History of aspirin tree in 1758 and noticed an astringency reminiscent of the standard—and expensive—ague cure of Peruvian bark. He collected, dried, and powdered a substantial amount of willow bark, and over the next five years tested it on a number of people sick with fever and agues. In his letter, Stone reported consistent success, describing willow extract's effects as identical to Peruvian bark, though a little less potent. (In fact, the active ingredient of Peruvian bark was quinine, which attacked the infectious cause of malaria, while the active ingredient of willow extract, salicin, relieved the symptoms of malaria but could not cure
Mechanism of action of aspirin form blood clots. Low-dose, long-term aspirin use irreversibly blocks the formation of thromboxane A in platelets, producing an inhibitory effect on platelet aggregation. This antiplatelet property makes aspirin useful for reducing the incidence of heart attacks; heart attacks are primarily caused by blood clots, and their reduction with the introduction of small amounts of aspirin has been seen to be an effective medical intervention. A dose of 40 mg of aspirin a day is able to inhibit a large proportion of maximum thromboxane A release provoked acutely, with the prostaglandin I2 synthesis being little affected; however, higher doses of aspirin