Eicosapentaenoic acid

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Eicosapentaenoic acid
Eicosapentaenoic acid
IUPAC name (5Z,8Z,11Z,14Z,17Z)-icosa-
 5,8,11,14,17-pentaenoic acid
Identifiers
CAS number [1553-41-9]
SMILES CCC=CCC=CCC=CCC=CCC=CCCCC(=O)O
Properties
Molecular formula C20H30O2
Molar mass 302.451 g/mol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and 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 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).

Contents

[edit] Sources

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.[1] It is available from some non-animal sources—spirulina and 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] Microalgae, and supplements derrived from it, are excellent alternative sources of EPA and other fatty acids, since fish often contain toxins due to pollution.[4]

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.[5]

[edit] 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.[6] 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.[7][8] 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 effect depression, and importantly, suicidal behavior. One such study,[9] 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.[10]

[edit] See also

[edit] References

Salmon is a rich source of EPA.
Salmon is a rich source of EPA.
  1. ^ Yvonne Bishop-Weston. Plant based sources of vegan & vegetarian Docosahexaenoic acid - DHA and Eicosapentaenoic acid EPA & Essential Fats. Retrieved on 2008-08-05.
  2. ^ Jess Halliday (12/01/2007). Water 4 to introduce algae DHA/EPA as food ingredient. Retrieved on 2007-02-09.
  3. ^ Simopoulos, Artemis P (2002). "Omega-3 fatty acids in wild plants, nuts and seeds" ([dead link]). Asia Pacific Journal of Clinical Nutrition 11 (s6): S163–S173. doi:10.1046/j.1440-6047.11.s.6.5.. 
  4. ^ Yvonne Bishop-Weston. Plant based sources of vegan & vegetarian Docosahexaenoic acid - DHA and Eicosapentaenoic acid EPA & Essential Fats. Retrieved on 2008-08-05.
  5. ^ http://www.foodsforlife.org.uk/nutrition/vegetarian-DHA-EPA.html
  6. ^ NIH Medline Plus. MedlinePlus Herbs and Supplements: Omega-3 fatty acids, fish oil, alpha-linolenic acid. Retrieved on 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". Schizophrenia Research 49 (3): 243–51. doi:10.1016/S0920-9964(00)00083-9. PMID 11356585. 
  8. ^ 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. cai.song@nrc.gc.ca (Expert Opin Investig Drugs. 2007 Oct;16(10):1627-38.) Pub-Med
  9. ^ Huan M, Hamazaki K, Sun Y, Itomura M, Liu H, Kang W, Watanabe S, Terasawa K, Hamazaki T. (2004). "Suicide attempt and n-3 fatty acid levels in red blood cells: a case control study in China." (abstract). Biological psychiatry 56 (7): 490-6. doi:10.1016/j.biopsych.2004.06.028. PMID 1540784. 
  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. 
v • d • e
Autacoids, unsaturated fatty acids: Eicosanoids
Prostanoids
Leukotrienes
Other
Arachidonic acids - Eicosapentaenoic acid - Lipoxins
v • d • e
Lipids: fatty acids
Saturated
n−3 Unsaturated
α-Linolenic • Stearidonic • Eicosapentaenoic • Docosahexaenoic
n−6 Unsaturated
n−9 Unsaturated