RESUMO
AIMS: 5-Lipoxygenase (5-LO) is the key enzyme of leukotriene (LT) biosynthesis and is critically involved in a number of inflammatory diseases such as arthritis, gout, bronchial asthma, atherosclerosis, and cancer. Because 5-LO contains critical nucleophilic amino acids, which are sensitive to electrophilic modifications, we determined the consequences of a drug-mediated intracellular release of nitric oxide (NO) on 5-LO product formation by human granulocytes and on 5-LO-dependent pulmonary inflammation in vivo. RESULTS: Clinically relevant concentrations of NO-releasing nonsteroidal anti-inflammatory drugs and other agents releasing NO intracellularly suppress 5-LO product synthesis in isolated human granulocytes via direct S-nitrosylation of 5-LO at the catalytically important cysteines 416 and 418. Furthermore, suppression of 5-LO product formation was observed in ionophore-stimulated human whole blood and in an animal model of pulmonary inflammation. INNOVATION: Here, we report for the first time that drugs releasing NO intracellularly are efficient 5-LO inhibitors in vitro and in vivo at least equivalent to approved 5-LO inhibitors. CONCLUSION: Our findings provide a novel mechanistic strategy for the development of a new class of drugs suppressing LT biosynthesis by site-directed nitrosylation. The results may also help to better understand the well-recognized anti-inflammatory clinically relevant actions of NO-releasing drugs. Furthermore, our study describes in detail a novel molecular mode of action of NO. Rebound Track: This work was rejected during standard peer review and rescued by Rebound Peer Review (Antioxid Redox Signal 16: 293-296, 2012) with the following serving as open reviewers: Angel Lanas, Hartmut Kühn, Joan Clària, Orina Belton. Antioxid. Redox Signal. 28, 1265-1285.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Araquidonato 5-Lipoxigenase/metabolismo , Antagonistas de Leucotrienos/farmacologia , Leucotrienos/metabolismo , Inibidores de Lipoxigenase/farmacologia , Óxido Nítrico/farmacologia , Animais , Aspirina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Inspired by nature: Natural product isopropylstilbene was identified as an inhibitor of soluble epoxide hydrolase exhibiting antiproliferative properties. Following the natural product inspired design approach, a library of (E)-styryl-1H-benzo[d]imidazoles was synthesized and evaluated with recombinant enzyme and on several cancer cell lines.
Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Estilbenos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Epóxido Hidrolases/metabolismo , Células HeLa , Células Hep G2 , Humanos , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Solubilidade , Estilbenos/síntese química , Estilbenos/química , Relação Estrutura-Atividade , Células U937RESUMO
Current research leads to the assumption that drugs affecting more than one target could result in a more efficient treatment of diseases and fewer safety concerns. Administration of drugs inhibiting only one branch of the arachidonic acid cascade is usually accompanied by side effects. We therefore designed and synthesized a library of hybrid molecules incorporating an imidazo[1,2-a]pyridine and an urea moiety as novel soluble epoxide hydrolase (sEH)/5-lipoxygenase (5-LO) dual inhibitors. Evaluation of the compounds was accomplished by in vitro testing using recombinant enzyme assays.
Assuntos
Araquidonato 5-Lipoxigenase/química , Epóxido Hidrolases/antagonistas & inibidores , Imidazóis/síntese química , Inibidores de Lipoxigenase/síntese química , Piridinas/síntese química , Ureia/análogos & derivados , Ureia/síntese química , Epóxido Hidrolases/química , Humanos , Imidazóis/química , Inibidores de Lipoxigenase/química , Piridinas/química , Proteínas Recombinantes/química , Relação Estrutura-Atividade , Ureia/químicaRESUMO
Microsomal prostaglandin E synthase 1 (mPGES-1) is a key enzyme of the arachidonic acid cascade. Its product PGE(2) plays an important role in various inflammatory processes, pain, fever, and cancer. Selective inhibition of mPGES-1 might be a promising step to avoid cyclooxygenase-related effects of NSAIDs. We studied a class of quinazolinone derivatives of the lead structure FR20 for their effects on the isolated human and murine enzymes, human HeLa cells, and in various settings of the whole blood assay. Novel compounds with direct enzyme inhibiting activity in the submicromolar range (IC(50): 0.13-0.37 µM) were designed using a bioisosteric replacement strategy and proved to be effective in both cells and human whole blood. Furthermore, pharmacological profiling of toxicity and eicosanoid screening with LC/MS-MS was applied to characterize this new class of mPGES-1 inhibitors.