Cyclooxygenase and lipoxygenase pathway enzyme (COX and LOX)

Cyclooxygenase and lipoxygenase pathway enzymes are two major families of iron-containing oxidative enzymes involved in the metabolism of arachidonic acid and related polyunsaturated fatty acids into bioactive lipid mediators known as eicosanoids[4][5][1]. Cyclooxygenases (COX; prostaglandin-endoperoxide synthase, PTGS) catalyze the conversion of arachidonic acid to prostaglandin H2 (PGH2), a precursor to prostanoids such as prostaglandins, prostacyclin, and thromboxanes, which play central roles in inflammation, pain, fever, platelet aggregation, and other physiological processes[5][2][3][6]. Two main COX isoforms exist in humans: COX-1 (constitutively expressed, physiologic homeostasis) and COX-2 (inducible, inflammation and disease contexts)[2][5][6]. Lipoxygenases (LOX) comprise a family of enzymes that oxygenate polyunsaturated fatty acids such as arachidonic acid, resulting in hydroperoxy derivatives that are further converted to leukotrienes, lipoxins, and hydroxyeicosatetraenoic acids (HETEs), key mediators in inflammation, allergy, asthma, and immune regulation[1][2][4]. Several LOX isoforms exist, defined by their regioselectivity (e.g., 5-LOX, 12-LOX, 15-LOX), each producing distinct sets of lipid mediators[4][1]. Both COX and LOX pathways are well-established therapeutic targets. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit COX activity to manage pain and inflammation, while leukotriene pathway modulators (e.g., zileuton, montelukast) target LOX products for asthma and allergy treatment[5][2]. Key safety challenges include gastrointestinal toxicity, cardiovascular risk (COX inhibitors), and hepatotoxicity (LOX inhibitors)[5].

Other names

prostaglandin-endoperoxide synthase (for cyclooxygenase)PTGS (for cyclooxygenase)COX (for cyclooxygenase)lipoxygenase (for lipoxygenase)LOX (for lipoxygenase)

Inhibition of prostaglandin synthesis (NSAIDs, COX inhibitors), Inhibition of leukotriene synthesis (LOX inhibitors), Selective COX-2 inhibition