Cyclooxygenase (COX) Activity Fluorometric Assay Kit

Cyclooxygenase (COX，EC1.14.99.1)， also known as prostaglandin-endoperoxide synthase (PTGS)， is the key rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandin H2. There are two main isoenzymes of COX: COX-1 and COX-2. COX-1 is constitutively expressed in most tissues and maintains physiological functions such as protecting gastrointestinal mucosa， regulating renal blood flow， and mediating platelet aggregation. In contrast， COX-2 is inducibly expressed and is typically strongly upregulated during inflammation， pain， or cellular injury， serving as a key mediator in inflammatory responses and pain perception. Nonsteroidal anti-inflammatory drugs (NSAIDs， e. g. ， aspirin， ibuprofen) exert their effects by inhibiting COX activity， while selective COX-2 inhibitors (e. g. ， celecoxib) can reduce gastrointestinal side effects. Therefore， cyclooxygenase represents a crucial target for anti-inflammatory therapy and drug development. Arachidonic acid is converted to prostaglandin G2 by the cyclooxygenase activity of COX; prostaglandin G2 is then transformed into prostaglandin H2 by the peroxidase activity of COX， while a fluorescent probe is oxidized to produce a strongly fluorescent product. COX activity is calculated by measuring the fluorescence intensity of this product at an excitation wavelength of 538 nm and an emission wavelength of 587 nm. Furthermore， by adding specific COX-1 or COX-2 inhibitors， the individual activities of COX-1 and COX-2 can be determined separately.