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Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
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Is homocysteine a pro-oxidant?

B Zappacosta1, A Mordente, S Persichilli

  • 1Instituto di Chimica e Chimica Clinica, CNR Centro Chimica dei Recettori Università Cattolica, Rome, Italy. b.zappacosta@uniserv.ccr.rm.cnr.it

Free Radical Research
|January 5, 2002
PubMed

Insights

High homocysteine levels are linked to cardiovascular issues. However, this study found homocysteine does not significantly produce hydrogen peroxide (H2O2) and may even protect against oxidative damage, challenging its role in cardiovascular disease.

Area of Science:

  • Biochemistry
  • Cardiovascular Science
  • Oxidative Stress Research

Background:

  • Elevated plasma homocysteine is associated with arterial and venous thrombosis and atherosclerosis.
  • Oxidative damage from hydrogen peroxide (H2O2) produced during homocysteine oxidation is a proposed mechanism for these vascular conditions.

Purpose of the Study:

  • To accurately quantify H2O2 production during homocysteine oxidation.
  • To investigate the interaction of homocysteine with potent oxidants to determine its pro-oxidant potential.

Main Methods:

  • Utilized a sensitive assay to measure H2O2 production during homocysteine oxidation.
  • Evaluated homocysteine's interaction with hypochlorite, peroxynitrite, and ferrylmyoglobin.

Main Results:

  • Homocysteine oxidation yielded negligible H2O2 (1/4000 mole/mole ratio).
  • Homocysteine demonstrated significant inhibition of luminol and dihydrorhodamine oxidation by hypochlorite and peroxynitrite.
  • Homocysteine rapidly reduced ferrylmyoglobin to metmyoglobin.

Conclusions:

  • The findings challenge the established view that homocysteine oxidation is a primary driver of cardiovascular damage.
  • Homocysteine may possess antioxidant properties rather than pro-oxidant effects in the context of cardiovascular disease.

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