• Nutrition Research and Practice
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• v.13 no.4
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• pp.286-294
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• 2019

BACKGROUND/OBJECTIVES: Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of ${\alpha}$-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by $PPAR{\alpha}$. MATERIALS/METHODS: The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among $PPAR{\alpha}$ homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate ($PPAR{\alpha}$ agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA. RESULTS: $PPAR{\alpha}$ ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, $PPAR{\alpha}$ activation increased hepatic Acox, Fads1, Fads2, and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex. CONCLUSIONS: LCPUFA enzyme expression was altered by $PPAR{\alpha}$. Either $PPAR{\alpha}$ deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.345-356
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• 2019

Docosahexaenoic acid (DHA), an omega-3-fatty acid, modulates multiple cellular functions. In this study, we addressed the effects of DHA on human umbilical vein endothelial cell calcium transient and endothelial nitric oxide synthase (eNOS) phosphorylation under control and adenosine triphosphate (ATP, $100{\mu}M$) stimulated conditions. Cells were treated for 48 h with DHA concentrations from 3 to $50{\mu}M$. Calcium transient was measured using the fluorescent dye Fura-2-AM and eNOS phosphorylation was addressed by western blot. DHA dose-dependently reduced the ATP stimulated $Ca^{2+}$-transient. This effect was preserved in the presence of BAPTA (10 and $20{\mu}M$) which chelated the intracellular calcium, but eliminated after withdrawal of extracellular calcium, application of 2-aminoethoxy-diphenylborane ($75{\mu}M$) to inhibit store-operated calcium channel or thapsigargin ($2{\mu}M$) to delete calcium store. In addition, DHA ($12{\mu}M$) increased ser1177/thr495 phosphorylation of eNOS under baseline conditions but had no significant effect on this ratio under conditions of ATP stimulation. In conclusion, DHA dose-dependently inhibited the ATP-induced calcium transient, probably via store-operated calcium channels. Furthermore, DHA changed eNOS phosphorylation suggesting activation of the enzyme. Hence, DHA may shift the regulation of eNOS away from a $Ca^{2+}$ activated mode to a preferentially controlled phosphorylation mode.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.220-231
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• 2023

Although omega-3 fatty acids including docosahexaenoic acid (DHA) contain various health-promoting effects, their poor aqueous solubility and stability make them difficult to be induced in dairy foods. The aims of this research were to manufacture casein derivative-based delivery system using acid-induced gelation method with glucono-σ-lactone and to investigate the effects of production variables, such as pH and charged amount of linoleic acid, on the physicochemical properties of delivery systems and oxidative stability of DHA during storage in model milk. Covalent modification with linoleic acid resulted in the production of casein derivatives with varying degrees of modification. As pH was reduced from 5.0 to 4.8 and the charged amount of linoleic acid was increased from 0% to 30%, an increase in particle size of casein derivative-based delivery systems was observed. The encapsulation efficiency of DHA was increased with decreased pH and increased charged amount of linoleic acid. The use of delivery system for DHA resulted in a decrease in the development of primary and secondary oxidation products. An increase in the degree of modification of casein derivatives with linoleic acid resulted in a decrease in the formation of primary and secondary oxidation products than of free DHA indicating that delivery systems could enhance the oxidative stability of DHA during storage in model milk. In conclusions, casein derivatives can be an effective delivery system for DHA and charged amount of linoleic acid played a key role determining the physicochemical characteristics of delivery system and oxidative stability of DHA.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.655-666
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• 2023

Purpose: Gestational nutrition has an impact on the growth and development of the fetus. Choline (C) and docosahexaenoic acid (DHA) are important and essential nutrients for humans that play a role in the structural integrity of the membranes as well as signalling. C is used in the synthesis of phosphatidylcholine, and cell membranes are highly enriched with DHA. The dietary intake of C or DHA during pregnancy directly influences fetal development. Currently, there is no evidence to prove the effectiveness of the combined dietary supplementation of both C and DHA during gestation on developmental outcomes in the offspring. Methods: The current study was designed to assess the physical, sensory, and motor development of rat pups born to mothers supplemented with C and/or DHA during the entire gestational period. Pregnant rat dams were divided into the following five groups: Normal control (NC), Saline control (SC), Choline (C), DHA, and Choline+DHA (C+DHA). The NC dams did not receive any supplementation during the entire gestation period. The experimental groups were supplemented with Saline, C, and/or DHA, respectively, during the entire gestation (E0 to delivery). Results: Rat pups (n = 6/group) exposed to combined C and DHA showed significant improvement in birth weight, fur development, eye-opening as well as weight gain on the 7th, 14th, and 21st postnatal day and pinnae detachment (assessed from birth to postnatal day 21) when compared with age-matched NC, SC or C or DHA pups. Further, significant reflex responses were observed in visual placing and bar holding of pups exposed to both C and DHA, whereas the differences in surface righting, negative geotaxis, and grasping reflexes were not significant between the groups. Conclusion: Gestational supplementation of both C and DHA rather than either of them alone is better in enhancing developmental outcomes in rat pups.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.166-170
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• 2005

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.565-569
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• 2003

The objective of this experiment was to determine the effects of different levels of refined cod liver oil (RCLO) on laying performance, n-3 polyunsaturated fatty acids composition (n-3 PUFAs) and the organoleptic evaluation of duck egg yolks. A total of 180 30 wk old laying Tsaiya ducks, at the beginning of peak production, were allotted into 6 treatments with 3 replicates each. Ducks were fed one of the 6 experimental diets, supplemented with 2% tallow (control) and graded levels of RCLO at 2, 3, 4, 5, and 6% to a corn-soybean diets, respectively, for 6 wks. All of the experimental diets were formulated to be both isocaloric and isonitrogenous. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the RCLO supplementation levels did not affect (p>0.05) egg production, egg mass, feed intake, feed efficiency or body weight change. Egg weight was the lightest when the ducks received the 6% RCLO diet. The eicosapentaenoic acid, docosahexaenoic acid, and total n-3 PUFAs contents in the yolks increased with increasing RCLO supplementation. The taste and general acceptability of the hard-boiled eggs were not significantly different among the treatments. However, a fishy flavor was much higher when ducks were fed diets supplemented with 5% and 6% RCLO diets.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.275-281
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• 2012

Yellow croaker Larimichthys polyactis muscle oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-$CO_2$), in a semi-batch flow extraction process. SC-$CO_2$ was applied at temperature $35^{\circ}C$ to $45^{\circ}C$ and $150^{\circ}C$ to $250^{\circ}C$ bar of pressure. The flow rate of $CO_2$ (27.79 g/min) was constant throughout the entire 1.5 h extraction period. The oil extraction yield was influenced by the physical properties of SC-$CO_2$ at different temperatures and pressures. The extracted oil was analyzed by gas chromatography to determine the fatty acid composition. According to our results, the SC-$CO_2$ extracted oil was high in eicosapentaenoic acid and docosahexaenoic acid. In addition, the SC-$CO_2$ extracted oil showed greater stability than n-hexane extracted oil based on the peroxide value and acid value. Thus, the quality of yellow croaker oil obtained by SC-$CO_2$ extraction was slightly higher than that of oil obtained by n-hexane extraction.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1646-1652
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• 2016

Mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth and metabolism and is sufficient to induce specific metabolic processes, including de novo lipid biosynthesis. Elongation of very-long-chain fatty acids 1 (ELOVL1) is a ubiquitously expressed gene and the product of which was thought to be associated with elongation of carbon (C) chain in fatty acids. In the present study, we examined the effects of rapamycin, a specific inhibitor of mTORC1, on ELOVL1 expression and docosahexaenoic acid (DHA, C22:6 n-3) synthesis in bovine mammary epithelial cells (BMECs). We found that rapamycin decreased the relative abundance of ELOVL1 mRNA, ELOVL1 expression and the level of DHA in a time-dependent manner. These data indicate that ELOVL1 expression and DHA synthesis are regulated by mTORC1 in BMECs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.779-792
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• 1995

The effects of deoxygenizer (Deoxy) and sodium-erythorbate (Na-ery) on the changes in fatty acid compositions were investigated to prevent the loss of n-3 polyunsaturated fatty acids in lipid of bolied and dried-anchovy during storage. After storage for 5 months, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) of total lipid (TL) in Deoxy group decreased only $3.0\%\;and\;0.5\%$, respectively, compared to those of before storage. However, those in Control group decreased 9.5\%\;and\;2.3\%,$ respectively. In the case of Na­ery group, the percentages of DHA and EPA decreased were lower than those of Control. Most of DHA and EPA in n was lost in the early stage of storage. Total DHA remained in phospholipid (PL), triglyceride (TG), and free fatty acid (FFA) fractions after storage for 5 months were $98\%,\;66\%\;and\;62\%$ in Deoxy, Na-ery and Control group, respectively, and total EPA remained was slightly high level compared with those of DHA. The loss of DHA was more in PL than in TG. Consequently, deoxygenizer was recognized as a good material to prevent the loss of DHA and EPA of the boiled and dried-anchovy during storage.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.67-73
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• 2014

The oil in mackerel muscle was extracted using an environment friendly solvent, supercritical carbon dioxide (SC-$CO_2$) at a semibatch flow extraction process and an n-hexane. The SC-$CO_2$ was maintained at a temperature of $45^{\circ}C$ under pressures ranging from 15 to 25 MPa. The flow rate of $CO_2$ (27 g/min) was constant during the entire 2 h extraction period. The fatty acid composition of the oil was analyzed using gas chromatography (GC). Significant concentrations of eicosapentaenoic acid (EPA) acid and docosahexaenoic acid (DHA) acid were present in the SC-$CO_2$ extracted oil. The oil extracted using SC-$CO_2$ exhibited increased stability compared with n-haxane extracted oil. Particles of mackerel oil together with the biodegradable polymer, polyethylene glycol (PEG) were formed using a gas saturated solution process (PGSS) with SC-$CO_2$ in a thermostatted stirred vessel. Different temperatures ($45-55^{\circ}C$), pressures (15-25 MPa) and a nozzle size $400{\mu}m$ were used for PGSS with a 1 h reaction time. The stability of mackerel oil in the particles did not changed significantly.