• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.10-15
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• 2002

Environmental and medium factors were investigated as basic data for optimizing DHA production when using Thraustochytrium aureum. To study the effect of environmental conditions, the rotation speed and culture temperature were changed. Plus the trend of the growth characteristics, lipid content in the biomass, and DHA content in lipids were evaluated according to various initial glucose concentrations. The biomass, lipid, and DHA analyses showed that the physiological characteristics of T. aureum were closely related with the environmental and medium conditions, as in the case of other marine microorganisms. For example, a low rotation speed of 50 rpm lowered the cell growth rate as well as the DHA content in the lipids. A low temperature had a negative effect on the cell growth, yet a positive effect on the lipid content in the biomass. Different initial glucose concentrations had no effect on the lipid content in the biomass or DHA content in the lipids, yet did affect the cell growth. Accordingly, these results show that environmental and medium factors must be synthetically considered in order to optimize DHA production when using T. aureum.

• Molecules and Cells
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• v.42 no.3
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• pp.252-261
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• 2019

The omega-3 fatty acid docosahexaenoic acid (DHA) is known to induce apoptosis and cell cycle arrest via the induction of reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress in many types of cancers. However, the roles of DHA in drug-resistant cancer cells have not been elucidated. In this study, we investigated the effects of DHA in cisplatin-resistant gastric cancer SNU-601/cis2 cells. DHA was found to induce ROS-dependent apoptosis in these cells. The inositol 1,4,5-triphosphate receptor ($IP_3R$) blocker 2-aminoethyl diphenylboninate (2-APB) reduced DHA-induced ROS production, consequently reducing apoptosis. We also found that G-protein-coupled receptor 120 (GPR120), a receptor of long-chain fatty acids, is expressed in SNU-601/cis2 cells, and the knockdown of GPR120 using specific shRNAs alleviated DHA-mediated ROS production and apoptosis. GPR120 knockdown reduced the expression of ER stress response genes, similar to the case for the pre-treatment of the cells with N-acetyl-L-cysteine (NAC), an ROS scavenger, or 2-APB. Indeed, the knockdown of C/EBP homologous protein (CHOP), a transcription factor that functions under ER stress conditions, markedly reduced DHA-mediated apoptosis, indicating that CHOP plays an essential role in the anti-cancer activity of DHA. These results suggest that GPR120 mediates DHA-induced apoptosis by regulating $IP_3R$, ROS, and ER stress levels in cisplatin-resistant cancer cells, and that GPR120 is an effective chemotherapeutic target for cisplatin resistance.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.85-91
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• 1998

To investigate the effects of antioxidative vitamins in combination with various fatty acids on breast cancer cell proliferation, MDA-MB231 human breast cancer cells were cultured for 3 days in the serum-free Iscove's modified Dulbecco's medium (IMDM) supplemented with 1.25mg/ml delipidized bovine serum albumin and 10㎍/ml insulin. Alpha-tocopherol, ascorbic acid or both vitamins were added to the medium at the concentrations of 10 and 50μM in the presence of 3μg/ml of oletic(Oa), linoleic(LA) α-linoleinic(LNA) and docosahexaenoic acid(DHA). Cell growth was reduced significantly by α-tocopherol in a dose-dependent manner, but not affected by ascorbic aicd. The four different fatty acids did not have significant effects on cell growth, although DHA exerted inhibitory effect on the growth after 1 day. However, the each fatty acid was well incorporated into celluar lipid as such or elongated forms. Addition of α-tocopherol remarkably increased its celluar contents and reduced cellular levels of thiobarbituric acid substances (TBARS) that were elevated notably in the presence of DHA in the culture media. But ascorbic acid addition did not change much of either cellular α-tocopherol or TBARS contents. northern blot hybridization showed that tumor supressor gene ρ53 was most highly expressed by the combination of ρ-tocopherol and DHA in 8 hours of cell culture. In conclusion , the growth inhibitory effect of vitamin E suggests that breast cancer cell proliferation is reduced by the mechanism other than cytotoxicity of lipid peroxide and it is related to expressionof tumor supprosser gene p53, that can be increased by both vitamin E and n-3 fatty acid, DHA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.285-292
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• 2010

To prepare high-quality fast foods using salmon, this study developed a docosahexaenoic acid (DHA)-enriched salmon patty, and compared its quality with soybean oil-added patty and commercial patty. The moisture and lipid contents of the DHA-enriched patty were 61.9% and 7.7%, respectively. The moisture content was lower than in the commercial patty, while the lipid content was higher. The lipophilic and hydrophilic browning indices of the DHA-enriched patty were 0.10 and 0.05, respectively, which were lower than those of the commercial patty. The DHA-enriched patty had 5% less trichloroacetic acid (TCA)-soluble nitrogen than the commercial patty, and it was firmer. There were no differences in the proximate composition, browning indices, TCA-soluble nitrogen content, and hardness between the soybean-added and DHA-enriched patties prepared in this experiment. Examining the fatty acid compositions of the patties, the saturated acid and monoenoic acid compositions decreased in the following order: DHA-enriched patty > soybean oil-added patty > commercial patty, while the polyenoic acid composition increased in that order. The total amino acid content of the DHA-enriched patty was 19.13 g/100 g, which was 32% higher than that of the commercial patty (14.47 g/100 g). No enriching effect of minerals would be expected on eating a 100 g DHA-enriched patty, except for phosphorus. The sensory evaluation indicated that the DHA-enriched patty was superior in color and taste to the commercial patty, while there was no difference in flavor between the patties.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.451-455
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• 2011

Proximate compositions, fatty acid profiles, and total amino acid compositions of the muscle and liver of Patagonian toothfish Dissostichus eleginoides were studied. Lipid contents of the muscle and liver of the fish were 22.3% and 35.3%, respectively. Protein content was higher in the fish muscle (12.8%) than in the liver (8.7%). Moisture content was also higher in the muscle (63.6%) than in the liver (49.8%). The prominent fatty acids in the total lipids of the fish muscle and liver were 18:1n-9, 16:0, 20:1n-9, 16:1n-7, 22:6n-3 (docosahexaenoic acid, DHA), 18:1n-7, 22:1n-11, 18:0, and 20:5n-3 (eicosapentaenoic acid, EPA). The fish muscle and liver contained approximately 1,000 to 2,500 mg of DHA and 400 to 600 mg of EPA per 100 g of tissue. Therefore, the fish muscle and liver are good sources of n-3 polyunsaturated fatty acids. On the other hand, the total amino acid content of the fish was 11.7 g/100 g muscle and 6.53 g/100 g liver. The prominent total amino acids profiles in the fish muscle and liver were glutamic acid, lysine, aspartic acid, leucine, and alanine, which are similar to those in other fishes.

• KSBB Journal
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• v.22 no.1
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• pp.37-42
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• 2007

The heterotrophic marine algae Thraustochytrium aureum ATCC 34304 produces substantial amount of polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA). In this study, changes in the lipid and fatty acid compositions of Thraustochytrium aureum ATCC 34304 were investigated according to the growth stage. The major lipids of Thraustochytrium aureum ATCC 34304 were found to be composed of triacylglyceride (TAG), phospholipid (PL), and sterol (ST). The content of triacylglyceride increased during the exponential phase of cell growth, but the content of phospholipid decreased. The composition of total polyunsaturated fatty acids decreased from 60.3% to 45.3% and that of docosahexaenoic acid from 42.1% to 33.9% in the triacylglyceride. The composition of total saturated fatty acids, however, increased from 24.9% to 27.8%. The content of total polyunsaturated fatty acids decreased greatly from 48.0% to 17.5% but the decrease in the content of saturated fatty acids was slight in phospholipid.

• Journal of Medicine and Life Science
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• v.18 no.1
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• pp.1-10
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• 2021

Omega-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) may be beneficial for the primary and secondary prevention of cardiovascular events (CVEs), especially in patients with myocardial infarction or heart failure with reduced ejection fraction. For this purpose, one to two seafood meals per week is preferentially recommended. Omega-3 fatty acids with a high-dose EPA formula (4 g/day) may be more effective than EPA+DHA mixed supplements for the secondary prevention of CVE. Krill oil also contains omega-3 fatty acids, but at a much lower dose compared to fish oil. Supplemental vitamins and minerals have not shown the preventive effects on CVE in prospective, and randomized clinical trials, except for one Chinese study showing the stroke prevention effects of folic acid. The clinical benefit of chelation therapy in reducing CVEs is uncertain.

• KSBB Journal
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• v.14 no.1
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• pp.109-113
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• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.179-183
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• 1996

The objective of this study was to investigate the difference of oxidative stability between DHA (docosahexaenoic acid) added and not added commercial mayonnaise, and then to find out stable condition for maintaining the quality of DHA added mayonnaise. During the storage at room temperature $(25^{\circ}C{\pm}1^{\circ}C)$, it showed that DHA added commercial mayonnaise was more sensitive to oxidation than DHA not added commercial mayonnaise. And sensory quality of DHA added commercial mayonnaise decreased drastically after 5 months from the production date of mayonnaise. During the storage at low temperature $(4^{\circ}C{\pm}1^{\circ}C)$, DHA added mayonnaise was also more sensitive to oxidation than DHA not added mayonnaise, but it showed no apparent and sensory problem with both samples during 8 months of cold storage test periods. In considering the distribution condition of mayonnaise in the country, it was suggested that shelf-life of the DHA added commercial mayonnaise should be shortened 2 or 3 months than that of the DHA not added commercial mayonnaise.

• 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.