Pharmacological and biochemical demonstration of the role of cyclooxygenase 2 in inflammation and pain

Antiinflammatory and neuroprotective actions of COX2 inhibitors in the injured brain

Overexpression of COX2 appears to be both a marker and an effector of neural damage after a variety of acquired brain injuries, and in natural or pathological aging of the brain. COX2 inhibitors may be neuroprotective in the brain by reducing prostanoid and free radical synthesis, or by directing arachidonic acid down alternate metabolic pathways. The arachidonic acid shunting hypothesis proposes that COX2 inhibitors' neuroprotective effects may be mediated by increased formation of potentially beneficial eicosanoids. Under conditions where COX2 activity is inhibited, arachidonic acid accumulates or is converted to eicosanoids via lipoxygenases and cytochrome P450 (CYP) epoxygenases. Several P450 eicosanoids have been demonstrated to have beneficial effects in the brain and/or periphery. We suspect that arachidonic acid shunting may be as important to functional recovery after brain injuries as altered prostanoid formation per se. Thus, COX2 inhibition and arachidonic acid shunting have therapeutic implications beyond the suppression of prostaglandin synthesis and free radical formation.

Methanol extract of Biophytum sensitivum alters the cytokine profile and inhibits iNOS and COX-2 expression in LPS/Con A stimulated macrophages

Biophytum sensitivum has been used in traditional folk medicine to treat numerous diseases. The molecular mechanism of B. sensitivum pharmacological and biochemical actions of macrophages in inflammation has not been clearly elucidated. We examined how the methanol extract of B. sensitivum regulates the production of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-6, and nitric oxide (NO) in vitro and in vivo. The extract inhibits the production of NO and proinflammatory cytokines in lipopolysaccharide (LPS) or Concanavalin (Con) A-stimulated primary macrophages. In vitro L929 bioassay revealed the inhibition of TNF-alpha production by B. sensitivum treatment. Moreover, the extract could suppress the inducible nitric oxide synthase and cyclo-oxygenase-2 mRNA expression in LPS or Con A-stimulated macrophages. These findings provide evidence that B. sensitivum possesses potential anti-inflammatory activity and may be beneficial for the treatment of endotoxin shock or sepsis.

Comparison of the effects of firocoxib, carprofen and vedaprofen in a sodium urate crystal induced synovitis model of arthritis in dogs

A randomized, placebo-controlled, four-period cross-over laboratory study involving eight dogs was conducted to confirm the effective analgesic dose of firocoxib, a selective COX-2 inhibitor, in a synovitis model of arthritis. Firocoxib was compared to vedaprofen and carprofen, and the effect, defined as a change in weight bearing measured via peak ground reaction, was evaluated at treatment dose levels. A lameness score on a five point scale was also assigned to the affected limb. Peak vertical ground reaction force was considered to be the most relevant measurement in this study. The firocoxib treatment group performed significantly better than placebo at the 3 h post-treatment time point and significantly better than placebo and carprofen at the 7 h post-treatment time point. Improvement in lameness score was also significantly better in the dogs treated with firocoxib than placebo and carprofen at both the 3 and 7 h post-treatment time points.

In vivo cancer biomarkers of esophageal neoplasia

The emergence of in vivo cancer biomarkers is promising tool for early detection, risk stratification, and therapeutic intervention in the esophagus, where adenocarcinoma is increasing at a rate that is faster than any other in industrialized nations. Exciting advances in target identification, probe development, and optical instrumentation are creating tremendous new opportunities for advancing techniques of molecular imaging. Progress in these areas is being made with small animal models of esophageal cancer using surgical approaches to induce reflux of acid and bile, and these findings are beginning to be evaluated in the clinic. Further identification of relevant targets, characterization of specific probes, and development of endoscopic imaging technologies are needed to further this direction in the field of molecular medicine. In the future, new methods that use in vivo cancer biomarkers for the early detection of neoplastic changes in the setting of Barrett's esophagus will become available.

Nutritionally essential fatty acids and biologically indispensable cyclooxygenases

The study of cyclooxygenases (COXs), targets of aspirin and related drugs, is rooted in the discovery of essential fatty acids (EFAs). There are two COXs that convert EFAs, primarily arachidonic acid, to prostaglandins. Each COX is involved with distinct biologies. COX-1 expression is constitutive while COX-2 is inducible. The two COXs might have evolved partly to permit prostaglandin formation at different tissue sites. However, COX-2 is sometimes induced in cells already expressing COX-1, and in these instances, COX-2 functions while COX-1 is latent. This can occur because of unique biochemical properties of COX-2 that enable cells to form prostaglandins when arachidonic acid comprises a small fraction of available fatty acids and the concentrations of peroxides that are necessary for COX to function are low.

Rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor increases pentylenetetrazol seizure threshold in mice: possible involvement of adenosinergic mechanism

Multiple lines of investigations have explored the role of cyclooxygenases (COX) in epilepsy and related neuropsychiatric disorders. Cyclooxygenase particularly, COX-2 expression was found to increase in brain during seizure paradigms. The present study was carried out to investigate the effect of rofecoxib, a selective COX-2 inhibitor against pentylenetetrazol (PTZ i.v.) seizure threshold in mice. The study was further extended to elucidate the possible involvement of adenosinergic mechanism in mediating its anticonvulsant action. Minimal dose of PTZ (i.v., mg/kg) needed to induce different phases (myoclonic jerks, generalized clonus and tonic extension) of PTZ convulsions were noted as an index of seizure threshold. Acute administration of rofecoxib (4mg/kg, i.p.) before PTZ infusion produced an elevation of seizure threshold for all the phases of convulsions. A lower dose of rofecoxib (2mg/kg, i.p.) showed an increase in PTZ seizure threshold for the onset of myoclonic jerks and tonic extension phases but not for generalized clonus. A still lower dose of rofecoxib (1mg/kg, i.p.) failed to increase the threshold in any of the convulsive phases induced by PTZ i.v. infusion. Pretreatment with sub-effective dose of rofecoxib (1mg/kg, i.p.) enhanced the action of sub-protective doses of either adenosine (25mg/kg, i.p.) or 2-chloroadenosine (1 or 2mg/kg, i.p.) in increasing the seizure threshold. On the contrary, treatment with caffeine (100 or 200mg/kg, i.p.) or theophylline (50 or 100mg/kg, i.p.), both non-selective A(1)/A(2) adenosine receptor antagonists reversed the anticonvulsant effect of rofecoxib (4mg/kg, i.p.). Further, dipyridamole (5mg/kg, i.p.), an adenosine uptake inhibitor displayed an anticonvulsant effect with rofecoxib (1mg/kg, i.p.). The study for the first time demonstrated the possible involvement of adenosinergic system in the anticonvulsant effects of rofecoxib against PTZ i.v. seizure threshold paradigm in mice.

The role of kinin B1 receptors in the nociception produced by peripheral protein kinase C activation in mice

The peripheral injection of phorbol myristate acetate (PMA) into the mouse paw induces nociception mediated through activation of protein kinase C (PKC). In the present study, we examine the contribution of kinin B1 receptor to PMA-induced nociception. Nociception was assessed after intraplantar injection of PMA or the B1 receptor agonist des-Arg9-bradykinin in mice. Mechanisms of nociception were studied using the combination of knockout mice, selective drugs, and measurement of B1 receptor mRNA and protein levels. Peripheral injection of PMA (50 pmol/paw) induced a nociceptive behaviour that was abolished by selective B1 receptor antagonist des-Arg9-Leu8-bradykinin or by the B1 receptor gene deletion. Moreover, PMA treatment did not alter B1 receptor mRNA levels, but greatly increased B1 receptor protein levels in the mouse paw. The injection of des-Arg9-bradykinin did not cause nociception in naive mice, but produced marked nociception in animals previously treated with a low dose of PMA (0.5 nmol/paw). The co-treatment of PMA with selective PKC or protein synthesis inhibitors, but not with p38 mitogen activated protein kinase (MAPK) or transcription inhibitors significantly reduced des-Arg9-bradykinin-induced nociception. On the other hand, the co-administration of selective PKC or p38 MAPK inhibitors, but not of protein synthesis or transcription inhibitors, reduced des-Arg9-bradykinin-induced nociception when evaluated in PMA pre-injected animals. These results suggest that the B1 receptor exerts a critical role in the nociception caused by PKC activation in peripheral tissues. Since the PKC pathway is downstream of several pro-inflammatory mediators, B1 receptor stimulation appears to contribute to the acute inflammatory pain process.

Structure-based design, synthesis, and biological evaluation of indomethacin derivatives as cyclooxygenase-2 inhibiting nitric oxide donors

Indomethacin, a nonselective cyclooxygenase (COX) inhibitor, was modified in three distinct regions in an attempt both to increase cyclooxygenase-2 (COX-2) selectivity and to enhance drug safety by covalent attachment of an organic nitrate moiety as a nitric oxide donor. A human whole-blood COX assay shows the modifications on the 3-acetic acid part of the indomethacin yielding an amide-nitrate derivative 32 and a sulfonamide-nitrate derivative 61 conferred COX-2 selectivity. Along with their respective des-nitrate analogs, for example, 31 and 62, the nitrates 32 and 61 were effective antiinflammatory agents in the rat air-pouch model. After oral dosing, though, only 32 increased nitrate and nitrite levels in rat plasma, indicating that its nitrate tether served as a nitric oxide donor in vivo. In a rat gastric injury model, examples 31 and 32 both show a 98% reduction in gastric lesion score compared to that of indomethacin. In addition, the nitrated derivative 32 inducing 85% fewer gastric lesions when coadministered with aspirin as compared to the combination of aspirin and valdecoxib.

Antinociceptive and anti-inflammatory effects of compounds isolated from Scaphyglottis livida and Maxillaria densa

Oral administration of a CH(2)Cl(2)-MeOH (1:1) extract of Scaphyglottis livida produced dose-dependent antinociceptive and anti-inflammatory effects when tested in mice and rats using the hot-plate (150-600 mg/kg) and carrageenan-induced inflammation (150-600 mg/kg) models, respectively. Morphine (1.5-6 mg/kg, p.o.) and indomethacin (10-40 mg/kg, p.o.) were used as positive controls, respectively. Four compounds were isolated from the active extract of Scaphyglottis livida, namely 5alpha-lanosta-24,24-dimethyl-9(11),25-dien-3beta-ol (LDD), 24,24,dimethyl-9,19-cyclolanosta-9(11),25-dien-3-one (cyclobalanone), gigantol and 3,4'-dihydroxy-3',4,5-trimethoxybibenzyl (DTB). LDD and gigantol (25-100 mg/kg, p.o.) significantly increased the hot-plate latency in comparison to vehicle-treated mice and decreased carrageenan-induced inflammation in rats. The antinociception provoked by LDD and gigantol was partially blocked by naloxone (1mg/kg, i.p.). However, pretreatment with L-NAME (100 mg/kg, i.p.) and glibenclamide (10 mg/kg, i.p.) did not affect the antinociceptive response induced by LDD or gigantol suggesting that their pharmacological effect could be partially due to activation of opioid receptors. Moreover, a CH(2)Cl(2)-MeOH (1:1) extract of Maxillaria densa reduced acetic acid-induced abdominal writhes but was not able to produce antinociception in the hot-plate assay. Two compounds were isolated from the active extract of Maxillaria densa, namely fimbriol A and erianthridin. Both compounds partially reduced acetic acid-induced writhes. The results tend to support the popular use of this species in folk medicine for treatment of painful complaints.

Inducible nitric oxide synthase and cyclooxygenase-2 participate in anti-inflammatory and analgesic effects of the natural marine compound lemnalol from Formosan soft coral Lemnalia cervicorni

Lemnalol (8-isopropyl-5-methyl-4-methylene-decahydro-1,5-cyclo-naphthalen-3-ol) is a natural compound isolated from the marine soft coral Lemnalia cervicorni. In the present study, the anti-inflammatory and anti-nociceptive properties of lemnalol were investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and carrageenan-injected rats, respectively. Our results demonstrate that lemnalol significantly inhibited the expression of the pro-inflammatory proteins, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-stimulated RAW 264.7 cells. An in vivo inflammation model was induced by intraplantar injection of carrageenan into rat hind paws. An intramuscular injection of lemnalol (15 mg/kg) 10 min before carrageenan injection resulted in significant inhibition of carrageenan-induced rat paw edema and thermal hyperalgesia behavior. Western blot experiments revealed that the carrageenan-induced expression of iNOS and COX-2 in paw tissue was significantly down-regulated by lemnalol. Moreover, post-intrathecal injection of lemnalol produced a dose-dependent anti-nociceptive effect in carrageenan-injected rats (1 and 5 microg). The present results indicate that the marine-derived compound lemnalol had anti-inflammatory and analgesic effects in LPS-stimulated RAW 264.7 cells and carrageenan-injected rats, respectively. In addition, inhibition of elevated iNOS and COX-2 protein expression as well as neurophil infiltration of carrageenan-injected paws may be involved in the beneficial effects of lemnalol.

Modeling and Simulation to Support Dose Selection and Clinical Development of SC-75416, a Selective COX-2 Inhibitor for the Treatment of Acute and Chronic Pain

Pharmacokinetic/pharmacodynamic (PK/PD) models were developed and clinical trial simulations were conducted to recommend a study design to test the hypothesis that a dose of SC-75416, a selective cyclooxygenase-2 inhibitor, can be identified that achieves superior pain relief (PR) compared to 400 mg ibuprofen in a post-oral surgery pain model. PK/PD models were developed for SC-75416, rofecoxib, valdecoxib, and ibuprofen relating plasma concentrations to PR scores using a nonlinear logistic-normal model. Clinical trial simulations conducted using these models suggested that 360 mg SC-75416 could achieve superior PR compared to 400 mg ibuprofen. A placebo- and positive-controlled parallel-group post-oral surgery pain study was conducted evaluating placebo, 60, 180, and 360 mg SC-75416 oral solution, and 400 mg ibuprofen. The study results confirmed the hypothesis that 360 mg SC-75416 achieved superior PR relative to 400 mg ibuprofen (DeltaTOTPAR6=3.3, P<0.05) and demonstrated the predictive performance of the PK/PD models.

In vitroanti-inflammatory activity of 4-arylcoumarins from endophyticStreptomyces aureofaciensCMUAc130 in murine macrophage RAW 264.7 cells

This research was undertaken to find the in vitro inflammatory action of 5,7-dimethoxy-4-p-methoxylphenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin produced by Streptomyces aureofaciens CMUAc130. We investigated the effects of 5,7-dimethoxy-4-p-methoxylphenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin not only on the formation of nitric oxide (NO), PGE(2), TNF-alpha, IL-6 and IL-1beta, but also on inducible NO synthase and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells. The data obtained were consistent with the modulation of iNOS enzyme expression. A similar fashion was also observed when LPS-induced PGE(2) release and COX-2 expression were tested. The significant inhibitory effects were shown in concentration-dependent manners. In addition, 5,7-dimethoxy-4-p-methoxylphenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin also mildly but significantly reduced the formation of TNF-alpha. These findings support the application of 5,7-dimethoxy-4-p-methoxylphenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin as anti-inflammatory agents.

Preclinical pharmacology profile of CS-706, a novel cyclooxygenase-2 selective inhibitor, with potent antinociceptive and anti-inflammatory effects

We report here the preclinical anti-inflammatory profile of CS-706 [2-(4-ethoxyphenyl)-4-methyl-1-(4-sulfamoylphenyl)-1H-pyrrole], a novel cyclooxygenase-2 (COX-2) selective inhibitor. CS-706 selectively inhibited COX-2 in a human whole blood assay with an IC(50) of 0.31 microM, compared with an IC(50) of 2.2 microM for COX-1. The selectivity ratio of CS-706 was higher than those of the conventional non-steroidal anti-inflammatory drugs naproxen, indomethacin, and Diclofenac-Na, whereas it was lower than those of rofecoxib, valdecoxib and etoricoxib. It was similar to that of celecoxib. The pharmacokinetic profile of CS-706 showed rapid absorption and dose-proportional exposure after oral administration to rats. CS-706 inhibited prostaglandin E(2) production in inflamed tissue induced by yeast-injection in rats with potency similar to that of indomethacin. However, it inhibited gastric mucosal prostaglandin E(2) production in normal rats weakly compared with indomethacin. CS-706 ameliorated both yeast-induced inflammatory acute pain (ED(50)=0.0090 mg/kg) and adjuvant-induced chronic arthritic pain (ED(50)=0.30 mg/kg) in rats. CS-706 showed more potent antinociceptive activity than celecoxib and rofecoxib in these models. In an adjuvant-induced arthritic model in rats, CS-706 suppressed foot swelling prophylactically with an ID(50) of 0.10 mg/kg/day, and decreased foot swelling in the established arthritis therapeutically in a dose range of 0.040 to 1.0 mg/kg/day. Single administration of up to 100 mg/kg of CS-706 induced no significant gastric lesions in rats. In conclusion, CS-706 is a COX-2-selective inhibitor with a potent antinociceptive and anti-inflammatory activity and a gastric safety profile.

Surface plasmon resonance studies and biochemical evaluation of a potent peptide inhibitor against cyclooxygenase-2 as an anti-inflammatory agent

Cyclooxygenase (COX) is a key enzyme in the biosynthetic pathway leading to the formation of prostaglandins, which are mediators of inflammation [D.L. Dewitt, W.L. Smith, Primary structure of prostaglandin G/H synthase from sheep vesicular gland determined from the complementary DNA sequence, Proc. Natl. Acad. Sci. USA 85 (1988) 1412-1416, 1]. It exists mainly in two isoforms COX-1 and COX-2 [A. Raz, A. Wyche, N. Siegel, P. Needleman, Regulation of fibroblast cyclooxygenase synthesis by interleukin-1, J. Biol. Chem. 263 (1988) 3022-3028, 2]. The conventional non-steroidal anti-inflammatory drugs (NSAIDs) have adverse gastrointestinal side-effects, because they inhibit both isoforms [T.D. Warner, F. Guiliano, I. Vojnovic, A. Bukasa, J.A. Mitchell, J.P. Vane, Nonsteroid drug selectivities for cyclo-oxygenase-1 rather than cyclo-oxygenase-2 are associated with human gastrointestinal toxicity: a full in vitro analysis, Proc. Natl. Acad. Sci. USA 96 (1999) 7563-7568, 3; L.J. Marnett, A.S. Kalgutkar, Cyclooxygenase 2 inhibitors: discovery, selectivity and the future, Trends Pharmacol. Sci. 20 (1999) 465-469, 4; J.R. Vane, NSAIDs, Cox-2 inhibitors, and the gut, Lancet 346 (1995) 1105-1106, 5]. Therefore drugs which selectively inhibit COX-2, known as coxibs were developed. Recent reports on the harmful cardiovascular and renovascular side-effects of the anti-inflammatory drugs have led to the quest for a novel class of COX-2 selective inhibitors. Keeping this in mind, we have used the X-ray crystal structures of the complexes of the COX-1 and COX-2 with the known inhibitors for a rational, structure based approach to design a small peptide, which is potent inhibitor for COX-2. The peptides have been checked experimentally by in-vitro kinetic studies using surface plasmon resonance (SPR) and other biochemical methods. We have identified a tripeptide inhibitor which is a potential lead for a new class of COX-2 inhibitor. The dissociation constant (K(D)) determined for COX-2 with peptide WCS is 1.90x10(-10)M, the kinetic constant (K(i)) determined by spectrophotometry is 4.85x10(-9)M and the IC(50) value is 1.5x10(-8)M by ELISA test.

Mathematical analysis of involvement ratio between central and peripheral COX-2 in rat pain models with two types of COX-2 inhibitors with different distribution, celecoxib and CIAA

The purpose of this study is to clarify involvement ratios between central and peripheral cyclooxygenase (COX)-2 in rat inflammatory pain models, by evaluating celecoxib and [6-chloro-2-(4-chlorobenzoyl)-1H-indol-3-yl]acetic acid (CIAA) on carrageenan-induced mechanical and thermal hyperalgesia. Celecoxib and CIAA exhibited ID(30) values with 1.5 and 7.7 mg/kg on mechanical hyperalgesia, respectively, and ID(25) values with 0.54 and 36 mg/kg on thermal hyperalgesia, respectively. By solving quadratic functional analysis with prostaglandin E(2) (PGE(2)) inhibitory activities, it was calculated that involvement ratios between central and peripheral COX-2 involvement were 0.47 and 0.53 on mechanical hyperalgesia, and 0.97 and 0.03 on thermal hyperalgesia, respectively. These data suggest that central and peripheral COX-2 are equally involved in mechanical hyperalgesia, while central COX-2 is predominantly involved in thermal hyperalgesia.

Geranylgeranylacetone induces cyclooxygenase-2 expression in cultured rat gastric epithelial cells through NF-kappaB

Geranylgeranylacetone (GGA) effectively protects the gastric mucosa against noxious agents. The precise mechanisms underlying the gastroprotective actions of GGA are not known. To elucidate the precise mechanism of GGA, the effect of GGA treatment on COX-2 expression in rat gastric epithelial (RGM1) cells was investigated. We used a prostaglandin E2 (PGE2) enzyme-linked immunoassay kit and Western blot analysis to measure PGE2 production and COX-2 induction by GGA treatment in serum-starved RGM1 cells. Gel-shift assay, Western blot analysis, and a reporter assay were performed to determine which COX-2 promoter was involved in GGA-induced COX-2 expression. GGA treatment dose dependently increased COX-2 expression and PGE2 production. The nuclear factor (NF)-kappaB sites of the COX-2 gene promoter were critical for GGA-mediated COX-2 expression. GGA induces COX-2 expression and increases PGE2 production in serum-starved RGM1 cells via activation of the NF-kappaB sites of COX-2 gene promoters.

Syntheses of new tetrasubstituted thiophenes as novel anti-inflammatory agents

A series of new tetrasubstituted thiophenes (4a-4i, 5a-5i and 6a-6f) have been synthesized as novel anti-inflammatory agents and were evaluated for their anti-inflammatory activity in carrageenin-induced rat hind paw oedema model at the doses of 10, 20 and 40mg/kg body weight. Among ester series, the best compound 4c showed 71% protection at 10mg/kg, 72% at 20mg/kg, and 76% at 40mg/kg to inflamed paw; while in acid series 5a showed 79% protection at 10mg/kg, 80% at 20mg/kg, and 70% at 40mg/kg, and 5c showed 72% protection at 10mg/kg, 75% at 20mg/kg, and 69% at 40mg/kg, to inflamed paw. In case of oxime series 6a-6f, the anti-inflammatory activities of the candidates were found to be poor as compared to acid and ester series. It was found on the basis of SAR studies of target compounds, that the presence of OCH(3) at R(2) position and H, OCH(3) at R(1) are one of the requirements for eliciting comparable anti-inflammatory activity in both tetrasubstituted thiophenes' ester and acid series. Compounds 4a-4i, 5a-5i were investigated for their analgesic activity in acetic acid induced writhing response model at 10mg/kg dose. Among the ester series compound 4e showed maximum protection of 60%, while 4a, 4b, and 4i exhibited 55%, 45%, and 43% protection, respectively. The result showed that presence of H, Cl at R(1) and OCH(3), CH(3) at R(2) in tetrasubstituted thiophene ester series enhances their analgesic activity. The candidates of acid series 5a-5i showed poor analgesic activity as compared to the standard drug ibuprofen. Compounds 4a-4i, 5a-5i were evaluated for their in vitro antioxidant nitric oxide radical scavenging assay. Among the ester series 4a showed maximum in vitro nitric oxide radical scavenging activity having IC(50) value 30.08microg/ml while in acid series 5a has IC(50) value 25.20microg/ml. The results showed that the presence of R(1)=H, R(2)=OCH(3) and R(1)=R(2)=OCH(3) enhances nitric oxide radical scavenging property in tetrasubstituted thiophenes' acid series.

Anti-inflammatory effects of compounds alpha-humulene and (−)-trans-caryophyllene isolated from the essential oil of Cordia verbenacea

This study evaluated the anti-inflammatory properties of two sesquiterpenes isolated from Cordia verbenacea's essential oil, alpha-humulene and (-)-trans-caryophyllene. Our results revealed that oral treatment with both compounds displayed marked inhibitory effects in different inflammatory experimental models in mice and rats. alpha-humulene and (-)-trans-caryophyllene were effective in reducing platelet activating factor-, bradykinin- and ovoalbumin-induced mouse paw oedema, while only alpha-humulene was able to diminish the oedema formation caused by histamine injection. Also, both compounds had important inhibitory effects on the mouse and rat carrageenan-induced paw oedema. Systemic treatment with alpha-humulene largely prevented both tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) generation in carrageenan-injected rats, whereas (-)-trans-caryophyllene diminished only TNFalpha release. Furthermore, both compounds reduced the production of prostaglandin E(2) (PGE(2)), as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) expression, induced by the intraplantar injection of carrageenan in rats. The anti-inflammatory effects of alpha-humulene and (-)-trans-caryophyllene were comparable to those observed in dexamethasone-treated animals, used as positive control drug. All these findings indicate that alpha-humulene and (-)-trans-caryophyllene, derived from the essential oil of C. verbenacea, might represent important tools for the management and/or treatment of inflammatory diseases.

Analgesic, anti-inflammatory and antipyretic activities of the ethanolic extract and its fractions of Cleome rutidosperma

Oral administration of the ethanolic extract (200 and 400 mg/kg, p.o) and its fractions (200 mg/kg each) of the aerial parts of Cleome rutidosperma produced significant analgesic activity in acetic acid-induced writhing and tail immersion tests, anti-inflammatory effect against carrageenin induced inflammation and adjuvant induced polyarthritis and antipyretic activity against yeast-induced pyrexia. Fractionation of the ethanolic extract potentiated the activities.

COX-2 expression in lobular in situ neoplasia of the breast: correlation with histopathological grading system according to the Tavassoli classification

AIMS

There is considerable evidence to link cyclooxygenase (COX)-2 to the development of cancer. The aim of this study was to assess COX-2 expression and its subcellular localization in lobular in situ neoplasia (LIN) of the breast and to verify differences in COX-2 expression between different grades of lesions according to the Tavassoli classification.

METHODS AND RESULTS

We analysed the expression of COX-2 protein by immunohistochemistry in tissue samples of 51 LIN lesions classified into three grades according to the Tavassoli classification. COX-2 immunostaining was observed in 78.4% of LIN samples and showed a prevalent membranous rather than cytoplasmic pattern. COX-2 was expressed in 16/17 (94.1%) LIN1, 22/25 (88%) LIN2 and 2/9 (22.2%) LIN3. As regards COX-2 expression, a statistically significant difference was found between LIN1 and LIN3 (P = 0.001) and between LIN2 and LIN3 (P =0.001). No difference was found between LIN1 and LIN2. Moreover, a significant negative correlation was found between LIN grade and COX-2 expression (P < 0.0001).

CONCLUSIONS

COX-2 is highly expressed in LIN, supporting a role for this protein in the early stage of breast carcinogenesis, representing the rationale for using COX-2 selective inhibitors in the earliest stages of breast cancer.

Expression of a cyclo-oxygenase-2 transgene in murine liver causes hepatitis

BACKGROUND

It has been proved that cyclo-oxygenase-2 (COX-2) is rapidly induced by inflammatory mediators. However, it is not known whether overexpression of COX-2 in the liver is sufficient to promote activation or secretion of inflammatory factors leading to hepatitis.

AIM

To investigate the role forced expression of COX-2 in liver by using inducible COX-2 transgenic (TG) mice.

METHODS

TG mice that overexpress the human COX-2 gene in the liver using the liver-specific transthyretin promoter and non-TG littermates were derived and fed the normal diet for up to 12 months. Hepatic prostaglandin E(2) (PGE(2)) content was determined using enzyme immunoassay, nuclear factor kappaB (NF-kappaB) activation by electrophoretic mobility shift assays, apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labelling and proliferation by Ki-67 immunohistochemistry.

RESULTS

COX-2 TG mice exhibited strongly increased COX-2 and PGE(2), elevated serum alanine aminotransferase level and histological hepatitis. Hepatic COX-2 expression in the TG mice resulted in activation of NF-kappaB and inflammatory cytokine cascade, with a marked expression of the proinflammatory cytokines tumour necrosis factor (TNF)-alpha (9.4-fold), interleukin (IL)-6 (4.4-fold), IL-1beta (3.6-fold), and of the anti-inflammatory cytokine IL-10 (4.4-fold) and chemokine macrophage inflammatory protein-2 (3.2-fold). The inflammatory response of the COX-2 TG mice was associated with infiltration macrophages and lymphocytes, increased cell proliferation and high rates of cell apoptosis. Administration of the COX-2 inhibitor celecoxib in TG mice restored liver histology to normal.

CONCLUSION

Enhanced COX-2 expression in hepatocytes is sufficient to induce hepatitis by activating NF-kappaB, stimulating the secretion of proinflammatory cytokines, recruiting macrophage and altering cell kinetics. Inhibition of COX-2 represents a mechanism-based chemopreventive approach to hepatitis.

A critical appraisal of COX-2 selective inhibition and analgesia: how good so far?

The development of COX-2 selective inhibitors has opened a new era of clinical investigation in NSAIDs. Discussion of the established concepts of inflammation and therapeutical uses of these drugs has changed the rationale for its clinical use and therapeutic labeling of these drugs. A comprehensive discussion across basic science and clinical areas involved in each of these concepts is presented. This led to a remarkable re-evaluation of our insights on their traditionally proposed mechanisms of analgesia, their side-effects, and the clinical indication of NSAIDs as "over the counter" pain killers. This may shift physicians toward a more rational use of this drug class.

The influence of timing of administration on the analgesic efficacy of parecoxib in orthopedic surgery

BACKGROUND

Parecoxib, a selective cyclooxygenase-2 inhibitor, may reduce postoperative pain without increasing bleeding when administered before surgery.

METHODS

We randomly assigned 62 patients scheduled for total hip arthroplasty to the following IV dosing schedule: 1) placebo at induction, at wound closure, and 12 h after induction (control); 2) parecoxib 40 mg at induction, placebo at wound closure, and parecoxib 40 mg 12 h after induction (pre); or, 3) placebo at induction, parecoxib 40 mg at wound closure, and parecoxib 40 mg 12 h after induction (post). Pain scores at rest and with movement were recorded every 4 h for 24 h using a visual analog scale. Treatment side effects were recorded every 4 h. Red cell loss for 5 days after surgery was calculated.

RESULTS

Postoperative pain scores were less in the pre and post groups than in the control group. Postoperative bleeding was similar in the three groups. There were no significant differences between the pre and post groups, nor was their any trend suggesting a preemptive analgesic efficacy from preincision administration of parecoxib. Morphine use in the Postanesthesia Care Unit was reduced in the pre and post groups compared with the control group (14.2 +/- 2.0, and 15.7 +/- 2.0, vs 20.4 +/- 2.3 mg), although the trend was only significant (P < 0.05) in the pre group. The first pain score was also reduced in the pre and post groups compared to the control group (56.1 +/- 7.5 and 64.2 +/- 7.0 vs 78.3 +/- 5), but this was also only significant for the pre group (P = 0.001). The delay for first analgesic demand was increased for both the pre and post group compared to the control group (38 +/- 9 and 28.2 +/- 6.6 vs 18 +/- 6 min) but, again, this was only significant for the pre group (P = 0.05). Twenty-four hour consumption of morphine was similar in the pre (26 +/- 12 mg) and post groups (25 +/- 13 mg); both were significantly less than in the control group (47 +/- 27 mg, P < 0.001).

CONCLUSIONS

Administration of parecoxib before hip arthroplasty did not provide preemptive analgesia. There was a trend towards improved analgesia immediately after surgery with preincision administration, consistent with the expected time course of nonsteroidal antiinflammatory drug's effect. Perioperative parecoxib administration, consisting of two injections spaced 12 h apart, improved postoperative analgesia over the first 24 h without increasing bleeding.

Interferon-gamma suppresses cyclooxygenase-2 promoter activity by inhibiting C-Jun and C/EBPbeta binding

OBJECTIVE

Cyclooxygenase-2 (COX-2) and interferon gamma (IFNgamma) are overexpressed in vascular inflammatory and atherosclerotic lesions. We postulated that IFNgamma suppresses COX-2 expression at the transcriptional level.

METHODS AND RESULTS

The effect of IFNgamma on COX-2 expression was evaluated in several types of human cells stimulated with phorbol 12-myristate 13-acetate (PMA), interleukin (IL)-1beta, or tumor necrosis factor (TNF) alpha. IFNgamma concentration-dependently inhibited COX-2 proteins and promoter activities induced by PMA or cytokines in human fibroblasts and monocytic and endothelial cells. PMA and cytokines stimulate binding of C-Jun, C-Fos, CCAAT/enhancer binding protein beta (C/EBPbeta), or NF-kappaB to their respective regulatory elements on COX-2 promoter. IFNgamma blocked C-Jun and C/EBPbeta but not C-Fos or p50 NF-kappaB binding as determined by in vitro binding assays and chromatin immunoprecipitation assay. p300 binding to COX-2 promoter was inhibited by IFNgamma in a manner comparable to C-Jun and C/EBPbeta binding.

CONCLUSIONS

IFNgamma suppresses proinflammatory mediator-induced COX-2 transcription by selective inhibition of C-Jun and C/EBPbeta DNA binding activity and p300 recruitment in human cells. Because IFNgamma is coexpressed with COX-2 in vascular lesions, it may play a role in controlling COX-2-mediated inflammatory changes.

Antiinflammatory and antinociceptive effects of the selective histamine H4-receptor antagonists JNJ7777120 and VUF6002 in a rat model of carrageenan-induced acute inflammation

The effects of the highly selective histamine H4 receptor antagonists JNJ7777120 and VUF6002 were investigated on the carrageenan-induced inflammation and thermal hyperalgesia in rats. JNJ7777120 (10 and 30 mg/kg, s.c.) and VUF6002 (10 mg/kg, s.c.) significantly reduced paw edema and hyperalgesia provoked by subplantar injection of carrageenan; the effect was evident against the early (2 h) phase of inflammation. An inactive analog of VUF6002, VUF6007 (10 mg/kg, s.c.) slightly aggravated paw edema, while leaving unaltered carrageenan-induced nociception. These findings indicate that histamine H4 receptors participate in the early phase of acute inflammation induced by carrageenan in rats, influencing both edema and thermal hyperalgesia.

In Vivo andIn Vitro anti-inflammatory activities of α-linolenic acid isolated from actinidia polygama fruits

The fruit of Actinidia polygama (AP) has long been used as a folk medicine in Korea for the treatment of pain, rheumatoid arthritis and inflammation. In the present study, bioassay-guided fractionation of AP led to the separation and identification of a polyunsaturated fatty acid, alpha-linolenic acid (ALA), which was found to show anti-inflammatory activity. The anti-inflammatory effects of ALA, using acetic acid or carrageenan-induced inflammation models, were investi gated in mice or rats, respectively. ALA significantly inhibited the acetic acid-induced vascular permeability in a dose dependent manner (34.2 and 37.7% inhibition at doses of 5 and 10 mg/ kg, respectively). ALA also significantly reduced a rat paw edema induced by a single treatment of carrageenan. To investigate the mechanism of the anti-inflammatory action of ALA, the effects of ALA on lipopolysaccharide (LPS)-induced responses in the murine mac rophages cell line, RAW 264.7, were examined. Exposure of LPS-stimulated cells to ALA inhibited the accumulation of nitrite and prostaglandin E2 (PGE2) in the culture medium. Consistent with these observations, the protein and mRNA expression levels of iNOS and COX-2 enzyme were markedly inhibited by ALA in a dose dependent manner. These results suggest that the anti-inflammatory activity of ALA might be due to the suppression of the expressions of iNOS and COX-2 mRNA.

Enzymes and receptors of prostaglandin pathways with arachidonic acid-derived versus eicosapentaenoic acid-derived substrates and products

Dietary fish oil containing omega 3 highly unsaturated fatty acids has cardioprotective and anti-inflammatory effects. Prostaglandins (PGs) and thromboxanes are produced in vivo both from the omega 6 fatty acid arachidonic acid (AA) and the omega 3 fatty acid eicosapentaenoic acid (EPA). Certain beneficial effects of fish oil may result from altered PG metabolism resulting from increases in the EPA/AA ratios of precursor phospholipids. Here we report in vitro specificities of prostanoid enzymes and receptors toward EPA-derived, 3-series versus AA-derived, 2-series prostanoid substrates and products. The largest difference was seen with PG endoperoxide H synthase (PGHS)-1. Under optimal conditions purified PGHS-1 oxygenates EPA with only 10% of the efficiency of AA, and EPA significantly inhibits AA oxygenation by PGHS-1. Two- to 3-fold higher activities or potencies with 2-series versus 3-series compounds were observed with PGHS-2, PGD synthases, microsomal PGE synthase-1 and EP1, EP2, EP3, and FP receptors. Our most surprising observation was that AA oxygenation by PGHS-2 is only modestly inhibited by EPA (i.e. PGHS-2 exhibits a marked preference for AA when EPA and AA are tested together). Also unexpectedly, TxA(3) is about equipotent to TxA(2) at the TP alpha receptor. Our biochemical data predict that increasing phospholipid EPA/AA ratios in cells would dampen prostanoid signaling with the largest effects being on PGHS-1 pathways involving PGD, PGE, and PGF. Production of 2-series prostanoids from AA by PGHS-2 would be expected to decrease in proportion to the compensatory decrease in the AA content of phospholipids that would result from increased incorporation of omega 3 fatty acids such as EPA.

Inhibitory effect of Panax notoginseng on nitric oxide synthase, cyclo-oxygenase-2 and neutrophil functions

A water extract of Panax notoginseng Buck F.H. Chen. (Arialiaceae) root (PN) is being used as a therapeutic agent to stop haemorrhages and as a tonic to promote health in Korean and Chinese medicine. The pharmacokinetic profiles of PN have not been accurately investigated. The preliminary aim was to elucidate the pharmacokinetic features of PN. First, the prevention of neutrophil functions was assessed. PN inhibited neutrophil functions, including degranulation, superoxide generation and leukotriene B4 production, without any effect on 5-lipoxygenase activity. PN reduced nitric oxide (NO) and prostaglandin (PG)E2 production in mouse peritoneal macrophages stimulated with lipopolysaccharide (LPS) while no influence on the activity of inducible NO synthase (iNOS), cyclo-oxygenase-2 (COX-2) or cyclo-oxygenase-1 (COX-1) was observed. PN significantly reduced mouse paw oedema induced by carrageenan. The results indicate that PN exerts antiinflammatory effects related to the inhibition of neutrophil functions and NO and PGE2 production, which could be due to a decreased expression of iNOS and COX-2.

Cyclooxygenase-1 inhibition delays recovery of the cutaneous barrier disruption caused by mechanical scratching in mice

BACKGROUND

Atopic dermatitis is a chronic inflammatory disease characterized by severe pruritus, and cutaneous barrier disruption by scratching contributes to further aggravation of the condition. We have previously shown that indomethacin delayed recovery from the effects of cutaneous barrier disruption caused by mechanical scratching in mice.

OBJECTIVES

This study was designed to assess the role of cyclooxygenase (COX)-1 and COX-2 inhibitors on recovery from the effects of cutaneous barrier disruption induced by mechanical scratching in mice.

METHODS

We examined the effects of SC-560 (a COX-1-selective inhibitor) or NS-398 (a COX-2-selective inhibitor) on recovery from the effects of cutaneous barrier disruption in mice induced by a wire brush, in terms of the skin prostaglandin (PG) levels.

RESULTS

While SC-560 significantly delayed recovery from the effects of cutaneous barrier disruption, NS-398 had no such effect. SC-560 was significantly more effective than NS-398 in reducing skin PG levels at 6 and 24 h after cutaneous barrier disruption. SC-560 strongly inhibited biosynthesis of cutaneous PGD(2) to a greater extent than that of other PGs.

CONCLUSIONS

COX-1-coupled PGD(2) biosynthesis may be an important factor in the recovery of cutaneous barrier disruption.

Evaluation of the anti-inflammatory and analgesic activity of Me-UCH9, a dual cyclooxygenase-2/5-lipoxygenase inhibitor

Recently, we reported the dual inhibition of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) activity by some phenylsulphonyl urenyl chalcone derivatives. 2,4-dichloro-4'N[N'(4''methylphenylsulphonyl)urenyl] chalcone (Me-UCH9), was selected in the present study to determine its potential anti-inflammatory and analgesic effect after oral administration in several animal models related to the activation of COX-2 and 5-LO pathways. In the zymosan stimulated mouse air pouch model, Me-UCH9, reduced in a dose-dependent manner leukotriene B(4) (LTB(4)) levels in pouch exudates obtained at 4 h, as well as prostaglandin E(2) (PGE(2)) generated through COX-2 activation at 24 h. Tumor necrosis factor alpha (TNF-alpha) and myeloperoxidase activity were also strongly inhibited in this model. Me-UCH9 significantly reduced granuloma size and vascular index determined in the murine air pouch granuloma model of angiogenesis. In the carrageenan-induced paw edema, this compound inhibited inflammatory response and pain, as well as PGE(2) and LTB(4) content in paw edematous fluid. Analgesic properties were corroborated in the murine phenyl-p-benzoquinone-induced writhing test. Finally, Me-UCH9 exerted anti-inflammatory effects in the chronic model of rat adjuvant-induced arthritis, both inhibiting paw swelling and reducing PGE(2) content. Our findings confirm that Me-UCH9 can modulate inflammatory and nociceptive responses in relation to the dual inhibition of COX-2 and 5-LO activities presented by this compound.

Inhibitory effects of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside on experimental inflammation and cyclooxygenase 2 activity

The inhibitory effects of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG), extracted from the roots of Polygonum multiflorum Thunb, on inflammatory activity in animal models and cyclooxygenase-2 (COX-2) activity in lipopolysaccharide (LPS)-induced mouse RAW264.7 macrophage cells were investigated. The carrageenin (CGN)-induced rat paw oedema model and dimethylbenzene-induced mouse ear oedema model were prepared; MTT assay, semi-quantitative RT-PCR, Western blot and ELISA were adopted. THSG 2.3, 4.6 and 9.2 mg kg(- 1) by oral administration inhibited mouse ear oedema and the percentage of inhibition of THSG 9.2 mg kg(- 1) is 87%. THSG 3.2, 6.4 and 12.8 mg kg(- 1) by oral administration dose-dependently inhibited rat paw oedema and the percentage of inhibition of THSG 12.8 mg kg(- 1) is 56% at 6 h. Indomethacin 13 and 9 mg kg(- 1) showed 90% and 57% inhibition in the same animal models, respectively. LPS 1 microg ml(- 1) significantly up-regulated prostaglandin E(2) (PGE(2)) production (inducing COX-2 activity) by 35% (exogenous arachidonic acid, AA), which was dose-dependently decreased by THSG 1, 10, and 100 micromol L(- 1) and the percentage of inhibition of THSG 10 micromol L(- 1) was 40%. NS-398 10 micromol L(- 1) decreased PGE(2) production by 42%. THSG 1, 10, 100 micromol L(- 1) was shown to markedly inhibit the LPS-induced COX-2 protein and mRNA expression in RAW264.7 cells (P < 0.05) but had no effect on COX-1 protein and mRNA (P>0.05). In summary, the data showed that THSG possessed an anti-inflammatory effect, which was perhaps related to the inhibition of COX-2 enzyme activity and expression in RAW264.7 macrophage cells.

Successful treatment of cystoid macular edema with valdecoxib

PURPOSE

To evaluate the safety and efficacy of the COX-2 inhibitor valdecoxib in treating macular edema after cataract surgery.

SETTING

University Eye Clinic, Freiburg, Germany and Reis Medical Institution, Liechtenstein.

METHODS

The COX-2 inhibitor valdecoxib (Bextra) was administered systemically to patients with significant visual loss resulting from macular edema in a prospective clinical trial.

RESULTS

Ten patients were enrolled. Valdecoxib was tolerated well and led to a significant visual improvement within 10 days of therapy in all patients.

CONCLUSION

The fast and persistent control of macular edema with valdecoxib warrants further investigation.

COX-2 expression induced by diesel particles involves chromatin modification and degradation of HDAC1

Cyclooxygenase-2 (COX-2) plays an important role in the inflammatory response induced by physiologic and stress stimuli. Exposure to diesel exhaust particulate matter (DEP) has been shown to induce pulmonary inflammation and exacerbate asthma and chronic obstructive pulmonary disease. DEP is a potent inducer of inflammatory reponses in human airway epithelial cells. The mechanism through which DEP inhalation induces inflammatory mediator expression is not understood. In this report, we demonstrate that DEP can induce the expression of COX-2 gene in a human bronchial epithelial cell line (BEAS-2B) at both transcriptional and protein levels. The induction of COX-2 gene expression involves chromatin modification, in particular acetylation and deacetylation of histones. We show that exposure to DEP increases the acetylation of histone H4 associated with the COX-2 promoter and causes degradation of histone deacetylase 1 (HDAC1). Further, we establish that HDAC1 plays a pivotal role in mediating the transcriptional activation of the COX-2 gene in BEAS-2B cells exposed to DEP, supported by evidence that the down-regulation of HDAC1 using siRNA leads to activation of COX-2 gene expression, whereas overexpression of HDAC1 results in its repression. Finally, DEP exposure induced recruitment of histone acetyltransferase (HAT) p300 to the promoter of the COX-2 gene, suggesting that acetylation is also important in regulating its expression in response to DEP exposure. These results show for the first time acetylation via selective degradation of HDAC1, and that recruitment of HAT plays an important role in DEP-induced expression of the COX-2 gene.

Anti-inflammatory and anti-allergic properties of the essential oil and active compounds from Cordia verbenacea

The anti-inflammatory and anti-allergic effects of the essential oil of Cordia verbenacea (Boraginaceae) and some of its active compounds were evaluated. Systemic treatment with the essential oil of Cordia verbenacea (300-600mg/kg, p.o.) reduced carrageenan-induced rat paw oedema, myeloperoxidase activity and the mouse oedema elicited by carrageenan, bradykinin, substance P, histamine and platelet-activating factor. It also prevented carrageenan-evoked exudation and the neutrophil influx to the rat pleura and the neutrophil migration into carrageenan-stimulated mouse air pouches. Moreover, Cordia verbenacea oil inhibited the oedema caused by Apis mellifera venom or ovalbumin in sensitized rats and ovalbumin-evoked allergic pleurisy. The essential oil significantly decreased TNFalpha, without affecting IL-1beta production, in carrageenan-injected rat paws. Neither the PGE(2) formation after intrapleural injection of carrageenan nor the COX-1 or COX-2 activities in vitro were affected by the essential oil. Of high interest, the paw edema induced by carrageenan in mice was markedly inhibited by both sesquiterpenic compounds obtained from the essential oil: alpha-humulene and trans-caryophyllene (50mg/kg, p.o.). Collectively, the present results showed marked anti-inflammatory effects for the essential oil of Cordia verbenacea and some active compounds, probably by interfering with TNFalpha production. Cordia verbenacea essential oil or its constituents might represent new therapeutic options for the treatment of inflammatory diseases.

Glycoprotein isolated from Rhus verniciflua Stokes inhibits inflammation-related protein and nitric oxide production in LPS-stimulated RAW 264.7 cells

Rhus verniciflua Stokes (RVS) has traditionally been used for medical purpose, such as healing of inflammatory diseases in South Korea. Glycoprotein (36 kDa) was isolated from RVS fruit, purified and used to evaluate the inhibitory effect on inflammatory-related proteins and nitric oxide (NO) production in lipopolysaccharide (LPS, 200 ng/ml)-stimulated RAW 264.7 (murine macrophage cell line). Our results were showed that RVS glycoprotein has a strong antioxidative activity against lipid peroxyl radicals in cell-free system, and inhibits NO production in LPS-stimulated RAW 264.7 cells. To elucidate the inhibitory effect of RVS glycoprotein on activities of inflammatory-related proteins, we firstly evaluated the amount of intracellular reactive oxygen species (ROS), and expression of intracellular protein kinase C (PKC), nuclear factor (NF)-kappaB, and activator protein-1 (AP-1). The results in the present study showed that RVS glycoprotein (200 microg/ml) inhibits ROS production and PKCalpha translocation, and down-regulates the expression of NF-kappaB and AP-1. Such upstream signals consequently inhibited the levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 expression. Therefore, we speculate that RVS glycoprotein inhibits the inflammatory-related protein and can act as an anti-inflammatory agent.

Interaction between cyclooxygenase (COX)-1- and COX-2-products modulates COX-2 expression in the late phase of acute inflammation

Prostanoid production depends on the activity of two cyclooxygenase (COX) isoforms. It is appreciated that COX-1 plays a role in physiological processes, whereas COX-2 acts in pathological conditions. However their roles, particularly roles of COX-1, have not yet been fully established in inflammation. Here, we examined the effects of COX inhibitors, having differential isoform selectivity, on the late phase of rat carrageenin-induced pleurisy to elucidate the role of COX-2 expressed in the draining lymph nodes and found substantial contribution of COX-1-product(s). Protein and mRNA of COX-2 were detectable with Western blotting analysis and reverse-transcription polymerase chain reaction (RT-PCR) analysis in parathymic lymph nodes, peaking at 48 h after induction of pleurisy. Microsomal prostaglandin E synthase (mPGES)-1 was detectable by immunohistochemical analysis in cells with dendritic processes, a morphological characteristic similar to that of COX-2 expressing cells. Although aspirin, indomethacin and a COX-1 inhibitor, ketorolac, significantly decreased the volume of pleural exudate, they did not affect the levels of COX-2 and mPGES-1 in the lymph node 24 h after induction of pleurisy. In contrast, COX-2 inhibitors, nimesulide and NS-398, had no effect on the exudate volume, but they increased the number of COX-2- and mPGES-1-expressing cells and extension of their dendritic processes with significant increase in the COX-2 level, which were antagonised by ketorolac. These results suggest that COX-2-expressing cells may negatively self-regulate their functions by producing PGE2 via mPGES-1: migration into the draining lymph node and their differentiation. Moreover, COX-1- and COX-2-derived prostanoids may play differential or sometimes antagonistic roles in the late phase of acute inflammation.

Anti-inflammatory effects of a triterpenoid isolated from Wilbrandia ebracteata Cogn

Wilbrandia ebracteata (WE), a Brazilian medicinal plant used in folk medicine for the treatment of rheumatic diseases, displays anti-inflammatory properties and constitutes a rich source of cucurbitacins and cucurbitacin-related compounds. The current study investigated the potential anti-inflammatory properties of Dihydrocucurbitacin B (DHCB), a cucurbitacin-derived compound isolated from roots of WE, in some in vivo and in vitro experimental models. Intraperitoneal treatment of mice with DHCB reduced both carrageenan-induced paw edema (0.3, 1 and 3 mg/kg caused inhibitions of 26, 44 and 56 % at 2 h after stimulation, respectively) and pleurisy (10 mg/kg inhibited leukocyte numbers and LTB(4) levels in the pleural fluid by 51 and 75% at 6 h after cavity challenge, respectively). In vitro, DHCB (up to 10 microg/mL) failed to modify LTB(4) production by human neutrophils or PGE(2) production by COS-7 cells transfected with COX-1, but PGE(2) production by COX-2 transfected COS-7 cells was markedly inhibited (by 72%). The levels of COX-1 or COX-2 proteins in IL-1alpha-stimulated NIH3T3 cells were unaffected by DHCB. The results corroborate the potential anti-inflammatory properties ascribed to W. ebracteata Cogn. in folk medicine and suggest that they might be attributed, at least in part, to the capacity of one of this plants main constituents, DHCB, to inhibit COX-2 activity (but not its expression) during inflammation.

Long-term efficacy and safety of celecoxib in Alzheimer's disease

BACKGROUND/AIMS

Cyclooxygenase-2 (COX-2) may play an important role in the neuropathology of Alzheimer's disease (AD). The efficacy and safety of celecoxib (200 mg bid), a COX-2 selective inhibitor, were assessed in patients > or =50 years with established mild-to-moderate AD to determine whether treatment was effective in retarding deterioration of cognitive function.

METHODS

This was a 52-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. The primary efficacy end points were the change from baseline to week 52 in the Alzheimer's Disease Assessment Scale-Cognitive Behavior (ADAS-cog) composite score and the week 52 Clinician's Interview-Based Impression of Change Plus (CIBIC+).

RESULTS

At 52 weeks, change in ADAS-cog scores from baseline was similar for placebo and celecoxib 200 mg bid groups (5.00 and 4.39, respectively). CIBIC+ scores were also similar (4.83 and 4.92). Two extension studies were conducted but were terminated early based on these efficacy results. Safety data from all 3 studies indicated that celecoxib was generally well-tolerated.

CONCLUSION

Celecoxib 200 mg bid did not slow the progression of AD in this study, and the occurrence of adverse events was as expected for an elderly population with a complex chronic medical condition.

Interleukin-6 is a candidate molecule that transmits inflammatory information to the CNS

Peripheral inflammation induces reactions within the CNS such as central sensitization, which is involved in the mechanism of inflammatory hyperalgesia. However, the precise mechanism of inflammatory signal transmission from the peripheral inflammatory site to the CNS is not clear. We studied the role of circulating interleukin (IL)-6 as a messenger of inflammatory information from the periphery to the CNS. In the rat model of inflammatory hyperalgesia induced by carrageenan, levels of IL-6 but not IL-1beta or tumor necrosis factor alpha (TNFalpha) were significantly elevated in the circulating blood 3 h after an injection of carrageenan. In addition, injecting carrageenan into the hind paw evoked thermal hyperalgesia and the release of prostaglandin E(2) (PGE(2)) from isolated blood vessels of the CNS ex vivo, as well as the induction of cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 and nuclear translocation of signal transducer and activator of transcription 3 (STAT3) in vascular endothelial cells of the CNS. A prior i.p. injection of IL-6 antiserum (IL-6AS) abolished or attenuated these responses. The present results suggested that circulating IL-6 could act as a messenger of inflammatory information from peripheral inflammatory sites to the CNS and as the afferent circulating signal to the CNS to produce prostaglandins in the vascular endothelial cells of the CNS through a COX-2 dependent pathway.

Synthesis and biological evaluation of some 5-ethoxycarbonyl-6-isopropylamino-4-(substitutedphenyl)aminopyrimidines as potent analgesic and anti-inflammatory agents

Synthesis and biological evaluation of some 5-ethoxycarbonyl-6-isopropylamino-4-(substitutedphenyl)aminopyrimidines have been achieved by cyclization of N-[2-ethoxycarbonyl-2-cyano-1-(isopropylamino)vinyl] formamidine in presence of dry HCl in dioxane followed by nucleophilic substitution of 4-chloro group with substituted aromatic amine or phenoxide. Target compounds were evaluated for their analgesic and anti-inflammatory potential by known experimental models. Some of the compounds emerged out as more potent than standard drugs. Very low ulcer index was observed for the potent compounds.

Effect of different cyclooxygenase inhibitors on gastric adaptive cytoprotection induced by 20% ethanol

In this study, we evaluated the effect of two different dosages of therapeutically prescribed nonsteroidal anti-inflammatory drugs (NSAIDs), ibuprofen, diclofenac, nimesulide, meloxicam, and celecoxib (ED80 for COX-1 and COX-2) on normal gastric mucosa and mucosa, previously exposed to 20% ethanol. At COX-2-inhibiting dosages, the NSAIDs tested were nonulcerogenic, and the same response profile was observed in "adapted" stomachs. Interestingly, low doses of nimesulide and celecoxib increase the levels of Prostaglandin E(2) and COX-2, and protect against subsequent 100% ethanol exposition, suggesting that these drugs may act as "mild irritants" to gastric mucosa. The ulcerogenic response to NSAIDs was prevented by the previous 20% ethanol exposition, probably the result of nitric oxide synthesis, because PGE(2) levels in gastric mucosa were reduced by these agents and a concomitant nitric oxide blockade reversed this protection.