Development of an antioxidant assay to study oxidative potential of airborne particulate matter
<p>Oxidative potential is a measure of redox activity of airborne particulate matter (PM) and is often used as a surrogate to estimate one form of PM toxicity. The evaluation of oxidative potential in a physiologically relevant environment is always challenging. In this work, we developed a ch...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2019-12-01
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Series: | Atmospheric Measurement Techniques |
Online Access: | https://www.atmos-meas-tech.net/12/6529/2019/amt-12-6529-2019.pdf |
Summary: | <p>Oxidative potential is a measure of redox activity of airborne
particulate matter (PM) and is often used as a surrogate to estimate one
form of PM toxicity. The evaluation of oxidative potential in
a physiologically relevant environment is always challenging. In this work, we
developed a chromatographic method, employing an ultra-high-performance
liquid chromatograph coupled to a triple–quadruple mass spectrometer, to
determine the oxidative potential of PM from different sources. To this
purpose, we measured the PM-induced oxidation of glutathione, cysteine, and
ascorbic acid, and formation of glutathione disulfide and cystine, following
PM addition to simulated epithelial lining fluids, which, in addition to the
antioxidants, contained inorganic salts, a phospholipid, and proteins. The
new method showed high precision and, when applied to standard reference PM,
the oxidative potential was found to increase with the reaction time and PM
concentration in the lung fluid. The antioxidant depletion rates were
considerably higher than the rates found with the conventional
dithiothreitol assay, indicating the higher sensitivity of the new method.
The presence of the lung fluid inorganic species increased the oxidative
potential determined through glutathione and cysteine, but showed an
opposite effect with ascorbic acid, whereas the presence of proteins
resulted in a moderate decrease in the oxidative potential. In the presence
of PM<span class="inline-formula"><sub>2.5</sub></span>, glutathione and cysteine demonstrated similar depletion
patterns, which were noticeably different from that of ascorbic acid,
suggesting that cysteine could be used as an alternative to glutathione for
probing oxidative potential.</p> |
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ISSN: | 1867-1381 1867-8548 |