F2-isoprostanes

F2-isoprostanes are a family of prostaglandin F2α-like compounds formed non-enzymatically by free radical-mediated peroxidation of arachidonic acid esterified in phospholipids; they are released into plasma and excreted in urine, where 8-iso-PGF2α (iPF2α-III) is the most widely measured species. Because their production depends on the rate of in vivo lipid peroxidation and is independent of dietary fatty acid intake at typical measurement conditions, urinary F2-isoprostanes are regarded as the most reliable in vivo biomarker of systemic oxidative stress. Elevated levels are consistently found in cigarette smokers, obese individuals, diabetics, and patients with cardiovascular disease or neurodegenerative disorders; values decrease with antioxidant-rich diets, caloric restriction, and exercise. In epidemiological studies, higher F2-isoprostane levels predict incident cardiovascular events and are associated with accelerated biological aging.