Biomarkers of Oxidative Stress

The human body is constantly exposed to free radicals and oxidants, both exogenously via the environment (food, air, smoke, irradiation, etc.) and endogenously as by-products of normal metabolism. As these molecules are reactive and potentially pathogenic they need to be balanced by the activity of antioxidants, protective factors that eliminate oxidants or prevent their oxidation reactions. Thus, it is extremely important that cells maintain a well-controlled redox-balance. An imbalance in the redox-system will induce oxidative stress, a condition characterized by a surplus of unrestrained oxidants, ROS and free radicals. An important group of oxidant molecules in humans and animals is reactive oxygen species (ROS), which includes for instance hydrogen peroxide, superoxide and the hydroxyl radical. Superoxide and the hydroxyl radical are also categorized as free radicals, a group of molecules that are highly reactive due to the presence of unpaired electrons in their outer electron shells. All these molecules have the potential to react with proteins, DNA and other molecular cell and tissue components, leading to unwanted modifications and ultimately loss of function.
Several physiological processes, such as inflammation, ischemia/reperfusion, diabetes, obesity and kidney insufficiency and neurodegenerative diseases are associated with oxidative stress. Furthermore, hemolytic diseases involving destruction of erythrocytes in an uncontrolled manner, leads to high levels of cell-free Hb which can induce oxidative stress through its reactive heme-chelated iron. Additionally, neutrophil activation during infections results in oxidative stress, mainly due to production of superoxide anions and hypochloric acid by the enzymes NADPH oxidase and myeloperoxidase.
As the pathways and metabolic processes of disease development are complex and involve many components, the identification of mechanistic biomarkers to improve understanding of disease pathogenesis, aid in the diagnosis of disease, develop therapeutic strategies, and monitor treatment compatibility, performance, and complications is vitally important. The intention of this research topic is to describe various biomarkers of oxidative stress and discuss their possible usefulness in the topics described above. Novel ideas and strategies to discover further biomarkers and potential applications will also be described.