Oxidative Stress Mechanisms Oxidative stress is defined as an imbalance between the production of reactive oxygen and nitrogen species (RONS) and the body's antioxidant defense systems. While RONS play essential roles in cell signaling and immune defense at physiological levels, their excessive accumulation damages vital macromolecules, including lipids, proteins, and DNA. Key damage mechanisms include lipid peroxidation (e.g., malondialdehyde, 4-HNE) which compromises cell membranes, protein carbonylation which impairs enzymatic function, and DNA lesions (e.g., 8-oxodG) which cause genomic instability.

Aging Theories The Free Radical Theory of Aging (FRTA), proposed in 1956, posits that cumulative oxidative damage is the primary driver of aging. This theory has evolved to encompass the "Signaling Disruption Theory" and "oxi-inflamm-aging," ...