Comet assay as a reliable tool to enhance knowledge about antioxidant potential in natural matrices
Conference Paper
Overview
Overview
abstract
Evaluating the antioxidant activity in natural matrices has been
among our primary research challenges (1 ). However, most of the
established methodologies still have significant limitations and
interferences, especially in examining whether antioxidant activity
is actually translated from in vi1ro to in vivo systems. Furthermore,
several antioxidant in vitro assays still pose difficulties when
comparing results between different procedures and researchers;
in fact, there is not a unique method that can provide unequivocal
results {2). In alternative, we have also used cell culture, which
might represent a closer approach to in vivo systems, but this
methodology presents also operational problems: cells adapt to
the imposed oxidative stress {changing their properties). some
cells suffer mutation, while others segregate antioxidant
compounds {like pyruvate) and antioxidants are unstable in cell
culture media and may generate one or more pro-oxidants or
react with components of cell culture media. In addition, the
fluctuating 02 levels in cell culture media have very different
antioxidant compositions from in vivo extracellular fluids (3). In
vivo assays could represent a way to overcome these difficulties,
but, despite some developments, electron spin resonance
methods to detect free radicals in humans, immuno spin-trapping
and hydroxylation of aromatic compounds as a method to detect
hydroxyl radicals , have proven to be difficult {3). Moreover, the
number of reports identifying new potential antioxidant
compounds grows rapidly, demanding their fast and reliable
evaluation. In contrast, from the available literature, it is possible
to conclude that there have been major advances to accurately
measure end products of oxidative damage to proteins, lipids, and
DNA. Comet assay, in particular, might represent a suitable
solution due to its sensitiveness for detecting low levels of DNA
damage, small number of cells and low amount of the test
substance, low cost, ease of application and flexibility. In addition,
a high potential research field is focused on the link between
antioxidants and DNA repair, this being an indirect mechanism to
confront oxidative stress {4). Therefore, Comet assay comprises a
valuable complementary tool for our research on antioxidant
activity.
