Lipidiperoksidaation

Lipid peroxidation is a process in which lipids undergo oxidation. This involves the degradation of unsaturated fatty acids within cell membranes and lipoproteins. Reactive oxygen species (ROS), such as free radicals, initiate the process by abstracting a hydrogen atom from a methylene group (CH2) adjacent to a double bond in a polyunsaturated fatty acid. This generates a lipid radical. This lipid radical then reacts with molecular oxygen to form a lipid peroxyl radical. The lipid peroxyl radical can then abstract a hydrogen atom from another fatty acid, propagating the chain reaction and leading to the formation of lipid hydroperoxides. These hydroperoxides are unstable and can break down into various reactive aldehydes and alkanes, including malondialdehyde and 4-hydroxynonenal. These breakdown products are cytotoxic and can damage cellular components, including proteins and DNA, contributing to oxidative stress and cellular dysfunction. Lipid peroxidation is implicated in various physiological and pathological processes, including aging, inflammation, and the development of diseases such as atherosclerosis and neurodegenerative disorders. Antioxidants play a crucial role in terminating or preventing the chain reactions of lipid peroxidation.