Anti-inflammatory, antinociceptive, and vasorelaxant effects of a new pyrazole compound 5-(1-(2-fluorophenyl)-1H-pyrazol-4-yl)-1H-tetrazole: role of NO/cGMP pathway and calcium channels.

Molecular modification of compounds remains important strategy towards the discovery of new drugs. In this sense, this study presents a new pyrazole derivative 5-(1-(2-fluorophenyl)-1H-pyrazol-4-yl)-1H-tetrazole (LQFM039) and evaluated the anti-inflammatory, analgesic, and vasorelaxant effects of this compound as well the mechanisms of action involved in the pharmacological effects. For this, mice were orally treated with LQFM039 (17.5, 35, or 70 mg/kg) prior acetic acid-induced abdominal writhing, formalin, tail flick, and carrageenan-induced paw edema protocols. In addition, vascular reactivity protocols were made with aortic rings contraction with phenylephrine and stimulated with graded concentrations of LQFM039. Abdominal writhing and licking time in both neurogenic and inflammatory phases of formalin were reduced with LQFM039 without altering latency to nociceptive response in the tail flick test. Carrageenan-induced paw edema showed that LQFM039 reduces edema and cell migration. In addition, the mechanism of action of LQFM039 involves NO/cGMP pathway and calcium channels, since this new pyrazole derivate elicited concentration-dependent relaxation attenuated by Nω-nitro-l-arginine methyl ester and 1H-[1,2,4] oxadiazolo [4,3-alpha]quinoxalin-1-one, and blockade of CaCl2-induced contraction. Altogether, our finding suggests anti-inflammatory, antinociceptive, and vasorelaxant effect of this new pyrazole derivative with involvement of NO/cGMP pathway and calcium channels.

Heteroaromatic salvinorin A analogue (P-3 l) elicits antinociceptive and anxiolytic-like effects.

Previous studies have attributed the prominent analgesic, hallucinogenic, sedative, and anxiolytic properties of Salvia divinorum to Salvinorin A. However, the overall pharmacological profile of this isolate limits its clinical applications. To address these limitations, our study evaluates the C(22)-fused-heteroaromatic analogue of salvinorin A [2-O-salvinorin B benzofuran-2-carboxylate] (P-3l) in mice nociception and anxiety models while assessing possible mechanism of action. In comparison with the control group, orally administered P-3l (1, 3, 10, and 30 mg/kg) attenuates acetic acid-induced abdominal writhing, formalin-induced hind paw licking, the thermal reaction to the hotplate, and/or aversive response in the elevated plus-maze, open field, and light-dark box; and potentiates the effect of morphine and diazepam at sub-effective doses (1.25 and 0.25 mg/kg, respectively) without eliciting significant alterations in relative organ weight, or haematological or biochemical parameters. The in vivo blockade of P-3 l effects by naloxone (non-selective opioid receptor antagonist), naloxonazine (antagonist of specific subtypes mu1 of µ-OR), and nor-binaltorphimine (selective ĸ-OR antagonist) supports initial results from binding assays and the interpretations made possible from computational modeling of the interactions of P-3 l with the opioid receptor subtypes. In addition to the opioidergic mechanism, the blockade of the P-3 l effect by flumazenil suggests benzodiazepine binding site involvement in its biological activities. These results support P-3 l potentially possessing clinical utility and substantiate the need for additional pharmacological characterization.

Pharmacological evaluation of antinociceptive and anti-inflammatory activities of LQFM202: a new piperazine derivative.

Advances have been made in the search for new multi-target modulators to control pain and inflammation. Therefore, compound 3,5-di-tert-butyl-4-hydroxyphenyl)(4-methylpiperazin-1-yl)methanone (LQFM202) was synthesised and evaluated. First, in vitro assays were performed for COX-1, COX-2, and 5-LOX enzymes. Subsequently, adult female Swiss albino mice treated orally with LQFM202 at doses of 25-200 mg/kg were subjected to acetic acid-induced writhing, formalin-induced pain, carrageenan-induced hyperalgesia, carrageenan- or zymosan-induced paw oedema, or pleurisy. LQFM202 inhibited COX-1, COX-2, and LOX-5 (IC50 = 3499 µM, 1565 µM, and 1343 µM, respectively). In acute animal models, LQFM202 (50, 100, or 200 mg/kg) decreased the amount of abdominal writhing (29%, 52% and 48%, respectively). Pain in the second phase of the formalin test was reduced by 46% with intermediate dose. LQFM202 (100 mg/kg) reduced the difference in nociceptive threshold in all 4 h evaluated (46%, 37%, 30%, and 26%, respectively). LQFM202 (50 mg/kg) decreased the carrageenan-oedema from the second hour (27%, 31% and 25%, respectively); however, LQFM202 (100 mg/kg) decreased the carrageenan-oedema in all hours evaluated (35%, 42%, 48% and 50%, respectively). When using zymosan, LQFM202 (50 mg/kg) decreased the oedema in all hours evaluated (33%, 32%, 31% and 20%, respectively). In the carrageenan-pleurisy test, LQFM202 (50 mg/kg) reduced significantly the number of polymorphonuclear cells (34%), the myeloperoxidase activity (53%), TNF-α levels (47%), and IL-1ß levels (58.8%). When using zymosan, LQFM202 (50 mg/kg) reduced the number of polymorphonuclear and mononuclear cells (54% and 79%, respectively); and the myeloperoxidase activity (46%). These results suggest antinociceptive and anti-inflammatory effects of LQFM202.

Anti-inflammatory and antinociceptive activity profile of a new lead compound - LQFM219.

LQFM219 is a molecule designed from celecoxibe (COX-2 inhibitor) and darbufelone (inhibitor of COX-2 and 5-LOX) lead compounds through a molecular hybridisation strategy. Therefore, this work aimed to investigate the antinociceptive and anti-inflammatory activities of this new hybrid compound. The acute oral systemic toxicity of LQFM219 was evaluated via the neutral red uptake assay. Acetic acid-induced abdominal writhing and CFA-induced mechanical hyperalgesia were performed to evaluate the antinociceptive activity, and the anti-oedematogenic activity was studied by CFA-induced paw oedema and croton oil-induced ear oedema. Moreover, the acute anti-inflammatory activity was determined by carrageenan-induced pleurisy. In addition, cell migration, myeloperoxidase enzyme activity, and TNF-α and IL-1ß levels were determined in pleural exudate. Moreover, a redox assay was conducted using electroanalytical and DPPH methods. The results demonstrated that LQFM219 was classified as GHS category 4, and it showed better free radical scavenger activity compared to BHT. Besides, LQFM219 decreased the number of writhings induced by acetic acid and the response to the mechanical stimulus in the CFA-induced mechanical hyperalgesia test. Furthermore, LQFM219 reduced oedema formation, cell migration, and IL-1ß and TNF-α levels in the pleural cavity and inhibited myeloperoxidase enzyme activity. Thus, our study provides that the new pyrazole derivative, LQFM219, demonstrated low toxicity, antinociceptive and anti-inflammatory potential in vitro and in vivo.

Investigation of anti-inflammatory potential of 5-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione compound.

The aim of this study was to synthesise the novel di-tert-butylphenol compound, 5-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-thioxo-dihydropyrimidine-4,6(1H, 5H)-dione (LQFM218), and evaluate the potential anti-nociceptive and anti-inflammatory activities in acute (mice) models in vivo. The compound was tested on acute models of pain such as acetic acid-induced abdominal writhing, formalin-induced nociception and carrageenan-induced mechanical hyperalgesia. The anti-inflammatory activity was observed in paw oedema, carrageenan-induced pleurisy tests and inflammatory mediator quantification. Key findings: oral treatment with the LQFM218 (50, 100 or 200 mg/kg) reduced abdominal writhing (18.8%, 31.6% and 48.3%). The dose intermediate (100 mg/kg) reduced the nociception in the second phase of the formalin test (61.4%), and also showed anti-hyperalgic activity in carrageenan-induced mechanical hyperalgesia (until 42.3%). In acute inflammation models, the treatment of mice LQFM218 (100 mg/kg) reduced the paw oedema all the time (33.8%, 42.6%, 37.4% and 36%) and in pleurisy test reduced: polymorphonuclear cell migration (35.4%), myeloperoxidase activity (52.2%) and the levels of inflammatory mediators such as PGE2 (23.0%), TNF-α (67.6%) and IL-1ß (53.4%). The present study showed that LQFM218 effectively reduced the nociception and inflammation in different models, and its mechanism might be related to the reduction of PGE2 and pro-inflammatory cytokines. These findings show LQFM218 as a potential anti-inflammatory drug.

Design, synthesis and pharmacological assessment of new pyrazole compounds.

AIMS: This study investigated the antinociceptive and anti-inflammatory effects of new pyrazole compounds LQFM011(5), LQFM043(6) and LQFM044(7) as well as the mechanisms of action and acute in vitro toxicity. MAIN METHODS: The antinociceptive activity was evaluated using the acetic acid-induced abdominal writhing test, formalin-induced pain test and the Randall-Selitto test. The anti-inflammatory activity was evaluated using models of paw oedema and pleurisy induced by carrageenan; cell migration, the levels of tumour necrosis factor α (TNF-α) and myeloperoxidase (MPO) enzyme activity were evaluated. In addition, the ability to inhibit phospholipase A2 (PLA2) in vitro and docking in PLA2 were used. Acute oral systemic toxicity in mice was evaluated through the neutral red uptake assay. KEY FINDINGS: The synthesised compounds (5-7), delivered via gavage (p.o.) at 70, 140 or 280 µmol/kg, decreased the number of writhings induced by acetic acid; the three compounds (280 µmol/kg p.o.) reduced the paw licking time in the first and second phase of the formalin test and decreased the nociceptive threshold variation in the Randall-Selitto test. Furthermore, this dose reduced oedema formation, leucocyte migration (specifically through reduction in polymorphonuclear cell movement) and increased mononuclear cells. MPO activity and the levels of pro-inflammatory cytokines TNF-α were decreased. Evaluation of PLA2 inhibition via the docking simulation revealed more interactions of LQFM043R(6) and LQFM044(7), data that corroborated the half-maximal inhibitory concentration (IC50) of PLA2 inhibition in vitro. Therefore, LQFM011(5), LQFM043(6) and LQFM044(7) were classified with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as category 4.

Mechanisms involved in the antinociceptive and anti-inflammatory effects of a new triazole derivative: 5-[1-(4-fluorophenyl)-1H-1,2,3-triazol-4-yl]-1H-tetrazole (LQFM-096).

The aim of this study was to design, synthesize and evaluate the potential analgesic and anti-inflammatory effects of 5-[1-(4-fluorphenyl)-1H-1,2,3-triazol-4-yl]-1H-tetrazole-(LQFM-096: a new triazole compound) as well as to elucidate its possible mechanisms of action. The oral administration of LQFM-096 (10, 20 or 40 mg/kg) decreased the number of writhing in mice. At the dose of 20 mg/kg, LQFM-096 reduced the licking time at both neurogenic and inflammatory phases of the formalin test. Pretreatment with naloxone (3 mg/kg) and glibenclamide (3 mg/kg) attenuated the antinociceptive effect of LQFM-096 in the first phase of the formalin test. At the dose of 20 mg/kg, LQFM-096 also decreased the licking time in the acidified saline-induced and capsaicin-induced nociception. This effect was blocked by naloxone (3 mg/kg) pretreatment prior to the administration of LQFM-096. In addition, LQFM-096 inhibited hyperalgesia induced by carrageenan and PGE2. Naloxone (3 mg/kg) attenuated the effect of LQFM-096 through disinhibition of PGE2-induced hyperalgesia. The anti-inflammatory effect of LQFM-096 was demonstrated in carrageenan-induced oedema or pleurisy as well as CFA-induced arthritis. The hyperalgesia and cellular migration in CFA-induced arthritis were reduced significantly. Altogether, these findings suggest antinociceptive effect of LQFM-096 and implicate the modulation of ASICs/TRPV1 channels by opioid/KATP pathway. The anti-inflammatory effect of LQFM-096 was mediated by a reduction in oedema, leukocytes migration, TNF-α, PGE2 levels and myeloperoxidase activity.

Antinociceptive effects of new pyrazoles compounds mediated by the ASIC-1α channel, TRPV-1 and µMOR receptors.

Pyrazoles are potent medicinal scaffolds and exhibit a wide spectrum of biological activities, such as analgesic, anti-inflammatory and antipyretic. In this paper we report on research we have performed with the aim of continuing the biological evaluation of the regio-isomeric pyrazole compounds, LQFM-020 (fluorine, para position), LQFM-021 (fluorine, meta position), and LQFM-039 (fluorine, ortho position) in models of pain induced by acidified saline, capsaicin, and formalin. We also investigated the mechanisms of action of these compounds via electrophysiological analyses using the two-electrode voltage-clamp technique and heterologous expression in Xenopus laevis oocytes. This enabled us to study different potassium channel subtypes: the ASIC-1α channel, TRPV-1, and µMOR receptors. Our results indicate that LQFM-020, LQFM-021, and LQFM-039 (15, 30 or 60 mg.kg-1) compounds inhibited the nociceptive response induced by acidified saline in a dose-dependent manner. The dose of 30 mg.kg-1 inhibited the nociceptive response induced by capsaicin by 53.3%, 51.4%, and 52.1%, respectively. In addition, we found that naloxone reverses the antinociceptive effect produced by the compounds in both phases of the formalin test. In electrophysiological analyses, we observed that the LQFM-020, LQFM-021, and LQFM-039 compounds did not modulate voltage-gated K + channel subtypes. In contrast, all the compounds tested inhibited the ASIC-1α channel at pH 4.5, with IC50-values of 96.1, 91.6, and 235.2 µM, respectively. All compounds also inhibited the TRPV-1 channel with IC50-values of 139.1, 212.5, and 159.1 µM, respectively. In contrast to the ASIC-1α and TRPV-1 targets, all compounds showed agonist activity on the µMOR receptor with an EC50-value of 117.4, 98.9, and 86.3 µM, respectively. We thus conclude that the ASIC-1α, TRPV-1, and µMOR channels are targets that are directly involved in the antinociceptive effect of LQFM-020, LQFM-021, and LQFM-039. Furthermore, the modifications of the fluorine positions in the phenyl analogs do not change the analgesic effect. However, LQFM-039 showed lower interaction with ASIC-1α channel.

Molecular docking and pharmacological/toxicological assessment of a new compound designed from celecoxib and paracetamol by molecular hybridization.

Nonsteroidal anti-inflammatory drugs are commonly used worldwide; however, they have several adverse effects, evidencing the need for the development of new, more effective and safe anti-inflammatory and analgesic drugs. This research aimed to design, synthesize and carry out a pharmacological/toxicological investigation of LQFM-102, which was designed from celecoxib and paracetamol by molecular hybridization. To evaluate the analgesic effect of this compound, we performed formalin-induced pain, hot plate and tail flick tests. The anti-inflammatory effect of LQFM-102 was evaluated in carrageenan-induced paw oedema and pleurisy tests. The biochemical markers indicative of toxicity-AST, ALT, GSH, urea and creatinine-as well as the index of gastric lesion after prolonged administration of LQFM-102 were also analyzed. In addition, the interaction of LQFM-102 with COX enzymes was evaluated by molecular docking. In all experimental protocols, celecoxib or paracetamol was used as a positive control at equimolar doses to LQFM-102. LQFM-102 reduced the pain induced by formalin in both phases of the test. However, this compound did not increase the latency to thermal stimuli in the hot plate and tail flick tests, suggesting an involvement of peripheral mechanisms in this effect. Furthermore, LQFM-102 reduced paw oedema, the number of polymorphonuclear cells, myeloperoxidase activity and TNF-α and IL-1ß levels. Another interesting finding was the absence of alterations in the markers of hepatic and renal toxicity or lesions of gastric mucosa. In molecular docking simulations, LQFM-102 interacted with the key residues for activity and potency of cyclooxygenase enzymes, suggesting an inhibition of the activity of these enzymes.

Anti-inflammatory effect of a new piperazine derivative: (4-methylpiperazin-1-yl)(1-phenyl-1H-pyrazol-4-yl)methanone.

AIMS: This study investigates the anti-nociceptive and anti-inflammatory effects of new piperazine compound (LQFM182) as well as the toxicity acute in vitro. MAIN METHODS: To evaluate the anti-nociceptive activity, the acetic acid-induced abdominal writhing test, tail flick test and formalin-induced pain test were used. The anti-inflammatory activity was evaluated using the models of paw oedema and pleurisy induced by carrageenan and some inflammatory parameters were evaluated, including cell migration, myeloperoxidase enzyme activity and the levels of TNF-α and IL-1ß cytokines in pleural exudate. The acute oral systemic toxicity of LQFM182 in mice was evaluated through the neutral red uptake (nru) assay. KEY FINDINGS: LQFM182 (50, 100 or 200 mg/kg, p.o.) decreased the number of writhings induced by acetic acid in a dose-dependent manner, and an intermediate dose (100 mg/kg, p.o.) reduced the paw licking time of animals in the second phase of the formalin test. Furthermore, LQFM182 (100 mg/kg, p.o.) reduced oedema formation at all hours of the paw oedema induced by carrageenan test and in pleurisy test reduced cell migration from the reduction of polymorphonuclear cells, myeloperoxidase enzyme activity and the levels of pro-inflammatory cytokines IL-1ß and TNF-α. Therefore, it was classified in GHS category 300 < LD50 < 2000 mg/kg. SIGNIFICANCE: Reduction of the TNF-α and IL-1ß levels.

A new piperazine derivative: 1-(4-(3,5-di-tert-butyl-4-hydroxybenzyl) piperazin-1-yl)-2-methoxyethan-1-one with antioxidant and central activity.

In the scope of a research program aimed at developing new drugs for the treatment of central nervous system diseases, we describe herein the synthesis and pharmacological evaluation of 1-(4-(3,5-di-tert-butyl-4-hydroxybenzyl) piperazin-1-yl)-2-methoxyethan-1-one (LQFM180). This compound showed antioxidant activity in two models, electroanalytical assays, and DPPH activity. Moreover, in behavioral tests as the open field test LQFM180 (9.4, 18.8, and 37.6 mg/kg, per oral (p.o.)), we detected anxiolytic-like activity. In the sodium pentobarbital-induced sleep test, LQFM180, in all doses, decreased the latency to sleep and increased sleep duration, indicating central depressant activity; moreover, in the chimney test, LQFM180 did not alter motor activity. LQFM180 (18.8 mg/kg, p.o.) increased the time and number of entries on open arms in the elevated plus maze test, suggesting anxiolytic-like activity, which was reversed by NAN-190 and p-chlorophenylalanine, indicating a role of the serotonergic pathway on this effect. In the forced swimming test, LFQM180 (18.8 mg/kg, p.o.) decreased immobility time, suggesting antidepressant-like activity, which was reversed by monoaminergic antagonists, indicating a role for the serotonergic, noradrenergic, and dopaminergic pathways. Competition binding assays showed that LQFM180 was able to bind to the α1B, 5-HT1A, and D2 receptors, however, within the low micromolar range. We conclude that LQFM180 should be considered as a scaffold for drug candidate development.

Potential anti-inflammatory effect of LQFM-021 in carrageenan-induced inflammation: The role of nitric oxide.

The pyrazole compound LQFM-021 exhibits vasorelaxant, antinociceptive and anti-inflammatory activities. Furthermore, it has low toxicity, indicating that this compound may be considered to be a good prototype for the development of new analgesic/anti-inflammatory drugs. Therefore, the aim of this study was to investigate the potential anti-inflammatory activity of LQFM-021 using a model of carrageenan-induced inflammation as well as the mechanism of action and role of nitric oxide in this effect. Acute treatments with LQFM-021 (30 and 60 mg/kg p.o.) reduced paw edema formation dose-dependently 2 h after carrageenan injection. In the carrageenan-induced pleurisy test, LQFM-021 (30 mg/kg p.o.) reduced the leukocyte (polymorphonuclear) count in the pleural cavity, as well as decreased protein extravasation and myeloperoxidase activity. This dose of LQFM-021 increased the NO (nitrite/nitrate) and IL-4 levels and decreased the TNF-α and IL-1ß levels in the pleural cavity. Moreover, pre-treatment with L-NAME reversed the effect of LQFM-021 on NO, leukocyte migration, and the TNF-α and IL-1ß levels. Additionally, we observed that LQFM-021 showed weak inhibitory activity on cyclooxygenases, but reduced the PGE2 levels in the pleural cavity. Immunoblot analyses showed that LQFM-021 promoted a decrease in COX-2 levels and increase in iNOS levels. In conclusion, we demonstrated that LQFM-021 has marked anti-inflammatory activity by reducing polymorphonuclear recruitment, which is associated with the inhibition of the production of inflammatory cytokines and eicosanoids. In addition, we found that the synthase/release of nitric oxide promoted by LQFM-021 is essential for the anti-inflammatory effect observed.

Anxiolytic-like effect of 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol is mediated through the benzodiazepine and nicotinic pathways.

In this study, we proposed the design, synthesis of a new compound 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol (LQFM032), and pharmacological evaluation of its anxiolytic-like effect. This new compound was subjected to pharmacological screening referred to as Irwin test, prior to sodium pentobarbital-induced sleep, open-field and wire tests. The anxiolytic-like effect of this compound was evaluated using elevated plus maze and light-dark box tests. In addition, the mnemonic activity was evaluated through step-down test. In sodium pentobarbital-induced sleep test, LQFM032 decreased latency and increased duration of sleep. In the open-field test, LQFM032 altered behavioral parameter, that suggested anxiolytic-like activity, as increased in crossings and time spent at the center of open field. In the plus maze test and light-dark box test, the LQFM032 showed anxiolytic-like activity, increased entries and time spent on open arms, and increased in number of transitions and time spent on light area, respectively. Those effects was antagonized by flumazenil but not with 1-(2-Methoxyphenyl)-4-(4-phthalimidobutyl)piperazine (NAN-190). The LQFM032 did not alter mnemonic activity. Moreover, the anxiolytic-like activity of LQFM032 was antagonized by mecamylamine. In summary, LQFM032 showed benzodiazepine and nicotinic pathways mediated anxiolytic-like activity without altering the mnemonic activity.

Pharmacological and toxicological evaluations of the new pyrazole compound (LQFM-021) as potential analgesic and anti-inflammatory agents.

Chronic inflammation is a world health problem. There is a need to develop new anti-inflammatory and analgesic drugs with improved activity and reduced side effects. In this context, the aim of this study was to evaluate the antinociceptive and anti-inflammatory effects of the pyrazole compound LQFM-021 after acute and sub-chronic administration in rats submitted to a CFA-induced chronic arthritis model, as well as compare the toxicity of this compound to that of dipyrone, given throughout 7 days. Firstly, we observed that acute oral administration of the higher dose (130 µmol/kg) of LQFM-021 reduced paw lifting time (PET) and edema formation. These effects disappeared on the following day, requiring another dose to maintain the effects. This dose also promoted reduction of the polymorphonuclear recruitment in the synovial fluid. In another experiment, both treatments with LQFM-021, 65 µmol/kg twice a day and 130 µmol/kg once a day, produced a progressive and permanent reduction of the PET and edema, also reducing polymorphonuclear recruitment. However, the single treatment with 130 µmol/kg was more effective than the double treatment with 65 µmol/kg. LQFM-021 did not produce toxicity signs. However, dipyrone (130 µmol/kg once a day) promoted erosion of the epithelial cells and decreased mucus in the gastric mucosa. These data indicate that LQFM-021 produced antinociceptive and anti-inflammatory effects in CFA-induced arthritis in rats. These effects occurred in the absence of apparent toxic effects, indicating that the pyrazole compound LQFM-021 may be considered a good prototype for development of new analgesic/anti-inflammatory drug.

Design, synthesis and pharmacological evaluation of new anti-inflammatory compounds.

Inflammatory diseases and pain are among the main problems that significantly influence the lifestyle of millions of people and existing therapies are not always effective and can cause several adverse effects. In this context, the molecular modifications or synthesis of compounds continue being the best strategies for the identification of new compounds for the treatment of pain and inflammation. The aim of this study was to evaluate the analgesic and anti-inflammatory activities of new analogues of pyrazole compounds containing subunits N-phenyl-1-H-pirazoles and 1,3,4-oxadiazole-2(3H)-thione, LQFM-146, LQFM-147 and LQFM-148. In the acetic acid-induced abdominal writhing test, treatments with LQFM-146, LQFM-147 or LQFM-148 at doses 89, 178 and 356µmol/kg p.o. reduced the abdominal writhing in a dose-dependent manner. In the formalin test, these compounds at dose 178µmol/kg p.o. reduced the licking time only in inflammatory phase of this test, suggesting an antinociceptive effect dependent of the anti-inflammatory effect. The treatment with the three compounds in intermediate dose (178µmol/kg p.o.) reduced the edema at all tested time points in the carrageenan-induced paw edema test and reduced polymorphonuclears cell migration, activity myeloperoxidase and TNF-α levels in the carrageenan-induced pleurisy test. Our date suggest that the new compounds LQFM-146, LQFM-147 and LQFM-148 possess satisfactory anti-inflammatory and antinociceptive effects that involves the reduction of pro-inflammatory cytokines and inhibition of the myeloperoxidase enzyme.

Antinociceptive and anti-inflammatory effects of Memora nodosa and allantoin in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves and stems bark of Memora nodosa (Silva Manso) Miers (Bignoniaceae) are used in Brazilian traditional medicine in the treatment of external ulcers and wounds; its roots are used to treat abdominal pain and scabies. AIM OF THE STUDY: Our aim was to evaluate the antinociceptive and anti-inflammatory activities of Memora nodosa roots ethanolic extract (EMN) and allantoin, a secondary metabolite isolated from this plant. MATERIALS AND METHODS: The EMN and allantoin antinociceptive activity were evaluated in mice using both chemical and heat-induced pain models such as acetic acid-induced writhing, formalin and tail-flick tests. In the formalin test, a pre-treatment with naloxone was used to verify an involvement of opioid receptor in the antinociceptive effect of EMN and allantoin. Pre-treatment with glibenclemide was used to verity an involvement of ATP-sensitive K(+)channel in the allantoin antinociceptive effect. EMN and allantoin anti-inflammatory activity were assessed by carrageenan-induced paw edema and pleurisy tests. RESULTS: The treatment with EMN (250, 500 and 1000mg/kg, p.o.) inhibit the acetic acid and formalin (both phases)-induced nociception. However, just at doses 500 and 1000mg/kg increased the latency time in tail-flick test. These results suggest the involvement of both peripheral and central antinociceptive mechanisms. The treatment with allantoin (40, 60 and 80mg/kg p.o.) produced a dose-dependent antinociceptive effect in both phases of formalin-induced nociception test; allantoin (60mg/kg) was not able to increase the latency time in tail flick-test. The pre-treatment with naloxone completely reversed the EMN (1000mg/kg) and allantoin (60mg/kg) effect in the first phase of formalin test; and glibenclamide reversed the allantoin effect. The administration of EMN (250, 500 and 1000mg/kg) and allantoin (60mg/kg) showed significant anti-inflammatory activity in the whole carrageenan-induced paw edema. Furthermore, EMN and allantoin reduced the leukocytes migration and pleural exudate to the pleural cavity. CONCLUSION: EMN have significant antinociceptive and anti-inflammatory effects, which appear to be, at least in part, due to the presence of allantoin. However, allantoin is not responsible for the EMN central antinociceptive activity. Allantoin has peripheral antinociceptive activity that involves the opioid receptor and ATP-sensitive K(+)channels. Opioid receptors are also involved in the EMN antinociceptive activity. These findings support the use of Memora nodosa in popular medicine and demonstrate that this plant has therapeutic potential for the development of antinociceptive and anti-inflammatory phytomedicines.

Anti-nociceptive and anti-inflammatory activities of 4-[(1-phenyl-1H-pyrazol-4-yl) methyl] 1-piperazine carboxylic acid ethyl ester: A new piperazine derivative.

Piperazine compounds possess anti-infective, anti-carcinogenic, anxiolytic, hypotensive, anti-hypertensive and vasorelaxant properties and are attractive candidates for the development of new analgesic and anti-inflammatory drugs. This study investigates the anti-nociceptive and anti-inflammatory effects of piperazine derivative 4-[(1-phenyl-1H-pyrazol-4-yl) methyl]1-piperazine carboxylic acid ethyl ester (LQFM-008) and the involvement of the serotonergic pathway. In the formalin test, treatments with LQFM-008 (15 and 30mg/kg p.o.) reduced the licking time in both neurogenic and inflammatory phases of this test. In the tail flick and hot plate tests, LQFM008 treatment (15 and 30mg/kg p.o.) increased latency to thermal stimulus, suggesting the involvement of central mechanisms in the anti-nociceptive effect of LQFM-008. In the carrageenan-induced paw edema test, LQFM-008 (p.o.) at the doses of 15 and 30mg/kg reduced the edema at all tested time points, while the dose of 7.5mg/kg reduced the edema only for the first hour. LQFM-008 (30mg/kg p.o.) reduced both cell migration and protein exudation in the carrageenan-induced pleurisy test. Furthermore, pre-treatment with NAN-190 (0.6mg/kgi.p.) and PCPA (100mg/kgi.p.) antagonized the anti-nociceptive effect of LQFM-008 in both phases of the formalin test. Our data suggest that LQFM-008 possesses anti-inflammatory and anti-nociceptive effects mediated through the serotonergic pathway.

Involvement of the NO/cGMP/KATP pathway in the antinociceptive effect of the new pyrazole 5-(1-(3-fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazole (LQFM-021).

The pyrazol compounds are known to possess antipyretic, analgesic and anti-inflammatory activities. This study was conducted to investigate the peripheral antinociceptive effect of the pyrazole compound 5-(1-(3-Fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazole (LQFM-021) and involvement of opioid receptors and of the NO/cGMP/K(ATP) pathway. The oral treatments in mice with LQFM-021 (17, 75 or 300 mg/kg) decreased the number of writhing. In the formalin test, the treatments with LQFM-021 at doses of 15, 30 and 60 mg/kg reduced the licking time at both neurogenic and inflammatory phases of this test. The treatment of the animals with LQFM-021 (30 mg/kg) did not have antinociceptive effects in the tail-flick and hot plate tests. Furthermore, pre-treatment with naloxone (3 mg/kg i.p.), L-name (10 mg/kg i.p.), ODQ (10 mg/kg i.p.) or glibenclamide (3 mg/kg i.p.) antagonized the antinociceptive effect of LQFM-021 in both phases of the formalin test. In addition, it was also demonstrated that the treatments of mice with LQFM-021(15, 30 and 60 mg/kg) did not compromise the motor activity of the animals in the chimney test. Only the highest dose used in the antinociceptive study promoted changes in the open field test and pentobarbital-induced sleep test, thus ruling out possible false positive effects on nociception tests. Our data suggest that the peripheral antinociception effects of the LQFM-021 were mediated through the peripheral opioid receptors with activation of the NO/cGMP/KATP pathway.