ABSTRACT
Selective inhibition of pro-inflammatory prostaglandin (PG)E(2) formation via microsomal PGE(2) synthase-1 (mPGES-1) might be superior over inhibition of all cyclooxygenase (COX)-derived products by non-steroidal anti-inflammatory drugs (NSAIDs) and coxibs. We recently showed that benzo[g]indol-3-carboxylates potently suppress leukotriene biosynthesis by inhibiting 5-lipoxygenase. Here, we describe the discovery of benzo[g]indol-3-carboxylates as a novel class of potent mPGES-1 inhibitors (IC(50)0.1 microM). Ethyl 2-(3-chlorobenzyl)-5-hydroxy-1H-benzo[g]indole-3-carboxylate (compound 7a) inhibits human mPGES-1 in a cell-free assay (IC(50)=0.6 microM) as well as in intact A549 cells (IC(50)=2 microM), and suppressed PGE(2) pleural levels in rat carrageenan-induced pleurisy. Inhibition of cellular COX-1/2 activity was significantly less pronounced. Compound 7a significantly reduced inflammatory reactions in the carrageenan-induced mouse paw edema and rat pleurisy. Together, based on the select and potent inhibition of mPGES-1 and 5-lipoxygenase, benzo[g]indol-3-carboxylates possess potential as novel anti-inflammatory drugs with a valuable pharmacological profile.
Subject(s)
Carboxylic Acids/chemical synthesis , Carboxylic Acids/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Indoles/chemical synthesis , Indoles/pharmacology , Intramolecular Oxidoreductases/antagonists & inhibitors , Animals , Anti-Inflammatory Agents/chemical synthesis , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Carboxylic Acids/chemistry , Cell Line, Tumor , Edema/drug therapy , Edema/enzymology , Enzyme Inhibitors/chemistry , Humans , Indoles/chemistry , Inhibitory Concentration 50 , Intramolecular Oxidoreductases/metabolism , Magnetic Resonance Spectroscopy , Male , Mice , Microsomes , Pleurisy/drug therapy , Pleurisy/enzymology , Prostaglandin-E Synthases , Rats , Rats, Wistar , Spectrometry, Mass, Electrospray IonizationABSTRACT
Compounds that inhibit 5-lipoxygenase (5-LO), the key enzyme in the biosynthesis of leukotrienes (LTs), possess potential for the treatment of inflammatory and allergic diseases as well as of atherosclerosis and cancer. Here we present the design and the synthesis of a series of novel 2-amino-5-hydroxyindoles that potently inhibit isolated human recombinant 5-LO as well as 5-LO in polymorphonuclear leukocytes, exemplified by ethyl 2-[(3-chlorophenyl)amino]-5-hydroxy-1H-indole-3-carboxylate (3n, IC(50) value congruent with 300 nM). Introduction of an aryl/arylethylamino group or 4-arylpiperazin-1-yl residues into position 2 of the 5-hydroxyindoles was essential for biological activity. Whereas the 4-arylpiperazin-1-yl derivatives were more potent in cell-free assays as compared to intact cell test systems, aryl/arylethylamino derivatives inhibited 5-LO activity in intact cells and cell-free assays almost equally well. On the basis of their 5-LO inhibitory properties, these novel 2-amino-5-hydroxyindoles represent potential candidates for the pharmacological intervention with LT-associated diseases.
