Flavin-dependent antioxidant properties of a new series of meso-N,N'-dialkyl-imidazolium substituted manganese(III) porphyrins.

Published

Journal Article

A number of synthetic manganese complexes exhibit both in vitro and in vivo catalytic antioxidant activities. This study reports that the antioxidant potencies of a new series of meso-N,N'-dialkyl-imidazolium substituted manganese(III) porphyrins are dependent, in part, on their ability to redox cycle with endogenous flavin-dependent oxidoreductases. Inhibition of lipid peroxidation activities of these novel cationic porphyrins was compared using rat brain homogenate as a source of lipids and endogenous oxidoreductases. Iron and ascorbate was used as initiators of lipid peroxidation, and two indices of lipid peroxidation (thiobarbituric acid reactive species (TBARS) and F(2)-isoprostanes) were determined. All meso-N,N'-dialkyl-imidazolium substituted porphyrins tested were potent inhibitors of lipid peroxidation with IC(50) ranging from 0.1 to 34 microM with a metal-dependent potency of Mn(III)>Co(III)>Zn(II). A flavin-dependent oxidoreductase antioxidant process was supported by the ability of the diphenyleneiodonium chloride (DPI, a flavoenzyme inhibitor) to decrease the potency of Mn-porphyrins in the lipid peroxidation model and that Mn-porphyrins stimulate NADPH oxidation in rat brain homogenates. These data suggest that metalloporphyrins may have differential antioxidant effects in tissues due to the presence or absence of flavin-dependent oxidoreductases.

Full Text

Duke Authors

Cited Authors

  • Kachadourian, R; Johnson, CA; Min, E; Spasojevic, I; Day, BJ

Published Date

  • January 1, 2004

Published In

Volume / Issue

  • 67 / 1

Start / End Page

  • 77 - 85

PubMed ID

  • 14667930

Pubmed Central ID

  • 14667930

International Standard Serial Number (ISSN)

  • 0006-2952

Digital Object Identifier (DOI)

  • 10.1016/j.bcp.2003.08.036

Language

  • eng

Conference Location

  • England