Effects of age and caloric restriction on lipid peroxidation:: Measurement of oxidative stress by F2-isoprostane levels

The free radical theory of aging proposes that the accumulation of oxidative damage is a key component of the aging process. The discovery of F-2-isoprostanes (F-2-isoPs) and their establishment as a sensitive and accurate biomarker of lipid peroxidation represents a major advance for measuring the oxidative stress status of an organism. We have shown that plasma free and total (free plus esterified) F-2-isoPs increase with age (185% and 66%, respectively), and that these increases are reduced by life-extending caloric restriction (50% and 23%, respectively). In addition, we found that levels of esterified F-2-isoPs increase 68% with age in liver, and 76% with age in kidney. Caloric restriction modulated the age-related increase, reducing the esterified F-2-isoPs levels 27% in liver and 35% in kidney. These age-related increases in esterified F-2-isoPs levels correlate well with DNA oxidation, as measured by 8-oxodeoxyguanosine production demonstrating that F-2-isoPs are an excellent biomarker for age-related changes in oxidative damage to membranes.