Studies on the singlet oxygen scavenging mechanism of human macular pigment

Arch Biochem Biophys. 2010 Dec 1;504(1):56-60. doi: 10.1016/ Epub 2010 Aug 1.


It is thought that direct quenching of singlet oxygen and scavenging free radicals by macular pigment carotenoids is a major mechanism for their beneficial effects against light-induced oxidative stress. Corresponding data from human tissue remains unavailable, however. In the studies reported here, electron paramagnetic resonance (EPR) spectroscopy was used to measure light-induced singlet oxygen generation in post-mortem human macula and retinal pigment epithelium/choroid (RPE/choroid). Under white-light illumination, production of singlet oxygen was detected in RPE/choroid but not in macular tissue, and we show that exogenously added macular carotenoids can quench RPE/choroid singlet oxygen. When the singlet oxygen quenching ability of the macular carotenoids was investigated in solution, it was shown that a mixture of meso-zeaxanthin, zeaxanthin, and lutein in a ratio of 1:1:1 can quench more singlet oxygen than the individual carotenoids at the same total concentration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Carotenoids / deficiency
  • Carotenoids / metabolism
  • Choroid / metabolism
  • Electron Spin Resonance Spectroscopy
  • Female
  • Free Radical Scavengers / metabolism*
  • Humans
  • Macula Lutea / cytology
  • Macula Lutea / metabolism*
  • Male
  • Middle Aged
  • Pigments, Biological / metabolism*
  • Retinal Pigment Epithelium / metabolism
  • Singlet Oxygen / metabolism*


  • Free Radical Scavengers
  • Pigments, Biological
  • Singlet Oxygen
  • Carotenoids