Search results for "Prostaglandin-Endoperoxide Synthases"
showing 10 items of 60 documents
Potential role of heme oxygenase-1 in the progression of rat adjuvant arthritis
2004
Rat adjuvant arthritis is an experimental model widely used to evaluate etiopathogenetic mechanisms in chronic inflammation. We have examined the participation of heme oxygenase-1 (HO-1) in this experimental arthritis. In this study, an increased nitric oxide (NO) production in the paw preceded the upregulation of HO-1, whereas selective inhibition of inducible NO synthase (iNOS) after the onset of arthritis decreased HO-1 expression, suggesting that the induction of this enzyme may depend on NO produced by iNOS. Therapeutic administration of the HO-1 inhibitor tin protoporphyrin IX was able to control the symptoms of arthritis. This agent significantly decreased leukocyte infiltration, hyp…
Prostaglandin E2 receptors and COX enxymes in human hepatocellular carcinoma: role in the regulation of cell growth
2008
The aim of this study was to investigate the expression of prostaglandin E 2 receptors (EP 1-4 ), cyclooxygenase-1 (COX-1), and COX-2 in nontumor and tumor human liver tissues, and also to evaluate the antitumor activity of selective EP 1 receptor antagonist used alone or in combination with COX-1 and COX-2 selective inhibitors. Semiquantitative PCR analyses revealed that EP 1-4 , COX-1, and COX-2 mRNA expression was detected in nearly all the tissue samples assayed, although with a high variability between nontumor and tumor tissues. In vitro EP 1 receptor antagonist inhibited anchorage-independent cell growth and reduced the viability of hepatocellular carcinoma (HCC) cells in a dose-depe…
Contribution of endothelin receptors and cyclooxygenase-derivatives to the altered response of the rabbit renal artery to endothelin-1 in diabetes
2006
Abstract The influence of diabetes on regulatory mechanisms and specific receptors implicated in the response of isolated rabbit renal artery to endothelin-1 was examined. Endothelin-1 induced a concentration-dependent contraction that was less potent in arteries from diabetic rabbits than in arteries from control rabbits. Endothelium removal or NG-nitro- l -arginine (L-NOARG) enhanced contractions to endothelin-1 either in control and diabetic arteries. Indomethacin inhibited endothelin-1-induced response in control arteries, but enhanced it in diabetic arteries. In contrast to that observed in rubbed and in L-NOARG treated arteries, in the presence of indomethacin the contractile action o…
The effect of postsurgical administration of a selective cyclo-oxygenase-2 inhibitor on the healing of intrabony defects following treatment with ena…
2003
Regenerative treatment with enamel matrix proteins (EMD) has been shown to promote regeneration in intrabony periodontal defects. However, up to now various postoperative regimens such as the routine administration of nonsteroidal anti-inflammatory drugs (NSAIDs) were often used in combination with enamel matrix proteins. Therefore, it cannot be excluded that the results might have been influenced by the effect of the postoperative medication. The aim of this randomized, controlled, blinded, clinical investigation was to determine the effect of postsurgical administration of a selective cyclo-oxygenase-2 inhibitor on the healing of intrabony periodontal defects following regenerative period…
Protection against 2,4,6-trinitrobenzenesulphonic acid-induced colonic inflammation in mice by the marine products bolinaquinone and petrosaspongioli…
2005
Proinflammatory mediators, namely eicosanoids, reactive oxygen and nitrogen species and cytokines, are clearly involved in the pathogenesis of intestinal bowel disease. bolinaquinone (BQ) and petrosaspongiolide M (PT), two marine products with potent anti-inflammatory action, have been shown to control the production of mediators in acute and chronic inflammatory processes. Hence, we have tested here the hypothesis that BQ and PT could ameliorate inflammation and oxidative stress parameters in 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis in Balb/c mice. BQ and PT were given orally in doses of 10 or 20mg/kg/day. Treatment of the animals with BQ or PT at the highest dose signifi…
Toll-like receptor 2 mediates prostaglandin E2 production in murine peritoneal macrophages and splenocytes in response to Candida albicans
2004
The involvement of Toll-like receptor 2 (TLR2) and TLR4 in triggering signal transduction pathways leading to prostaglandin E(2) (PGE(2)) production in response to Candida albicans has been studied in cells from wild-type, TLR2-/- and TLR4-/- knockout mice. In vitro PGE(2) production by macrophages challenged with zymosan, yeast or hypha cells was strongly inhibited in TLR2-deficient cells, but not in TLR4-/- cells, as compared to macrophages from wild-type mice. PGE(2) production was dependent on de novo cyclooxygenase-2 (Cox2) synthesis, since unchallenged cells failed to produce PGE(2) and specific Cox2 inhibition during challenge totally blocked PGE(2) production. Similar results were o…
Influence of heme oxygenase 1 modulation on the progression of murine collagen-induced arthritis.
2005
Contains fulltext : 48023.pdf (Publisher’s version ) (Closed access) OBJECTIVE: Heme oxygenase 1 (HO-1) can be induced by inflammatory mediators as an adaptive response. The objective of the present study was to determine the consequences of HO-1 modulation in the murine collagen-induced arthritis (CIA) model. METHODS: DBA/1J mice were treated with an inhibitor of HO-1, tin protoporphyrin IX (SnPP), or with an inducer of HO-1, cobalt protoporphyrin IX (CoPP), from day 22 to day 29 after CIA induction. The clinical evolution of disease was monitored visually. At the end of the experiment, joints were examined for histopathologic changes. Cytokine levels in paws were measured by enzyme-linked…
Cycloamphilectenes, a new type of potent marine diterpenes: inhibition of nitric oxide production in murine macrophages.
2003
The inhibitory effect of a series of 6 cycloamphilectenes, novel marine diterpenes based on amphilectene skeletons and isolated from the Vanuatu sponge Axinella sp., on NO, PGE(2) and TNFalpha production in murine peritoneal macrophages was studied. These compounds reduced potently nitric oxide production in a concentration-dependent manner with IC(50) values in the submicromolar range (0.1-4.3 microM). Studies on intact cells and Western blot analysis showed that the more potent cycloamphilectenes reduced the expression of inducible nitric oxide synthase without affecting cyclo-oxygenase-2 expression. Among them cycloamphilectene 2, the unique compound bearing an exocyclic methylene group,…
Inhibition of 5-lipoxygenase activity by the natural anti-inflammatory compound aethiopinone
2001
Objetive and Design: We have investigated the mechanisms of action of aethiopinone, an anti-inflammatory compound from Salvia aethiopis L. roots.¶Material and Subjects: Human neutrophils from healthy volunteers and murine peritoneal macrophages. Swiss mice were randomly divided into groups of six animals.¶Treatment: Test compounds were applied topically in the mouse ear oedema test. In the air pouch, mice received aethiopinone (0.001-0.5 μmol/pouch or 12.5-50 mg/kg p.o.).¶Methods: LTB4 production was assayed in human neutrophils and COX-2 and iNOS activities in murine macrophages. Air pouches were induced subcutaneously in mice and injected with zymosan on the day six. Mouse ear oedema was …
Dysidotronic acid, a new sesquiterpenoid, inhibits cytokine production and the expression of nitric oxide synthase.
2001
In a previous study, we reported a new bioactive sesquiterpenoid, named dysidotronic acid, to be a potent, selective human synovial phospholipase A(2) inhibitor. Dysidotronic acid is a novel, non-complex manoalide analogue lacking the pyranofuranone ring. We now investigate the effect of this compound on cytokine, nitric oxide and prostanoid generation on the mouse macrophage cell line RAW 264.7, where it showed a dose-dependent inhibition with inhibitory concentration 50% values in the micromolar range. This effect was also confirmed in the mouse air pouch injected with zymosan. Dysidotronic acid inhibited the production of tumor necrosis factor alpha and interleukin-1 beta as well as the …