Antioxidant effects of angiotensin-converting enzyme (ACE) inhibitors: free radical and oxidant scavenging are sulfhydryl dependent, but lipid peroxidation is inhibited by both sulfhydryl- and nonsulfhydryl-containing ACE inhibitors

J Cardiovasc Pharmacol. 1992 Mar;19(3):330-40. doi: 10.1097/00005344-199203000-00005.

Abstract

With an assay that generates free radicals (FR) through photooxidation of dianisidine sensitized by riboflavin, 4 x 10(-5) M captopril, epicaptopril (SQ 14,534, captopril's stereoisomer), zofenopril, and fentiapril [all sulfhydryl (-SH)-containing angiotensin-converting enzyme (ACE) inhibitors] were shown effective scavengers of nonsuperoxide free radicals whereas non-SH ACE inhibitors were not. Captopril was a more effective FR scavenger at pH 5.0 than at pH 7.5. Captopril (2 x 10(-5) M) also scavenged the other toxic oxygen species hydrogen peroxide and singlet oxygen and inhibited microsomal lipid peroxidation. Finally, captopril reduced the amount of superoxide anion-radical detected after neutrophils in whole blood were activated with zymosan, probably by inhibiting leukocyte superoxide production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin-Converting Enzyme Inhibitors / pharmacology*
  • Animals
  • Antioxidants / pharmacology*
  • Captopril / pharmacology
  • Dianisidine / pharmacology
  • Drug Interactions
  • Free Radical Scavengers
  • Free Radicals / metabolism
  • Granulocytes / drug effects
  • Granulocytes / metabolism
  • Lipid Peroxidation / drug effects*
  • Male
  • Microsomes, Liver / metabolism
  • Neutrophils / drug effects
  • Neutrophils / metabolism
  • Oxidation-Reduction
  • Oxygen / metabolism
  • Oxygen Consumption / drug effects
  • Photochemistry
  • Rats
  • Rats, Inbred Strains
  • Stimulation, Chemical
  • Sulfhydryl Compounds / pharmacology*
  • Superoxides / metabolism

Substances

  • Angiotensin-Converting Enzyme Inhibitors
  • Antioxidants
  • Free Radical Scavengers
  • Free Radicals
  • Sulfhydryl Compounds
  • Superoxides
  • Captopril
  • Dianisidine
  • Oxygen