Acetylsalicylic acid (ASA) affects arachidonic acid metabolites, dihydroxyeicosatrienoic acids and hydroxyeicosatetraenoic acids and suppresses Thromboxane B2 in human plasma and urine. A randomized single blinded trial evaluating the effects of ASA on polyunsaturated fatty acid metabolism within a period of 24 hours

Acetylsalicylic acid (ASA) is an analgesic and antipyretic drug which is also therapeutically used in various diseases, e.g. coronary artery disease. ASA inhibits the synthesis of polyunsaturated fatty acid derivatives such as prostaglandins. Nevertheless, the effect of ASA on polyunsaturated fatty acids (PUFAs), such as hydroxyeicosatetraenoic acids (HETE) and linoleic acid metabolites in humans are not completely known. This study addressed the influence of ASA on PUFA metabolism as well as possible diurnal changes of these substances in human plasma and urine. We discovered ASA-dependent differences, especially inhibition of arachidonic acid and its metabolites thromboxane B2, 11,12-DHET, 15-Oxo-ETE, 20-HETE and PGG2 as well as ASA-dependent effects in linoleic acid derivatives 13-HpODE and 9-HpODE and negligible ASA effects on alpha-linoleic acid derived metabolites. Moreover, we detected a diurnal rhythm in arachidonic acid plasma concentrations in male individuals that was independent of ASA effects.