Microsomal lipid peroxidation (LPO)

Hepatocyte microsome lipid peroxidation is a complex biochemical process involving the oxidative degradation of polyunsaturated fatty acids within the endoplasmic reticulum (microsomal fraction) of liver cells. This process is primarily initiated by reactive oxygen species (ROS) or free radicals, often generated during the phase I metabolism of xenobiotics by the cytochrome P450 system (NIH, PubChem). The resulting self-propagating chain reaction leads to the formation of reactive lipid hydroperoxides and toxic secondary metabolites like malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), which can cross-link proteins and damage DNA (PubMed: 15304161). While not a discrete molecular target like a receptor or enzyme, microsomal lipid peroxidation is a major pathological mechanism in drug-induced liver injury (DILI) and chronic liver diseases such as NASH (StatPearls). In the pharmaceutical industry, it is widely utilized as a standard in vitro toxicological endpoint to evaluate the pro-oxidant potential or hepatotoxicity of drug candidates. Protective strategies often involve the use of antioxidants that interrupt the radical chain reaction or agents that maintain glutathione levels to neutralize reactive intermediates (Wikipedia, LiverTox).

Other names

Hepatocyte microsomal lipid peroxidationHepatic lipid peroxidationMembrane lipid peroxidationOxidative degradation of lipids

Inhibition of the process is typically achieved through free radical scavenging, chelation of transition metals (like iron) that catalyze the reaction, or inhibition of cytochrome P450 enzymes (e.g., CYP2E1) that generate initiating reactive oxygen species.