Multianalyte Microphysiometry of Macrophage Responses to Phorbol Myristate Acetate,Lipopolysaccharide, and Lipoarabinomannan

This study examined the hypothesis that mycobacterial antigens generate different metabolic responses in macrophages as compared to gram‐negative effectors and macrophage activators. To this end, we utilized platinum electrodes and a light addressable potentiometric sensor to observe dynamic electrochemical changes in metabolic flux, as well as extracellular acidification. While phorbol myristate acetate (PMA) is commonly used to study macrophage activation, the concentration used to create this physiological response varies. The response of RAW‐264.7 macrophages is concentration‐dependent, where the metabolic response to high concentrations of PMA decreases suggesting deactivation. The gram‐negative effector, lipopolysaccharide (LPS), was seen to promote oxygen production which was used to produce a delayed onset of oxidative burst. Pre‐incubation with interferon‐γ (IFN‐γ) allowed a synergistic effect between IFN‐γ and LPS, allowing immediate initiation of oxidative burst. These studies exhibited a stark contrast with lipoarabinomannan (LAM), an antigenic glycolipid component associated with the bacterial genus Mycobacterium. The presence of LAM effectively inhibits any metabolic response preventing consumption of glucose and oxygen for the promotion of oxidative burst and to ensure pathogenic proliferation. This study demonstrates for the first time the immediate inhibitory metabolic effects LAM has on macrophages, suggesting implications for future intervention studies with Mycobacterium tuberculosis.     

Anti-inflammatory effects of Scutellaria baicalensis water extract in LPS-induced THP-1 Macrophages through metabolomics study

(1) Background: Scutellaria baicalensis (Huang Qin) is a traditional Chinese Medicine possess beneficial effects of anti-inflammation in various diseases. In this study, we aimed to use untargeted metabolomics approach to investigate the possible underlying metabolic mechanisms of anti-inflammation effects of Scutellaria baicalensis in LPS-induced macrophages.; (2) Methods: Scutellaria baicalensis water extract (SBE) were applied to the THP-1 cells which were induced by phorbol 12-myristate 13-acetate (PMA) into macrophages under the LPS treated conditions. The cell lysate were collected and metabolites were extracted before characterizing by ultra-performance liquid chromatography (UPLC) combined with Q-Exactive mass/mass spectrometry (LC-MS/MS). The differential accumulated metabolites and related metabolism pathways affected by SBE in LPS-induced macrophages were identified. Further investigation of the secretion and expression of inflammatory cytokines IL-1β, TNF-ɑ and VEGFR were tested by real-time polymerase chain reaction (RT-PCR). (3) Results: The metabolome profile have indicated that retinol metabolism, arachidonic acid metabolism and linoleic acid metaoblism pathways were the most significantly enriched pathways response to SBE in LPS induced inflammatory model. Besides, SBE could inhibit the expression of the pro-inflammatory cytokines IL-1β and TNF-ɑ, and downregulation of the macrophage migration accelerator VEGFR1 in a dose dependent manner; (4) Conclusions: These findings indicated that SBE may exerted anti-inflammatory ability by regulating multiple fatty acids metabolism pathways as well as inhibiting the secretion of pro-inflammatory cytokines and VEGFR. This study provides evidences for Scutellaria baicalensis as the material for developing natural, effective anti-inflammatory products.     

Effect of nitrite on cell growth and antibody production in mouse splenic B cells stimulated with lipopolysaccharide and B cell hybridomas.

Nitric oxide, nitrite and nitrate are released by activated macrophages in an immune response. We showed here that nitrite influenced cell growth and antibody production in mouse lipopolysaccharide (LPS)-stimulated splenic B cells and B cell hybridomas. The addition of 10(-7) and 10(-6) M nitrite enhanced deoxyribonucleic acid (DNA) synthesis of LPS-stimulated splenic B cells. However, DNA synthesis and antibody production in the case of total spleen cells stimulated with LPS were suppressed by nitrite in a dose dependent-manner. These phenomena were also observed in a similar experiment involving mouse B cell hybridomas. Antibody production of all B cell hybridomas was significantly suppressed by the addition of nitrite. This suppressing effect could not be explained by changes in viable cell yields. This data suggests that the antibody production and cell proliferation of B cells may be influenced by nitrite from activated macrophages in the immune response.     

A Comparison of the Nanostructure of Lead Zirconate,Lead Titanate and Lead Zirconate Titanate Sols

Sol-gel processing has been widely used for the fabrication of lead zirconate titanate (PZT) thin films. To successfully and consistently make high quality thin films for different applications, we must develop a fundamental understanding of the structures of the sols. In this study, the characters of lead titanate (PT) and lead zirconate (PZ)sols were studied by measuring the rheological properties and particle sizes in them and comparing their behaviours. The average particle sizes in unhydrolysed PT, PZ and PZT sols are 11.5, 1.0, and 6.0 nm, respectively. PT sol has the highest rate of hydrolysis. It gels at about 24 h after hydrolysis. PZ and PZT sols have a quite similar feature in hydrolysis. The reasons for the differences in the hydrolysis behaviour of the different types of sol are discussed in terms of a model which indicates that the inhomogeneous sols consist of 5 to 6 nm PT particles surrounded by much smaller PZ particles, which tend to dominate the sol behaviour.     

Cholinesterases,carbonic anhydrase inhibitory properties and in silico studies of novel substituted benzylamines derived from dihydrochalcones

A series of novel urea, sulfamide and N,N-dipropargyl substituted benzylamines were synthesized from dihydrochalcones. The synthesized compounds were evaluated for their cholinesterases and carbonic anhydrase inhibitory actions. The known dihydrochalcones were converted into four new benzylamines via reductive amination. N,N-Dipropargylamines, ureas and sulfamides were synthesized following the reactions of benzylamines with propargyl bromide, N,N-dimethyl sulfamoyl chloride and N,N-dimethyl carbamoyl chloride. The novel substituted benzylamines derived from dihydrochalcones were evaluated against some enzymes such as human erythrocyte carbonic anhydrase I and II isoenzymes (hCA I and hCA II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The novel substituted benzylamines derived from dihydrochalcones exhibited K_i values in the range of 0.121–1.007 nM on hCA I, and 0.077–0.487 nM on hCA II closely related to several pathological processes. On the other hand, K_i values were found in the range of 0.112–0.558 nM on AChE, 0.061–0.388 nM on BChE. As a result, novel substituted benzylamines derived from dihydrochalcones showed potent inhibitory profiles against indicated metabolic enzymes. In addition, Induced-Fit Docking (IFD) simulations and ADME prediction studies have also been carried out to elucidate the inhibition mechanisms and drug-likeness of the synthesized compounds. Therefore, these results can make significant contributions to the treatment of some global diseases, especially Alzheimer's diseases and glaucoma, and the development of new drugs.     

Crataegus laevigata Suppresses LPS-Induced Oxidative Stress during Inflammatory Response in Human Keratinocytes by Regulating the MAPKs/AP-1, NFκB,and NFAT Signaling Pathways

Crataegus laevigata belongs to the family Rosaceae, which has been widely investigated for pharmacological effects on the circulatory and digestive systems. However, there is limited understanding about its anti-oxidative stress and anti-inflammatory effects on skin. In this study, 70% ethanol C. laevigata berry extract (CLE) was investigated on lipopolysaccharide (LPS)-stimulated keratinocytes. The LPS-induced overproduction of reactive oxygen species (ROS) was suppressed by the treatment with CLE. In response to ROS induction, the overexpression of inflammatory regulating signaling molecules including mitogen-activated protein kinases (MAPK)/activator protein-1 (AP-1), nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB), and nuclear factor of activated T-cells (NFAT) were reduced in CLE-treated human keratinocytes. Consequently, CLE significantly suppressed the mRNA levels of pro-inflammatory chemokines and interleukins in LPS-stimulated cells. Our results indicated that CLE has protective effects against LPS-induced injury in an in vitro model and is a potential alternative agent for inflammatory treatment.     

Inhibitory effect of Astragalus polysaccharides on lipopolysaccharide-induced TNF-a and IL-1β production in THP-1 cells

Astragalus polysaccharides (APS), one of main bioactive components in Astragalus membranaceus Bunge, has been reported to possess anti-inflammatory activities, but the molecular mechanisms behind this activity are largely unknown. This study aimed to investigate expression of inflammatory cytokines and the MAPK/NF-κB pathway in human THP-1 macrophages induced by lipopolysaccharide (LPS). The results showed that the concentrations of TNF-a and IL-1β released from LPS stimulated THP-1 cells increased significantly compared to control (p < 0.01). After treatment with APS, the TNF-a and IL-1β levels were significantly lower than those in the LPS group (p < 0.05). The mRNA expression of TNF-a and IL-1β were also inhibited. Mechanistic studies indicated that APS strongly suppressed NF-κB activation and down-regulated the phosphorylation of ERK and JNK, which are important signaling pathways involved in the production of TNF-a and IL-1β, demonstrating that APS could suppress the production of TNF-a and IL-1β by LPS stimulated macrophages by inhibiting NF-κB activation and ERK and JNK phosphorylation.     

Anti-Inflammatory Effects of 6-Methylcoumarin in LPS-Stimulated RAW 264.7 Macrophages via Regulation of MAPK and NF-κB Signaling Pathways

Persistent inflammatory reactions promote mucosal damage and cause dysfunction, such as pain, swelling, seizures, and fever. Therefore, in this study, in order to explore the anti-inflammatory effect of 6-methylcoumarin (6-MC) and suggest its availability, macrophages were stimulated with lipopolysaccharide (LPS) to conduct an in vitro experiment. The effects of 6-MC on the production and levels of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α) and inflammatory mediators (nitric oxide (NO), prostaglandin E₂ (PGE₂)) in LPS-stimulated RAW 264.7 cells were examined. The results showed that 6-MC reduced the levels of NO and PGE₂ without being cytotoxic. In addition, it was demonstrated that the increase in the expression of pro-inflammatory cytokines caused by LPS stimulation, was decreased in a concentration-dependent manner with 6-MC treatment. Moreover, Western blot results showed that the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which increased with LPS treatment, were decreased by 6-MC treatment. Mechanistic studies revealed that 6-MC reduced the phosphorylation of the mitogen-activated protein kinase (MAPK) family and IκBα in the MAPK and nuclear factor-kappa B (NF-κB) pathways, respectively. These results suggest that 6-MC is a potential therapeutic agent for inflammatory diseases that inhibits inflammation via the MAPK and NF-κB pathways.     

Heat capacity at constant pressure and thermodynamic properties of phase transitions in PbMO<Subscript>3</Subscript> (<Emphasis Type="Italic">M</Emphasis>=Ti,Zr and Hf)

The heat capacity of PbMO₃ (M=Ti, Zr and Hf) at constant pressure was measured using a differential scanning calorimeter (DSC) from room temperature up to 870 K. Large anomalies were found in the heat capacity curves, corresponding to the ferroelectricparaelectric phase transition in PbTiO₃ (PT), the antiferroelectric-paraelectric phase transitions in PbZrO₃ (PZ) and PbHfO₃ (PH). The transition entropies were estimated as 7.3 J K⁻¹ mol⁻¹ (PT), 9.9 J K⁻¹ mol⁻¹ (PZ) and 9.3 J K⁻¹ mol⁻¹ (PH). These values of transition entropies are much larger than that of a typical displacive-type phase transition.     

Study of the Lead Environment in Liquid and As-Dried Precursors of PZ, PT and PZT Thin Films

The environment of lead and zirconium atoms in liquid and as-dried precursors for PbZrO3 (PZ), PbTiO3 (PT) and Pb1.1Zr0.53Ti0.47O3 (PZT) thin film deposition were analyzed by EXAFS. The sols were prepared by 2-methoxyethanol route with lead acetate and lead oxide as lead sources. Pb—O—M (M = Zr and/or Ti, depending on the sol composition) linkages were determined in all sols. The choice of lead source weakly influences the lead environment, and strongly influences that of zirconium in both PZ and PZT sols. By drying lead oxide based sols the Pb–M correlation is moderately reduced in PZ, PT and is strongly reduced in PZT.     

Study of the Antioxidant and Anti-Inflammatory Properties of the Biological Extracts of Psophocarpus tetragonolobus Using Two Extraction Methods

Psophocarpus tetragonolobus has long been used in traditional medicine and cuisine. In this study, Psophocarpus tetragonolobus extracts were isolated by maceration and ultrasound-assisted extraction and were evaluated for their antioxidant and anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The obtained results show that both extracts (maceration and ultrasound) were rich in bioactive molecules and exerted substantial antioxidant and anti-inflammatory effects. The P. tetragonolobus extracts’ treatment in LPS-stimulated RAW264.7 macrophages resulted in a significant downregulation of the expressions of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β mRNA. In addition, the P. tetragonolobus extracts’ treatment attenuated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. Our observations indicate that there is no significant difference between the two studied extracts of P. tetragonolobus in terms of biological properties (specifically, antioxidant and anti-inflammatory effects. Regardless of the extraction method, P. tetragonolobus could be used for treating diseases related to oxidative stress and inflammatory reactions.     

Isolation of heptadepsin, a novel bacterial cyclic depsipeptide that inhibits lipopolysaccharide activity

Lipopolysaccharide (LPS) is considered to cause various inflammatory reactions. We searched among microbial secondary metabolites for compounds that could inhibit LPS-stimulated adhesion between human umbilical vein endothelial cells (HUVEC) and human myelocytic cell line HL-60 cells. In the course of our screening, we isolated a novel cyclic depsipeptide, which we named heptadepsin, from the whole culture broth of Paenibacillus sp. The addition of heptadepsin prior to LPS stimulation decreased HL-60 cell-HUVEC adhesion without showing any cytotoxicity. It also inhibited the cellular adhesion induced by lipid A, the active component of LPS, but it did not inhibit TNF-alpha or IL-1beta-induced cell adhesion. The result of surface plasmon resonance (SPR) analysis revealed that heptadepsin interacted with lipid A directly. Thus, heptadepsin, a novel naturally occurring cyclic heptadepsipeptide, was shown to inactivate LPS by direct interaction with LPS.     

TAK1/AP-1-Targeted Anti-Inflammatory Effects of Barringtonia augusta Methanol Extract

Barringtonia augusta methanol extract (Ba-ME) is a folk medicine found in the wetlands of Thailand that acts through an anti-inflammatory mechanism that is not understood fully. Here, we examine how the methanol extract of Barringtonia augusta (B. augusta) can suppress the activator protein 1 (AP-1) signaling pathway and study the activities of Ba-ME in the lipopolysaccharide (LPS)-treated RAW264.7 macrophage cell line and an LPS-induced peritonitis mouse model. Non-toxic concentrations of Ba-ME downregulated the mRNA expression of cytokines, such as cyclooxygenase and chemokine ligand 12, in LPS-stimulated RAW264.7 cells. Transfection experiments with the AP-1-Luc construct, HEK293T cells, and luciferase assays were used to assess whether Ba-ME suppressed the AP-1 functional activation. A Western blot assay confirmed that C-Jun N-terminal kinase is a direct pharmacological target of Ba-ME action. The anti-inflammatory effect of Ba-ME, which functions by β-activated kinase 1 (TAK1) inhibition, was confirmed by using an overexpression strategy and a cellular thermal shift assay. In vivo experiments in a mouse model of LPS-induced peritonitis showed the anti-inflammatory effect of Ba-ME on LPS-stimulated macrophages and acute inflammatory mouse models. We conclude that Ba-ME is a promising anti-inflammatory drug targeting TAK1 in the AP-1 pathway.     

Selective Inhibitors of the Inducible Nitric Oxide Synthase as Modulators of Cell Responses in LPS-Stimulated Human Monocytes

Inducible nitric oxide synthase (iNOS) is a crucial enzyme involved in monocyte cell response towards inflammation, and it is responsible for the production of sustained amounts of nitric oxide. This free radical molecule is involved in the defense against pathogens; nevertheless, its continuous and dysregulated production contributes to the development of several pathological conditions, including inflammatory and autoimmune diseases. In the present study, we investigated the effects of two new iNOS inhibitors, i.e., 4-(ethanimidoylamino)-N-(4-fluorophenyl)benzamide hydrobromide (FAB1020) and N-{3-[(ethanimidoylamino)methyl]benzyl}-l-prolinamidedihydrochloride (CM554), on human LPS-stimulated monocytes, using the 1400 W compound as a comparison. Our results show that CM544 and FAB1020 are selective and decrease cytotoxicity, IL-6 secretion and LPS-stimulated monocyte migration. Furthermore, the modulation of iNOS, nitrotyrosine and Nrf2 were analyzed at the protein level. Based on the collected preliminary results, the promising therapeutic value of the investigated compounds emerges, as they appear able to modulate the pro-inflammatory LPS-stimulated response in the low micromolar range in human monocytes.     

Regulation of inflammatory cytokines in lipopolysaccharide-stimulated RAW 264.7 murine macrophage by 7-O-methyl-naringenin

7-O-Methylnaringenin, extracted from Rhododendron speciferum, belongs to the flavanone class of polyphenols. In the present study, we investigated the anti-inflammatory effects of 7-O-methylnaringenin on cytokine production by lipopoly-saccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. The results showed that pretreatment with 10, 20 or 40 μg/mL of 7-O-methylnaringenin could downregulate tumour necrosis factor (TNF-α), interleukin (IL-6) and interleukin (IL-1β) in a dose-dependent manner. Furthermore, we investigated the signal transduction mechanisms to determine how 7-O-methylnaringenin affects RAW 264.7 macrophages. The activation of mitogen-activated protein kinases (MAPK) and IκBα were measured by Western blotting. The data showed that 7-O-methylnaringenin could downregulate LPS-induced levels of phosphorylation of ERK1/2, JNK and IκBα. These observations indicated that 7-O-methylnaringenin modulated inflammatory cytokine responses by blocking NF-?B, ERK1/2 and JNK/MAPKs activation.     

Exogenous rhTRX reduces lipid accumulation under LPS-induced inflammation

Redox-regulating molecule, recombinant human thioredoxin (rhTRX) which shows anti-inflammatory, and anti-oxidative effects against lipopolysaccharide (LPS)-stimulated inflammation and regulate protein expression levels. LPS-induced reactive oxygen intermediates (ROI) and NO production were inhibited by exogenous rhTRX. We identified up/downregulated intracellular proteins under the LPS-treated condition in exogenous rhTRX-treated A375 cells compared with non-LPS-treated cells via 2-DE proteomic analysis. Also, we quantitatively measured cytokines of in vivo mouse inflammation models using cytometry bead array. Exogenous rhTRX inhibited LPS-stimulated production of ROI and NO levels. TIP47 and ATP synthase may influence the inflammation-related lipid accumulation by affecting lipid metabolism. The modulation of skin redox environments during inflammation is most likely to prevent alterations in lipid metabolism through upregulation of TIP47 and ATP synthase and downregulation of inflammatory cytokines. Our results demonstrate that exogenous rhTRX has anti-inflammatory properties and intracellular regulatory activity in vivo and in vitro. Monitoring of LPS-stimulated pro-inflammatory conditions treated with rhTRX in A375 cells could be useful for diagnosis and follow-up of inflammation reduction related with candidate proteins. These results have a therapeutic role in skin inflammation therapy.     

Cytotoxic C-benzylated dihydrochalcones from Uvaria acuminata

Two new C-benzylated dihydrochalcones, isochamuvaritin (1) and acumitin (2), have been isolated from the African medicinal plant Uvaria acuminata, together with the previously reported benzylbenzoate (3), uvaretin (4), isouvaretin (5), diuvaretin (6), and uvangoletin (7). The structural elucidation of compounds 1 and 2 in spectroscopic studies is described. C-Benzylated dihydrochalcones, especially 1, 2, 4, and 6, showed considerable cytotoxicity toward human promyelocytic leukemia HL-60 cells.     

Modulation of macrophage immune responses by Echinacea

Echinacea preparations are widely used herbal medicines for the prevention and treatment of colds and minor infections. There is little evidence for the individual components in Echinacea that contribute to immune regulatory activity. Activity of an ethanolic Echinacea extract and several constituents, including cichoric acid, have been examined using three in vitro measures of macrophage immune function - NF-kappaB, TNF- alpha and nitric oxide (NO). In cultured macrophages, all components except the monoene alkylamide (AA1) decreased lipopolysaccharide (LPS) stimulated NF-kappaB levels. 0.2 microg/ml cichoric acid and 2.0 microg/mL Echinacea Premium Liquid (EPL) and EPL alkylamide fraction (EPL AA) were found to significantly decrease TNF-alpha production under LPS stimulated conditions in macrophages. In macrophages, only the alkylamide mixture isolated from the ethanolic Echinacea extract decreased LPS stimulated NO production. In this study, the mixture of alkylamides in the Echinacea ethanolic liquid extract did not respond in the same manner in the assays as the individual alkylamides investigated. While cichoric acid has been shown to affect NF-kappaB, TNF-alpha and NO levels, it is unlikely to be relevant in the Echinacea alterations of the immune response in vivo due to its non- bioavailability - i.e. no demonstrated absorption across the intestinal barrier and no detectable levels in plasma. These results demonstrate that Echinacea is an effective modulator of macrophage immune responses in vitro.