Eicosatetraenoic acid (ETA) designates any straight chain 20:4 fatty acid. Eicosatetraenoic acid belongs to the family of eicosanoids, molecules synthesized from oxidized polyunsaturated fatty acids (PUFAs) to mediate cell-cell communication. The eicosanoids, working in tandem, contribute to a lipid signaling complex widely responsible for inducing an inflammatory immune response.[1] Common signs of inflammation are both internal and external, with effects like visible redness, pain in the surrounding area, swelling, and the sensation of heat—many of these an effect of varying eicosanoid species.[2] These effects are associated with and have been observed in patients with cancers and various neurological/metabolic disorders.[3]

See Essential Fatty Acid for nomenclature.

Two isomers, both of them essential fatty acids, are of particular interest:

Some chemistry sources define 'arachadonic acid' to designate any of the eicosatetraenoic acids. However, almost all writings in biology, medicine and nutrition limit the use of the term 'arachidonic acid' to all-cis-5,8,11,14-eicosatetraenoic acid (ω-6).

Related studies

ETA is found in green-lipped mussel and appears to act as dual inhibitor of arachidonic acid oxygenation by both the cyclooxygenase (COX) and lipoxygenase pathway.[4]

Mutants of Mortierella alpina 1S-4 is a fungus employed for producing arachidonic acid. These mutants produce larger amounts of ETA due to the expression of an ω-3-desaturase gene, typically responsible for the significant production of the more abundant PUFAs.[5]

In addition to their inflammatory nature, eicosanoids such as ETA can also contribute to an anti-inflammatory response.[5]

See also


  1. ^ Dennis EA, Norris PC (August 2015). "Eicosanoid storm in infection and inflammation". Nature Reviews. Immunology. 15 (8): 511–23. doi:10.1038/nri3859. PMC 4606863. PMID 26139350.
  2. ^ Lone AM, Taskén K (2013). "Proinflammatory and immunoregulatory roles of eicosanoids in T cells". Frontiers in Immunology. 4: 130. doi:10.3389/fimmu.2013.00130. PMC 3671288. PMID 23760108.
  3. ^ Deng H, Li W (April 2020). "Monoacylglycerol lipase inhibitors: modulators for lipid metabolism in cancer malignancy, neurological and metabolic disorders". Acta Pharmaceutica Sinica B. 10 (4): 582–602. doi:10.1016/j.apsb.2019.10.006. PMC 7161712. PMID 32322464.
  4. ^ Bierer TL, Bui LM (June 2002). "Improvement of arthritic signs in dogs fed green-lipped mussel (Perna canaliculus)". The Journal of Nutrition. 132 (6 Suppl 2): 1634S–6S. doi:10.1093/jn/132.6.1634S. PMID 12042477.
  5. ^ a b Okuda T, Ando A, Negoro H, Kikukawa H, Sakamoto T, Sakuradani E, Shimizu S, Ogawa J (September 2015). "Omega-3 eicosatetraenoic acid production by molecular breeding of the mutant strain S14 derived from Mortierella alpina 1S-4". Journal of Bioscience and Bioengineering. 120 (3): 299–304. doi:10.1016/j.jbiosc.2015.01.014. PMID 25845716.