Lipid peroxidation of polyunsaturated lipids of subcellular membranes produces -

Lipofuscin is an insoluble pigment, also know n as lipochrome or wear-and-tear pigment. Lipofuscin is composed of polymers of lipids and phospholipids in complex with protein, suggesting that it is derived through lipid peroxidation of polyunsaturated lipids of subcellular membranes. Lipofuscin is not injurious to the cell or its functions. Its importance lies in its being a telltale sign of free radical injury and lipid peroxidation. The term is derived from the Latin (fuscus, brown), referring to brown lipid. In tissue sections, it appears as a yellow-brown, finely granular cytoplasmic, often perinuclear, pigment.