Oxidative Stress: Mechanisms, Quantification and its role in human aging

Oxidative stress refers to the imbalance between the production of oxidant species and the body’s ability to quench them using antioxidants, favoring the rise in oxidant levels. This leads to the damage of cellular macromolecules such as lipids, DNA, RNA, and proteins. The body’s ability to manage oxidative stress and maintain it at an optimum level is crucial for overall health. Oxidative damage, if left unmitigated, contributes to the aging process characterized by the progressive deterioration of physiological functions and cellular structures. Understanding the mechanisms of oxidative stress along with its reliable quantification can enable consistency and comparability in clinical practice across diseases. While direct quantification of oxidant species in the body would be ideal for assessing oxidative stress, it is not feasible owing to their high reactivity, short half-life, and quantification challenges using conventional techniques. Quantifying oxidative damage products and antioxidants pose as appropriate markers, indicating the degree of oxidative stress in the body. This review comprehensively discusses the mechanism of generation of key oxidant species, their sources, the beneficial roles played by them at low levels and the detrimental effects exerted by their elevated levels. The review also provides insights into the effective quantification techniques for damage products of lipids nucleic acids, and proteins along with the endogenous and exogenous antioxidant markers. Effective quantification of oxidative stress may improve our understanding on the phenomenon which may aid in maintaining cellular integrity, preventing age-associated diseases, and thereby promoting optimal well-being and longevity.