Eicosapentaenoic and docosahexaenoic acids

Adapted from Trautwein (2001). The data presented are average values. EPA, eicosapentaenoic acid DHA, docosahexaenoic acid. 

In humans, the conversion of ALA to EPA and DHA is extremely slow, with only about 15% and 5% of ALA converted to EPA and DHA, respectively (Cunnane, 1995). This conversion appears to be affected by a number of dietary factors. For example, a diet rich in linoleic acid has been found to reduce this conversion by as much as 40% (Emken, 1995). In addition, saturated and lruns fatty acids also interfere with ALA desaturation and elongation steps (Ackman and Cunnane, 1992 HouwelingenandHornstra, 1994). DHA can be reconverted back to EPA, although in humans it appears to be a very minor pathway (Brossard et al., 1996). DHA appears to play an important in the brain and retina and was found to be incorporated during the last trimester of pregnancy and the first year of life. Visual acuity was shown to develop much faster in preterm infants fed formulas rich in DHA compared with standard infant formulas low in long chain n-3 fatty acids (Jorgensen et al., 1996). 

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There is some evidence that, in these patients, the interconversion between the polyunsaturated fatty acids is disturbed, which restricts the formation of eicosapentaenoic and docosahexaenoic acids. Such children are less likely to have been breastfed (breast milk contains these omega-3 fatty acids) they are more likely to suffer from allergies associated with essential fatty acid deficiency and also dry skin and hair and the membranes of the erythrocytes contain less omega-3 fatty acids compared with normal children. So far, the results of supplementation of the diet of these children with this disorder have not been conclusive. 

Ikeda, I., Cha, J. Y., Yanagita, T., Nakatani, N., Oogami, K., Imaizumi, K., and Yazawa, K. 1998. Effects of dietary a-linoleic, eicosapentaenoic and docosahexaenoic acids on hepatic lipogenesis and P-oxidation in rats. Biosci. Biotech. Biochem., 62, 675-680. 

Haraldsson, G. G., Halldorsson, A., and Kulas, E. 2000. Chemoenzymatic synthesis of structured triacylglycerols containing eicosapentaenoic and docosahexaenoic acids /. Am. Oil Chem. Soc., 77,1139-1145. 

Mori, T.A., Burke, V., Puddey, I.B., Watts, G.F., O Neal, D.N., Best, J.D. and Beilin, L.J. (2000a) Purified eicosapentaenoic and docosahexaenoic acids have differential effects on serum lipids and lipoproteins, LDL particle size, glucose, and insulin in mildly hyperlipidemic men. Am. J. Clin. Nutr. 71 1085-1094. 

Halvorsen, D.S., Hansen, J.B., Grimsgaard, S., Bonaa, K.H., Kierulf, P., andNordoy, A. 1997. The effect of highly purified eicosapentaenoic and docosahexaenoic acids on monocyte phagocytosis in man. Lipids 32, 935-942. 

Kew, S., Mesa, M.D., Tricon, S., Buckley, R., Minihane, A.M., and Yaqoob, P. 2004. Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on immune cell composition and function in healthy humans. Am. J. Clin. Nutr. 79, 674-681. 

D. R., Corey, E.J., Lewis, R.A., and Austen, K.F. 1985. Effect of dietary enrichment with eicosapentaenoic and docosahexaenoic acids on in vitro neutrophil and monocyte leukotriene generation and neutrophil function. N. Engl. J. Med. 312, 1217-1224. 

Yamashita, N., Maruyama, M., Yamazaki, K., Hamazaki, T., and Yano, S. 1991. Effect of eicosapentaenoic and docosahexaenoic acid on natural killer cell activity in human peripheral blood lymphocytes. Clin. Immunol. Immunopathol. 59, 335-345. 

Hinds A, Sanders TAB. The effect of increasing levels of dietary fish oil rich in eicosapentaenoic and docosahexaenoic acids on lymphocyte phospholipid fatty acid composition and cell-mediated immunity in the mouse. Br J Nutr 1993 69 423-429. 

Nordoy A, Barstad L. Connor Wl i, Hatcher L. Absorption of the n-3 eicosapentaenoic and docosahexaenoic acids as ethyl esters and triglycerides by humans. Am J Clin Nutr 1991 53 1185-1190. 

Paulsen JE, Elvsaas I-KO, Steffensen 1-L, Alexander J. A fish oil derived concentrate enriched in eicosapentaenoic and docosahexaenoic acid as ethyl ester suppresses the formation and growth of intestinal polyps in the Min mouse. Carcinogenesis 1997 18 1905-1910. 

Peterson LD, Jeffery NM, Thies F, Sanderson P. Newsholme EA. Calder PC. Eicosapentaenoic and docosahexaenoic acids alter rat spleen leukocyte fatty acid composition and prostaglandins E2 production but have different effects on lymphocyte functions and cell-mediated immunity. Lipids 1998 33 171-180. 

Recjent studies on the role of cxnega-S fatty acids in fitness and health have stimulated considerable interest in the develc xnent of supercritical fluid extraction processes for concentrating them from marine oils. The basic approaches utilized by several researchers in their attempts to realize this goal are reviewed in this paper. The various parameters influencing the purity and yield of eicosapentaenoic and docosahexaenoic acids obtained from fi oils with different pretreatments are discussed. 

Sanders, T.A.B., Vickers, M., and Haines, A.R, Effect on blood lipids and hemostasis of a supplement of cod-liver oil, rich in eicosapentaenoic and docosahexaenoic acids, in healthy young men, Clin. Set, 61, 317, 1981. 

Bravo, M.G., Antueno R.J., Toledo, J., Tomas M.E., Mercuri O.F., and Quintans, C. (1991) Effect of an Eicosapentaenoic and Docosahexaenoic Acid Concentrate on a Human Lung Carcinoma Growth in Nude Mice, Lipids 26, 866-870. 

Das, U.N. (1994) Beneficial Effect of Eicosapentaenoic and Docosahexaenoic Acids in the Management of Systemic Lupus Erythematosus and Its Relationship to the C)4okine Network, Prostaglandins Leukot. Essent. Fatty Acids 51,207-213. 

Bonaa, KH., Bjerve, K.S., Straume, B., Gram, I.T., andTheUe, D. (1990) Effect of Eicosapentaenoic and Docosahexaenoic Acids on Blood Pressure in H5fpertension. A Population-Based Intervention Trial from the Tromso Study, N. Eng. J. Med. 322, 795-801. 

Dardel. V.. Narce. M.. Delachambre. M.-C.. and Poisson. J.-P. (1998) Polyunsaturated Fatty Acid Biogenesis and Influence of a Diet Enriched with Eicosapentaenoic and Docosahexaenoic Acids in Genetically Hypertensive Rat. Ocl-ol Corps Gras Lipi-des 5,226-232. 

Tokiwa, S., Kanazawa, A., and Teshima, S. (1981) Preparation of Eicosapentaenoic and Docosahexaenoic Acids by Reversed Phase High Performance Liquid Chromatography, Bull. Jpn. Soc. Sci. Fish. 47,675-6n. 

Jennings, B.H., and Akoh, C.C. (1999) Enzymatic Modification of Triacylglycerols of High Eicosapentaenoic and Docosahexaenoic Acids Contents to Produce Structured Lipids, /. Am. Oil Chem. Soc. 76,1133 1137. 

Hun, C.S., Hasegawa, K., Kawabata,T., Kato, M., Shimokawa, T., and Kagawa, Y. (1999) Increased Uncoupling Protein 2 mRNA in White Adipose Tissue, and Decrease in Leptin, Visceral Fat, Blood Glucose, and Cholesterol in KK-Ay Mice Fed with Eicosapentaenoic and Docosahexaenoic Acids in Addition to Linolenic Acid,Biochem. Biophys. Res. Commun. 259,85-90. 

Von Schacky, C. Weber, P.C. 1985. J. Clin. Invest., 76, 2446-2450. Metabolism and effects of platlet function of the purified eicosapentaenoic and docosahexaenoic acid in humans. 

Fer, M., Y. Dieano et al. 2008. Metabolism of eicosapentaenoic and docosahexaenoic acids by recombinant human cytochromes P450. 471(2) 116-125. 

Sharma, N. P., L. Dong et al. 2010. Asymmetric acetylation of the cyclooxygenase-2 homodimer by aspirin and its effects on the oxygenation of arachidonic, eicosapentaenoic, and docosahexaenoic acids. MolPhmTnaml 77(6) 979-986. 

Because the 12,15-diene has a 1,4-diene system, it oxidizes like linoleate to form two conjugated dienoic 12- and 16-hydroperoxides. However, in contrast to linoleate, the external 16-hydroperoxide is formed at a higher concentration than the internal 12-hydroperoxide, (with normalized concentrations of 58% and 42%) (Figure 2.12). Therefore, both the 9,15- and 12,15-dienes produce allylic radicals in which the terminal carbons 16 and 17, closest to the end of the fatty acid chain, are the most reactive with oxygen. The same preference of oxygen attack at the terminal double bond position is also observed in other polyunsaturated fatty acids with n-3 double bonds (linolenate, eicosapentaenoic and docosahexaenoic acids), and n-6 double bonds (arachidonic acid). Volatile decomposition products derived from hydroperoxides containing an n-3 double bond are particularly significant for their impact on flavor (Chapter 4). 

Croset M, Lagarde M (1986) In vitro incorporation and metabolism of eicosapentaenoic and docosahexaenoic acids in human platelets. Effect on aggregation. Thromb Haemost 56 57-62... 

Production of TAG enriched with polyunsaturated fatty acids (PUFA) via lipase catalysis in codliver oil has also been described (Haraldsson et ah, 1989). Preparation of y-linolenic acid enriched TAG via rapeseed lipases (Syed Rahmatullah et aL, 1994 Jachmanian and Mukerjee, 1996) and microbial lipases (Akoh et aL, 1995, 1996) has also been reported. Incorporation of eicosapentaenoic and docosahexaenoic acids into peanut oil via transesterification catalysed by microbial lipases has been reported by Sridhar and Lakshminarayana (1992). According to Wada and Koizumi (1986) and Kimoto et aL (1994) interesterification of fish oils to form TAG containing PUFA in the 2-position rather than the 1,3-positions increases the oxidative stability of the modified oil as compared to its original counterpart. 

Grandgirard, A., Piconneaux, A., Sebedio, J.-L., O Keefe, S.F., Semon E. and Le Quere, J.-L. (1989) Occurrence of geometrical isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids of rats fed heated linseed oil. Lipids 24, 799-804. 

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