Reactive oxygen species and oxidized cellular thiols (ROS/Oxidized thiols)

Reactive oxygen species (ROS) and oxidized cellular thiols represent a broad class of chemically reactive molecules and modified proteins that serve as central mediators of oxidative stress and redox signaling (Sies & Jones, 2020). ROS, including superoxide and hydrogen peroxide, are natural byproducts of oxygen metabolism but can cause significant damage to DNA, lipids, and proteins when produced in excess (Forman & Torres, 2002). Oxidized cellular thiols, such as protein disulfides and sulfenic acids, reflect the redox state of the cell and often act as redox switches that alter protein function in response to oxidative environments (Giles et al., 2003). In many diseases, including cancer and neurodegeneration, the balance between ROS production and antioxidant defense is disrupted, leading to chronic inflammation and cell death (Circu & Aw, 2010). Therapeutic strategies targeting these species typically involve the use of antioxidants or reducing agents to neutralize ROS or restore the reduced state of critical protein thiols, thereby mitigating tissue damage (Rushworth & Megson, 2014). However, because ROS are also essential for normal signaling and immune function, non-specific targeting remains a significant therapeutic challenge (Halliwell, 2011).

Other names

ROSOxidative stress productsProtein thiolsSulfhydryl groupsRedox-active speciesReactive oxygen metabolites

Direct chemical neutralization (scavenging) of reactive oxygen species, enzymatic reduction of oxidized thiol groups (disulfides) back to sulfhydryls, and replenishment of the endogenous antioxidant pool, particularly glutathione (Rushworth & Megson, 2014).