Inhibitory effects of non-steroidal anti-inflammatory drugs on human myeloperoxidase
Date
1979
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Health & Medical Publishing Group
Abstract
Myeloperoxidase with an A420!280 ratio of 0,48 was prepared
from normal human leucocytes. This partially purified
preparation catalysed guaiacol oxidation, iodination of
bovine serum albumin and de-iodination of 1251-thyroxine.
Non-steroidal anti-inflammatory drugs (naproxen, indomethacin
and f1ufenamic acid) showed a significant inhibitory
effect on myeloperoxidase-catalysed iodination at
concentrations of 10"4M and higher. Guaiacol also inhibited
myeloperoxidase-catalysed iodination, and its iodination
inhibition curve was nearly identical to that obtained with
the anti-inflammatory drugs.
At concentrations between 10"'M and 10"M the antiinflammatory
drugs had very little or no effect on thyroxine
de-iodination. Flufenamic acid and indomethacin,
however, inhibited de-iodination significantly at a concentration
of 10'M.
It is postulated that non-steroidal anti-inflammatory
drugs may inhibit myeloperoxidase-catalysed protein iodination
by acting as oxidizable cofactors which compete
with other oxidiza'ble substrates for oxidants formed by
the peroxidase-hydrogen peroxide complex. In view of this
and because the myeloperoxidase-hydrogen peroxide
system may be involved in inflammatory tissue damage,
the possibility should be considered that the action of
non-steroidal anti-inflammatory drugs is at least partly
attributable to a radical scavenging effect or to sequestration
of oxidants.
Description
CITATION: Theron, C. N., Lubbe, S. & Van Zyl, A. 1979. Inhibitory effects of non-steroidal anti-inflammatory drugs on human myeloperoxidase. South African Medical Journal, 56:670-675.
The original publication is available at http://www.samj.org.za
The original publication is available at http://www.samj.org.za
Keywords
Anti-inflammatory agents