In vivo trypanosomicidal activity of imidazole- or pyrazole-based benzo[g]phthalazine derivatives against acute and chronic phases of Chagas disease

J Med Chem. 2011 Feb 24;54(4):970-9. doi: 10.1021/jm101198k. Epub 2011 Jan 13.

Abstract

The in vivo trypanosomicidal activity of the imidazole-based benzo[g]phthalazine derivatives 1-4 and of the new related pyrazole-based compounds 5 and 6 has been studied in both the acute and chronic phases of Chagas disease. As a rule, compounds 1-6 were more active and less toxic than benznidazole in the two stages of the disease, and the monosubstituted derivatives 2, 4, and 6 were more effective than their disubstituted analogs. Feasible mechanisms of action of compounds 1-6 against the parasite have been explored by considering their inhibitory effect on the Fe-SOD enzyme, the nature of the excreted metabolites and the ultrastructural alterations produced. A complementary histopathological analysis has confirmed that the monosubstituted derivatives are less toxic than the reference drug, with the behavior of the imidazole-based compound 4 being especially noteworthy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chagas Disease / drug therapy*
  • Chlorocebus aethiops
  • Female
  • Histocytochemistry
  • Humans
  • Imidazoles / chemical synthesis*
  • Imidazoles / chemistry
  • Imidazoles / pharmacology
  • Inhibitory Concentration 50
  • Magnetic Resonance Spectroscopy
  • Mice
  • Microscopy, Electron, Transmission
  • Phthalazines / chemical synthesis*
  • Phthalazines / chemistry
  • Phthalazines / pharmacology
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / chemistry
  • Pyrazoles / pharmacology
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrophotometry, Infrared
  • Structure-Activity Relationship
  • Superoxide Dismutase / antagonists & inhibitors
  • Trypanocidal Agents / chemical synthesis*
  • Trypanocidal Agents / chemistry
  • Trypanocidal Agents / pharmacology*
  • Trypanosoma cruzi / drug effects*
  • Trypanosoma cruzi / enzymology
  • Trypanosoma cruzi / growth & development
  • Trypanosoma cruzi / ultrastructure
  • Vero Cells

Substances

  • Imidazoles
  • Phthalazines
  • Pyrazoles
  • Trypanocidal Agents
  • Superoxide Dismutase