<prompt> Aspirin acts byCyclo oxygenase pathwayLipo oxygenase pathwayMembrane phospholipasesCyclic AMP  <response>: A Cyclo oxygenase pathway ASPIRIN prduces its antithrombotic effect by irreversibly acetylating and inhibiting platelet cyclo-oxygenase COX-1, a critical enzyme in the biosynthesis of thromboxane A2. At high doses, aspirin also inhibits COX-2, an inducible COX isoform found in endothelial cells and inflammatory cells. Analgesic action of aspirin is mainly due to obstructing of peripheral pain receptors and prevention of prostaglandin mediated sensitization of nerve endings. Aspirin some NSAIDs blocked PG generation by inhibiting cyclooxygenase COX enzyme. Aspirin, even in small doses, irreversibly inhibit TXA2 synthesis Aspirin resets the hypothalamic thermostat rapidly reduces fever by promoting heat loss but does not decrease heat production 