Oxidative Stress: Pathological Driver in Chronic Neurodegenerative Diseases

Oxidative stress has become a common impetus of various diseases, including neurodegenerative diseases. This review introduces the generation of reactive oxygen species (ROSs) in the nervous system, the cellular oxidative damage, and the high sensitivity of the brain to ROSs. The literature review focuses on the roles of oxidative stress in neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). Oxidative stress occurs when excessively produced free radicals are beyond the capability of endogenous antioxidants to scavenge, leading to the oxidation of proteins, lipids, and nucleic acids, stimulating neuroinflammatory responses, causing neuronal dysfunction, senescence, and death. The dysfunctional mitochondria and aberrant activities of metabolic enzymes are the major source of ROSs. The high vulnerability of the nervous system to ROSs underlies the critical roles of oxidative stress in neurodegenerative diseases. Gene mutations and other risk factors promote the generation of ROSs, which have been considered a crucial force causing the main pathological features of AD, PD, HD, and ALS. As a result, antioxidants hold therapeutic potential in these neurodegenerative diseases. The elucidation of the pathogenic mechanisms of oxidative stress will facilitate the development of antioxidants for the treatment of these diseases.