A Review of Various Oxidative Stress Testing Methods

Oxidative stress is caused by the presence of any of a number of reactive oxygen species (ROS) which the cell is unable to counterbalance. The result is damage to one or more biomolecules including DNA, RNA, proteins and lipids. Oxidative stress has been implicated in the natural aging process as well as a variety of disease states: Neoplastic- Hematological and Solid Tumor, Metabolic- Obesity and Diabetes, and Neurological- Alzheimer's and Parkinson's diseases.

The presence of oxidative stress may be tested in one of three ways: (1) direct measurement of the ROS; (2) measurement of the resulting damage to biomolecules; and (3) detection of antioxidant levels. Directly measuring ROS might seem the preferred method, but many reactive oxygen species are extremely unstable and difficult to measure directly. Because of this, many scientists prefer to measure the damage on proteins, DNA, RNA, lipids, or other biomolecules. While this is an indirect approach, many markers of damage are extremely stable and therefore provide a more reliable method to measure oxidative stress. Another approach is to measure the levels of antioxidant enzymes and other redox molecules which serve to counterbalance ROS generated in the cell. Assays are available to measure the activity of specific antioxidant enzymes, such as catalase and superoxide dismutase. Additionally, there are assays that can test the antioxidant capacity of certain biomolecules and food extracts.

The process of selecting assays to measure oxidative stress should begin with first determining the sample type to be studied. There are many markers of oxidative stress, but some are more easily detected in certain sample types (cells, tissues, urine, blood, etc).