Reactive oxygen species and oxidized cellular components (ROS)

Reactive oxygen species (ROS) are highly reactive oxygen-containing molecules, including free radicals like superoxide and non-radicals like hydrogen peroxide, which are natural byproducts of cellular metabolism (StatPearls, 2023). While they play critical roles in cell signaling and host defense, an imbalance between ROS production and antioxidant defenses leads to oxidative stress, resulting in the damage of cellular components such as lipids, proteins, and DNA (NIH, 2022). These oxidized cellular components, such as oxidized LDL or carbonylated proteins, often serve as pathological drivers in various diseases including atherosclerosis and neurodegeneration (PubMed, 2021). Therapeutically, ROS and their oxidized products are targeted by antioxidant scavengers and reducing agents to mitigate tissue damage (PubChem, 2024). However, targeting ROS is challenging due to their dual role in essential physiological signaling processes, where excessive suppression can lead to reductive stress (Wikipedia, 2024). This entry is considered incorrect as a specific therapeutic target because it represents a broad class of reactive chemicals and damaged byproducts rather than a single, discrete molecular entity or protein (UniProt, 2024).

Other names

Free radicalsOxidantsReactive oxygen speciesOxidized macromoleculesReactive nitrogen species (RNS)Oxidative stress markers

The primary mechanism involves the direct chemical neutralization or scavenging of free radicals and reactive species, thereby preventing the oxidation of vital cellular macromolecules (PubMed, 2020). Some agents act as sacrificial targets or electron donors to reduce already oxidized components, such as lipid peroxides, back to their stable forms (StatPearls, 2023).