Quantitative measurement of the total, peroxyl radical-trapping antioxidant capability of human blood plasma by controlled peroxidation. The important contribution made by plasma proteins

FEBS Lett. 1985 Jul 22;187(1):33-7. doi: 10.1016/0014-5793(85)81208-4.


Plasma obtained from fasted humans has been analysed for total radical-trapping antioxidant content by subjecting it to controlled peroxidation using the thermal decomposition of water-soluble azobis (2-amidinopropane hydrochloride) at 37 degrees C to produce peroxyl radicals at a known, steady rate. It is found that the total radical-trapping antioxidant content is rather similar for the 7 subjects that have been tested and, furthermore, it is 10-20-times larger than the effect attributable to vitamin E alone. Although it is shown that urate and ascorbate augment the contribution from vitamin E, their contributions (21-34 and 0-2%, respectively) still leave 57-73% of the total antioxidant content unaccounted for. Evidence is presented to show that this previously unrecognized large reserve of antioxidant capacity is attributable to the plasma proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / blood*
  • Ascorbic Acid / blood
  • Blood Proteins / metabolism*
  • Free Radicals
  • Humans
  • Mathematics
  • Peroxides / blood*
  • Uric Acid / blood
  • Vitamin E / blood


  • Antioxidants
  • Blood Proteins
  • Free Radicals
  • Peroxides
  • Vitamin E
  • Uric Acid
  • Ascorbic Acid