Therapeutic potential and strategies for inhibiting tumor necrosis factor-alpha

Asymmetric α-Allylation of Amino Acid Esters with Alkynes Enabled by Chiral Aldehyde/Palladium Combined Catalysis

A highly efficient, atom-economical α-allylation reaction of NH2-unprotected amino acid esters and alkynes is achieved by chiral aldehyde/palladium combined catalysis. A diverse range of α,α-disubstituted nonproteinogenic α-amino acid esters are produced in 31-92% yields and 84-97% ee values. The allylation products are utilized for the synthesis of drug molecule BMS561392 and other chiral molecules possessing complex structures. Mechanistic investigations reveal that this reaction proceeds via a chiral aldehyde-/palladium-mediated triple cascade catalytic cycle.

Dereplication Based Strategy for Rapid Identification and Isolation of a Novel Anti-inflammatory Flavonoid by LCMS/MS from Colebrookea oppositifolia

Colebrookea oppositifolia is a folkloric medicinal plant, well known for its tremendous medicinal properties such as curing epilepsy, ulcers, and urinary problems. The aim of the present study was to apply the dereplication strategy on the ethanol extract of C. oppositifolia with potent anti-inflammatory activity for the rapid identification and isolation of novel bioactive molecules to aid the drug discovery process. An integrated approach using liquid chromatography-mass spectrometry (LCMS) followed by preparative high-performance liquid chromatography (HPLC) was used for the isolation of potent molecules from the anti-inflammatory extract of C. oppositifolia . Purity of the compounds (>98.5%) was established by HPLC, and identification was carried out by NMR and ESI-MS. 5,6,7-Trihydroxyflavone-3-O-glucuronide methyl ester (compound III) isolated from C. oppositifolia was extensively studied for anti-inflammatory potential in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the mice model. Compound III significantly repressed various proinflammatory mediators and upregulated the release of anti-inflammatory cytokine IL-10. Compound III reduced inflammation when studied for parameters such as the phagocytic index, carrageenan-induced paw edema in mice, and effect on organ weight. It reduced inflammation in a dose-dependent manner both in vitro and in vivo. Further molecular insights into the study revealed that compound III blocks the phosphorylation of I kappa b kinase α/β (IKKα/β), IκBα, and nuclear factor kB p65 (NF-κBp65) which is a key controller of inflammation, thereby showing anti-inflammatory potential. Hence, this study permits further investigation to develop compound III as an anti-inflammatory drug.

Effect of Eriodictyol on Collagen-Induced Arthritis in Rats by Akt/HIF-1α Pathway

Purpose

The aim of the experiment was to explore the effect of eriodictyol (ERI) on arthritis.

Methods

We established a rat model of collagen-induced rheumatoid arthritis (CIA) using type II collagen plus Freund’s complete adjuvant. We evaluated the degree of paw swelling, joint pathology, inflammatory cytokine levels, and the Akt/hypoxia-inducible factor (HIF)-1α signaling pathway in the CIA rats.

Results

ERI significantly ameliorated joint swelling; improved joint pathology; and suppressed the release of interleukin-6, interleukin-1 beta, and tumor necrosis factor-alpha. Moreover, ERI inhibited the Akt/HIF-1α pathway in the joints of rats and in lipopolysaccharide-treated RAW264.7 cells.

Conclusion

ERI ameliorated arthritis in a manner involving the Akt/HIF-1α signaling pathway.

Protective effect of betulinic acid on Freund's complete adjuvant-induced arthritis in rats

The purpose of the experiment was to study the effects of betulinic acid (BA) on adjuvant-induced arthritis in rats. The rat model of rheumatoid arthritis (AA) was established by Freund's complete adjuvant. Arthritis index, joint pathology, toe swelling, hemorheology, related cytokines and ROCK/NF-κB signaling pathway were measured in rats. BA can significantly inhibit the arthritis index, improve joint pathology, reduce toe swelling, improve blood rheology, improve synovial cell apoptosis, and restore related cytokine negative regulation of ROCK/NF-κB signaling pathways. BA has an obvious therapeutic effect on joint inflammation of toes in AA model rats, which may be due to the regulation of ROCK/NF-κB signaling pathway.

Effect of umbelliferone on adjuvant-induced arthritis in rats by MAPK/NF-κB pathway

Purpose

Umbelliferone (Umb), a member of coumarin family, is found in many plants and is a promising molecule with potential anti-inflammatory, anti-oxidative, and anti-tumor activities. However, the effect of Umb on arthritis remains unclear.

Methods

A rat model with Freund's complete adjuvant (FCA)-induced arthritis was developed and used to test the efficacy of Umb on arthritis rats. Rats were given an intragastric injection of Umb (20 and 40 mg/kg) once daily from days 21 to 28 after the administration of FCA. Hind paw volume was assessed using a volume meter. The pro-inflammatory cytokine levels and prostaglandin E2 (PEG2) level in serum and synovial fluid were detected by ELISA. HE staining was used to determine representative histological changes in joint tissues, and Western blot analysis was employed to study the effects of Umb on MAPK/NF-κB signaling pathway.

Results

Our results showed that Umb suppressed the release of IL-6, IL-1β, tumor necrosis factor-alpha, and PEG2. In addition, Umb could also dramatically ameliorate the pathological changes observed in rat joints. Based on the results of Western blot, we also observed that Umb could strikingly suppress the expression of MAPK/NF-κB pathway molecules.

Conclusion

These results proved that treatment with Umb is very effective for arthritis and inhibiting the MAPK/NF-κB signaling pathway may be a potential therapeutic target for treatment of arthritis.

Facile synthesis of some pyrazoline-based compounds with promising anti-inflammatory activity

Aim: Search for new anti-inflammatory agents with higher efficacy and lower toxicity is an urgent demand in drug discovery era. Methodology: Different pyrazoline derivatives 4a,b, 5a,b, 6a–h and 7a–f were prepared from the condensation reactions of 1,5-bis(5-methylfuran/thiophen-2-yl)penta-1,4-dien-3-ones 3a,b with different hydrazine derivatives. All compounds were screened for their anti-inflammatory activity using the carrageenan-induced paw edema method in rats and TNF-α inhibition assay. Results: Many compounds revealed promising anti-inflammatory activity relative to indomethacin especially compounds 4a, 5a, 5b, 6b, 6d, 6f and 7b. They were safe to the gastric mucosa and did not cause toxicity up to tenfolds the anti-inflammatory dose, in addition, all compounds inhibited TNF-α with IC50 values of 1.7–100 nM.

WITHDRAWN: Anti-arthritic effect of pilose antler peptide on adjuvant-induced rheumatoid arthritis in rats

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Four new carbazole alkaloids fromMurraya koenigiithat display anti-inflammatory and anti-microbial activities

Four new and 18 known carbazole alkaloids were isolated from CHCl₃ : MeOH crude extracts of the stem and leaves ofMurraya koenigii(Linn.) Spreng, and evaluated for their anti-inflammatory and antimicrobial activity.

Design of selective TACE inhibitors using molecular docking studies: Synthesis and preliminary evaluation of anti-inflammatory and TACE inhibitory activity

Tumor necrosis factor-α (TNF-α) converting enzyme (TACE) has been considered one of the principal therapeutic targets for the treatment of TNF-dependent pathologies. Several TACE inhibitors have been reported, but none of them has been successfully passed to phase II clinical trials. In the present work, we attempted to design highly selective new non-hydroxamate sulfonamide TACE inhibitors. The docking study was performed on one of the crystal structures of TACE, selected based on its resolution and R value, to tackle the flexibility issue of the active site. The results allowed us to distinguish the analogues with a higher binding affinity toward the active site of TACE and to identify the substituent of analogues needed for binding with the surrounding site of the enzyme. Finally the analogues were docked on crystal structures of six different matrix metalloproteinases (MMPs) for a selectivity study of TACE over MMPs. Some of these analogues were synthesized and subjected to preliminary testing for in vivo anti-inflammatory activity and TACE inhibitory activity.

Effects of cichoric acid extract from Echinacea purpurea on collagen-induced arthritis in rats

Cichoric acid extract (CAE) from Echinacea purpurea L. was used to investigate the anti-arthritic effect by using collagen-induced arthritis (CIA) rat model. The hind paw swelling volume and the body weight were measured and recorded. All the drug solutions were administered orally to rats for a total of 28 days. On day 28, the rats were anaesthetized and decapitated. The thymus and spleen were weighed for the determination of the organ index. The concentration of tumor necrosis factor alpha (TNFα), interleukin-1 beta (IL-1β) and prostaglandin E2 (PGE-2) in the serum was measured using commercially available ELISA kits. Total and phosphor-NF-κB and Cox-2 protein expression in synovial tissues were determined by histological slides quantification and western blot analysis. Our data showed that administration of all doses of CAE (8, 16, and 32 mg/kg) significantly decreased the paw swelling, restored body weight gain and decreased the organ index of the thymus and spleen compared with that of the CIA group. CAE (8, 16, and 32 mg/kg) treatment significantly reduced the levels of TNFα, IL-1β and PGE-2 in serum compared with the CIA group. Histopathological analysis demonstrated that CAE has obvious anti-arthritic activity. In addition, CAE (32 mg/kg) significantly decreased the levels of nuclear factor-κB (NF-κB), TNFα and cyclooxygenase 2 (Cox-2) in synovium tissues of the ankle joint compared with the CIA group. Furthermore, CAE administration significantly decreased the protein expression of phosphor-NF-κB and Cox-2 in synovium tissues of the knee joint compared with the CIA group. The results suggest that the anti-inflammatory activity of CAE may account for its anti-arthritic effect, and CAE could be a potential therapeutic drug for the treatment of rheumatoid arthritis (RA).

Molecular Descriptors in Modelling the Tumour Necrosis Factor-α Converting Enzyme Inhibition Activity of Novel Tartrate-Based Analogues

The tumour necrosis factor-α converting enzyme inhibition activity of a series comprising of novel tartrate-based analogues has been quantitatively analysed in terms of molecular descriptors. The statistically validated quantitative structure-activity relationship models provided rationales to explain the inhibition activity of these congeners. The descriptors identified through combinatorial protocol in multiple linear regression analysis have highlighted the role of Moran autocorrelation of lag 7, weighted by atomic van der Waals volume, presence of both prime and nonprime amide carbonyl oxygen in the tartrate moiety and occurrence of five membered ring bearing substituents at varying sites. A few potential novel tartrate-based analogues have been suggested for further investigation.

Synthesis, preliminary structure-activity relationships, and in vitro biological evaluation of 6-aryl-3-amino-thieno[2,3-b]pyridine derivatives as potential anti-inflammatory agents

In our previous study, a series of 6-aryl-3-amino-thieno[2,3-b]pyridine derivatives exhibited potent antiproliferative activities and an unique hepatocellular carcinoma (HCC)-specific anticancer activity was also observed. In further anti-inflammatory research, thienopyridine derivative 1a showed potent inhibition of nitric oxide (NO) production. So a series of thienopyridine analogues of 1a were synthesized and evaluated for anti-inflammatory activities. The structure-activity relationships (SARs) revealed that the most potent analogues 1f and 1o were identified as potent inhibitors of NO production with IC50 values of 3.30 and 3.24 μM, respectively. These results suggest that these 6-aryl-3-amino-thieno[2,3-b]pyridine derivatives might potentially constitute a novel class of anti-inflammatory agents, which require further studies.

Structure-based 3D-QSAR models and dynamics analysis of novel N-benzyl pyridinone as p38α MAP kinase inhibitors for anticytokine activity

A novel series of anticytokine N-benzyl pyridinone derivatives that targets p38α MAP kinase has been analyzed by utilizing a combination of molecular modeling techniques. Statistically significant structure-based 3D-QSAR models were generated for both CoMFA and CoMSIA, and validated through acceptable predictive ability to support both internal and external set of compounds. Structural changes within the protein key backbone residues (Met109 and Gly110), DFG loop position, and side chain movements (Lys53 and Asn114) as resulted by different substituents on these inhibitors were also examined by molecular dynamics simulation. The protocol applied in this study could be helpful to rationalize potent compounds with better inhibitory activity and selectivity profiles against p38α MAP kinase.

Effects of taurochenodeoxycholic acid on adjuvant arthritis in rats

Taurochenodeoxycholic acid (TCDCA) is one of the main bioactive substances of animals' bile acid. In this study, we aimed to investigate the anti-arthritic effects and potential mechanism of TCDCA on adjuvant arthritis (AA) in rats. Freund's complete adjuvant (FCA) was used to induce AA in rats. Paw swelling, index of thymus and spleen and body weight growth rate were measured, and polyarthritis index and radiologic changes were observed. The production of TNF-α, IL-1β, IL-6 and IL-10 was detected by ELISA in serum and synoviocytes. mRNA expression of TNF-α, IL-1β, IL-6 and IL-10 was determined by real-time RT-PCR in synovium tissue and synoviocytes. In both prophylactic and therapeutic treatment, TCDCA significantly suppressed paw swelling and polyarthritis index, increased the loss body weight and index of thymus and spleen, and amended radiologic changes in AA rats. The overproduction and mRNA expression of TNF-α, IL-1β and IL-6 were remarkably suppressed in serum and synovium tissue of all TCDCA-treated rats, however, IL-10 was markedly increased in prophylactic treatment. In a definite concentration ranging from 300 μg/mL to 500 μg/mL, TCDCA showed marked inhibition in the overproduction and mRNA expression of TNF-α, IL-1β and IL-6 in synoviocytes in a concentration-dependent manner, but opposite action on IL-10. In conclusion, treatment with TCDCA confers a good anti-adjuvant arthritis activity in rats, which its reparative effects could be mediated via reduction of the protein and mRNA expression of TNF-α, IL-1β and IL-6, and augment of IL-10 in rats.

Protective effects of IL-4 on Bacillus Calmette-Guerin and lipopolysaccharide induced immunological liver injury in mice

OBJECTIVE

Mice injected with Bacillus Calmette-Guérin (BCG) were challenged with lipopolysaccharide (LPS) to induce inflammatory liver injury. This study was performed to explore the protective effects of interleukin (IL)-4 against liver injury induced by BCG and LPS in mice.

MATERIALS AND METHODS

Mice injected with BCG (125 mg/kg) were challenged with LPS (10 μg/kg) to induce the model of inflammatory liver injury. Half an hour after injection of LPS, mice were subcutaneously administered rmIL-4 at 5 and 0.5 μg/kg, respectively. Liver injury was evaluated by serum transaminase assay and H & E staining. Liver cytokine concentrations were determined by enzyme-linked immunosorbent assay, and intrahepatic cytokine and iNOS mRNA levels by reverse transcriptase polymerase chain reaction. Intrahepatic apoptosis was evaluated by terminal deoxynucleotidyl transferase mediated nick end labeling. NF-κB p65 and ERK signal pathway was detected by Western-blotting. NF-κB signal pathway was also detected by electrophoretic mobility shift assay.

RESULTS

IL-4 reduced the serum ALT, AST and LDH, alleviated the inflammatory cells infiltration, down regulated the expression of TNF-α, IL-1β, IFN-γ, IL-6 and iNOS mRNA in liver, and alleviated hepatic glutathione depletion (GSH). In addition, IL-4 displayed inhibition of extracellular signal-regulated kinase phosphorylation and NF-κB activation.

CONCLUSION

IL-4 may protect mice against BCG/LPS-induced immune liver injury, besides ERK and NF-κB signal pathways were involved in the effects.

Synthesis, preliminary biological evaluation and molecular modeling of some new heterocyclic inhibitors of TACE

Central heteroaryl ring analogues belonging to a series of potent hydroxamate TACE inhibitors were synthesized. The TACE inhibitory activities of these compounds were evaluated by in vitro WBA and in silico molecular modeling studies using crystal structure of human TACE. Compound 14 showed very good in vitro inhibition, supported by the in silico docking studies.

Prostaglandin E(2) binding peptide screened by phage displaying: a new therapeutic strategy in rheumatoid arthritis

Objective

To investigate the therapeutic potential and mechanism of action of the mimotope of PGE₂ receptor EP4 (PBP, named by our team) screened by phage displaying technique in the treatment of adjuvant-induced arthritis (AA).

Methods

Freund's complete adjuvant-induced arthritis was induced in Wistar rats. At the first clinical sign of disease, mice were given with daily injections of PBP or saline for 21 days. Disease progression was monitored by measurement of paw swelling. Inflammation and joint destruction were assessed histologically. The IL-1β and TNF-α were studied by ELISA in the ankle steeps of arthritis model. The degree of proliferation and apoptosis of synoviocytes of RA patients were assessed by CCK-8 kit and AnnexinⅤ-FITC/PI respectively.

Results

PBP-treated animals displayed significantly less cartilage and bone destruction than model controls. Tumor necrosis factor α and IL-1β expression were reduced after PBP treatment. The proliferation and apoptosis of synoviocytes of RA patients were influenced by PBP.

Conclusions

The data support the view that PBP is a potential therapy for RA that may help to diminish both joint inflammation and destruction. And the activities of PBP are related with the effect on synoviocytes directly.

Structure based optimization of chromen-based TNF-α converting enzyme (TACE) inhibitors on S1' pocket and their quantitative structure-activity relationship (QSAR) study

A series of coumarin based TACE inhibitors were designed to bind in S1' pocket of TACE enzyme based on their docking study. Twelve analogues were synthesized and most of compounds were active in vitro TACE enzyme inhibition as well as cellular TNF-α inhibition. Among these, 15l effectively inhibited the production of serum TNF-α by oral administration at a dose of 30 mg/kg. Compound 15l also showed a good oral bioavailability at 42% and effectively inhibited paw edema in rat carrageenan model. Quantitative structure-activity relationship (QSAR) study using genetic function approximation technique (GFA) and docking study were performed to confirm the series of coumarin core TACE inhibitors. QSAR model have been evaluated internally and externally using test set prediction. Through docking study of each molecule, it is validated that the electrostatic descriptors from the QSAR equation could explain the importance of S1' pocket and the TACE inhibitory activity well.

2-(2-Aminothiazol-4-yl)pyrrolidine-based tartrate diamides as potent, selective and orally bioavailable TACE inhibitors

TNF-α converting enzyme (TACE) inhibitors are promising agents to treat inflammatory disorders and cancer. We have investigated novel tartrate diamide TACE inhibitors where the tartrate core binds to zinc in a unique tridentate fashion. Incorporating (R)-2-(2-N-alkylaminothiazol-4-yl)pyrrolidines into the left hand side amide of the tartrate scaffold led to the discovery of potent and selective TACE inhibitors, some of which exhibited good rat oral bioavailability.

Molecular modeling and biological effects of peptidomimetic inhibitors of TACE activity

We investigated the molecular basis of specificity for the interaction between tumor necrosis factor-alpha converting enzyme (TACE) and peptidomimetic inhibitors. Four novel peptidomimetic TACE inhibitors (8a-d) were designed and synthesized by introducing a substituted sulfur group and a hydrophobic group to a novel matrix metalloprotease (MMP) inhibitor. Inhibition was determined by in vitro lipopolysaccharide (LPS) cytotoxicity tests in HL-60 cell lines and by measuring the expression of mTNF-alpha using FCM techniques and immunohistochemistry in vivo. We simulated the interaction of the inhibitors with the 3D structure of the TACE active site in the Brookhaven Protein Database (PDB). The four inhibitors (8a-d) inhibited activity by 9.1%, 54.5%, 27.3%, and 54.5%, respectively. 8b and 8d showed significant in vitro inhibition in cytotoxicity tests, which corresponded to the molecular docking results. 8d also showed inhibitory activity in vivo. We explored the interface between enzyme and substrate by combining bioinformatics with experimental observations to further the development of specific TACE inhibitors to reduce inflammatory responses.

ADAM-17: the enzyme that does it all

This review focuses on the role of ADAM-17 in disease. Since its debut as the tumor necrosis factor converting enzyme (TACE), ADAM-17 has been reported to be an indispensible regulator of almost every cellular event from proliferation to migration. The central role of ADAM-17 in cell regulation is rooted in its diverse array of substrates: cytokines, growth factors, and their receptors as well as adhesion molecules are activated or inactivated by their cleavage with ADAM-17. It is therefore not surprising that ADAM-17 is implicated in numerous human diseases including cancer, heart disease, diabetes, rheumatoid arthritis, kidney fibrosis, Alzheimer's disease, and is a promising target for future treatments. The specific role of ADAM-17 in the pathophysiology of these diseases is very complex and depends on the cellular context. To exploit the therapeutic potential of ADAM-17, it is important to understand how its activity is regulated and how specific organs and cells can be targeted to inactivate or activate the enzyme.

Synthesis and biological evaluation of a novel series of 2,2-bisaminomethylated aurone analogues as anti-inflammatory and antimicrobial agents

This is the first report on aurones as a new class of drugs with anti-inflammatory and antimicrobial agents. A series of 2,2-bisaminomethylated aurone analogues (4a-j) were synthesized by Mannich reaction from 1,3,5-trimethoxybenzene in three steps. The structures of the newly synthesized compounds were confirmed by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were screened against the pro-inflammatory cytokines (TNF-alpha, IL-6) and antimicrobial (antibacterial and antifungal) activity. Compounds 4a, 4b, 4c, 4d, and 4e showed promising results against IL-6 at 10 microM concentration (74-100%). Compounds 4a, 4b and 4c were found to be active against TNF-alpha (76-100%) at 10 microM. Interestingly, all compounds have shown good antimicrobial activity. Compounds 4d, 4e and 4f showed excellent antimicrobial activity as compared with standard drugs.

Novel TACE inhibitors in drug discovery: a review of patented compounds

TNF-alpha converting enzyme (TACE), a pro-inflammatory cytokine, catalyzes the formation of TNF-alpha from membrane bound TNF-alpha precursor protein. TNF-alpha is believed to play pathophysiological roles in inflammation, anorexia, cachexia, septic shock, viral replication and so on. TNF-alpha is a key player in inflammation and joint damage in rheumatoid arthritis. While a variety of TACE inhibitors have been reported in the literature, a vast majority of these compounds are peptidic and peptide-like compounds that are expected to have bioavailability and pharmacokinetic problems, common to such compounds, limiting their clinical effectiveness. Low molecular mass, long acting, orally bioavailable inhibitors of TACE are, therefore, highly desirable for the treatment of potential chronic diseases mentioned above. A review of patented compounds as TACE inhibitors in drug discovery is given. A selection of interesting patents recorded from 2001 to 2009 is presented. Various novel TACE inhibitors developed by different companies have been discussed.

BACE and gamma-secretase characterization and their sorting as therapeutic targets to reduce amyloidogenesis

Secretases are named for enzymes processing amyloid precursor protein (APP), a prototypic type-1 membrane protein. This led directly to discovery of novel Aspartyl proteases (beta-secretases or BACE), a tetramer complex gamma-secretase (gamma-SC) containing presenilins, nicastrin, aph-1 and pen-2, and a new role for metalloprotease(s) of the ADAM family as a alpha-secretases. Recent advances in defining pathways that mediate endosomal-lysosomal-autophagic-exosomal trafficking now provide targets for new drugs to attenuate abnormal production of fibril forming products characteristic of AD. A key to success includes not only characterization of relevant secretases but mechanisms for sorting and transport of key metabolites to abnormal vesicles or sites for assembly of fibrils. New developments we highlight include an important role for an 'early recycling endosome' coated in retromer complex containing lipoprotein receptor LRP-II (SorLA) for switching APP to a non-amyloidogenic pathway for alpha-secretases processing, or to shuttle APP to a 'late endosome compartment' to form Abeta or AICD. LRP11 (SorLA) is of particular importance since it decreases in sporadic AD whose etiology otherwise is unknown.

Inhibition of LPS-induced production of inflammatory factors in the macrophages by mono-carbonyl analogues of curcumin

Curcumin (diferuloylmethane) is an orange-yellow compound from turmeric (Curcuma longa), a spice found in curry powder. Traditionally known for its anti-inflammatory effects, curcumin has established itself in the last two decades to be a potent immunomodulatory agent that can regulate the activation of a variety of immunocytes and the expression of inflammatory factors. Considering that the beta-diketone moiety of curcumin may result in its instability and poor metabolic property, we previously designed a series of mono-carbonyl analogues of curcumin with enhanced stability by deleting this moiety. These compounds demonstrate improved pharmacokinetic profiles both in vitro and in vivo. In this study, we reported a total of 44 mono-carbonyl analogues, which have been evaluated for the inhibitory activities against LPS-induced TNF-alpha and IL-6 release in the macrophages. Based on the screening results of these analogues, five active compounds A01, A03, A13, B18 and C22 were investigated to inhibit TNF-alpha and IL-6 release in a dose-dependent manner, three of which further demonstrated inhibitory effects on LPS-induced TNF-alpha, IL-1beta, IL-6, MCP-1, COX-2, PGES, iNOS and p65 NF-kappaB mRNA production. The results indicated that these mono-carbonyl analogues may possess anti-inflammatory activities similar to curcumin despite the absence of the beta-diketone. These mono-carbonyl analogues may be a favourable alternative for the development of curcumin-based anti-inflammatory drugs both pharmacokinetically and pharmacologically. We further examined the biological properties of A13, the only hydrosoluble analogue when combined with hydrochloric acid. The results showed a dose-dependent inhibition of LPS-induced cytokine production. These data further indicated that compound A13 may be explored as a promising anti-inflammatory molecule.

A ceramide-1-phosphate analogue, PCERA-1, simultaneously suppresses tumour necrosis factor-alpha and induces interleukin-10 production in activated macrophages

Tight regulation of the production of the key pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha) is essential for the prevention of chronic inflammatory diseases. In vivo administration of a synthetic phospholipid, named hereafter phospho-ceramide analogue-1 (PCERA-1), was previously found to suppress lipopolysaccharide (LPS)-induced TNF-alpha blood levels. We therefore investigated the in vitro anti-inflammatory effects of PCERA-1. Here, we show that extracellular PCERA-1 potently suppresses production of the pro-inflammatory cytokine TNF-alpha in RAW264.7 macrophages, and in addition, independently and reciprocally regulates the production of the anti-inflammatory cytokine interleukin-10 (IL-10). Specificity is demonstrated by the inability of the phospholipids ceramide-1-phosphate (C1P), sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) to perform these activities. Similar TNF-alpha suppression and IL-10 induction by PCERA-1 were observed in macrophages when activated by Toll-like receptor 4 (TLR4), TLR2 and TLR7 agonists. Regulation of cytokine production is demonstrated at the mRNA and protein levels. Finally, we show that, while PCERA-1 does not block activation of nuclear factor (NF)-kappaB and mitogen-activated protein kinases by LPS, it elevates the intracellular cAMP level. In conclusion, the anti-inflammatory activity of PCERA-1 seems to be mediated by a cell membrane receptor, upstream of cAMP production, and eventually TNF-alpha suppression and IL-10 induction. Thus, identification of the PCERA-1 receptor may provide new pharmacological means to block inflammation.

Studies on novel 2-imidazolidinones and tetrahydropyrimidin-2(1H)-ones as potential TACE inhibitors: design, synthesis, molecular modeling, and preliminary biological evaluation

Compounds belonging to the class of 2-imidazolidinones and tetrahydropyrimidin-2(1H)-ones were synthesized and evaluated for their TACE inhibitory activity. Most of the compounds showed very good TACE inhibitory activity. Docking study clearly indicates importance of the P1' group of the inhibitor for the TACE inhibitory activity. This work proves that these two classes of molecules could be used as potential leads for the development of TACE inhibitors.

Suppression of complete Freund's adjuvant-induced adjuvant arthritis by cobratoxin

AIM

Cobratoxin (CTX), the long-chain alpha-neurotoxin from Thailand cobra venom, has been demonstrated to have analgesic action in rodent pain models. The present study evaluated the anti-inflammatory and anti-nociceptive effects of CTX on adjuvant arthritis (AA) in rats.

METHODS

Arthritis was induced by injection of complete Freund's adjuvant (CFA) in rats. Paw swelling and hyperalgesia of AA rats were measured at various times after CFA administration. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-2 (IL-2) and interleukin-10 (IL-10) levels in serum were determined with ELISA. Histopathological changes in synoviocytes were examined under a microscope. Involvement of the cholinergic system in the effects of CTX was examined by pretreatment of animals with the alpha(7) nicotinic receptor (alpha(7)-nAChR) antagonist methyllycaconitine (MLA).

RESULTS

CFA induced marked paw swelling and reduced thresholds of mechanical and cold-induced paw withdrawal. The levels of TNF-alpha, IL-1 and IL-2 in the serum of AA rats were increased, whereas the level of IL-10 was decreased. Histopathological examination of synoviocytes showed pronounced inflammation and accumulation of collagen. The administration of CTX (17.0 microg/kg, ip) significantly reduced paw swelling and mechanical and thermal hyperalgesia. CTX also reduced the production of TNF-alpha, IL-1, and IL-2 but increased the production of IL-10 and altered pathohistological changes. The analgesic and anti-inflammatory efficacy of CTX was significantly reduced by MLA (3 mg/kg, sc).

CONCLUSION

These results indicate that CTX has a beneficial effect on CFA-induced arthritis by modulating the production of inflammatory cytokines. alpha(7)-nAChR appears to mediate the anti-nociceptive and anti-inflammatory actions of CTX.