Pathways in biosynthesis of eicosanoids from arachidonic acid: there are parallel paths from EPA & DGLA.
Eicosanoids are signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs) that are, similar to arachidonic acid, around 20 carbon units in length. Eicosanoids are a sub-category of oxylipins, i.e. oxidized fatty acids of diverse carbon units in length, and are distinguished from other oxylipins by their overwhelming importance as cell signaling molecules. Eicosanoids function in diverse physiological systems and pathological processes such as: mounting or inhibiting inflammation, allergy, fever and other immune responses; regulating the abortion of pregnancy and normal childbirth; contributing to the perception of pain; regulating cell growth; controlling blood pressure; and modulating the regional flow of blood to tissues. In performing these roles, eicosanoids most often act as autocrine signaling agents to impact their cells of origin or as paracrine signaling agents to impact cells in the proximity of their cells of origin. Some eicosanoids, such as prostaglandins, may also have endocrine roles as hormones to influence the function of distant cells.[1][2]
There are multiple subfamilies of eicosanoids, including most prominently the prostaglandins, thromboxanes, leukotrienes, lipoxins, resolvins, and eoxins.[1] For each subfamily, there is the potential to have at least 4 separate series of metabolites, two series derived from ω-6 PUFAs (arachidonic and dihomo-gamma-linolenic acids), one series derived from the ω-3 PUFA (eicosapentaenoic acid), and one series derived from the ω-9 PUFA (mead acid). This subfamily distinction is important. Mammals, including humans, are unable to convert ω-6 into ω-3 PUFA. In consequence, tissue levels of the ω-6 and ω-3 PUFAs and their corresponding eicosanoid metabolites link directly to the amount of dietary ω-6 versus ω-3 PUFAs consumed.[3] Since certain of the ω-6 and ω-3 PUFA series of metabolites have almost diametrically opposing physiological and pathological activities, it has often been suggested that the deleterious consequences associated with the consumption of ω-6 PUFA-rich diets reflects excessive production and activities of ω-6 PUFA-derived eicosanoids, while the beneficial effects associated with the consumption of ω-3 PUFA-rich diets reflect the excessive production and activities of ω-3 PUFA-derived eicosanoids.[4][5][6][7] In this view, the opposing effects of ω-6 PUFA-derived and ω-3 PUFA-derived eicosanoids on key target cells underlie the detrimental and beneficial effects of ω-6 and ω-3 PUFA-rich diets on inflammation and allergy reactions, atherosclerosis, hypertension, cancer growth, and a host of other processes.
^ ab"Eicosanoid Synthesis and Metabolism: Prostaglandins, Thromboxanes, Leukotrienes, Lipoxins". The Medical Biochemistry Page. 2024. Retrieved 9 April 2024.
^"15.2C: Chemistry of Hormones". Medicine LibreTexts. 2018-07-21. Retrieved 2024-04-09.
^Edwards IJ, O'Flaherty JT (2008). "Omega-3 Fatty Acids and PPARgamma in Cancer". PPAR Research. 2008: 358052. doi:10.1155/2008/358052. PMC 2526161. PMID 18769551.
^DeCaterina, R; Basta, G (June 2001). "n-3 Fatty acids and the inflammatory response – biological background". European Heart Journal Supplements. 3, Suppl D: D42–D49. doi:10.1016/S1520-765X(01)90118-X. S2CID 22691568.
^Funk, Colin D. (30 November 2001). "Prostaglandins and Leukotrienes: Advances in Eicosanoid Biology". Science. 294 (5548): 1871–1875. Bibcode:2001Sci...294.1871F. doi:10.1126/science.294.5548.1871. PMID 11729303.
^Piomelli, Daniele (2000). "Arachidonic Acid". Neuropsychopharmacology: The Fifth Generation of Progress. Archived from the original on 2006-07-15. Retrieved 2006-03-03.
^Soberman, Roy J.; Christmas, Peter (2003). "The organization and consequences of eicosanoid signaling". J. Clin. Invest. 111 (8): 1107–1113. doi:10.1172/JCI18338. PMC 152944. PMID 12697726.
Eicosanoids are signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs)...
(also called prostaglandin I2 or PGI2) is a prostaglandin member of the eicosanoid family of lipid molecules. It inhibits platelet activation and is also...
Nonclassic eicosanoids are biologically active signaling molecules made by oxygenation of twenty-carbon fatty acids other than the classic eicosanoids. "Eicosanoid"...
Most of the eicosanoid receptors are integral membrane protein G protein-coupled receptors (GPCRs) that bind and respond to eicosanoid signaling molecules...
along with the major eicosanoids from AA, EPA, and DGLA. Dietary ω-3 and GLA counter the inflammatory effects of AA's eicosanoids in three ways: displacement...
Prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have...
In molecular biology the MAPEG (Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism) family of proteins are a group of membrane associated...
and oils. Examples of biologically important fatty acids include the eicosanoids, derived primarily from arachidonic acid and eicosapentaenoic acid, that...
(when combatting bacterial infection for example) and pro-inflammatory eicosanoids have completed their function, healing proceeds in 4 phases. In the recall...
release vasoactive amines such as histamine and serotonin, as well as eicosanoids such as prostaglandin E2 and leukotriene B4 to remodel the local vasculature...
inflammatory exudate for up to 15 hours, although there was less effect on eicosanoid production when compared to the effects produced by NSAIDs such as phenylbutazone...
Prostaglandin E synthase (EC 5.3.99.3, or PGE synthase) is an enzyme involved in eicosanoid and glutathione metabolism, a member of MAPEG family. It generates prostaglandin...
contains 20 carbon atoms, including a 5-carbon ring. They are a subclass of eicosanoids and form the prostanoid class of fatty acid derivatives. The prostaglandins...
membrane or from diet. Eicosanoids initiate either autocrine stimulation or paracrine stimulation. There are two main types of eicosanoids: prostaglandins and...
ω-6 strongly affects function. They are modified to make the classic eicosanoids (affecting inflammation and many other cellular functions) the endocannabinoids...
Thromboxane is a member of the family of lipids known as eicosanoids. The two major thromboxanes are thromboxane A2 and thromboxane B2. The distinguishing...
aminoalkylindoles, 1,5-diarylpyrazoles, quinolines, and arylsulfonamides as well as eicosanoids related to endocannabinoids. Medical uses include the treatment of nausea...
family of eicosanoids, molecules synthesized from oxidized polyunsaturated fatty acids (PUFAs) to mediate cell-cell communication. The eicosanoids, working...
hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and...
Leukotrienes are a family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachidonic acid (AA) and the essential fatty...
hydroxeicosatetraenoic acids, e.g. 18-HETE, 17-HETE, and 16-HETE, see eicosanoid and lipoxygenase pages. This disambiguation page lists articles associated...
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