Trypanosoma cruzi dihydrolipoamide dehydrogenase as target of reactive metabolites generated by cytochrome c/hydrogen peroxide (or linoleic acid hydroperoxide)/phenol systems

Free Radic Res. 2010 Nov;44(11):1345-58. doi: 10.3109/10715762.2010.507669.

Abstract

This study determines that cytochrome c (cyt c) catalyses the oxidation of phenol compounds (Phen) in the presence of H2O2 or linoleic acid hydroperoxide (LOOH), generating Phen-derived free radicals or other reactive metabolites. These products irreversibly inactivated the dihydrolipoamide dehydrogenase from Trypanosoma cruzi (T cruzi LADH), depending on: the Phen structure, peroxide type, activated cyt c, incubation time and presence of an antioxidant. Nordihydroguaiaretic acid (NDGA) and caffeic acid (CAFF) with cyt c/H2O2 or cyt c/LOOH were the most effective inhibitors of T cruzi LADH. The comparison of inactivation values for T cruzi and mammalian heart enzymes demonstrated a greater sensitivity of T cruzi LADH to Phen. GSH, N-acetylcysteine, NAD(P)H, ascorbate and trolox, prevented T cruzi LADH inactivation by acetaminophen. The role of the Phen as potential trypanocidal systems is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytochromes c / chemistry*
  • Cytochromes c / metabolism
  • Cytochromes c / pharmacology
  • Dihydrolipoamide Dehydrogenase / metabolism*
  • Hydrogen Peroxide / chemistry
  • Hydrogen Peroxide / metabolism
  • Hydrogen Peroxide / pharmacology
  • Linoleic Acid / chemistry
  • Linoleic Acid / metabolism
  • Linoleic Acid / pharmacology
  • Oxidants / pharmacology
  • Oxidation-Reduction
  • Phenols / chemistry
  • Phenols / metabolism
  • Phenols / pharmacology
  • Protozoan Proteins / metabolism*
  • Swine
  • Trypanosoma cruzi / metabolism*

Substances

  • Oxidants
  • Phenols
  • Protozoan Proteins
  • Cytochromes c
  • Linoleic Acid
  • Hydrogen Peroxide
  • Dihydrolipoamide Dehydrogenase