• Journal of Nutrition and Health
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• v.34 no.6
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• pp.626-636
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• 2001

To compare the effect of three kinds of n-3 fatty acids-eicosapentaenoic acid(EPA), docosahexaenoic acid(DHA) and perilla oil (PO)-on serum and liver lipid levels and fatty acid composition of liver phospholipid(PL) at low fat level(5%, w/w), 4-weeks old Sprague-Dawley rats were fed with one of five different oil diets for 4 weeks. Beef tallow(BT) and corn oil(CO) was used as control for sturated or n-6 fatty acid respectively. Se겨m concentrations of cholesterol(TC) and phospholipid(PL) were lower in PO DHA and EPA groups than in BT and CO groups. HDL-cholesterol levels were higher in CO and PO groups than in EPA, DHA and BT groups. Liver PL concentrations were higher in DHA and EPA groups than in CO, PO and BT groups, but liver TC and heal PL and TC concentrations did not show any significant difference among groups. Hepatic fatty acid composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), two major phospholipids in liver, reflected their dietary fatty acid composition. In PC and PE, total percentage own-6 series was higher in CO group than in any other groups, and that own-3 series was higher in DHA and PO groups than in EPA, CO and BT groups. Moreover, the ratio of 20 : 4/18 : 2 was lower in PO and DHA groups than in EPA, CO and BT groups. On the contrary, the percentage of C22 : 6 was lower in EPA, CO and BT groups than in PO and DHA groups. These results revealed that n-3 series(EPA, DHA and PO) were more effective in lowering um lipids than n-6 fatty acids or saturated fatty acid. Based on the results of fatty acid composition of hepatic phospholipid, we suggest that the dietary effect of PO and DHA on antiatherogenic characteristics seems to be similar extent. In addition, the effect of EPA might not be significantly different from that of BT or CO in the view of eicosanoids production from the precursor fatty acid. These difference of hepatic fatty acid composition might come from other characteristics of dietary oil as well as the type of unsaturation, not from the carbon chain length or the degree of unsaturation of n-3 fatty acid.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.125-129
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• 2008

To predict Daphnia secondary productivity along a trophic gradient indexed as total phosphorus (TP) concentration, we estimated energy transfer efficiencies from food quality for Daphnia such as eicosa-pentaenoic acid (EPA) or docosahexaenoic acid (DHA) content. Eleven flow-through Daphnia magna growth experiments were conducted with seston from 9 lakes, ponds and river waters. Primary productivities were estimated from food supply rates in the flow-through experiments, producing energy transfer efficiencies from seston to D. magna. We found DHA content was the best predictor of energy transfer efficiencies among the essential fatty acids. An asymptotic saturation model explained 79.6% of the variability In energy transfer efficiencies. Based on empirical data in this study and empirical models from literature, we predict that Daphnia productivity would peak in mesotrophic systems by decreasing food quality and Increasing food quantity along trophic gradient.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.231-235
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• 2006

The objectives of this study were to investigate the effects of dietary fish oil inclusion on the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents and organoleptic characteristics of breast meat in mule ducks. Three hundred mule ducks at four weeks of age were randomly assigned to three dietary treatments with five replicate pens in each. One replicate pen had ten males and females each with a total of 100 ducks in each treatment. The diet in the three treatments contained 0, 1.5, and 3.0% fish oil, respectively. Body weights at 4, 6, 8, and 10 weeks of age, and feed efficiency at 4 to 6, 6 to 8, and 8 to 10 weeks of age were recorded. At 10 weeks of age, one male and one female from each replicate were sacrificed for oxidative stability of breast meat and the sacrificed males were employed for the analysis of fatty acids in breast meat and skin. Sensory evaluation of breast meat was also performed. A level of 3.0% fish oil in the diet significantly deteriorated feed efficiency and body weight gain. Dietary fish oil inclusion had a trend of increasing abdominal fat deposition and decreasing the flavor of breast meat. The EPA and DHA contents in the breast meat were higher than those in the breast skin irrespective of oil sources. The EPA and DHA contents in breast meat and breast skin was significantly increased in the 3.0% fish oil group. Although EPA and DHA were not efficiently deposited in the duck meat through dietary fish oil inclusion, this method can still provide a partial supplementation of EPA and DHA.

• Nutritional Sciences
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• v.4 no.2
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• pp.73-78
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• 2001

This study investigated the effect of different dietary fats and fibers on colon tumor incidence and cell proliferation, the levels of eicosanoids and polyamines in colonic mucosa of DMH-treated rats. The experiment was conducted on male Sprague Dawley rats using a 2 $\times$3 factorial design with two fats (corn oil and DHA-rich fish oil) and two fibers (cellulose and pectin) and a fiber-free control. The rats were find an experimental diet containing 15% (w/w) dietary fat and 6% (w/w) fiber for 25 weeks. Tumor incidence was Bower in rats fed fish oil as opposed to corn oil. The levels of arachidonic acid (AA) and eicosanoids ($PGE_2, and TXB_2$) in normal colonic mucosa were significantly lower in rats fed fish oil and there was a concomitant increase of docosahexaenoic acid (DHA). The levels of eicosanoids and AA in tumor tissues were significantly higher than those of normal colonic mucosa. The level of polyamines in normal colonic mucosa was not affected by dietary fats but was significantly lower than that in rumor tissues. Dietary fiber did not have a significant effect on rumor incidence and the levels of AA, eicosanoids and polyamines. Overall, fish oil rich in DHA reduced cell prolifiration and thus inhibited colon carcinogenesis through its effect on the distribution of AA and production of eicosanoids in normal colonic mucosa. However, its effect on colon carcinogenesis revealed a lack of consistency depending on the type of dietary fiber in diet.

• 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 Poultry Science
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• v.31 no.4
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• pp.283-291
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• 2004

Feeding trials were conducted with Euglena strains grown under different media. The effect of supplementation of Euglena on the laying performance, egg quality and fatty acid composition of egg yolk was studied. In experiment I, two hundred eighty 32-wk-old ISA Brown layers were randomly assigned to seven dietary treatments for 4 wks. Each treatment consisted of 4 replications with 10 birds each housed in two birds cages. Control diet was formulated to have $17\%$ CP and 2,750 kcal ME/kg. Euglena gracilis Z. (EG) was added to control diet at the level of 0.25, 0.5, $1.0\%$ and Euglena gracilis Z. bleached and DHA enriched (EGBD; a strain mutated by streptomycin and cultivated in DHA enriched medium) at the level of 0.5, 1.0, $2.0\%$ in the diet. In experiment 2, three hundred 84-wk-old ISA brown layers were randomly assigned to five dietary treatments: T1; Control, T2; T1 + EGBD $0.5\%$, T3; T1 + Euglena gracilis Z. DHA enriched (EGD; cultivated in DHA enriched medium) $0.5\%$, T4; T1 + EGD $1.0\%$, T5; T1 + EGD $2.0\%$. Each treatment had 5 replication of 12 birds each housed in two birds cages. In experiments 1 and 2, Euglena suppplementation did not significantly affect egg production but increased egg weight and feed intake. In experiment 1, EG was more effective in increasing egg yolk color score than EGBD. Egg yolk color of EG $1\%$ treatment showed the highest score. EGBD supplementation increased DHA concentration of egg yolk. EGBD $2\%$ treatment showed the highest DHA and the lowest palmitic and stearic acids concentration in the egg yolk. In experiment 2, EGBD $0.5\%$ treatment showed highest DHA level in egg yolk (P<0.05). It was conducted that EGBD is a single cell protein source rich in DHA, that can be used to produce DHA enriched eggs.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.93-102
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• 2009

Polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have significantly beneficial effects on health in relation to cardiovascular, immune, and inflammatory conditions and they are involved in determining the biophysical properties of membranes as well as being precursors for signaling molecules. PUFA biosynthesis is catalyzed by sequential desaturation and fatty acyl elongation reactions. This aerobic biosynthetic pathway was thought to be taxonomically conserved, but an alternative anaerobic pathway for the biosynthesis of PUFA is now known to contain analogous polyketide synthases (PKS). Certain fish oil can be a rich source of PUFA although processed marine oil is generally undesirable as food ingredients because of the associated objectionable flavors that are difficult and cost-prohibitive to remove. Oil-seed plants contain only the 18-carbon polyunsaturated fatty acid alpha-linolenic acid, which is not converted in the human body to EPA and DHA. It is now possible to engineer common oilseeds which can produce EPA and DHA and this has been the focus of a number of academic and industrial research groups. Recent advances and future prospects in the production of EPA and DHA in oilseed crops are discussed here.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.391-397
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• 2015

Two hundred and sixteen Institut de S$\acute{e}$lection Animale (ISA) brown layers (40 wks of age) were studied for 6 wks to examine the effect of microalgae powder (MAP) on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i) CON (basal diet), ii) 0.5% MAP (CON+0.5% Schizochytrium powder), and iii) 1.0% MAP (CON+1.0% Schizochytrium powder). From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034); however, there was no difference on the egg production from 40 to 43 wks (p>0.05). Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively). Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044). Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05). Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3) was increased in treatment groups fed with MAP (linear, p<0.05). The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05). These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.973-978
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• 2017

Objective: The aim of this study was to investigate the effects of simultaneous supplementation of laying hens with alpha-linolenic acid (ALA) resources (flax, perilla, and Eucommia ulmoides [E. ulmoides] seeds) and eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) resources (Schizochytrium sp.) on egg quality and n-3 polyunsaturated fatty acids (PUFA) profile. Methods: Dietary treatments were as follows: i) diet C (control diet); ii) diet F (diet C+10% flaxseeds); iii) diet P, (diet C+10% perilla seeds); iv) diet E (diet C+10% E. ulmoides seeds); v) diet A (diet C+1.5% microalage); vi) diet AF (diet C+10% flaxseeds+1.5% microalage); vii) diet AP (diet C+10% perilla seeds+1.5% microalgae); viii) diet AE (diet C+10% E. ulmoides seeds+ 1.5% microalage). Results: Egg weight, yolk weight and production ratio were not significantly affected by either algae or in combination with seeds (p>0.05). No significant difference was observed in ALA and DHA concentration in eggs between flaxseed, perila, and E. ulmodies seeds supplementation alone (p>0.05). N-3 PUFA in eggs was slightly improved by microalgae supplementation. The best supplementation, a combination of microalgae and perilla seeds, elevated (p<0.05) ALA from 19.7 to 202.5 mg/egg and EPA+DHA from 27.5 to 159.7 mg/egg. Highest n-3 PUFA enrichment (379.6 mg/yolk) was observed with supplementation of a combination of perilla seed and microalgae (362.2 mg/yolk), followed by a combination of flaxseed and microalgae (348.4 mg/yolk). The ALA, EPA, and DHA content obtained with a combination of microalgae and seeds surpassed the total sum of that obtained with microalgae or ALA-seeds alone. Conclusion: It is feasible to enrich eggs with n-3 PUFAs by perilla or E. ulmodies seeds instead of flaxseeds. Simultaneous supplementation of microalgae and seeds helped improve the transfer from EPA and docosapentaenoic acid into DHA.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1413-1421
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• 2013

The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.