Oxidative
stress describes the state of a cell where there is an imbalance between free
radical formation and antioxidants due to either excess formation of reactive
oxygen species (ROS) or inadequate antioxidant defence. It is very well known that
oxidative stress plays an important role in the pathophysiology of various
diseases through impaired intracellular redox homeostasis. To evaluate and
imply the excess production of ROS, various biomarkers are used and suggested,
yet it is also known that there is a lack of standardization and validation for
these methods. It is almost very difficult to measure ROS directly because of
their short half-life, yet it is still possible with a suitable technique. The
most frequently used biomarkers are represented by oxidized macromolecules such
as lipids, proteins, and nucleic acids, which are modified via ROS, and
also the amounts or activities of antioxidant molecules and enzymes,
respectively. There are also various genetic biomarkers measuring the susceptibility
of modification due to oxidative stress. However, the preferred biomarker would
be dependent on the aim of the study and the clinical relevance.
Keywords: Antioxidants, Oxidative biomarkers, Oxidative stress, Reactive oxygen species.
