Tumor Necrosis Factor-alpha Release Research Articles

MicroRNAs Regulate Human Adipocyte Lipolysis: Effects of miR-145 Are Linked to TNF-α

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and have multiple effects in various tissues including adipose inflammation, a condition characterized by increased local release of the pro-lipolytic cytokine tumor necrosis factor-alpha (TNF-α). Whether miRNAs regulate adipocyte lipolysis is unknown. We set out to determine whether miRNAs affect adipocyte lipolysis in human fat cells. To this end, eleven miRNAs known to be present in human adipose tissue were over-expressed in human in vitro differentiated adipocytes followed by assessments of TNF-α and glycerol levels in conditioned media after 48 h. Three miRNAs (miR-145, -26a and let-7d) modulated both parameters in parallel. However, while miR-26a and let-7d decreased, miR-145 increased both glycerol release and TNF-α secretion. Further studies were focused therefore on miR-145 since this was the only stimulator of lipolysis and TNF-α secretion. Time-course analysis demonstrated that miR-145 over-expression up-regulated TNF-α expression/secretion followed by increased glycerol release. Increase in TNF-α production by miR-145 was mediated via activation of p65, a member of the NF-κB complex. In addition, miR-145 down-regulated the expression of the protease ADAM17, resulting in an increased fraction of membrane bound TNF-α, which is the more biologically active form of TNF-α. MiR-145 overexpression also increased the phosphorylation of activating serine residues in hormone sensitive lipase and decreased the mRNA expression of phosphodiesterase 3B, effects which are also observed upon TNF-α treatment in human adipocytes. We conclude that miR-145 regulates adipocyte lipolysis via multiple mechanisms involving increased production and processing of TNF-α in fat cells.

Adaptive immune responses triggered by oxidative stress contribute to hepatic inflammation in NASH

Previous studies have shown that human nonalcoholic steatohepatitis (NASH) is often associated with the presence of circulating antibodies against protein adducted by lipid peroxidation products. Here we used the methionine-choline deficient (MCD) model of NASH to characterize the possible involvement of adaptive immunity in NASH. In mice fed up to 8 weeks with the MCD diet the extension of liver injury and lobular inflammation paralleled the development of immunoglobulin G (IgG) against malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE)-derived antigens as well as with the hepatic recruitment of CD4(+) and CD8(+) T-lymphocytes responsive to the same antigens. Moreover, in these animals the individual IgG reactivity against MDA-adducts positively correlated with transaminase release and hepatic tumor necrosis factor alpha (TNF-α) expression. To substantiate the role of immune responses triggered by oxidative stress in the progression of NASH, mice were immunized with MDA-adducted bovine serum albumin (MDA-BSA) before feeding the MCD diet. MDA-BSA immunization did not affect control mice livers, but further stimulated transaminase release, lobular inflammation, and the hepatic expression of proinflammatory cytokine in MCD-fed mice. The increased severity of NASH in immunized MCD-fed mice involved liver recruitment and the T helper (Th)-1 activation of CD4(+) T cells that, in turn, further stimulated macrophage M1 responses. Moreover, hepatic fibrosis was also evident in these animals in relation with an IL-15-mediated increase of natural killer T-cells (NKT) and the up-regulation in liver production of osteopontin by NKT cells and hepatic macrophages. These results indicate that oxidative stress can contribute to the progression of NASH by stimulating both humoral and cellular immune responses, pointing to the possible role of adaptive immunity in the pathogenesis of the disease.

Toll-like Receptor 4 Inhibitor TAK-242 Treatment Does Not Influence Perfusion Recovery in Tissue Ischemia

Toll-like receptors (TLRs) are important in innate immune responses, which are crucial in collateral artery formation (arteriogenesis). TLR4⁻/⁻ mice undergoing hind limb ischemia show decreased perfusion recovery accompanied by an impaired infiltration of inflammatory cells. TLR antagonists are currently developed and tested with the objective to inhibit acute exacerbation of organ damaging immune responses. However, systemic inhibition of innate immune responses may negatively influence arteriogenesis. In this study, we evaluated if TLR4 inhibition by a potent TLR4 inhibitor (TAK-242) would negatively influence perfusion recovery in a mouse model for arteriogenesis. Whole blood from human and mouse origin was stimulated with the TLR4 ligand lipopolysaccharide following TAK-242 incubation. After stimulation, cellular TLR4 activation was measured using fluorescence-activated cell sorting and tumor necrosis factor alpha release was measured using enzyme-linked immunosorbent assay. Next, the effect of TAK-242 was tested in a mouse model for arteriogenesis on perfusion recovery. TLR4 responses measured by tumor necrosis factor alpha levels were inhibited by TAK-242 in human and mouse blood after long-term stimulation. TAK-242 attenuated TLR4 responses in vivo but did not inhibit perfusion recovery in mice. In conclusion, TAK-242 does not negatively influence perfusion recovery following hind limb ischemia despite its TLR4 inhibiting properties.

Mycobacterium avium Biofilm Attenuates Mononuclear Phagocyte Function by Triggering Hyperstimulation and Apoptosis during Early Infection

Mycobacterium avium subsp. hominissuis is an opportunistic human pathogen that has been shown to form biofilm in vitro and in vivo. Biofilm formation in vivo appears to be associated with infections in the respiratory tract of the host. The reasoning behind how M. avium subsp. hominissuis biofilm is allowed to establish and persist without being cleared by the innate immune system is currently unknown. To identify the mechanism responsible for this, we developed an in vitro model using THP-1 human mononuclear phagocytes cocultured with established M. avium subsp. hominissuis biofilm and surveyed various aspects of the interaction, including phagocyte stimulation and response, bacterial killing, and apoptosis. M. avium subsp. hominissuis biofilm triggered robust tumor necrosis factor alpha (TNF-α) release from THP-1 cells as well as superoxide and nitric oxide production. Surprisingly, the hyperstimulated phagocytes did not effectively eliminate the cells of the biofilm, even when prestimulated with gamma interferon (IFN-γ) or TNF-α or cocultured with natural killer cells (which have been shown to induce anti-M. avium subsp. hominissuis activity when added to THP-1 cells infected with planktonic M. avium subsp. hominissuis). Time-lapse microscopy and the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay determined that contact with the M. avium subsp. hominissuis biofilm led to early, widespread onset of apoptosis, which is not seen until much later in planktonic M. avium subsp. hominissuis infection. Blocking TNF-α or TNF-R1 during interaction with the biofilm significantly reduced THP-1 apoptosis but did not lead to elimination of M. avium subsp. hominissuis. Our data collectively indicate that M. avium subsp. hominissuis biofilm induces TNF-α-driven hyperstimulation and apoptosis of surveilling phagocytes, which prevents clearance of the biofilm by cells of the innate immune system and allows the biofilm-associated infection to persist.

Toll-like receptor and pro-inflammatory cytokine expression during prolonged hyperinsulinaemia in horses: Implications for laminitis

Equine laminitis, a disease of the lamellar structure of the horse's hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Toll-like receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-inflammatory cytokine production is increased in lamellae and skeletal muscle during equine hyperinsulinaemia. Standardbred horses were treated with either a prolonged, euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged, glucose infusion (p-GI), which induced marked and moderate hyperinsulinaemia, respectively. Age-matched control horses were treated simultaneously with a balanced electrolyte solution. Treated horses developed clinical (p-EHC) or subclinical (p-GI) laminitis, whereas controls did not. Skeletal muscle and lamellar protein extracts were analysed by Western blotting for TLR4, IL-6, TNF-α and suppressor of cytokine signalling 3 (SOCS3) expression. Lamellar protein expression of TLR4 and TNF-α, but not IL-6, was increased by the p-EHC, compared to control horses. A significant positive correlation was found between lamellar TLR4 and SOCS3. Skeletal muscle protein expression of TLR4 signalling parameters did not differ between control and p-EHC-treated horses. Similarly, the p-GI did not result in up-regulation of lamellar protein expression of any parameter. The results suggest that insulin-sensitive tissues may not accurately reflect lamellar pathology during hyperinsulinaemia. While TLR4 is present in the lamellae, its activation appears unlikely to contribute significantly to the developmental pathogenesis of hyperinsulinaemic laminitis. However, inflammation may have a role to play in the later stages (e.g., repair or remodelling) of the disease.

Tumor necrosis factor-alpha mediates hyperthermia-induced glioma invasiveness decreases

BackgroundThermotherapy has already been proved effective for the treatment of various tumors, including glioma. This study was performed to determine whether tumor necrosis factor-alpha was involved in the regulation of this biological process. MethodsRT-PCR and immunocytochemistry were used to investigate the levels of tumor necrosis factor-alpha mRNA and heat shock factor-1 protein, respectively, in glioma cells. Radioimmunoassay was used to dynamically monitor contents of TNF-a in nutrient fluid for C6 cells after hyperthermia treatment. Crystal violet staining method was used to detect glioma invasiveness. ResultsThe most obvious increase of heat shock factor-1 protein and tumor necrosis factor -alpha mRNA in C6 cells were observed at 30 min and 60 min after hyperthermia, respectively. In addition, the radioactivity of tumor necrosis factor-alpha in C6 cells' culture fluid also reached peak at 120 min of hyperthermia. The glioma invasiveness decreases and the concentration of tumor necrosis factor-alpha reached the maximum at 120 min of hyperthermia. ConclusionOur results showed that the hyperthermia-mediated glioma invasiveness decreases was due to accelerated release of tumor necrosis factor-alpha, which could cause the decreases of glioma invasiveness by promoting the release heat shock factor-1 from neurospongioma cells.

Roflumilast Inhibits Lipopolysaccharide-Induced Tumor Necrosis Factor-α and Chemokine Production by Human Lung Parenchyma

BackgroundRoflumilast is the first phosphodiesterase-4 (PDE4) inhibitor to have been approved for the treatment of COPD. The anti-inflammatory profile of PDE4 inhibitors has not yet been explored in human lung tissues. We investigated the effects of roflumilast and its active metabolite roflumilast-N-oxide on the lipopolysaccharide (LPS)-induced release of tumor necrosis factor-alpha (TNF-α) and chemokines by human lung parenchymal explants. We also investigated roflumilast’s interaction with the long-acting β2-agonist formoterol.MethodsExplants from 25 patients undergoing surgical lung resection were incubated with Roflumilast, Roflumilast-N-oxide and formoterol and stimulated with LPS. Levels of TNF-α, chemokines (in the culture supernatants) and cyclic adenosine monophosphate (in tissue homogenates) were determined with appropriate immunoassays.ResultsRoflumilast and Roflumilast-N-oxide concentration-dependently reduced the release of TNF-α and chemokines CCL2, CCL3, CCL4, CXCL9 and CXCL10 from LPS-stimulated human lung explants, whereas CXCL1, CXCL5 and CXCL8 release was not altered. Formoterol (10 nM) partially decreased the release of the same cytokines and significantly increased the inhibitory effect of roflumilast on the release of the cytokines.ConclusionsIn human lung parenchymal explants, roflumilast and roflumilast-N-oxide reduced the LPS-induced release of TNF-α and chemokines involved in the recruitment of monocytes and T-cells but not those involved in the recruitment of neutrophils. Addition of formoterol to roflumilast provided superior in vitro anti-inflammatory activity, which may translate into greater efficacy in COPD.

Nitric Oxide and Tumor Necrosis Factor-Alpha Inhibitory Substances from the Rhizomes of Kaempferia Marginata

The ethanol extract of the rhizomes of Kaempferia marginata showed a potent inhibitory effect against lipopolysaccharide (LPS)-induced nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) release in RAW264.7 cells. Moreover, the partition with various organic solvents also inhibited NO production. One new pimarane-type diterpene, 1alpha-acetoxysandaracopimaradien-2alpha-ol (5), along with four known diterpenes (1-4), were isolated from the n-hexane and chloroform layers, respectively. Among these metabolites, compounds 1 and 4 were isolated for the first time from K. marginata. Compounds 1-5 showed significant inhibitory effects on NO production, with IC50 values ranging from 38.6 to 51.9 microM. Furthermore, compound 2 also exhibited significant activity against TNF-alpha release (IC50 = 48.3 microM). These findings may support the use of K. marginata by traditional doctors for treatment of inflammatory-related diseases.

Sericin–carboxymethyl cellulose porous matrices as cellular wound dressing material

In this study, porous three-dimensional (3D) hydrogel matrices are fabricated composed of silk cocoon protein sericin of non-mulberry silkworm Antheraea mylitta and carboxymethyl cellulose. The matrices are prepared via freeze-drying technique followed by dual cross-linking with glutaraldehyde and aluminum chloride. The microstructure of the hydrogel matrices is assessed using scanning electron microscopy and biophysical characterization are carried out using Fourier transform infrared spectroscopy and X-ray diffraction. The transforming growth factor β1 release from the cross-linked matrices as a growth factor is evaluated by immunosorbent assay. Live dead assay and 3-[4,5-dimethylthiazolyl-2]-2,5-diphenyl tetrazolium bromide assay show no cytotoxicity of blended matrices toward human keratinocytes. The matrices support the cell attachment and proliferation of human keratinocytes as observed through scanning electron microscope and confocal images. Gelatin zymography demonstrates the low levels of matrix metalloproteinase 2 (MMP-2) and insignificant amount of MMP-9 in the culture media of cell seeded matrices. Low inflammatory response of the matrices is indicated through tumor necrosis factor alpha release assay. The results indicate that the fabricated matrices constitute 3D cell-interactive environment for tissue engineering applications and its potential use as a future cellular biological wound dressing material.

Paeonol attenuates inflammation-mediated neurotoxicity and microglial activation.

Chronic activation of microglial cells endangers neuronal survival through the release of various proinflammatory and neurotoxic factors. The root of Paeonia lactiflora Pall has been considered useful for the treatment of various disorders in traditional oriental medicine. Paeonol, found in the root of Paeonia lactiflora Pall, has a wide range of pharmacological functions, including anti-oxidative, anti-inflammatory and neuroprotective activities. The objective of this study was to examine the efficacy of paeonol in the repression of inflammation-induced neurotoxicity and microglial cell activation. Organotypic hippocampal slice cultures and primary microglial cells from rat brain were stimulated with bacterial lipopolysaccharide. Paeonol pretreatment was performed for 30 minutes prior to lipopolysaccharide addition. Cell viability and nitrite (the production of nitric oxide), tumor necrosis factor-alpha and interleukin-1beta products were measured after lipopolysaccharide treatment. In organotypic hippocampal slice cultures, paeonol blocked lipopolysaccharide-related hippocampal cell death and inhibited the release of nitrite and interleukin-1beta. Paeonol was effective in inhibiting nitric oxide release from primary microglial cells. It also reduced the lipopolysaccharide-stimulated release of tumor necrosis factor-alpha and interleukin-1β from microglial cells. Paeonol possesses neuroprotective activity in a model of inflammation-induced neurotoxicity and reduces the release of neurotoxic and proinflammatory factors in activated microglial cells.

Anti-inflammatory effect of tetrahydrocoptisine from Corydalis impatiens is a function of possible inhibition of TNF-α, IL-6 and NO production in lipopolysaccharide-stimulated peritoneal macrophages through inhibiting NF-κB activation and MAPK pathway

The extracts or constituents from Corydalis impatiens are known to have many pharmacological activities. Tetrahydrocoptisine (THC), a protoberberine compound from Corydalis impatiens, was found to possess a potent anti-inflammatory effect in different acute or chronic inflammation model animals. Pretreatment with THC (i.p.) inhibited the paw and ear edema in the carrageenan-induced paw edema assay and xylene-induced ear edema assay, respectively. In the lipopolysaccharide (LPS)-induced systemic inflammation model, THC significantly inhibited serum tumor necrosis factor-alpha (TNF-α) release in mice. To clarify its possible molecular mechanisms underlying this anti-inflammatory effect, we investigated the effect of THC on LPS-induced responses in peritoneal macrophages. Our data demonstrated that THC significantly inhibited LPS-induced TNF-α, interleukin-6(IL-6) and nitric oxide (NO) production. THC inhibited the production of TNF-α and IL-6 by down-regulating LPS-induced IL-6 and TNF-α mRNA expression. Furthermore, it attenuated the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) and phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2) as well as the expression of nuclear factor kappa B(NF-κB), in a concentration-dependent manner. Taken together, our data suggest that THC is an active anti-inflammatory constituent by inhibition of TNF-α, IL-6 and NO production possibly via down-regulation of NF-κB activation, phospho-ERK1/2 and phospho-p38MAPK signal pathways.

Stilbenes and Anthocyanins Reduce Stress Signaling in BV-2 Mouse Microglia

Blueberries contain an array of phytochemicals that may decrease both inflammatory and oxidative stress. This study determined if pterostilbene, resveratrol, and two anthocyanins commonly found in blueberries, delphinidin-3-O-glucoside and malvidin-3-O-glucoside, would be efficacious in protecting microglia from inflammatory-induced stress signaling. Microglia that were pretreated with blueberry extract (0.25, 0.5, 1, 2 mg/mL) or its components (1, 10, 20, 30 μM pterostilbene, resveratrol, delphinidin-3-O-glucoside, or malvidin-3-O-glucoside) prior to exposure to lipopolysaccharide (100 ng/mL) demonstrated concentration-dependent reductions in nitric oxide and tumor necrosis factor-alpha release and decreased expression of inducible nitric oxide synthase and cyclooxygenase-2. However, much higher concentrations of the individual components than those found in blueberries were needed to demonstrate the effects. For example, 1 mg/mL blueberry extract significantly reduced LPS-induced nitric oxide release; this concentration of blueberry extract contains 2.6 μM malvidin-3-O-glucoside, but when malvidin-3-O-glucoside was tested individually, 20 μM was necessary to observe a significant reduction in nitric oxide release. Therefore the protective effects of blueberries may not be due to any one component, but rather a synergism of the activity of the compounds tested and/or other blueberry compounds not tested here. These results lend further support that blueberry and its active components are able to combat some of the inflammatory mediators of aging at the cellular level.

AB0613 Omega-3 polyunsaturated fatty acids for the treatment of rheumatoid arthritis: A meta-analysis

BackgroundOmega-3 polyunsaturated fatty acids (PUVAs) may lead to a reduction of pain and inflammation via competitively inhibiting the production of PGE2 and LTB4 and inhibiting the release of interleukin-1 beta...

HnRNP A1/A2 and SF2/ASF Regulate Alternative Splicing of Interferon Regulatory Factor-3 and Affect Immunomodulatory Functions in Human Non-Small Cell Lung Cancer Cells

Heterogeneous nuclear ribonucleoparticule A1/A2 (hnRNP A1/A2) and splicing factor 2/alternative splicing factor (SF2/ASF) are pivotal for precursor messenger RNA (pre-mRNA) splicing. Interferon regulatory factor-3 (IRF-3) plays critical roles in host defense against viral and microbial infection. Truncated IRF-3 proteins resulting from alternative splicing have been identified and characterized as functional antagonists to full-length IRF-3. In this study, we examined the molecular mechanism for splicing regulation of IRF-3 pre-mRNA and first reported the regulatory effect of hnRNP A1/A2 and SF2/ASF on IRF-3 splicing and activation. RNA interference-mediated depletion of hnRNP A1/A2 or SF2/ASF in human non-small cell lung cancer (NSCLC) cells increased exclusion of exons 2 and 3 of IRF-3 gene and reduced expression levels of IRF-3 protein and IRF-3 downstream effector molecules interferon-beta and CXCL10/IP-10. In addition, direct binding of hnRNP A1 and SF2/ASF to specific binding motifs in IRF-3 intron 1 was confirmed by RNA electrophoretic mobility shift assay. Subsequent minigene splicing assay showed that IRF-3 minigenes with mutated hnRNPA 1/A2 or SF2/ASF binding motifs increased exclusion of exons 2 and 3. Moreover, knockdown of hnRNP A1/A2 or SF2/ASF in NSCLC cells reinforced phytohemagglutinin-induced tumor necrosis factor-alpha release by peripheral blood mononuclear cells (PBMC) but suppressed that of interleukin-10 in NSCLC/PBMC co-cultures. Taken together, our results suggest that specific knockdown for hnRNP A1/A2 or SF2/ASF increase exclusion of exons 2 and 3 of IRF-3 pre-mRNA and influence immunomodulatory functions of human NSCLC cells.

Valsartan attenuates oxidative stress and NF-κB activation and reduces myocardial apoptosis after ischemia and reperfusion

Myocardial apoptosis is primarily triggered during reperfusion. Various mechanisms are involved, including oxidative stress which activates the translocation of nuclear factor-kappa B (NF-κB) and stimulates the release of tumor necrosis factor-alpha (TNF-α). However, the relative contribution of the renin angiotensin system (RAS) to the development of myocardial apoptosis during reperfusion remains unknown. In the present study, we examined whether inhibition of RAS with Valsartan, an Angiotensin II 1 receptor (AT1) antagonist, could reduce apoptosis during reperfusion. We constructed a rat model of myocardial ischemia reperfusion injury. Rats were pretreated with Valsartan for 2 weeks, and then subjected to 30min ischemia and 4h reperfusion. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Levels of malondialdehyde (MDA), superoxide dismutase (SOD), TNF-α, and caspase-3 were detected by ELISA. NF-κB, Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase expression was assessed by Western blot analysis. Valsartan inhibited apoptosis (TUNEL staining) in ischemic myocardium (P<0.05), consistent with reduced caspase-3 activity. Valsartan also inhibited of NF-κB translocation to nucleus (P<0.05), and decreased plasma TNF-α levels (P<0.05). Valsartan pretreatment suppressed MDA content and preserved SOD activity, consistent with reduced NADPH oxidase expression (P<0.01). These data provided substantial evidence that RAS was involved in NF-κB activation, mediated by AT1 dependent oxidative stress; thus, RAS might ultimately promote myocardial apoptosis during reperfusion pathogenesis.

Glia Maturation Factor Induces Interleukin-33 Release from Astrocytes: Implications for Neurodegenerative Diseases

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and Multiple sclerosis (MS) involve activation of glial cells and release of inflammatory mediators leading to death of neurons. Glia maturation factor (GMF) is up-regulated in the central nervous system (CNS) in these neurodegenerative diseases. Interleukin-33 (IL-33) is highly expressed constitutively in the CNS. We have treated mouse astrocytes, mixed culture with glial cells and neurons, and only neurons with GMF and/or IL-33 in vitro. Both GMF and IL-33-induced chemokine (C-C motif) ligand 2 (CCL2) release in a dose and time-dependent manner. We report that GMF induced IL-33 release, and that IL-33 augments GMF-induced tumor necrosis factor-alpha (TNF-α) release from mouse astrocytes. IL-33 induces CCL2, TNF-α and nitric oxide release through phosphorylation of ERK in mouse astrocytes. Incubation of mixed culture containing glial cells and neurons or only neuronal culture with IL-33 reduced the number of neurons positive for microtubule-associated protein 2. In conclusion, IL-33 augments GMF-mediated neuroinflammation and may provide a new drug target for neurodegenerative and autoimmune diseases.

Assessing the impact of the physical properties of industrially produced carbon nanotubes on their interaction with human primary macrophages in vitro

Currently it is not fully understood how carbon nanotubes (CNTs) may affect human health. Despite this, CNTs are produced at a tonne mass scale yearly. Due to their large production and intended use within a variety of applications it is imperative that a clear understanding of the hazard potential of CNTs is gained. The aim of this study therefore was to assess the impact of five different industrially produced CNTs which varied in their physical properties on the viability of human monocyte derived macrophages (MDM), and subsequently, at sub-lethal concentrations (0.005–0.02 mg/mL), their ability to cause oxidative stress and a pro-inflammatory response in these important immune cells over a 24-h period. None of the CNTs caused significant cytotoxicity up to 0.02 mg/mL after 24 h. Only the long multi-walled CNTs (MWNCTs) caused a significant, dose-dependent (0.005–0.02 mg/mL) reactive oxygen species production, whilst bundled MWCNTs showed a significant tumor necrosis factor alpha release after 24 h exposure at 0.02 mg/mL. No effects were observed for either tangled MWCNTs or short MWCNTs. It can be concluded from the findings of the present study that the industrially produced CNTs studied can cause hazardous effects in vitro that may be associated with their physical properties.

Some bioactive potentials of two biflavanols isolated from Garcinia kola on cadmium-induced alterations of raw U937 cells and U937-derived macrophages

ObjectiveTo investigate the abilities of two flavonoids - Garcinia biflavanol-1 (GB-1) and Garcinia biflavanol-2 (GB-2) from Garcinia kola (G. kola) in reducing cadmium-induced effects on raw U937 cells and U937-derived macrophages. MethodsMacrophage U937 cells were incubated with cadmium followed by treatment with the flavonoids and cell viability assessed via trypan blue staining. In the other experiment, the U937 cells were transformed to the macrophage form and treated with cadmium in order to activate them. The cells were later incubated with the flavonoids and finally the supernatant of each cell culture was analysed for the secretion of nitric oxide, catalyse activity, and the release of tumour necrosis factor-alpha, interleukin-1 and interleukin-2 as indices of macrophage activation. Quercetin (a flavonol) was used as the reference flavonoid in all experiments. ResultsIt revealed that the flavonoids significantly increased the viability of the cells and also reduced the cadmium-induced activation of the macrophage cells in a concentration-dependent manner. The flavanols GB-1 and GB-2 possessed higher activities than quercetin in all cases (P<0.05). Garcinia biflavanol-2 possessed a higher bioactivity than GB-1 significantly (P<0.05). ConclusionsIn addition to corroborating the several reported importance of G. kola as a potential neutraceutical and pharmacological condiment, the study also clearly indicates the role hydroxylation especially at the 3′- position of polyphenols could play in enhancing bioactivities of flavonoids.

Pharmacological evaluation of a novel enhydrazone ester (CEE-1) as a dual inhibitor of the release of pro-inflammatory cytokines and prostanoids from human monocytes

CEE-1 (ethyl 4-phenylhydrazinocyclohex-3-en-2-oxo-6-phenyl-1-oate)—a novel enhydrazone ester, was tested in vitro for anti-inflammatory activity against the release of pro-inflammatory cytokine and prostanoid from lipopolysaccharide-activated human monocytes or human monocytic cell line (U937). The effects were compared with those of standard anti-inflammatory drugs dexamethasone and indomethacin. CEE-1 potently and strongly inhibited the release of both tumor necrosis factor-alpha (TNF-α) and prostaglandin E2 (PGE2). The concentrations producing 50% inhibition (IC50 values) were 2.0 μM and 2.4 μM for TNF-α and PGE2, respectively. At 30 μM, the drug achieved almost complete inhibition of both mediators. Dexamethasone had similar effects but indomethacin inhibited only the PGE2 release, and although CEE-1 was less potent than these two drugs, it had comparable efficacy. The compound appeared to act, at least, in part by inhibiting the up-regulation of the mRNA for TNF-α as well as that of the prostanoid-synthetic enzyme, cyclo-oxygenase-2 (COX-2). However, like dexamethasone, but unlike indomethacin, CEE-1 did not affect COX-2 enzyme function. Thus, the profile of activity of CEE-1 is similar to that of steroids rather than the non-steroidal anti-inflammatory drugs. Structure-activity study showed that the presence of a simple aromatic ring attached via an NH-NH group was critical for activity. At the concentrations that completely inhibited mediator release, the compound displayed no significant in vitro toxicity on the cells. These results show that CEE-1 is a dual inhibitor of the release of cytokines and prostanoids, and therefore could be a potential alternative to steroids in the treatment of inflammatory diseases.

Serum adipocyte fatty acid-binding protein in the critically ill

Sepsis due to unabated inflammation is common. Increased production of pro-inflammatory cytokines, free radicals, and eicosanoids has been detected in sepsis and other critical illnesses but could also be due to decreased synthesis and release of anti-inflammatory molecules. Increased serum adipose-fatty acid-binding protein (A-FABP) levels can cause insulin resistance and have been reported in the critically ill, serve as a marker of prognosis, and thus link metabolic homeostasis and inflammation. A-FABP can be linked to the expression of Toll-like receptors, macrophage activation, synthesis and release of pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, activation of cyclooxygenase 2 (COX-2) expression, and eicosanoid synthesis, events that can cause insulin resistance and initiation and progression of inflammation and sepsis. Unsaturated fatty acids and their anti-inflammatory products, such as lipoxins, resolvins, and protectins, may suppress A-FABP expression, inhibit macrophage and COX-2 activation, and decrease production of pro-inflammatory cytokines and ultimately could lead to a decrease in insulin resistance and resolution of inflammation and recovery from sepsis. Serial measurement of these pro- and anti-inflammatory molecules and correlation of their levels to the progression to or recovery from (or both) sepsis and other inflammatory processes may form a new approach to predict prognosis in inflammatory conditions and eventually could lead to the development of new therapeutic strategies.