Systemic antioxidant pathways and enzymes

Systemic antioxidant pathways and enzymes comprise a sophisticated network of endogenous molecules responsible for neutralizing reactive oxygen species (ROS) and maintaining cellular redox balance. Key enzymatic components include superoxide dismutase (SOD), which dismutates superoxide radicals; catalase (CAT), which decomposes hydrogen peroxide; and glutathione peroxidase (GPx), which reduces lipid hydroperoxides (Ighodaro & Akinloye, 2018). The system is primarily regulated by the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), which orchestrates the expression of numerous cytoprotective genes in response to oxidative stress (He et al., 2020). Dysregulation of these pathways is a hallmark of oxidative stress, contributing significantly to the pathogenesis of chronic conditions such as Parkinson's disease, atherosclerosis, and various cancers (Sies & Jones, 2020). Therapeutic strategies include the use of Nrf2 activators like dimethyl fumarate or glutathione precursors like N-acetylcysteine to bolster cellular defenses. However, the 'antioxidant paradox' suggests that excessive suppression of ROS can be detrimental, as low levels of oxidants are essential for normal cellular signaling and immune function (Forman & Zhang, 2021). Consequently, this entry is categorized as incorrect for a specific therapeutic target because it describes a broad physiological system rather than a single molecular entity suitable for standardized drug-target classification.

Other names

Antioxidant defense systemEndogenous antioxidant networkRedox homeostasis pathwaysReactive oxygen species scavenging system

Pharmacological agents modulate these pathways by acting as precursors for antioxidant molecules (e.g., glutathione), directly scavenging free radicals, or activating the Nrf2-KEAP1 signaling pathway to induce the expression of phase II antioxidant enzymes.