced SW1353 cells. Besides, 10% and 20% FYD-CS also significantly reduced iNOS protein expression by about 60% and 70% (both p<0.01), respectively. Furthermore, 10% and 20% FYD-CS markedly decreased IκBα degradation by about 45% and 26% (p<0.01 or p<0.05), lessened P65 content in the nucleus by about 28% and 60% (both p<0.01), and repressed DNA binding activity of P65 by about 30% and 45% (both p<0.01) in IL-1β-induced SW1353 cells.

CONCLUSIONS

These findings suggested that FYD could inhibit NO production and iNOS expression in IL-1β-induced chondrocytes through suppressing NF-κB activation.

AP-1 pathway-targeted inhibition of inflammatory responses in LPS-treated macrophages and EtOH/HCl-treated stomach by Archidendron clypearia methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Archidendron clypearia Jack. (Fabaceae) is a representative ethnomedicinal herbal plant prescribed for various inflammatory diseases such as pharyngolaryngitis and tonsillitis. However, the pharmacology behind this plant's anti-inflammatory properties has not been fully understood. Therefore, in this study, the anti-inflammatory mechanism of a 95% methanol extract (Ac-ME) was explored.

MATERIALS AND METHODS

The anti-inflammatory mechanism of Ac-ME on the AP-1 activation pathway, which plays a critical role in the production of prostaglandin (PG)E2 in RAW264.7 cells and peritoneal macrophages and in induction of acute gastritis caused by HCl/EtOH, was investigated using immunoblotting, immunoprecipitation analyses, and reporter gene activity assays. In particular, enzyme assays and HPLC analysis were employed to identify direct target enzymes of Ac-ME and to detect active chemical components from the plant extract.

RESULTS

Ac-ME clearly reduced the nuclear levels of total and phospho-forms of c-Jun, FRA-1, and ATF-2. Consequently, this extract suppressed both the production of PGE2 in lipopolysaccharide (LPS)-activated RAW264.7 and peritoneal macrophage cells and PGE2-dependent induction of gastritis lesion in stomach under EtOH/HCl exposure. Analysis of AP-1 upstream signalling revealed that the AP-1 activation pathway consisting of IRAK1, TRAF6, TAK1, MKK3/6, and p38 was predominantly inhibited by Ac-ME. Similarly, this extract directly blocked the enzyme activity of IRAK1, indicating that this enzyme is an inhibitory target of Ac-ME and is involved in the suppression of the AP-1 pathway. HPLC analysis showed that quercetin, which inhibits PGE2 production, is an active component in Ac-ME.

CONCLUSION

Ac-ME is an ethnomedicinal remedy with an IRAK1/p38/AP-1-targeted inhibitory property. Since AP-1 is a major inflammation-inducing transcription factor, the therapeutic potential of Ac-ME in other AP-1-mediated inflammatory symptoms will be further tested.

Methanol extract of Hopea odorata suppresses inflammatory responses via the direct inhibition of multiple kinases

ETHNOPHARMACOLOGICAL RELEVANCE

Hopea odorata Roxb. (Dipterocarpaceae) is a representative Thai ethnopharmacological herbal plant used in the treatment of various inflammation-related diseases. In spite of its traditional use, systematic studies of its anti-inflammatory action have not been performed.

MATERIALS AND METHODS

The inhibitory activities of a Hopea odorata methanol extract (Ho-ME) on the production of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin E(2) (PGE(2)) in RAW264.7 cells and peritoneal macrophages were investigated. The effects of Ho-ME on the gastritis symptoms induced by HCl/EtOH and on ear oedemas induced by arachidonic acid were also examined. Furthermore, to identify the immunopharmacological targets of this extract, nuclear fractionation, a reporter gene assay, immunoprecipitation, immunoblot analysis, and a kinase assay were employed.

RESULTS

Ho-ME strongly inhibited the release of NO, PGE(2), and TNF-α in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ho-ME also clearly suppressed the gene expression of pro-inflammatory cytokines and chemokines, such as interferon (IFN)-β, interleukin (IL)-12, and monocyte chemotactic protein-1 (MCP-1). By analysing the inhibited target molecules, Syk and Src were found to be suppressed in the inhibition of nuclear factor (NF)-κB pathway. In addition, the observed downregulation of activator protein (AP)-1 and cAMP response element-binding (CREB) was due to the direct inhibition of interleukin-1 receptor-associated kinase (IRAK)1 and IRAK4, which was also linked to the suppression of c-Jun N-terminal kinase (JNK) and p38. In agreement with the in vitro observations, this extract also ameliorated the inflammatory symptoms in EtOH/HCl-induced gastritis and arachidonic acid-induced ear oedemas in mice.

CONCLUSION

Ho-ME has potential as a functional herbal remedy targeting Syk- and Src-mediated anti-inflammatory mechanisms. Future pre-clinical studies will be needed to investigate this possibility.

Prooxidant-induced c-Src/nuclear factor kappa B-coupled signalling in sensory ganglia mediates cutaneous hyperalgesia

BACKGROUND

Persistent pain resulting from peripheral injury/inflammation is associated with altered sensitivity to cutaneous stimuli, which can manifest as hyperalgesia. The role of oxidant stress in the development, progression and maintenance of hyperalgesia is still not understood. Furthermore, there appears to be a relationship between c-Src kinase in the pain pathway and oxidative stress.

METHODS

We have used a novel prooxidant inflammatory pain model that involves potassium peroxychromate (PPC), a unique prooxidant that produces the same reactants as activated phagocytes. This model was used to investigate the role of oxidant-activated c-Src in mediating hyperalgesia. We compared the effects of PP2 (a Src family kinase inhibitor) and c-Src siRNA on behavioural hyperalgesia with sodium stibogluconate (SSG) (a non-receptor tyrosine phosphatase inhibitor) and AG 1478 (a receptor tyrosine kinase inhibitor).

RESULTS

PP2 and c-Src siRNA attenuated PPC-induced thermal hyperalgesia, while SSG enhanced it. AG 1478 had no effect. PP2 decreased the levels of IL-1β, c-Src/inhibitory kappa B kinase complex formed and prostaglandin E2 produced in the dorsal root ganglia (DRG) ipsilateral to the inflamed paw, while SSG increased the levels of these parameters. c-Src siRNA decreased Src expression and activity in the DRG ipsilateral to the inflamed paw.

CONCLUSIONS

These results confirm that prooxidant-activated c-Src plays a role in initiating and maintaining hyperalgesia by regulating a stimulus-response coupling between the inflamed tissue and the DRG in the pain pathway. Our data also suggest that oxidant-induced dysregulation of c-Src/nuclear factor kappa B coupling may contribute to our understanding of the transition from acute to chronic dysfunctional pain state seen in many human diseases.

The role of Src kinase in macrophage-mediated inflammatory responses

Src kinase (Src) is a tyrosine protein kinase that regulates cellular metabolism, survival, and proliferation. Many studies have shown that Src plays multiple roles in macrophage-mediated innate immunity, such as phagocytosis, the production of inflammatory cytokines/mediators, and the induction of cellular migration, which strongly implies that Src plays a pivotal role in the functional activation of macrophages. Macrophages are involved in a variety of immune responses and in inflammatory diseases including rheumatoid arthritis, atherosclerosis, diabetes, obesity, cancer, and osteoporosis. Previous studies have suggested roles for Src in macrophage-mediated inflammatory responses; however, recently, new functions for Src have been reported, implying that Src functions in macrophage-mediated inflammatory responses that have not been described. In this paper, we discuss recent studies regarding a number of these newly defined functions of Src in macrophage-mediated inflammatory responses. Moreover, we discuss the feasibility of Src as a target for the development of new pharmaceutical drugs to treat macrophage-mediated inflammatory diseases. We provide insights into recent reports regarding new functions for Src that are related to macrophage-related inflammatory responses and the development of novel Src inhibitors with strong immunosuppressive and anti-inflammatory properties, which could be applied to various macrophage-mediated inflammatory diseases.