Eicosapentaenoic acid

Chembox new
Name = Eicosapentaenoic acid
ImageFile = EPAnumbering.png ImageSize = 400px
ImageName = Eicosapentaenoic acid
IUPACName = (5Z,8Z,11Z,14Z,17Z)-icosa-
5,8,11,14,17-pentaenoic acid
Section1 = Chembox Identifiers
CASNo = 1553-41-9
SMILES = CCC=CCC=CCC=CCC=CCC=CCCCC(=O)O
Section2 = Chembox Properties
Formula = C₂₀H₃₀O₂
MolarMass = 302.451 g/mol
MeltingPt =

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 and its metabolites act in the body largely by their interactions with the metabolites of arachidonic acid; see Essential fatty acid interactions for detail."EPA is a polyunsaturated fatty acid that acts as a precursor for prostaglandin-3 (which inhibits platelet aggregation), thromboxane-3, and leukotriene-5 groups (all eicosanoids).

ources

It is obtained in the human diet by eating oily fish or fish oil—cod liver, herring, mackerel, salmon, menhaden and sardine. It is also found in human breast milk.

However, fish do not naturally produce EPA, but obtain it from the algae they consume.cite web|url=http://www.vegetarian-dha-epa.co.uk/|title=Plant based sources of vegan & vegetarian Docosahexaenoic acid - DHA and Eicosapentaenoic acid EPA & Essential Fats|author=Yvonne Bishop-Weston|accessdate=2008-08-05] It is available to humans from some non-animal sources (eg, commercially, from spirulina and microalgae). Microalgae are being developed as a commercial source.cite web|url=http://www.nutraingredients.com/news/ng.asp?n=73324-water-omega-algae|title=Water 4 to introduce algae DHA/EPA as food ingredient|author=Jess Halliday |date=12/01/2007 |accessdate=2007-02-09] EPA is not usually found in higher plants, but it has been reported in trace amounts in purslane.cite journal|url=http://www.healthyeatingclub.org/APJCN/Volume11/vol11sup6/S163.pdf
author= Simopoulos, Artemis P |year=2002|title=Omega-3 fatty acids in wild plants, nuts and seeds
journal=Asia Pacific Journal of Clinical Nutrition|volume= 11 |issue=s6|pages= S163–S173
doi=10.1046/j.1440-6047.11.s.6.5.|accessdate=2007-02-09|format=Dead link|date=May 2008|doi_brokendate=2008-06-22] Microalgae, and supplements derived from it, are excellent alternative sources of EPA and other fatty acids, since fish often contain toxins due to pollution.

The human body can (and in case of a purely vegetarian diet often must, unless the aforementioned algae or supplements derived from them are consumed) also convert α-linolenic acid (ALA) to EPA, but this is much less efficient than the resorption of EPA from food containing it, and ALA is itself an essential fatty acid, an appropriate supply of which must be ensured. 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 DHA. Medical conditions like diabetes or certain allergies may significantly limit the human body's capacity for metabolization of EPA from ALA. [ [http://www.foodsforlife.org.uk/nutrition/vegetarian-DHA-EPA.html Plant based sources of vegan & Vegetarian DHA & EPA and Omega 3 essential fatty acids ] ]

Clinical significance

The US National Institute of Health's MedlinePlus lists a large number of conditions in which EPA (alone or in concert with other ω-3 sources) is known or thought to be effective.cite web|url=http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-fishoil.html | title=MedlinePlus Herbs and Supplements: Omega-3 fatty acids, fish oil, alpha-linolenic acid | author = NIH Medline Plus| accessmonthday= February 14 |accessyear=2006] Most of these involve its ability to lower inflammation.

Among omega-3 fatty acids, in particular EPA is thought to possess beneficial potential in mental conditions, such as schizophrenia.cite journal |author=Peet M, Brind J, Ramchand CN, Shah S, Vankar GK |title=Two double-blind placebo-controlled pilot studies of eicosapentaenoic acid in the treatment of schizophrenia
url=http://jerrycott.com/user/peet.pdf |journal=Schizophrenia Research |volume=49 |issue=3 |pages=243–51 |year=2001 |pmid=11356585 |doi= 10.1016/S0920-9964(00)00083-9|accessdate=2007-12-21] [Song C., Zhao S. "Omega-3 fatty acid eicosapentaenoic acid. A new treatment for psychiatric and neurodegenerative diseases: a review of clinical investigations." University of Prince Edward Island, Department of Biomedical Sciences, AVC, 550 University Avenue, Charlottetown, PE, Canada. [e-mail] (Expert Opin Investig Drugs. 2007 Oct;16(10):1627-38.) [http://www.ncbi.nlm.nih.gov/pubmed/17922626?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum Pub-Med] ] Several studies report an additional reduction in scores on symptom scales used to assess the severity of symptoms, when additional EPA is taken.

Recent studies have suggested that EPA may affect depression, and importantly, suicidal behavior. One such study, [cite journal |author=Huan M, Hamazaki K, Sun Y, Itomura M, Liu H, Kang W, Watanabe S, Terasawa K, Hamazaki T. |title=Suicide attempt and n-3 fatty acid levels in red blood cells: a case control study in China | journal= Biological psychiatry |volume=56 |issue=7 |pages=490–6 |year=2004 |pmid=1540784|doi=10.1016/j.biopsych.2004.06.028|url=http://www.journals.elsevierhealth.com/periodicals/bps/article/PIIS0006322304007061/abstract |format=abstract] took blood samples of 100 suicide-attempt patients and compared the blood samples to those of controls and found that levels of Eicosapentaenoic acid were significantly lower in the washed red blood cells of the suicide-attempt patients.

EPA has 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.cite journal
author=Yao HT, Chang YW, Lan SJ, Chen CT, Hsu JT, Yeh TK
title=The inhibitory effect of polyunsaturated fatty acids on human CYP enzymes
journal=Life Sci.
volume=79
issue=26
pages=2432–40
year=2006
pmid=16978661
doi=10.1016/j.lfs.2006.08.016]

ee also

* Chlorella
* Cyanobacteria
* Docosahexaenoic acid
* List of omega-3 fatty acids
* Polyunsaturated fatty acids
* Snake oil
* Wakame

References