<prompt> Isoprostanes are formed from archidonic acid by -CycloxygenaseLipoxygenaseEpoxide hydrolaseNon-enzymatic free radical peroxidation  <response>: isoprostanes are prostaglandin stereoisomers Cycloxygenase pathway Thrombaxne and prostaglandin are formed Lipoxyenase pathway leukotienes are formed these are formed by Non-enzymatic free radical peroxidation of AA these have potent vasoconstrictor activity and modulate WBC and platelet adhesion ref robbins 9th ed page 84 