7-ketocholesterol

7-ketocholesterol (7-KC) is the predominant oxysterol formed by free radical-mediated auto-oxidation of cholesterol at the C-7 position, accumulating in oxidatively stressed lipid membranes and lipoproteins, and exerting cytotoxic, pro-apoptotic, and pro-atherogenic effects. Salivary 7-ketocholesterol measured by lipidomics reflects systemic cholesterol oxidation and lipid peroxidation, providing a measure of membrane oxidative damage complementary to aqueous-phase oxidative stress markers like 8-OHdG. Vejux et al. (2009) characterised 7-ketocholesterol as a key cytotoxic oxysterol whose elevation indicates significant oxidative lipid damage relevant to overtraining and chronic inflammatory states.