Formation Of Tumor Necrosis Factor-α Research Articles

Highly adhesive and dual-crosslinking hydrogel via one-pot self-initiated polymerization for efficient antibacterial, antifouling and full-thickness wound healing

A multifunctional hydrogel dressing system with high adhesion and dual-crosslinking for efficient antibacterial, antifouling and full-thickness wound healing is designed, synthesized via one-pot self-initiated polymerization and evaluated. Arginine-modified chitosan-oligosaccharide (COS-Arg)-doped hydrogel system is prepared by exploiting the spontaneous radical polymerization of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA). SBMA is cross-linked with methacrylamide dopamine (DMA) and methacrylatoethyl trimethyl ammonium chloride (DMC) through covalent bonding to form the hydrogel framework at room temperature under nitrogen atmosphere. The catechol groups on DMA, zwitterionic SBMA and the quaternary ammonium groups in the system endows the functional hydrogel system with good strength, excellent adhesion to the wound and a tight fit even under motion. The hemolytic activity, CCK-8, cell scratching and live/dead staining assays confirm the excellent cytocompatibility of the multifunctional hydrogel. Antibacterial tests demonstrate the excellent antibacterial activity of the hydrogel against E. coli and S. aureus . Animal studies show that hydrogels are effective in maintaining a moist microenvironment at the wound site, promoting the production of vascular endothelial growth factor (VEGF) and hydroxyproline and reducing the formation of tumor necrosis factor-α (TNF-α), thus effectively accelerating wound healing in vivo , which idicating the satisfactory effect of the dual-crosslinking multifunctional hydrogel dressings for wound healing. • The hydrogels were prepared by one-pot method and self-initiated polymerization. • The dual crosslinking hydrogels revealed high adhesion and mechanical properties. • The hydrogel dressing showed excellent antibacterial and antifouling properties. • The hydrogel dressing achieved the full-thickness regeneration of severe wounds.

Anti-allergic actions of F-PASA, a novel herbal cocktail, in IgE/antigen-mediated allergic responses in RBL-2H3 cells and passive cutaneous anaphylaxis in mice

BackgroundThe anti-inflammatory actions of Polygonum cuspidatum, Angelica gigas, Sophora flavescens and Arctium fruit are well known. Nonetheless, effects of herbal combination (PASA) or its fermentation by microorganisms (F-PASA) on the allergic response remain unknown. PurposeWe investigated whether PASA or F-PASA could inhibit IgE/antigen complex (IgE/Ag)-mediated allergic responses. MethodsTo evaluate and compare anti-allergic actions of PASA and F-PASA, we performed cell viability, β-hexosaminidase activity, ELISA assays for cytokines and eicosanoids, immunoblot analysis, HPLC analysis and passive cutaneous anaphylaxis (PCA) models. ResultsF-PASA had stronger anti-degranulation actions (IC50, 510.9 µg/ml) than PASA (IC50, 1,261 µg/ml) without cytotoxicity until 2000 µg/ml in IgE/Ag-activated RBL-2H3 cells. Additionally, F-PASA inhibited formation of tumor necrosis factor-α (IC50, 147.4 µg/ml), interleukin-4 (IC50, 213.4 µg/ml), prostaglandin D2 (IC50, 42.40 µg/ml) and leukotriene C4 (IC50, 157.9 µg/ml). Moreover, F-PASA dose-dependently inhibited the phosphorylation and expression of proteins that are related to the FcεRI and arachidonate cascades. Consistent with in vitro studies, F-PASA from 25 to 100 mg/kg also suppressed IgE/Ag-induced PCA reaction more than PASA did in mice. In phytochemical analysis, using PASA and F-PASA, F-PASA showed a higher level of emodin-8-O-β-d-glucoside, whereas the level of arctiin, an artigenin glycoside, was reduced compared with that using PASA. ConclusionThese findings indicate that F-PASA, including both artigenin and emodin-8-O-β-d-glucoside, possesses stronger anti-allergic properties. Therefore, F-PASA may be useful as a functional food or as a phytomedicine for allergic diseases.

Inhibitory Effect of Loranthus parasiticus on IgE-Mediated Allergic Responses in RBL-2H3 Cells.

The mistletoe Loranthus parasiticus has been used as a compound for traditional medicine in Northeast Asia for a long time and is known to possess neuroprotective action. Nonetheless, the effect of Loranthus parasiticus on allergic responses remains unknown. In the present study, we evaluated whether the water extract of Loranthus parasiticus (LPE) could inhibit IgE-mediated allergic responses in RBL-2H3 cells. LPE inhibited the release of β-hexosaminidase (IC50, 184.5 μg/mL) and the formation of tumor necrosis factor-α (IC50, 84.27 μg/mL), interleukin-4 (IC50, 93.43 μg/mL), prostaglandin E2 (IC50, 84.10 μg/mL), prostaglandin D2, and leukotriene C4 (IC50, 43.27 μg/mL) in a concentration-dependent manner. Moreover, LPE inhibited phosphorylation of Syk, PLCγ1/2, PKCδ, ERK, JNK, p38, and Akt. In the late phase, LPE decreased 5-lipoxygenase phosphorylation and COX-2 expression but not cPLA2 phosphorylation. Additionally, LPE included total phenolic compounds (10.72 mg/g dry weight) and total flavonoids (56.20 mg/g dry weight). These results suggest that the phenolic compounds or flavonoids contained in LPE may be associated with antiallergic activity. The phenolic compounds and flavonoids in LPE are antiallergic phytochemicals capable of inhibiting the activation of the FcεRI signaling cascade in mast cells. Such effects may provide further information for the development of a phytomedicine for allergic diseases.

Inhibitory effect of plant extract on tumor necrosis factor-α formation from carboxymethyllysine stimulated macrophages

Inhibitory effect of plant extract on tumor necrosis factor-α formation from carboxymethyllysine stimulated macrophages

ChemInform Abstract: Protective Effects of Cilostazol Against Transient Focal Cerebral Ischemia and Hemorrhagic Transformation

AbstractReview: 25 refs.

Protective Effects of Cilostazol against Transient Focal Cerebral Ischemia and Hemorrhagic Transformation

Cilostazol, a selective inhibitor of phosphodiesterase III, is an antiplatelet drug and a vasodilator via increased cAMP levels. It has been approved for the treatment of ischemic symptoms in chronic peripheral arterial obstruction or intermittent claudication and for secondary prevention of cerebral infarction (CSPS I). Recently, cilostazol has been reported to be more effective than aspirin in the secondary prevention of all types of stroke in patients and, in particular, prevent the secondary attack of hemorrhagic stroke in patients (CSPS II). Laboratory investigations revealed that cilostazol has a neuroprotective effect against ischemic brain injury. The neuroprotective potential is dependent on its antiinflammatory and antiapoptotic effects mediated by scavenging hydroxyl radicals, decreasing formation of tumor necrosis factor-α, and inhibition of poly (ADP-ribose) polymerase activity. In addition, increasing evidence indicates that cilostazol may offer endothelial protection via both the inhibition of lipopolysaccharide-induced apoptosis and induced nitric oxide (NO) production by endothelial NO synthase activation. The breakdown of the barrier permeability of the blood brain barrier (BBB) often accelerates the progression of diseases such as cerebral ischemia. However, the molecular mechanisms involved in BBB disruption have not been fully determined. Identification of the molecules responsible for the disruption of the endothelial barrier may yield new therapeutic targets in intractable diseases. This article reviews the protective effects of cilostazol against transient focal cerebral ischemia and hemorrhagic transformation and its mechanism of action.

The leaf extract of Spondias mombin L. displays an anti-inflammatory effect and suppresses inducible formation of tumor necrosis factor-α and nitric oxide (NO)

Extracts of Spondias mombin L. (Anacardiacea) is used in the traditional medicine of Africa and Latin America to treat many inflammatory conditions, with repeated claims of efficacy. However, there are no scientific data yet to support these claims and the mechanism through which the extract may be acting is still unknown. This study was undertaken to investigate the effects of the methanolic extract of the leaf of S. mombin (SM) on inflammation and to uncover some of the possible mechanisms that could explain any observed changes. The anti-inflammatory activity of the extract was investigated in Wistar rats using intraplantar injection of carrageenan as an in vivo model of inflammation. The effect of oral supplementation of the SM extract on tumor necrosis factor (TNF)-α levels after an intraperitoneal lipopolysaccharide (LPS; 1 mg/kg) challenge was investigated in mice. The effect of SM on TNF-α and inducible nitric oxide (iNO) production by LPS-stimulated bone marrow-derived macrophages (BM-MØ) was also investigated in vitro. BM-MØ were preincubated for 2 h with SM (0–100 µg/ml), activated with LPS, and then TNF-α and NO production measured in the cell-free conditioned culture supernatant after 24 h of incubation. The study showed that pre-treatment of rats with the SM extract (at 100, 200, and 400 mg/kg, per os) caused a significant dose-related inhibition of carrageenan-induced paw edema over a 4-h period. In treated mice, LPS-inducible (systemic) TNF-α levels were found to be significantly lower as a result of their receiving the SM extract. In vitro, SM treatment caused a dose-dependent decrease in LPS-inducible TNF-α and NO production by BM-MØ compared to the effects of treatment of the cells with LPS alone. Taken together, the results of these studies suggest that supplementation with SM extract can alleviate inflammatory responses and that this could possibly be via a suppression of the production of pro-inflammatory mediators and cytokines such as TNF-α and iNO.

Macrophage-activating lipopeptide-2 (MALP-2) induces a localized inflammatory response in rats resulting in activation of brain sites implicated in fever

Macrophage-activating lipopeptide-2 (MALP-2) has been identified as the pathogen-associated molecular pattern of Mycoplasma fermentans, which causes stimulation of the innate immune system through the activation of the heterodimeric Toll-like receptors (TLRs) 2 and 6. Based on the reported protective effects of MALP-2 on healing of skin wounds, the central goal of this study was to evaluate the capacity of MALP-2 to induce a localized inflammatory response in an established model of a subcutaneous air pouch. Injections of MALP-2 into the pouch caused fever and some components of sickness behavior in rats. At the subcutaneous site of localized inflammation, a massive formation of tumor necrosis factor-α (TNF), interleukin-6 (IL-6), and prostaglandin E 2 (PGE 2) could be demonstrated in response to injections of MALP-2. Moderate amounts of IL-6 and PGE 2 seemed to enter the systemic circulation of MALP-2-treated rats. The IL-6, which appeared in the blood after injection of MALP-2 into the air pouch was sufficient to cause a direct activation of brain cells in areas which lack a complete blood-brain barrier, namely in the sensory circumventricular organs (sCVOs), the organum vasculosum laminae terminalis (OVLT), the subfornical organ (SFO), and the area postrema (AP). The stimulation of cells at these brain sites was revealed by demonstration of a nuclear translocation of the transcription factor STAT3 (signal transducer and activator of transcription 3). Corresponding to the circulating levels of IL-6, the nuclear STAT3 activation of cells within the sCVOs was much less pronounced after local subcutaneous when compared to systemic treatment with MALP-2. In conclusion, cells within the subcutaneous compartment are activated by the TLR2/6 agonist MALP-2. Fever and sickness behavior induced by injection of MALP-2 into subcutaneous tissue may, in part, be mediated by a spillover of IL-6 from the subcutaneous site of inflammation into the blood to cause activation of brain sites which are implicated in the manifestation of these illness responses.

Cilostazol Reduces Atherosclerosis by Inhibition of Superoxide and Tumor Necrosis Factor-α Formation in Low-Density Lipoprotein Receptor-Null Mice Fed High Cholesterol

This study shows that 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) suppresses the atherosclerotic lesion formation in the low-density lipoprotein receptor (Ldlr)-null mice. Ldlr-null mice fed a high cholesterol diet showed multiple plaque lesions in the proximal ascending aorta including aortic sinus, accompanied by increased macrophage accumulation with increased expression of vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1). Supplementation of cilostazol (0.2% w/w) in diet significantly decreased the plaque lesions with reduced macrophage accumulation and suppression of VCAM-1 and MCP-1 in situ. Increased superoxide and tumor necrosis factor-alpha (TNF-alpha) production were significantly lowered by cilostazol in situ as well as in cultured human umbilical vein endothelial cells (HUVECs). TNF-alpha-induced increased inhibitory kappaBalpha degradation in the cytoplasm and nuclear factor-kappaB (NF-kappaB) p65 activation in the nuclei of HUVECs were reversed by cilostazol (1 approximately 100 microM) as well as by (E)-3[(4-t-butylphenyl)sulfonyl]-2-propenenitrile (BAY 11-7085) (10 microM), suggesting that cilostazol strongly inhibits NF-kappaB activation and p65 translocation into the nuclei. Furthermore, in gel shift and DNA-binding assay, cilostazol inhibited NF-kappaB/DNA complex and nuclear DNA-binding activity of the NF-kappaB in the nuclear extracts of the RAW 264.7 cells. Taken together, it is suggested that the anti-atherogenic effect of cilostazol in cholesterol-fed Ldlr-null mice is ascribed to its property to suppress superoxide and TNF-alpha formation, and thereby reducing NF-kappaB activation/transcription, VCAM-1/MCP-1 expressions, and monocyte recruitments.

Contradictory effects of chlorpromazine on endothelial cells in a rat model of endotoxic shock in association with its actions on serum TNF-α levels and antioxidant enzyme activities

We examined the effects of the phenothiazine derivative, chlorpromazine on thoracic aortic endothelial cell histology (14 h after LPS challenge) in a model of endotoxic shock in rats. Since excessive formation of tumor necrosis factor-α (TNF-α) and oxygen-derived free radicals contribute to endothelial injury in endotoxemia, we also evaluated the effect of the drug on the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase in liver tissue in this model and tried to find out whether this possible effect was associated with a change in serum TNF-α levels (measured 90 min after chlorpromazine administration). Endotoxemia was induced by a single i.p. injection of lipopolysaccharide (LPS) (5 mg kg −1 in 1.5 ml of saline; LPS from Escherichia coli serotype 055:B5, L-2880, Sigma Chemical Company). Electron microscopic evaluation of the aortas revealed that chlorpromazine (administered 30 min prior to LPS challenge), in smaller doses (3 mg kg −1) ameliorated the endothelial cell injury caused by LPS, whereas it caused deterioration of endothelial cell morphology in higher doses (10 and 25 mg kg −1). Chlorpromazine administration caused a significant reduction in serum TNF-α levels, which was correlated well with an increase in SOD activity in all drug doses (3, 10 and 25 mg kg −1). Catalase activity was increased only in the 25 mg kg −1 chlorpromazine group.

Interferon-γ-primed monocytoid cell lines: optimizing their use for in vitro detection of bacterial pyrogens

In order to reduce animal testing for quality control of pharmaceutical agents intended for parenteral use, the Limulus amebocyte lysate (LAL) assay is now being accepted in many cases as an alternative to measuring pyrogenic activity of samples in rabbits. However, since the LAL test is specific for cell wall components from Gram-negative bacteria and is sometimes difficult to perform in samples containing large amounts of protein, this alternative still leaves a considerable diagnostic gap. Here, we have optimized a previously established test based on assessing the formation of neopterin or nitrite in interferon-γ-treated human (THP-1) or murine (J774A.1, RAW264.7) monocytoid cell lines, respectively, in response to bacterial pyrogens. Optimal results were obtained either with THP-1 cells in serum-containing media and using a high concentration of interferon-γ (IFN-γ) or with RAW264.7 cells in serum-free media and independent of the IFN-γ dose. Results were significantly correlated with those obtained by another cell-culture-based assay in which formation of tumor necrosis factor-α by THP-1 1G3 cells was assessed. Also in RAW264.7 murine monocytoid cells, formation of nitrite and of tumor necrosis factor-α in response to a variety of samples was correlated. Samples shown to be pyrogenic in rabbits in a previous study were unambiguously detected with the test presented here. As expected, the LAL test was negative with cell-free supernatants from Staphylococcus aureus, but nevertheless a strong activation of IFN-γ-primed monocytoid cells was observed. Gel filtration experiments suggest that this activity is mediated by compounds of various molecular masses (6.5 to >66 kDa). Taken together, these results indicate that the use of monocytoid cell lines and the detection of metabolites which are triggered in the course of immunostimulation could fill the gap left by the LAL test and help to further reduce animal testing for pyrogens.

Local inhibition of LPS-induced hypothalamic TNF-formation by pentoxifylline has no effect on production of IL-6 within the anterior hypothalamus

Push–pull perfusions of the anterior hypothalamus were performed in four groups of guinea pigs characterized as follows: (a) hypothalamus perfused with artificial cerebrospinal fluid (CSF), intramuscular (im) injection of 20 μg/kg bacterial lipopolysaccharide (LPS); (b) hypothalamus perfused with CSF, im injection of saline; (c) hypothalamus perfused with CSF which contained 0.1 μg/μl pentoxifylline, im injection of LPS; (d) hypothalamus perfused with CSF which contained 0.1 μg/μl pentoxifylline, im injection of saline. Injection of LPS resulted in a significant rise of hypothalamic tumor necrosis factor-α (TNF), 60 min and 180 min after administration of LPS compared to the value measured 60 min before LPS was injected. In animals injected with saline, the baseline level of TNF in hypothalamic perfusates remained manifest. Perfusion of the anterior hypothalamus with CSF which contained 0.1 μg/μl pentoxifylline resulted in a complete suppression of hypothalamic TNF formation and release in animals injected with LPS or saline. The LPS-induced rise of hypothalamic interleukin-6 (IL-6) was the same in guinea-pigs perfused with CSF or CSF plus pentoxifylline. The LPS-induced rise of rectal temperature, measured about 3 h after LPS injection (fever peak) was the same in guinea-pigs perfused with CSF or CSF plus pentoxifylline. The results indicate that the hypothalamic rise of IL-6 and the febrile temperature peak in response to peripheral injection of LPS does not depend on the local formation of TNF within the anterior hypothalamus.

Development of the Carbocyclic Nucleoside MDL 201449A: A Tumor Necrosis Factor-α Inhibitor

An efficient synthesis of (1S,4R)-(−)-4-tert-butyldimethylsilyloxy-2-cyclopentenyl acetate and (1R,4S)-(−)-4-tert-butyldimethylsilyloxy-2-cyclopentenol is described utilizing a furfuryl alcohol rearrangement, followed by a lithium aluminum hydride reduction with high facial selectivity and an efficient enzymatic resolution with pancreatin. Both of these intermediates were successfully utilized in the preparation of the carbocyclic nucleoside 9N-[(1‘R,3‘R)-trans-3‘-hydroxycyclopentanyl]adenine hydrochloride, an agent which inhibits the formation of tumor necrosis factor-α.

Hormone replacement therapy reduces the reactivity of monocytes and platelets in whole blood — A beneficial effect on atherogenesis and thrombus formation?

OBJECTIVE: Our purpose was to investigate the effects of hormone replacement therapy on the reactivity of monocytes and platelets in whole blood, measured by tissue factor activity, tumor necrosis factor-α, and thromboxane B 2. STUDY DESIGN: Thirty-two women were randomized into either transdermal or oral combined hormone replacement therapy and underwent blood sampling before and after 3 and 12 months of treatment. The tissue factor activity in monocytes was measured both in unstimulated whole blood and after a weak lipopolysaccharide stimulation. Tumor necrosis factor-α and thromboxane B 2 formation in plasma were measured after a weak lipopolysaccharide stimulation of whole blood. RESULTS: After 12 months of hormone replacement therapy there were significant reductions of tissue factor activity in both unstimulated and lipopolysaccharide-stimulated monocytes ( p < 0.001) and significant reductions in the formation of tumor necrosis factor-α ( p < 0.03) and thromboxane B 2 ( p < 0.02). There were no differences in these parameters between the transdermal and the oral groups. No changes were observed after 3 months of therapy. CONCLUSION: Twelve months of hormone replacement therapy reduces cellular activation of blood monocytes and platelets; these changes may account for some of the beneficial effects in reducing the risk of cardiovascular disease.