Lipid peroxides and lipid peroxyl radicals (LOOH/LOO•)

Lipid peroxides and lipid peroxyl radicals are highly reactive chemical species generated during the process of lipid peroxidation, which involves the oxidative degradation of polyunsaturated fatty acids (PUFAs) within cellular membranes (Ayala et al., 2014, Oxid. Med. Cell. Longev.). The process is initiated by reactive oxygen species (ROS) that abstract hydrogen atoms from lipids, forming lipid radicals that react with oxygen to produce lipid peroxyl radicals (LOO•) (Yin et al., 2011, Chem. Rev.). These radicals propagate a chain reaction, leading to the formation of lipid hydroperoxides (LOOH) and secondary reactive aldehydes like malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) (Gaschler & Stockwell, 2017, Biochem. Biophys. Res. Commun.). These species are critical mediators of ferroptosis, an iron-dependent form of regulated cell death that is distinct from apoptosis and necrosis (Dixon et al., 2012, Cell). Pathologically, the accumulation of lipid peroxides is implicated in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, as well as cardiovascular diseases like atherosclerosis (Niki, 2014, Free Radic. Biol. Med.). Therapeutic interventions target these species using radical-trapping antioxidants (RTAs) or by enhancing the activity of endogenous protective enzymes like glutathione peroxidase 4 (GPX4) (Conrad & Pratt, 2019, Nat. Chem. Biol.).

Other names

Lipid hydroperoxidesLipid peroxyl radicalsLOOHLOO•Lipid oxidation productsLipid radicals

Radical scavenging and chain-breaking antioxidant activity to neutralize lipid peroxyl radicals and prevent the propagation of lipid peroxidation chain reactions.