Eicosanoid system

The eicosanoid system is a complex network of bioactive lipid mediators derived from 20-carbon fatty acids, primarily arachidonic acid [1]. These mediators, including prostaglandins, thromboxanes, and leukotrienes, function as autocrine and paracrine signaling molecules that regulate inflammation, vascular tone, and platelet aggregation [2]. The system is characterized by three major enzymatic pathways: the cyclooxygenase (COX) pathway, the lipoxygenase (LOX) pathway, and the cytochrome P450 pathway [3]. Dysregulation of these pathways is central to the pathogenesis of various inflammatory diseases, asthma, and cardiovascular conditions [4]. Pharmacological modulation of the eicosanoid system is a cornerstone of modern medicine, utilizing drugs like NSAIDs to block prostaglandin synthesis or leukotriene modifiers to treat respiratory ailments [5]. However, because these pathways are interconnected, inhibiting one branch can lead to the "biochemical shunting" of substrates into others, potentially causing adverse effects like aspirin-induced asthma [1].

Other names

Arachidonic acid cascadeEicosanoid signaling pathwayProstanoid and leukotriene systemsEicosanoid systems

Drugs targeting this system primarily function through the competitive or irreversible inhibition of biosynthetic enzymes (e.g., COX-1, COX-2, 5-LOX) or by acting as competitive antagonists at downstream G protein-coupled receptors (e.g., CysLT1, TP receptors) [1][4].