Cyclooxygenase (COX)

An enzyme involved in the synthesis of nitric oxide, eicosanoids, prostaglandins, prostacyclins and thromboxanes from arachidonic acid. This enzyme thus plays an important role in inflammation, pain, fever, and embryo implantation, suppresses immunosurveillance, and stimulates tumorous growth. Inducible nitric oxide synthase specifically binds COX2, S-nitrosylates it, and enhances its catalytic activity. This system is important for inflammation responses (Kim SF et al 2005 Science 310:1966). Resveratrol, a product of grapes and the legume Cassia quinqueangulata, acts as a chemopreventive of the tumorigenic effect of cyclooxygenases. The common drug aspirin acetylates both COX-1 (prostaglandin-endoperoxyde synthase 1; 9q32-q33.3) and COX-2 (prostaglandin-endoperoxide synthase 2; 1q25.2-q25.3) and irreversibly inactivates COX-2. Acetylated COX-1 has antithrombotic (protection against heart diseases) as well as inflammatory effects (causing heartburn, etc.), whereas shutting off COX-2...