Hexaenoic acid

Omega-3 fatty acids (eicosapentaenoic acid and docosa-hexaenoic acid), the predominant fatty acids in the oil of cold-water fish, lower triglycerides by as much as 35% when taken in large amounts. Fish oil supplements may be useful for patients with high triglycerides despite diet, alcohol restriction, and fibrate therapy. This effect may be modulated thru PPAR-a and a reduction in apolipoprotein B-100 secretion. Omega-3 fatty acids reduce platelet aggregation and have... 

Recent interest has focused on the C20 5 eicosa-pentaenoic acid (EPA) and the C22 6 docosa-hexaenoic acids (DHA). These 3 (or n-3) polyunsaturated acids are formed from linolenic acid by marine algae and are found in fish oils.h The C22 5 and C22 6 acids can be converted to prostaglandins of the PG4 and PG5 series. DHA together with the 0)6 C22 4 acid constitutes over 30% of the fatty acids in brain phospholipids. In the... 

Either native winterized or concentrated whole-body fish oils or fish liver oils have been utilized in most studies as dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The physiological effects and possible health benefits of administered fish oils generally have been attributed to either EPA or DHA alone or to a synergistic effect between the two. As a result, there has been controversy over the contribution of individual fish oil constituents to particular pharmacological actions and the optimal dosages required for achieving established and/or suspected beneficial effects. The predominant marine triglyceride-derived m-3-fatty acids are all-cA-5,8,11,14,17-eicosapentaenoic acid (C20 5i3, EPA) and all-ci.v-4,7,10,13,16,19-docosa-hexaenoic acid (C22 6,3, DHA). 

Other fatty acids as absorption enhancers have been reported. Ogiso et al. [112] demonstrated that lauric acid (C12) produced the largest increase in permeation rate, penetration coefficient, and partition coefficient of propranolol. Onuki et al. [113] reported that docosa-hexaenoic acid (DHA) has a strong insulin permeability enhancement effect and little toxicity, compared to oleic acid and eicosapentaenoic acid (EPA) using a water-in-oil-in-water (W/O/W) multiple emulsion with no or little mucosal damage. 

Shulman, G.E. and Yakovleva, K.K. (1983). Hexaenoic acid and natural mobility of fish (In Russian). Zhumal Obshchey Biologii 44,529-540. 

Shimada, Y., Watanabe, Y., and Sugihara, A. 2003d. Ethyl esterification of docosa-hexaenoic acid in an organic solvent-free system with immobilized Candida antarc-tica Lipase. In Y.-S. Huang, S.-J. Lin, and P.-C. Huang (Eds.), Essential Fatty Acids and Eicosanoids (pp. 18-23). Champaign, IL AOCS Press. 

Yanagita, T., Wang, Y. M., Nagao, K., Ujino, Y., and Inoue, N. 2005. Conjugated linoleic acid-induced fatty liver can be attenuated by combination with docosa-hexaenoic acid in C57BL/6N mice. J. Agric. Food Chem., 53, 9629-9633. 

Docosa-4 7 10 13 16 19-hexaenoic acid DHA CH3CH2(CH=CHCH2)6(CH2)COOH 22 6(03... 

Under conditions of low light intensity, the all-trans-retinaldehyde released from rhodopsin is reduced to aU-fra s-retinol, which is then transported to the retinal pigment epithelium bound to the interphotoreceptor RBP. This protein also binds fatty acids, including palmitate and docosa-hexaenoic acid (C22 6 co3), which is known to be essential for vision and which comprises some 50% of the phospholipid of photoreceptor cells. 

Roberts LJ 2nd, Montine TJ, Markesbery WR, Tapper AR, Hardy P, Chemtob S, Dettbarn WD, Morrow JD. Formation of isoprostane-like compounds (neuroprostanes) in vivo from docosa-hexaenoic acid. J. Biol. Chem. 1998 273 13605. 

Alpha-linolenic acid (18 3n-3) is an 18-carbon fatty acid with three double bonds at carbons 9, 12, and 15. It is an essential n-3 fatty acid that is a required nutrient for human beings and can be obtained through diets including both plant and animal sources. Alpha-linolenic acid can be converted by elongases and desaturases to other beneficial n-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosa-hexaenoic acid (DHA), which are implicated in normal brain development, normal vision, and a decreased risk of heart disease. Novel dietary sources of n-3 fatty acids are desired for those who do not consume adequate amounts of fish or fish-based food products rich in long-chain n-3 fatty acids. This section summarized fruit, spice, and herb seed oils rich in a-linolenic acid (18 3n-3). These include black raspberry, red raspberry, boysenberry, marionberry, blueberry, cranberry, sea buckthorn, basil, and hemp seed oils. 

Synonyms (all Z)-4,7,10,13,16,19-Docosa docosahexaenoate hexaenoic acid ethyl ester Ethyl Source Liang, J. H. Yeh, A. I. J. Am. Oil Chem. 

The endocannabinoids represent a typical example of mediators whose levels are controlled through the regulation not only of biosynthetic but also of catabolic enzymes (Table 1). Furthermore, these compounds are produced from biosynthetic precursors that in turn derive from phospholipids whose levels are potentially influenced by the diet and by its relative contents in 0)3 and o)6 polyunsaturated fatty acids, in particular arachidonic and docosa-hexaenoic acids (AA and DHA). Indeed, diets defective or rich in DHA will increase or decrease, respectively, the brain levels of 2-AG (Watanabe et al. 2003), whereas milk deprived of both AA and DHA will lead to lower brain levels of AEA in newborns (Berger et al. 2001). 

Dietary eicosapentaenoic acid (EPA) and docosa-hexaenoic acid (DHA), the two major components of fish oil, partially replace arachidonic acid (AA), which is the initiating component of the homonymous metabolic pathway, in a time- and dose-dependent manner, in plasma and cellular phospholipids (PLs). Being less readily released upon cell stimulation, these components reduce substrate availability for eicosanoid generation. 

Although most hpids required for cell structure, fuel storage, or hormone synthesis can be synthesized from carbohydrates or proteins, we need a minimal level of certain dietary hpids for optimal health. These hpids, known as essential fatty acids, are required in our diet because we cannot synthesize fatty acids with these particular arrangements of double bonds. The essential fatty acids a-linoleic and a-linolenic acid are supphed by dietary plant oils, and eicosapentaenoic acid (ERA) and docosa-hexaenoic acid (DHA) are supplied in fish oils. They are the precursors of the eicosanoids (a set of hormone-like molecules that are secreted by cells in small quantities and have numerous important effects on neighboring cells). The eicosanoids include the prostaglandins, thromboxanes, leukotrienes, and other related compounds. 

Maeda, Y, Ishikawa, M., Yamamoto, M., Terada, S., Masui, T., andWatanabe, Y, 1985, Effect of cooking on contents of fatty acids, especially eicosapentaenoic acid and docosa-hexaenoic acid in sardine, Bull Jap. Soc. Set Fisheries, 38, 447. 

In AD brain, stimulation of PlsEtn-PLA2 may produce a deficiency of docosa-hexaenoic acid, a m-3 long-chain polyunsaturated fatty acid, which increases viscosity and augments energy consumption (Farooqui, 2009b Ferrer, 2009). It is proposed that abnormal neural membrane composition may modify the activity of key enzymes that modulate the cleavage of the amyloid precursor protein to form toxic Ap (see below). 

Wang, N., and Anderson, R.E. (1993) Synthesis of Docosa-hexaenoic Acid by Retina and Retinal Pigment Epithelium, Biochemistry 32,13703-13709. 

Fig.1. Effect of ethanol content on esterification of docosa-hexaenoic acid (DHA) with immobilized C. antarctica lipase. A 10-g mixture consisting of DHA and 1-10 molar equivalents of ethanol was shaken at 30°C with 200 mg immobilized lipase. Open bars degree of DHA ethyl esterification after 1 h hatched bars after 7 h closed bars after 24 h.

Fig. 5. Effect of flow rate on ethyl esterification of docosa-hexaenoic acid (DHA) in a fixed-bed bioreactor. The first-step esterification was conducted at 30 "C by feeding a mixture of DHA/ethanol (1 1, mol/mol) into a reactor packed with 2.0 g immobilized I lipase at different flow rates. The reaction mixture flowing from the first-step flow reaction was dehydrated. Five molar equivalents of ethanol against unesterified DHA was added to the dehydrated mixture. The second-step reaction was conducted by feeding the resulting mixture into another reactor of the same size as that for the first-step reaction at 30°C and different flow rates. O, The first-step reaction the second-step reaction.

Abbreviations ROS, reactive oxygen species LDL, low density lipoprotein FO, fish oil ERA, eicosapentaenoic acid DHA, docosa-hexaenoic acid GLA, y-linolenic acid EE, ethyl ester TBARS, thiobarbituric acid-reactive substances. 

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