Discovery of novel analgesic and anti-inflammatory 3-arylamine-imidazo[1,2-a]pyridine symbiotic prototypes

Bioorg Med Chem. 2009 Jan 1;17(1):74-84. doi: 10.1016/j.bmc.2008.11.018. Epub 2008 Nov 17.

Abstract

We describe herein the design, synthesis and pharmacological evaluation of novel 3-arylamine-imidazo[1,2-a]pyridine derivatives structurally designed as novel symbiotic prototypes presenting analgesic and anti-inflammatory properties. The derivatives obtained were submitted to in vivo assays of nociception, hyperalgesia and inflammation, and to in vitro assays of human PGHS-2 inhibition. These assays allowed the identification of compound LASSBio-1135 (3a) as an anti-inflammatory and analgesic symbiotic prototype. This compound inhibited moderately the human PGHS-2 enzyme activity (IC(50)=18.5 microM) and reverted the capsaicin-induced thermal hyperalgesia (100 micromol/kg, po) similarly to p38 MAPK inhibitor SB-203580 (2). Additionally, LASSBio-1135 (3a) presented activity similar to celecoxib (1) regarding the reduction of the carrageenan-induced rat paw edema (33% of inhibition at 100 micromol/kg, po). We also discovered derivatives LASSBio-1140 (3c) and LASSBio-1141 (3e) as analgesic and anti-inflammatory prototypes, which were able to attenuate the capsaicin-induced thermal hyperalgesia (100 micromol/kg, po) and reduce the carrageenan-induced paw edema (ED(50)=11.5 micromol/kg (3.3mg/kg) and 14.5 micromol/kg (4.1mg/kg), respectively), being both more active than celecoxib (1), despite the fact that their effects involve a different mechanism of action. Additionally, derivative LASSBio-1145 (3j) showed remarkable analgesic (ED(50)=22.7 micromol/kg (8.9 mg/kg)) and anti-inflammatory (ED(50)=8.7 micromol/kg (3.4 mg/kg)) profile in vivo (100 micromol/kg; po), in AcOH-induced abdominal constrictions in mice and carrageenan-induced rat paw edema models, respectively, being a novel orally-active anti-inflammatory drug candidate that acts as a selective PGHS-2 inhibitor (IC(50)=2.8 microM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics / chemical synthesis*
  • Analgesics / pharmacology
  • Animals
  • Anti-Inflammatory Agents / chemical synthesis*
  • Anti-Inflammatory Agents / pharmacology
  • Cell Line
  • Cyclooxygenase 2 Inhibitors / chemical synthesis*
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Disease Models, Animal
  • Drug Design
  • Drug Discovery
  • Edema / drug therapy
  • Humans
  • Hyperalgesia / drug therapy
  • Pyridines / chemical synthesis*
  • Pyridines / pharmacology
  • Rats

Substances

  • Analgesics
  • Anti-Inflammatory Agents
  • Cyclooxygenase 2 Inhibitors
  • Pyridines