Cyclooxygenase (COX) waa enzyme ka masuulka ah soo saarista prostaglandins ee arachidonic acid ee jirka. Waxaa jira laba isoforms ee enzyme: COX-1 iyo COX-2. COX-1 waxaa si buuxda loogu muujiyey unugyo badan waxayna ku lug leeyihiin ilaalinta hawlaha jireed ee caadiga ah. COX-2, dhanka kale, waxaa loo soo jiiday ka jawaab celinta kicinta bararka waxayna mas'uul ka tahay soo saarista prostaglandins ee dhexdhexaadiya xanuunka, qandhada, iyo bararka. Daawooyinka nonsteroid anti-inflammatory (NSAIDs) waxay u shaqeeyaan iyagoo joojinaya dhaqdhaqaaqa COX-1 iyo COX-2 labadaba, si ay u yareeyaan wax soo saarka prostaglandins waxayna yareeyaan xanuunka iyo bararka.