sc-236 and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Polymorphoneutrophils (PMNs) are activated by inflammatory mediators following splanchnic ischemia/reperfusion (I/R), potentially injuring organs such as the lung. As a result, some patients develop respiratory failure following abdominal aortic aneurysm repair. Pulmonary cyclooxygenase (COX)-2 protects against acid aspiration and bacterial instillation via lipoxins, a family of potent anti-inflammatory lipid mediators. We explored the role of COX-2 and lipoxin A(4) in experimental I/R-mediated lung injury.. Sprague-Dawley rats were assigned to one of the following five groups: (1) controls; (2) aortic cross-clamping for 45 min and reperfusion for 4 h (I/R group); (3) I/R and SC236, a selective COX-2 inhibitor; (4) I/R and aspirin; and (5) I/R and iloprost, a prostacyclin (PGI(2)) analogue. Lung injury was assessed by wet/dry ratio, myeloperoxidase (MPO) activity, and bronchoalveolar lavage (BAL) neutrophil counts. BAL levels of thromboxane, PGE(2), 6-keto-PGF(1)α (a hydrolysis product of prostacyclin), lipoxin A(4), and 15-epi-lipoxin A(4) were analyzed by enzyme immunoassay (EIA). Immunostaining for COX-2 was performed.. I/R significantly increased tissue MPO, the wet/dry lung ratio, and neutrophil counts. These measures were significantly further aggravated by SC236 and improved by iloprost. I/R increased COX-2 immunostaining and both PGE(2) and 6-keto-PGF(1α) levels in BAL. SC236 markedly reduced these prostanoids and lipoxin A(4) compared with I/R alone. Iloprost markedly increased lipoxin A(4) levels. The deleterious effect of SC236 and the beneficial effect of iloprost was associated with a reduction and an increase, respectively, in lipoxin A(4) levels.. Lipoxin A(4) warrants further evaluation as a mediator of COX-2 regulated lung protection.

Topics: Animals; Aspirin; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Iloprost; Lipoxins; Lung; Lung Injury; Male; Protective Agents; Pyrazoles; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfonamides

Various kinds of stress are thought to precipitate psychiatric disorders, such as major depression. Whereas studies in rodents have suggested a critical role of medial prefrontal cortex (mPFC) in stress susceptibility, the mechanism of how stress susceptibility is determined through mPFC remains unknown. Here we show a critical role of prostaglandin E(2) (PGE(2)), a bioactive lipid derived from arachidonic acid, in repeated social defeat stress in mice. Repeated social defeat increased the PGE(2) level in the subcortical region of the brain, and mice lacking either COX-1, a prostaglandin synthase, or EP1, a PGE receptor, were impaired in induction of social avoidance by repeated social defeat. Given the reported action of EP1 that augments GABAergic inputs to midbrain dopamine neurons, we analyzed dopaminergic response upon social defeat. Analyses of c-Fos expression of VTA dopamine neurons and dopamine turnover in mPFC showed that mesocortical dopaminergic pathway is activated upon social defeat and attenuated with repetition of social defeat in wild-type mice. EP1 deficiency abolished such repeated stress-induced attenuation of mesocortical dopaminergic pathway. Blockade of dopamine D1-like receptor during social defeat restored social avoidance in EP1-deficient mice, suggesting that disinhibited dopaminergic response during social defeat blocks induction of social avoidance. Furthermore, mPFC dopaminergic lesion by local injection of 6-hydroxydopamine, which mimicked the action of EP1 during repeated stress, facilitated induction of social avoidance upon social defeat. Taken together, our data suggest that PGE(2)-EP1 signaling is critical for susceptibility to repeated social defeat stress in mice through attenuation of mesocortical dopaminergic pathway.

Topics: 3,4-Dihydroxyphenylacetic Acid; Analysis of Variance; Animals; Benzazepines; Calcium-Binding Proteins; Corticosterone; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Disease Susceptibility; Dominance-Subordination; Dopamine; Dopamine Antagonists; Homovanillic Acid; Interpersonal Relations; Maze Learning; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Microfilament Proteins; Neural Pathways; Oxidopamine; Prefrontal Cortex; Pyrazoles; Receptors, Prostaglandin E; Signal Transduction; Stress, Psychological; Sulfonamides; Time Factors; Tyrosine 3-Monooxygenase; Ventral Tegmental Area

The induction of renal cyclooxygenase-2 (COX-2) in diabetes has been implicated in the renal functional and structural changes in models where hypertension or uninephrectomy was superimposed. We examined the protective effects of 3 mo treatment of streptozotocin-diabetic rats with a highly selective COX-2 inhibitor (SC-58236) in terms of albuminuria, renal hypertrophy, and the excretion of TNF-α and TGF-β, which have also been implicated in the detrimental renal effects of diabetes. SC-58236 treatment (3 mg·kg(-1)·day(-1)) of diabetic rats resulted in reduced urinary excretion of PGE(2), 6-ketoPGF(1α), and thromboxane B(2), all of which were increased in the diabetic rat compared with age-matched nondiabetic rats. However, serum thromboxane B(2) levels were unchanged, confirming the selectivity of SC-58236 for COX-2. The renal protective effects of treatment of diabetic rats with the COX-2 inhibitor were reflected by a marked reduction in albuminuria, a reduction in kidney weight-to-body weight ratio, and TGF-β excretion and a marked decrease in the urinary excretion of TNF-α. The protective effects of SC-58236 were independent of changes in plasma glucose levels or serum advanced glycation end-product levels, which were not different from those of untreated diabetic rats. In an additional study, the inhibition of COX-2 with SC-58236 for 4 wk in diabetic rats resulted in creatinine clearance rates not different from those of control rats. These results confirm that the inhibition of COX-2 in the streptozotocin-diabetic rat confers renal protection and suggest that the induction of COX-2 precedes the increases in cytokines, TNF-α, and TGF-β.

Topics: Albuminuria; Animals; Blood Glucose; Body Weight; Cyclooxygenase 2 Inhibitors; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Male; Pyrazoles; Rats; Rats, Wistar; Streptozocin; Sulfonamides; Transforming Growth Factor beta; Treatment Outcome; Tumor Necrosis Factor-alpha

Epileptic seizures drive expression of the blood-brain barrier efflux transporter P-glycoprotein via a glutamate/cyclooxygenase-2 mediated signalling pathway. Targeting this pathway may represent an innovative approach to control P-glycoprotein expression in the epileptic brain and to enhance brain delivery of antiepileptic drugs. Therefore, we tested the effect of specific cyclooxygenase-2 inhibition on P-glycoprotein expression in two different status epilepticus models. Moreover, the impact of a cyclooxygenase-2 inhibitor on expression of the efflux transporter and on brain delivery of an antiepileptic drug was evaluated in rats with recurrent spontaneous seizures. The highly selective cyclooxygenase-2 inhibitors SC-58236 and NS-398 both counteracted the status epilepticus-associated increase in P-glycoprotein expression in the parahippocampal cortex and the ventral hippocampus. In line with our working hypothesis, a sub-chronic 2-week treatment with SC-58236 in the chronic epileptic state kept P-glycoprotein expression at control levels. As described previously, enhanced P-glycoprotein expression in chronic epileptic rats was associated with a significant reduction in the brain penetration of the antiepileptic drug phenytoin. Importantly, the brain delivery of phenytoin was significantly enhanced by sub-chronic cyclooxygenase-2 inhibition in rats with recurrent seizures. In conclusion, the data substantiate targeting of cyclooxygenase-2 in the chronic epileptic brain as a promising strategy to control the expression levels of P-glycoprotein despite recurrent seizure activity. Cyclooxygenase-2 inhibition may therefore help to increase concentrations of antiepileptic drugs at the target sites in the epileptic brain. It needs to be further evaluated whether the approach also enhances efficacy.

Topics: Animals; Anticonvulsants; ATP Binding Cassette Transporter, Subfamily B, Member 1; Blood-Brain Barrier; Brain; Chronic Disease; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Epilepsy; Female; Male; Nitrobenzenes; Phenytoin; Pyrazoles; Rats; Rats, Sprague-Dawley; Rats, Wistar; Seizures; Signal Transduction; Status Epilepticus; Sulfonamides

Status epilepticus (SE) leads to upregulation of pro-inflammatory proteins including cyclooxygenase-2 (cox-2) which could be implicated in the epileptogenic process and epileptic seizures. Recent studies show that cox-2 can regulate expression of P-glycoprotein (P-gp) during epileptogenesis and epilepsy. P-gp could cause pharmacoresistance by reducing brain entry of anti-epileptic drugs such as phenytoin (PHT). Here we have investigated the effects of cox-2 inhibition on epileptogenesis, spontaneous seizures and PHT treatment in a rat model for temporal lobe epilepsy (TLE).. A 3-day treatment with the cox-2 inhibitor SC-58236 (SC) was started 1 day before electrically induced SE. Chronic epileptic rats were treated with SC for 14 days, which was followed by a 7-day period of SC/PHT combination treatment. Seizure activity was monitored continuously using electroencephalography.. SC treatment did not affect SE duration, but led to an increased number of rats that died during the first 2 weeks after SE. Cox-2 inhibition during the chronic period led to an increased number of seizures in the 2nd week of treatment in 50% of the rats. SC/PHT treatment reduced seizures significantly for only 2 days.. Both SC treatment that started before SE and the 14-day treatment in chronic epileptic rats led to adverse effects in the TLE rat model. Despite a temporal reduction in seizure frequency with SC/PHT treatment, SC does not seem to be a suitable approach for anti-epileptogenic or anti-epileptic therapy.

Topics: Animals; Chronic Disease; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Electroencephalography; Epilepsy, Temporal Lobe; Male; Pyrazoles; Rats; Rats, Sprague-Dawley; Sulfonamides

Inflammation is an important biological process that is activated after status epilepticus and could be implicated in the development of epilepsy. Here we tested whether an anti-inflammatory treatment with a selective cox-2 inhibitor (SC58236) could prevent the development of epilepsy or modify seizure activity during the chronic epileptic phase. SC58236 was orally administered (10mg/kg) during the latent period for 7 days, starting 4h after electrically induced SE. Seizures were monitored using EEG/video monitoring until 35 days after SE. Cell death and inflammation were investigated using immunocytochemistry (NeuN and Ox-42). Sprouting was studied using Timm's staining after 1 week and after 4-5 months when rats were chronic epileptic. SC58236 was also administered during 5 days in chronic epileptic rats. Hippocampal EEG seizures were continuously monitored before, during and after treatment. SC58236 effectively reduced PGE(2) production but did not modify seizure development or the extent of cell death or microglia activation in the hippocampus. SC58236 treatment in chronic epileptic rats did not show any significant change in seizure duration or frequency of daily seizures. The fact that cox-2 inhibition, which effectively reduced prostaglandin levels, did not modify epileptogenesis or chronic seizure activity suggests that this type of treatment (starting after SE) will not provide an effective anti-epileptogenic or anti-epileptic therapy.

Topics: Adolescent; Adult; Animals; Brain; CD11b Antigen; Cell Death; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dinoprostone; Disease Models, Animal; Electroencephalography; Electroshock; Epilepsy, Temporal Lobe; Female; Gene Expression Regulation; Hippocampus; Humans; Inflammation; Male; Middle Aged; Phosphopyruvate Hydratase; Pyrazoles; Rats; Rats, Sprague-Dawley; Seizures; Sulfonamides; Time Factors; Young Adult

Periodontal disease is an inflammatory condition of tooth-supporting tissues. Arachidonic acid metabolites have been implicated in development of periodontal disease, especially those derived from the cyclo-oxygenase (COX) pathway. This study investigated the role of inhibitors of cyclo-oxygenases (COX-1 and COX-2) in a model of periodontal disease in rats.. A ligature was placed around the molar of rats. Losses of fiber attachment and of alveolar bone were measured morphometrically in histologically prepared sections. Infiltration of cells into gingival tissue surrounding the ligated tooth was also determined.. Systemic and local administration of non-selective and selective COX-2 inhibitors, preventively, resulted in significant reduction of the losses of fiber attachment and alveolar bone, as well as decreased leukocyte numbers in gingival tissue. Preventive selective inhibition of COX-1 was as effective as COX-2 inhibition in reducing local fiber attachment loss and cell migration, but did not prevent alveolar bone loss.. Our results provide evidence for participation of COX-1 and COX-2 in early stages of periodontal disease in rats. Furthermore, local administration of COX inhibitors reduced the signs of periodontal disease to the same extent as systemic treatment. Therapeutic approaches incorporating locally delivered anti-inflammatory drugs could be of benefit for patients suffering from periodontal disease.

Topics: Alveolar Bone Loss; Animals; Arachidonic Acid; Celecoxib; Cyclooxygenase Inhibitors; Disease Models, Animal; Indomethacin; Male; Periodontal Attachment Loss; Periodontal Ligament; Periodontitis; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Sprague-Dawley; Sulfonamides

To investigate the effect of selective Cycloo-xygenase-2 (COX-2) inhibitor 4-[5-(4-Chloro-phenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide (SC-236), on the cholecystokinin (CCK)-octapeptide-induced acute pancreatitis (AP) in rats.. Wistar rat weighing 240 g to 260 g were divided into three groups. (1) Normal DMSO treated group, (2) SC-236 at 4 mg/kg treated group; SC-236 systemically administered via the intravenous (i.v.) catheter, followed by 75 microg/kg CCK octapeptide subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 d. (3) Dimethyl sulfoxide (DMSO) treated group: an identical protocol was used in this group as in the SC-236 cohort (see 2. above). Repeated CCK octapeptide treatment resulted in a typical experimentally induced pancreatitis in the Wistar rats.. SC-236 improved the severity of CCK-octapeptide-induced AP as measured by laboratory criteria [the pancreatic weight/body weight (p.w/b.w) ratio, the level of serum amylase and lipase]. The SC-236 treated group showed minimal histologic evidence of pancreatitis and a significant reduction in myeloperoxidase activity. SC-236 also increased heat shock protein (HSP)-60 and HSP72 compared with the DMSO-treated group in the CCK-octapeptide-induced AP and also reduced the pancreatic levels of COX-2. Furthermore, SC-236 reduced proinflammatory cytokine synthesis and inhibited NF-kappaB activation compared with the DMSO-treated group in the CCK-octapeptide-induced AP.. Our results suggested that COX-2 plays pivotal role in the development of AP and COX-2 inhibitors may play a beneficial role in preventing AP.

Topics: Acute Disease; Animals; Chaperonin 60; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Gene Expression Regulation; HSP72 Heat-Shock Proteins; Interleukin-1; Interleukin-6; Male; NF-kappa B; Pancreas; Pancreatitis; Pyrazoles; Rats; Rats, Wistar; Sincalide; Sulfonamides; Tumor Necrosis Factor-alpha

SC-236, (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-]benzenesulfonamide; C(16)H(11)ClF(3)N(3)O(2)S) is a highly selective cyclooxygenase (COX)-2 inhibitor. Recently, there have been reports that SC-236 protects against cartilage damage in addition to reducing inflammation and pain for those with osteoarthritis. However, the mechanism involved in an inflammatory allergic reaction in a murine model has not been examined. The aim of the present study is to elucidate whether and how SC-236 modulates the inflammatory allergic reaction in a murine model. In this study, the anti-allergic effect was investigated using rat peritoneal mast cells, IgE-induced passive cutaneous anaphylaxis (PCA), and the ear-swelling model in mice. Also, we examined the inhibitory effect of SC-236 on the expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha. SC-236 was found to inhibit the ear-swelling response and histamine release in the murine model. Additionally, SC-236 was revealed to inhibit the PCA response and COX-2 expression. As a final step, the inhibitory mechanism of SC-236 was shown to occur through phosphorylation of extracellular signal-regulated protein kinase (ERK). These in vitro and in vivo results provide new insight into the pharmacological actions of SC-236 as a potential molecule for therapy for inflammatory allergic diseases.

Topics: Animals; Anti-Inflammatory Agents; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Histamine; Immunoglobulin E; Interleukin-6; Mice; NF-kappa B; Phosphorylation; Pyrazoles; Rats; Sulfonamides; Tumor Necrosis Factor-alpha

Oval cell proliferation precedes neoplasia in many rodent models of hepatocellular carcinoma and prevention of this proliferative response can reduce the risk of subsequent carcinoma. This study aimed to determine whether a selective cyclo-oxygenase-2 (COX-2) inhibitor, SC-236, affects (i) the oval cell response to liver injury in a mouse model of hepatocarcinogenesis and (ii) an oval cell line. Four-week-old mice were fed either normal chow or a choline deficient, ethionine supplemented (CDE) diet in the presence or absence of SC-236. Liver histology and oval cell numbers were determined after 2, 4, 12 and 52 weeks of treatment. Oval cells were scored using morphological criteria and positive immuno-staining for the M(2)-isozyme of pyruvate kinase (M2PK) or A6. An immortalized oval cell line (PIL-2) was used to study the in vitro effects of SC-236 on oval cell proliferation, apoptosis and Akt phosphorylation. The percentage of M2PK-positive oval cells and COX-2-positive cells was reduced by 80% and 45%, respectively, in CDE-fed mice receiving SC-236 compared with CDE-fed animals not receiving SC-236. Some M2PK-positive oval cells were also COX-2 positive. The percentage of A6-positive cells was not affected by SC-236 administration to CDE-fed mice. Administration of SC-236 increased apoptosis as evidenced by a 73% increase in the number of TUNEL-positive cells at 2 weeks in CDE-fed mice. Primary oval cells and PIL-2 cells expressed COX-2. In vitro treatment of PIL-2 cells with SC-236 resulted in a dose-dependent preferential death of A6-negative cells. Administration of 25 and 50 microM Prostaglandin E(2) partially attenuated SC-236 induced cell death by 25%. In vitro oval cell death was associated with apoptosis and a 70% reduction in Akt phosphorylation. These results suggest that the SC-236 induced reduction of M2PK-positive oval cell numbers may be due to COX-2 dependent inhibition of Akt phosphorylation and induction of apoptosis.

Topics: Animals; Antimetabolites; Apoptosis; Cell Proliferation; Choline Deficiency; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Diet; Dietary Supplements; Disease Models, Animal; Ethionine; Liver; Liver Diseases; Mice; Mice, Inbred C57BL; Microfilament Proteins; Phosphorylation; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-akt; Pyrazoles; Pyruvate Kinase; Stem Cells; Sulfonamides

The aim of this study was to determine if cyclooxygenase (COX) inhibitors influence immune cell distribution in the small intestinal mucosa and mesenteric lymph nodes (MLNs), the grade of mucosal damage, and the rate of apoptosis in septic rats. The effects induced by a selective COX-2 inhibitor (SC-236) were compared with those of a nonselective COX-1 and -2 inhibitor (indomethacin). Cecal ligation and puncture (CLP), CLP + SC-236 p.o, and CLP + indomethacin p.o, were evaluated. Animals were harvested 6 and 24 h after CLP, respectively. The concentration of proinflammatory cytokines was higher in ascitic fluid than in blood. CLP + SC-236 attenuated IL-6 in plasma and in ascitic fluid and CLP + indomethacin augmented TNF-alpha in ascitic fluid compared with CLP at 6 h. CLP + SC-236 gave a lesser degree of mucosal damage compared with CLP alone or with indomethacin at 6 and 24 h (P < 0.05). Untreated CLP had significant reductions in the number of T lymphocytes in the villi and increases of macrophages in the mucosa and MLNs compared with controls (P < 0.05). CLP + indomethacin decreased T lymphocytes in the villi and MLNs. CLP caused an enhanced apoptosis in the mucosa compared with controls (P < 0.05), pretreatment with COX inhibitors did not significantly change this. Both COX inhibitors enhanced apoptosis in MLNs and attenuated the increase of macrophages in mucosa and MLNs (P < 0.05). It is proposed that the increased apoptosis and the decrease in T cells in the mucosa may be causally related. Apoptosis of lymphocytes may impair the immunologic defense in sepsis. Furthermore, loss of intestinal epithelial cells may compromise bowel wall integrity and facilitate translocation.

Topics: Animals; Apoptosis; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Disease Models, Animal; Immunity, Mucosal; Indomethacin; Interleukin-6; Intestinal Mucosa; Intestine, Small; Male; Membrane Proteins; Mesentery; Pyrazoles; Rats; Rats, Wistar; Sepsis; Sulfonamides; T-Lymphocytes; Time Factors; Tumor Necrosis Factor-alpha

The impact of chronic joint inflammation on articular vascular function in rats was investigated to address whether joint swelling and the associated vascular dysfunction are dependent upon a common prostanoid mechanism. Urinary nitrate/nitrite (NO(x)) and PGE(2) excretion, knee joint diameter and body weight were measured following induction of adjuvant-induced arthritis (AIA). Ten days postinduction of AIA, joint vascular reactivity was assessed by measuring the perfusion response using a laser Doppler imager (LDI) to topical application of acetylcholine (ACh) and sodium nitroprusside (SNP). Four groups were compared: a non-inflamed control group and three AIA groups treated i.p. with vehicle, indomethacin or SC-236 (at equimolar doses). The selective cyclooxygenase-2 (COX-2) inhibitor (SC-236) was used to differentiate between COX-1 and -2-derived prostaglandins. Urinary NO(x) and PGE(2) levels increased substantially during the early phase of AIA but decreased thereafter. Toxicity to indomethacin but not SC-236 was observed, as indicated by a marked decrease in body weight. Joint swelling was similarly attenuated by indomethacin and SC-236 (P= 0.0001 cf. vehicle-treated AIA; n= 5-6 per group), indicating that this is due to COX-2 and not COX-1 inhibition. The AIA-induced changes in urinary NO(x) and PGE(2) were corrected by both COX inhibitors. While vascular reactivity to ACh and SNP was significantly attenuated by AIA (P < 0.002; n= 5-10 per group), the perfusion responses to these vasodilating agents were similar in all three AIA groups, demonstrating that the vascular dysfunction was not corrected by inhibition of either COX-1 or COX-2 enzymes. Furthermore, the attenuation of both ACh and SNP-induced responses in AIA suggest that vascular dysfunction was not exclusively endothelial in nature. In conclusion, the joint swelling and vascular dysfunction associated with AIA appear to be mediated, at least in part, by independent mechanisms. While COX-1/COX-2 inhibition reduced joint swelling, vascular dysfunction in AIA is independent of constitutive or inducible prostanoid mechanisms, and appears not to be solely endothelial-derived, but to involve other components such as the vascular smooth muscle.

Topics: Acetylcholine; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Body Weight; Chronic Disease; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Indomethacin; Isoenzymes; Knee Joint; Laser-Doppler Flowmetry; Male; Membrane Proteins; Nitrates; Nitric Oxide; Nitrites; Nitroprusside; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Sulfonamides; Vascular Resistance

Fractionation of an ethyl acetate-soluble extract of the bark of Artocarpus dadah has led to the isolation of three new prenylated stilbenoid derivatives, 3-(gamma,gamma-dimethylallyl)resveratrol (1), 5-(gamma,gamma-dimethylallyl)oxyresveratrol (2), 3-(2,3-dihydroxy-3-methylbutyl)resveratrol (3), and a new benzofuran derivative, 3-(gamma,gamma-dimethylpropenyl)moracin M (4), along with six known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, (-)-epiafzelechin, dihydromorin, and epiafzelechin-(4beta-->8)-epicatechin. From an ethyl acetate-soluble extract of the twigs of the same plant were isolated compound 4 and two new neolignan derivatives, dadahols A (5) and B (6), as well as 10 known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, resveratrol, steppogenin, moracin M, isogemichalcone B, gemichalcone B, norartocarpetin, and engeletin. The structures of compounds 1-6 were determined using spectroscopic and chemical methods. Isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 (COX-1) and -2 (COX-2) and in a mouse mammary organ culture assay.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Acetylation; Animals; Benzofurans; Breast; Catechin; Cell Transformation, Neoplastic; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Indonesia; Isoenzymes; Membrane Proteins; Methylation; Mice; Mice, Inbred BALB C; Molecular Structure; Moraceae; Nuclear Magnetic Resonance, Biomolecular; Organ Culture Techniques; Plant Bark; Plant Extracts; Plant Shoots; Plants, Medicinal; Prostaglandin-Endoperoxide Synthases; Spectroscopy, Fourier Transform Infrared; Stereoisomerism; Stilbenes

We previously reported that renal cortical cyclooxygenase (COX-2) expression increased following subtotal nephrectomy, and chronic treatment with a selective COX-2 inhibitor, SC58236, reduced proteinuria and retarded the development of glomerulosclerosis. The present studies were designed to examine the effects of COX-2 inhibition in a model of diabetic nephropathy.. Rats were divided into three groups: control, diabetic (streptozotocin-induced diabetic animals with superimposed DOCA/salt hypertension; right nephrectomy and DOCA treatment), and treated (administration of the selective COX-2 inhibitor, SC58236, to a subset of diabetic/DOCA/salt rats). Insulin was administered to maintain blood glucose in the 200 to 300 mg/dL range.. Systolic blood pressure in the two diabetic groups was elevated within one week and remained elevated until sacrifice at six weeks (control, 108 +/- 2 mm Hg; diabetic, 158 +/- 4 mm Hg; treated, 156 +/- 7 mm Hg). When measured at six weeks, immunoreactive COX-2 expression in the renal cortex of the diabetic rats was 2.5 +/- 0.3-fold of control animals (N = 7). Immunohistochemical localization indicated increased expression in macula densa and surrounding cortical thick ascending limb of Henle (cTALH). The COX-2 inhibitor decreased COX-2 expression in diabetic rats to 1.3 +/- 0.1-fold control. In addition, SC58236 decreased expression of PAI-1 (diabetic vs. treated, 3.2 +/- 0.5 vs. 1.7 +/- 0.2-fold control, N = 7, P < 0.05), vascular endothelial growth factor (VEGF; 2.0 +/- 0.2 vs. 1.2 +/- 0.2; N = 7, P < 0.05), fibronectin (2.4 +/- 0.3 to 1.3 +/- 0.1; N = 7, P < 0.05) and transforming growth factor-beta (TGF-beta; 2.1 +/- 0.2 vs. 1.3 +/- 0.2; N = 7, P < 0.05). Proteinuria at six weeks was decreased in the SC58236-treated rats (149 +/- 8 vs. 92 +/- 8 mg/24 h; N = 7, P < 0.01). The mesangial sclerosis index, defined as increases in extracellular matrix within the mesangial space, was determined at six weeks; the control group had an index of 0.06 +/- 0.01, the diabetic group was 2.7 +/- 0.04 and the treated group was 0.6 +/- 0.03 (P < 0.0001 compared to the diabetic group).. These results suggest that in an experimental model of diabetes and hypertension, inhibition of COX-2 expression decreases potential mediators of glomerular and tubulointerstitial injury and also decreases biochemical, functional and structural markers of renal injury.

Topics: Animals; Blood Glucose; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Diabetic Nephropathies; Disease Models, Animal; Hypertension, Renal; Isoenzymes; Kidney Cortex; Male; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Sprague-Dawley; Sulfonamides

Cyclooxygenase-2 (COX-2), the inducible isoform of COX, has been identified as the key enzyme to regulate prostaglandin E2 synthesis in inflammatory conditions. Although it has been reported that COX-2 is present in herniated disc samples obtained from patients, little is known concerning the relationships between COX-2 and painful radiculopathy. The purpose of this study was to evaluate whether epidural injection of COX-2 inhibitor abolishes hyperalgesia induced by nucleus pulposus, which is a pain-related behavior in the rat. Rats, in which nucleus pulposus was relocated on the nerve root, exhibited evidence of mechanical hyperalgesia. Epidural injection of COX-2 inhibitor resulted in decrease in mechanical hyperalgesia 1 h, 3 and 7 days after the epidural injection of COX-2 inhibitor (0.1 mg/kg SC-'236 dissolved in the vehicle). There were no significant differences in sensitivity to thermal noxious stimuli after either application of the nucleus pulposus or epidural injections. These results suggest that prostaglandins and thromboxane, which are produced by COX-2 in inflammatory cells, appear to be related to the inflammatory process produced by application of nucleus pulposus to the nerve root. It is possible that COX-2 plays a significant role in painful radiculopathy following herniated nucleus pulposus.

Topics: Animals; Behavior, Animal; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Hindlimb; Hot Temperature; Hyperalgesia; Injections, Epidural; Intervertebral Disc; Intervertebral Disc Displacement; Isoenzymes; Lumbar Vertebrae; Male; Motor Activity; Pain Measurement; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Radiculopathy; Rats; Rats, Sprague-Dawley; Reaction Time; Spinal Nerve Roots; Sulfonamides; Transplantation, Homologous

Focal ischemia was induced in the fronto-parietal region of rat brain, by injection of Rose Bengal, followed by light activation. Focal ischemia was accompanied by formation of PGD(2) peaking 60-90 min post irradiation and declining thereafter. Increased Cycloxygenase-2 (COX-2) expression was also observed. Control ischemic rats showed distinct morphological alterations with necrosis of neurons, glial cells and blood vessels, surrounded by a halo with pyknotic cells with cytoplasm swelling and vacuolization. Compound SC58236, a selective COX-2 inhibitor, dose-dependently prevented, ischemia-induced eicosanoid formation (area under the curve (AUC) of controls: 3.11 +/- 0.87; AUC of 20 mg/kg SC58236: 0.39 +/- 0.24), and caused significant reduction of damaged area (30.7 and 18.9% at SC58236 20 and 6.6 mg/kg), suggesting that selective inhibitors of COX-2 are neuroprotective.

Topics: Animals; Brain Ischemia; Cerebral Cortex; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Fluorescent Dyes; Isoenzymes; Male; Microdialysis; Microscopy, Electron; Necrosis; Nerve Degeneration; Neurons; Neuroprotective Agents; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Rose Bengal; Sulfonamides

Cyclooxygenase-2 (COX-2), an enzyme that is induced in the central nervous system after various insults, has been localized to neurons and in cells associated with the cerebral vasculature, where it may be involved in the inflammatory component of the ischemic cascade. COX-2 is part of the initial reaction that involves the arachidonic acid cascade, which produces molecules that support an inflammatory response. The present study evaluated the pharmacological effects of a specific long-acting COX-2 inhibitor, SC-236, in a reversible rabbit spinal cord ischemia model using clinical rating scores (behavioral analysis) as the primary end point.. SC-236 was administered (10 to 100 mg/kg SC) 5 minutes after the start of occlusion to groups of rabbits exposed to ischemia induced by temporary (10 to 40 minutes) occlusion of the infrarenal aorta. Behavioral analysis, which allowed for the calculation of an ET(50) value representing the duration of ischemia (minutes) associated with a 50% probability of resultant permanent paraplegia, was conducted 18 and 48 hours later. A drug was determined to be neuroprotective if it prolonged the ET(50) significantly compared with the appropriate control group.. Since SC-236 is not readily soluble in aqueous solutions, it was dissolved in 100% dimethyl sulfoxide (DMSO) for subcutaneous administration. Therefore, the vehicle-treated control group consisted of rabbits given an equal volume of DMSO without drug. In the DMSO-treated control group, the ET(50) assessed 18 hours after initiation of aortal occlusion was 18.84+/-3.19 minutes. In contrast, treatment with 100 mg/kg of SC-236 given 5 minutes after the start of occlusion prolonged the ET(50) of the group significantly to 30.04+/-3.55, an effect that was still evident 48 hours later. In addition, lower doses of the drug (10 and 50 mg/kg) also showed a trend for an increase in ET(50). SC-236 (100 mg/kg) did not significantly alter body temperature after a subcutaneous injection.. The present study suggests that COX-2 plays an important role in the ischemic cascade of events that translate into ischemia-induced behavioral deficits and furthermore that selective COX-2 inhibitors may be useful in the treatment of ischemic stroke to improve behavioral functions.

Topics: Animals; Aorta; Behavior, Animal; Body Temperature; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Isoenzymes; Male; Motor Activity; Neurons; Neuroprotective Agents; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rabbits; Spinal Cord; Spinal Cord Ischemia; Sulfonamides; Treatment Outcome

Both in experimental colitis and in inflammatory bowel disease, colonic eicosanoid generation is enhanced and may contribute to the pathogenesis of the inflammatory response.. To evaluate the effect of selective cyclo-oxygenase-2 (COX-2) inhibitors on the extent and severity of two models of experimental colitis.. Colitis was induced by intra-caecal administration of 2 ml 5% acetic acid or intra-colonic administration of 0.1 ml 3% iodoacetamide. Rats were treated intra-gastrically with nimesulide 2 x 10 mg/kg/day, or once with SC-236 6 mg/kg, and killed 1 or 3 days after damage induction. The colon was isolated, weighed, macroscopic damage was measured, and mucosal samples were obtained for histology and for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and eicosanoid generation. The serum levels of thromboxane B2 (TXB2), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were determined.. Nimesulide significantly decreased the extent of colitis induced by acetic acid. Both nimesulide and SC-236 significantly decreased the extent of iodoacetamide-induced colonic damage. The decrease in the extent of colitis induced by nimesulide was accompanied by a significant decrease in mucosal MPO and NOS activities. Nimesulide and SC-236 decreased the enhanced colonic eicosanoid generation in acetic acid and iodoacetamide-induced colitis, and, in iodoacetamide-treated rats, nimesulide also decreased the elevated serum TNF-alpha and IL-1beta levels.. The effective nimesulide and SC-236-induced amelioration of the severity of the colitis in acetic acid and iodoacetamide-treated rats confirms the role of eicosanoids in their pathogenesis and suggests that COX-2 inhibitors may be of value in the treatment of inflammatory bowel disease.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Colitis; Cyclooxygenase Inhibitors; Disease Models, Animal; Eicosanoids; Indomethacin; Inflammation; Interleukin-1; Male; Nitric Oxide Synthase; Peroxidase; Pyrazoles; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Sulfonamides; Tumor Necrosis Factor-alpha

Prostaglandins (PGs) have proven important during parturition, but inhibition of PG production treating preterm labor (PTL) results in significant maternal and fetal side effects. We hypothesize that specific inhibition of either cyclooxygenase (COX)-1 or -2 may result in separation of therapeutic and toxic effects. We demonstrate that COX-2, but not COX-1, is induced during inflammation-mediated PTL caused by lipopolysaccharide (LPS) administration. A two- to threefold increase in uterine and ovarian PG concentrations coincides with this induction of COX-2. The COX-2-selective inhibitor SC-236 proved effective in stopping preterm delivery and the increases in PGs. The COX-1-selective inhibitor SC-560 also attenuated uterine and ovarian PG production after LPS but did not inhibit PTL as efficiently as SC-236. COX-1-deficient mice, which show delay in the onset of term labor, exhibited no delay in onset of PTL after LPS. These findings suggest that the mechanisms for initiation of inflammation-mediated PTL and term labor differ and that selective COX-2 inhibition may provide a means of stopping inflammation-induced PTL in humans.

Topics: Animals; Blotting, Northern; Calcium; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Female; Gene Expression Regulation, Enzymologic; Indomethacin; Ionophores; Isoenzymes; Labor, Obstetric; Lipopolysaccharides; Membrane Proteins; Mice; Mice, Inbred C3H; Mice, Knockout; Obstetric Labor, Premature; Ovary; Peritonitis; Pregnancy; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Pyrazoles; RNA, Messenger; Sulfonamides; Uterus

The pathogenesis of motor neuron loss in amyotrophic lateral sclerosis (ALS) is thought to involve both glutamate-mediated excitotoxicity and oxidative damage due to the accumulation of free radicals and other toxic molecules. Cyclooxygenase-2 (COX-2) may play a key role in these processes by producing prostaglandins, which trigger astrocytic glutamate release, and by inducing free radical formation. We tested the effects of COX-2 inhibition in an organotypic spinal cord culture model of ALS. The COX-2 inhibitor (SC236) provided significant protection against loss of spinal motor neurons in this system, suggesting that it may be useful in the treatment of ALS.

Topics: Amyotrophic Lateral Sclerosis; Animals; Cyclooxygenase 2; Disease Models, Animal; Isoenzymes; Motor Neurons; Organ Culture Techniques; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Spinal Cord; Sulfonamides

Low back pain is a common problem, affecting approximately two-thirds of the adult population. Of these individuals, a significant percentage will exhibit symptoms of radicular pain or sciatica. The purpose of this study was to determine the effect of one systemic (2 mg/kg) or intrathecal (0.2 mg/kg) dose of a selective cyclooxygenase-2 inhibitor (SC-236) in decreasing existing mechanical allodynia in a rat model of radiculopathy. Gait disturbance and mechanical allodynia (increased response to non-noxious von Frey monofilament stimuli) were assessed daily until the rats were killed 7 days after surgery. Robust mechanical allodynia developed in the rats in all groups except for those in the sham group by day 1 after surgery. Mechanical allodynia was significantly lower in the rats that received the systemic or the intrathecal dose of SC-236 than in those in the vehicle control group (analysis of variance followed by Bonferroni multiple comparison test, p = 0.002). The intrathecal drug route of administration produced greater attenuation in allodynia than the systemic dose, supporting a central mechanism of action of the cyclooxygenase-2 inhibitor (p = 0.002). The hypothesis that cyclooxygenase-2 is involved in spinal nociceptive processing after a nerve root injury was supported by this study. In addition, these data support continued basic science research to further elucidate central inflammatory processes that follow nerve root injury.

Topics: Animals; Cyclooxygenase Inhibitors; Denervation; Disease Models, Animal; Hyperalgesia; Low Back Pain; Male; Mechanoreceptors; Pain Threshold; Physical Stimulation; Pyrazoles; Radiculopathy; Rats; Rats, Sprague-Dawley; Spinal Nerve Roots; Sulfonamides