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
History of aspirin showed that NSAIDs such as aspirin worked by inhibiting cyclooxygenase, the enzyme responsible for converting arachidonic acid into a prostaglandin. Aspirin's effects on blood clotting (as an antiplatelet agent) were first noticed in 1950 by Lawrence Craven. Craven, a family doctor in California, had been directing tonsillectomy patients to chew Aspergum, an aspirin-laced chewing gum. He found that an unusual number of patients had to be hospitalized for severe bleeding, and that those patients had been using very high amounts of Aspergum. Craven began recommending daily aspirin to all his patients, and claimed that the patients who followed the aspirin