Eicosapentaenoic acid

EPA and its metabolites act in the body largely by their interactions with the metabolites of arachidonic acid; see Essential fatty acid interactions for detail.
Eicosapentaenoic acid
Names
IUPAC name
(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid
Identifiers
10417-94-4 Yes
ChEBI CHEBI:28364 Yes
ChEMBL ChEMBL460026 Yes
ChemSpider 393682 Yes
DrugBank DB00159 Yes
Jmol-3D images Image
UNII AAN7QOV9EA Yes
Properties
C20H30O2
Molar mass 302.451 g/mol
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 Yes verify (what is: Yes/?)
Infobox references

Eicosapentaenoic acid (EPA or also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.

EPA is a polyunsaturated fatty acid (PUFA) that acts as a precursor for prostaglandin-3 (which inhibits platelet aggregation), thromboxane-3, and leukotriene-5 groups (all eicosanoids).

Sources

It is obtained in the human diet by eating oily fish or fish oil, e.g. cod liver, herring, mackerel, salmon, menhaden and sardine, and various types of edible seaweed phytoplankton. It is also found in human breast milk.

However, fish do not naturally produce EPA, but obtain it from the algae they consume.[1] It is available to humans from some non-animal sources (e.g. commercially, from microalgae). Microalgae are being developed as a commercial source.[2] EPA is not usually found in higher plants, but it has been reported in trace amounts in purslane.[3] In 2013, it was reported that a genetically modified form of the plant Camelina produced significant amounts EPA.[4][5]

The human body converts alpha-linolenic acid (ALA) to EPA. ALA is itself an essential fatty acid, an appropriate supply of which must be ensured. The efficiency of the conversion of ALA to EPA, however, is much lower than the absorption of EPA from food containing it. Because EPA is also a precursor to docosahexaenoic acid (DHA), ensuring a sufficient level of EPA on a diet containing neither EPA nor DHA is harder both because of the extra metabolic work required to synthesize EPA and because of the use of EPA to metabolize into DHA. Medical conditions like diabetes or certain allergies may significantly limit the human body's capacity for metabolization of EPA from ALA.

Clinical significance

Salmon is a rich source of EPA.

The US National Institute of Health's MedlinePlus lists medical conditions for which EPA (alone or in concert with other ω-3 sources) is known or thought to be an effective treatment.[6] Most of these involve its ability to lower inflammation.

Among omega-3 fatty acids, it is thought that EPA in particular may possess some beneficial potential in mental conditions, such as schizophrenia.[7][8]

Studies have suggested that EPA may be efficacious in treating depression. A 2009 meta analysis found that people taking omega-3 supplements with a higher EPA:DHA ratio experienced fewer depressive symptoms.[9]

EPA has an inhibitory effect on CYP2C9 and CYP2C19 hepatic enzymes. At high dose, it may also inhibit the activity of CYP2D6 and CYP3A4, important enzymes involved in drug metabolism.[10]

Research suggests that EPA improves the response of patients to chemotherapy, possibly by modulating the production of eicosanoid.[11]

References

  1. ↑ Yvonne Bishop-Weston. "Plant based sources of vegan & vegetarian Docosahexaenoic acid - DHA and Eicosapentaenoic acid EPA & Essential Fats". Retrieved 2008-08-05.
  2. ↑ Jess Halliday (12/01/2007). "Water 4 to introduce algae DHA/EPA as food ingredient". Retrieved 2007-02-09. Check date values in: |date= (help)
  3. ↑ Simopoulos, Artemis P (2002). "Omega-3 fatty acids in wild plants, nuts and seeds" (PDF). Asia Pacific Journal of Clinical Nutrition 11 (Suppl 2): S163–73. doi:10.1046/j.1440-6047.11.s.6.5.x.
  4. ↑ Ruiz-Lopez, N.; Haslam, R. P.; Napier, J. A.; Sayanova, O. (January 2014). "Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop". The Plant Journal 77 (2): 198–208. doi:10.1111/tpj.12378.
  5. ↑ Coghlan, Andy (4 January 2014) "Designed plant oozes vital fish oils"' New Scientist, volume 221, issue 2950, page 12, also available on the Internet at
  6. ↑ NIH Medline Plus. "MedlinePlus Herbs and Supplements: Omega-3 fatty acids, fish oil, alpha-linolenic acid". Retrieved February 14, 2006.
  7. ↑ Peet M, Brind J, Ramchand CN, Shah S, Vankar GK (2001). "Two double-blind placebo-controlled pilot studies of eicosapentaenoic acid in the treatment of schizophrenia" (PDF). Schizophrenia Research 49 (3): 243–51. doi:10.1016/S0920-9964(00)00083-9. PMID 11356585.
  8. ↑ Song C, Zhao S (Oct 2007). "Omega-3 fatty acid eicosapentaenoic acid. A new treatment for psychiatric and neurodegenerative diseases: a review of clinical investigations". Expert Opin Investig Drugs 16 (10): 1627–38. doi:10.1517/13543784.16.10.1627. PMID 17922626.
  9. ↑ Martins, JG (Oct 2009). "EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials.". Journal of the American College of Nutrition 28 (5): 525–42. doi:10.1080/07315724.2009.10719785. PMID 20439549.
  10. ↑ Yao HT, Chang YW, Lan SJ, Chen CT, Hsu JT, Yeh TK (2006). "The inhibitory effect of polyunsaturated fatty acids on human CYP enzymes". Life Sci. 79 (26): 2432–40. doi:10.1016/j.lfs.2006.08.016. PMID 16978661.
  11. ↑ Hardman,W Elaine (2004). "(n-3)Fatty Acids and Cancer Therapy". Journal of Nutrition 134 (12): 3427S–3430S. PMID 15570049.