Overview
Lipid peroxidation is the oxidative degradation of polyunsaturated fatty acids (PUFAs) in cell membranes by reactive oxygen species (ROS). The process generates toxic aldehydes — malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) — that damage proteins, DNA, and mitochondria. When iron-dependent and self-propagating, lipid peroxidation drives ferroptosis — the regulated cell death pathway central to neurodegeneration, CKD, and cancer.
Metal Drivers
Heavy metals are potent initiators of lipid peroxidation:
- Iron: Fe2+ catalyzes Fenton chemistry (Fe2+ + H2O2 → Fe3+ + OH• + OH−), generating hydroxyl radicals that attack membrane PUFAs. This is the basis of ferroptosis pendergrass 2026 microbial metallomics parkinsons ferroptosis riederer 2021 iron concert master parkinsons.
- Nickel: Induces lipid peroxidation in brain tissue, correlating with neurobehavioral deficits lamtai 2018 nickel neurobehavior.
- Cadmium, lead, mercury: All generate ROS and deplete glutathione (the primary endogenous lipid peroxidation defense), amplifying oxidative membrane damage mishra 2022 molecular mechanisms heavy metals ckd briffa 2020 heavy metal pollution environment toxicological effects humans.
Microbiome Connection
The gut microbiome modulates lipid peroxidation through:
- Glutathione production: Certain commensals contribute to glutathione synthesis; dysbiosis reduces the antioxidant pool.
- SCFA-mediated protection: Butyrate enhances mitochondrial function and reduces ROS generation.
- Iron ecology: Microbial iron acquisition (siderophores) alters the labile iron pool available for Fenton chemistry.
Cross-References
- ferroptosis — iron-dependent lipid peroxidation-driven cell death
- reactive oxygen species — ROS initiate the peroxidation chain
- glutathione — primary defense against lipid peroxidation
- iron — Fenton chemistry catalyst
- oxidative stress — broader context