Efficacy of a phenol derivative, isopropyl vanillate, as an anti-inflammatory agent: A new small molecule inhibitor of COX and neutrophil migration.

Inflammation is the response of the body to noxious stimuli such as infections, trauma, or injury. Experimental studies have shown that vanillic acid has anti-inflammatory effects. The objective of this study was to investigate the anti-inflammatory and antipyretic properties of the derivative of vanillic acid, isopropyl vanillate (ISP-VT), in mice. The results of this study indicated that ISP-VT reduced paw edema induced by carrageenan, dextran sulfate (DEX), compound 48/80, serotonin, bradykinin (BK), histamine (HIST), and prostaglandin E2 (PGE2). Furthermore, ISP-VT reduced recruitment of leukocytes and neutrophils and reduced its adhesion and rolling, and decreased myeloperoxidase enzyme activity (MPO), cytokine levels (tumor necrosis factor-α and interleukin-6), and vascular permeability. ISP-VT also significantly reduced the expression of cyclooxygenase-2 (COX-2) in subplantar tissue of mice. ISP-VT inhibited COX-2 selectively compared to the standard drug. Our results showed that although ISP-VT binds to COX-1, it is less toxic than indomethacin, as evidenced by MPO analysis of gastric tissue. Treatment with the ISP-VT significantly reduced rectal temperature in yeast-induced hyperthermia in mice. Our results showed that the main mechanism ISP-VT-induced anti-inflammatory activity is by inhibition of COX-2. In conclusion, our results indicate that ISP-VT has potential as an anti-inflammatory and antipyretic therapeutic compound.

Synthesis, in vitro and in vivo biological evaluation, COX-1/2 inhibition and molecular docking study of indole-N-acylhydrazone derivatives.

The objective of this work was to obtain and evaluate anti-inflammatory in vitro, in vivo and in silico potential of novel indole-N-acylhydrazone derivatives. In total, 10 new compounds (3a-j) were synthesized in satisfactory yields, through a condensation reaction in a single synthesis step. In the lymphoproliferation assay, using mice splenocytes, 3a and 3b showed inhibition of lymphocyte proliferation of 62.7% (±3.5) and 50.7% (±2), respectively, while dexamethasone presented an inhibition of 74.6% (±2.4). Moreover, compound 3b induced higher Th2 cytokines production in mice splenocytes cultures. The results for COX inhibition assays showed that compound 3b is a selective COX-2 inhibitor, but with less potency when compared to celecoxib, and compound 3a not presented selectivity towards COX-2. The molecular docking results suggest compounds 3a and 3b interact with the active site of COX-2 in similar conformations, but not with the active site of COX-1, and this may be the main reason to the COX-2 selectivity of compound 3b. In vivo carrageenan-induced paw edema assays were adopted for the confirmation of the anti-inflammatory activity. Compound 3b showed better results in suppressing edema at all tested concentrations and was able to induce an edema inhibition of 100% after 5 h of carrageenan injection at the 30 mg kg-1 dosage, corroborating with the COX inhibition and lymphoproliferation results. I addition to our experimental results, in silico analysis suggest that compounds 3a and 3b present a well-balanced profile between pharmacodynamics and pharmacokinetics. Thus, our preliminary results revealed the potentiality of a new COX-2 selective derivative in the modulation of the inflammatory process.

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.

Synthesis and antinociceptive evaluation of bioisosteres and hybrids of naproxen, ibuprofen and paracetamol.

The aim of this work was to design, synthesize and characterize the potential anti-nociceptive and anti-inflammatory activities of a new series of bioisosteres and hybrids from known non-steroidal anti-inflammatory drugs (NSAIDs). The compounds 4-(acetylamino)phenyl (2S)-2-(6-methoxy-2-naphthyl)propanoate (GUF-1) and 4-(acetylamino)phenyl 2-(R,S)-(4-isobutylphenyl)propanoate (GUF-2) were synthesized as hybrids (also known as heterodimers); whereas those named 2-(R,S)-(4-isobutylphenyl)-N-1H-tetrazol-5-ylpropanamide (GUF-3), (2S)-2-(6-methoxy-2-naphthyl)-N-1H-tetrazol-5-ylpropanamide (GUF-4), [2-(R,S)-N-hydroxy-2-[4-(2-methylpropyl)phenyl]propanamide] (GUF-5), and (2S)-N-hydroxy-2-(6-methoxy-2-naphthyl)propanamide (GUF-6) were synthesized as bioisosteres of the NSAIDs paracetamol, ibuprofen, and naproxen, respectively. All these compounds were characterized by spectroscopic and spectrometric analysis. Antinociceptive activity of GUF-1 to GUF-6 was evaluated using the formalin test in rats. Pharmacological responses of GUF-1, GUF-2 (hybrids), and GUF-5 (bioisostere) demonstrated significant antinociceptive effects; thus these compounds were assayed in an inflammation test like carrageenan-induced paw oedema in rats. Complete molecular docking of cyclooxygenase and the GUF-1 and GUF-2 hybrids showed high docking scores, compared to the reference drugs. Our data demonstrate that compounds GUF-1, GUF-2, and GUF-5 possesses antinociceptive and antiinflammatory activities resembling and improving those known for the traditional NSAIDs, paracetamol, naproxen and ibuprofen.

Isoindoline Derivatives of α-Amino Acids as Cyclooxygenase 1 and 2 Inhibitors.

IC50 values were obtained for two series of isoindolines derived from α-amino acids over cyclooxygenase 1 and 2 (COX-1 and COX-2). In order to explain the biological activity observed, a structure-activity relationship (SAR) model was achieved for the tested compounds and 19 reference compounds with known selective inhibitory activity, through the correlation of the binding energies calculated from rigid docking of the best conformations into the catalytic sites of COX-1 and COX-2, as well as their molecular descriptors: Log P, molecular weight (MW), volume (V), and solvation energy (Esol) versus their experimental IC50 values by MLR and LS-SVM methods. The model probed whether the COX-1 and COX-2 inhibitory activities of the isoindolines correlate with steric, hydrophobic, and thermodynamic parameters. The correlation values with MLR for COX-1 and COX-2 (r(2) = 0.4193 and r(2) = 0.5929) were optimized with LS-SVM until r(2) = 0.6818 for COX-1 and r(2) = 0.8985 for COX-2, resulting in a good predictive ability for COX-1 and -2 inhibition with this model. In conclusion, the data suggests that the physicochemical descriptors evaluated have an impact on the inhibitory activity and selectivity of isoindolines over COX-1 and COX-2.

Discovery of new orally effective analgesic and anti-inflammatory hybrid furoxanyl N-acylhydrazone derivatives.

We report the design, the synthesis and the biological evaluation of the analgesic and anti-inflammatory activities of furoxanyl N-acylhydrazones (furoxanyl-NAH) by applying molecular hybridization approach. Hybrid compounds with IL-8-release inhibition capabilities were identified. Among them, furoxanyl-NAH, 17, and benzofuroxanyl-derivative, 24, together with furoxanyl-NAH derivative, 31, without IL-8 inhibition displayed both orally analgesic and anti-inflammatory activities. These hybrid derivatives do not have additional LOX- or COX-inhibition activities. For instance, LOX-inhibition by furoxanyl-NAH derivative, 42, emerged as a structural lead to develop new inhibitors. The lack of mutagenicity of the active derivatives 17, 31, and 42, allow us to propose them as candidates for further clinical studies. These results confirmed the success in the exploitation of hybridization strategy for identification of novel N-acylhydrazones (NAH) with optimized activities.

Structure-activity relationships for the design of small-molecule inhibitors.

One of the most important stages of the drug discovery process is the generation of lead compounds. Structure-activity relationships (SAR) are well-integrated in modern drug discovery and have been largely used for the finding of new leads, scaffold generation, the optimization of receptor or enzyme affinity, as well as of pharmacokinetic and physicochemical properties. This review highlights some SAR approaches that can be used to optimize leads through a continuous, multi-step process based on knowledge gained at each stage, thus exploiting SAR in the design of selective, potent, small-molecule drug candidates.

Synthesis and pharmacological evaluation of new flosulide analogues, synthesized from natural safrole.

Four new aryl-sulfonamide derivatives (3a, 4a, 5a-b), having methylenedioxy group attached to phenyl ring, were prepared from natural safrole and evaluated as anti-inflammatory agents. The N-methylsulfonamide 3a and corresponding retrosulfonamide derivative 5a were more active than standards indomethacin and nimesulide, at the same molar concentration, in carrageenan-induced pleurisy assay.