What is oxidative stress and name two biomarkers used to assess it?

• A. An imbalance between pro-oxidants and antioxidants causing cellular damage; biomarkers include malondialdehyde (MDA) and 8-oxo-dG.
• B. A process of increased energy production; biomarkers include ATP and glucose.
• C. A type of allergic reaction; biomarkers histamine and IgE.
• D. A purely genetic phenomenon; biomarkers DNA sequences.

Answer: (A)

Oxidative stress occurs when the balance tips in favor of pro-oxidants, such as reactive oxygen species, over the body’s antioxidant defenses, leading to damage of lipids, proteins, and DNA. To assess this condition, researchers look for specific signs of such damage. Malondialdehyde (MDA) is a common marker of lipid peroxidation, reflecting damage to cell membranes. 8-oxo-2'-deoxyguanosine (8-oxo-dG) indicates oxidative damage to DNA.

Other choices aren’t appropriate because they reflect processes not central to oxidative damage: ATP and glucose measure energy metabolism, not redox injury; histamine and IgE relate to allergic responses; and DNA sequences describe genetic information rather than oxidative damage.