ReviewIsoprostanes: Novel Bioactive Products of Lipid Peroxidation

Abstract

Isoprostanes, are a novel group of prostaglandin-like compounds that are biosynthesised from esterified polyunsaturated fatty acid (PUFA) through a non-enzymatic free radical-catalysed reaction. Several of these compounds possess potent biological activity, as evidenced mainly through their pulmonary and renal vasoconstrictive effects, and have short half-lives. It has been shown that isoprostanes act as full or partial agonists through thromboxane receptors. Both human and experimental studies have indicated associations of isoprostanes and severe inflammatory conditions, ischemia-reperfusion, diabetes and atherosclerosis. Reports have shown that F2-isoprostanes are authentic biomarkers of lipid peroxidation and can be used as potential in vivo indicators of oxidant stress in various clinical conditions, as well as in evaluations of antioxidants or drugs for their free radical-scavenging properties. Higher levels of F2-isoprostanes have been found in the normal human pregnancy compared to non-pregnancy, but their physiological role has not been well studied so far. Since bioactive F2-isoprostanes are continuously formed in various tissues and large amounts of these potent compounds are found unmetabolised in their free acid form in the urine in normal basal conditions with a wide inter-individual variation, their role in the regulation of normal physiological functions could be of further biological interest, but has yet to be disclosed. Their potent biological activity has attracted great attention among scientists, since these compounds are found in humans and animals in both physiological and pathological conditions and can be used as reliable biomarkers of lipid peroxidation.

Oxidative stress and bone mineral density in elderly men: Antioxidant activity of alpha-tocopherol

“…A free radical-mediated arachidonic acid oxidation leads to the formation of isoprostanes in vivo, and 8-iso-PGF 2α is currently recognized as the gold marker determinant of in vivo oxidative stress in both humans and animals [53,54]. The measurement of 8-iso-PGF 2α in urine is considered to be more appropriate than in plasma when the basal levels are to be evaluated due to less fluctuation at higher basal levels in urine than in plasma [10].…”

Oxidative lipid, protein, and DNA damage as oxidative stress markers in vascular complications of diabetes mellitus

“…15-F2t-IsoP in the diabetic group with complications, not well-regulated with medication, would suggest an interaction between hyperglycemia and glucose variability with respect to the formation of reactive oxygen species. Increased levels of F2-isoprostanes can be found in the plasma or urine of patients a ected by several diseases, including diabetes, and are used as indicators of lipid peroxidation [24][25][26][27][28]. Increased isoprostane levels in diabetic patients with chronic heart failure have been shown to be correlated with antioxidant status and disease severity [29].…”

Activation of Peroxisome Proliferator–Activated Receptor (PPAR)δ Promotes Reversal of Multiple Metabolic Abnormalities, Reduces Oxidative Stress, and Increases Fatty Acid Oxidation in Moderately Obese Men

“…F 2 -isoprostanes appear to be the most reliable and clinically relevant markers of global oxidative stress in vivo in humans (36,37). The content of F 2 -isoprostanes was determined by using a validated radioimmunoassay with a specific antibody raised against F 2 -isoprostanes, as previously described (38).…”