• Journal of Life Science
• /
• v.10 no.2
• /
• pp.115-124
• /
• 2000

The present study was undertaken to separate the available components effectively, such as tetrodotoxin(TTX), docosahexaenoic acid(DHA, C22:6,ω-3) and eicosapentaenoic acid (EPA, C20:5,ω -3) from pufferfish liver waste, which are known to have high values as bioactive materials. By using ultrafiltration, it was possible to separate high contents of 68mg TTX from pufferfish liver waste. In contrast, by activated charcoal column, it was to obtain about 54mg TTX. The recovering ratios were 65.3% and 45.0% in the two different methods of ultrafiltration and activated charcoal column, respectively. From the results of HPLC and gas chromatography-mass spectrometry(GC-MS), the obtained toxins were identified to be TTX and its derivatives. In addition, it was also possible to obtain 72.3g DHA and 11.4g EPA from 1kg of pufferfish liver by high performance liquid chromatography (HPLC). These amounts of DHA and EPA were also 17.70% and 1.04% in the total lipid of pufferfish liver oil from analysis of gas chromatography(GC), respectively.

• Journal of Aquaculture
• /
• v.17 no.3
• /
• pp.187-196
• /
• 2004

This study was carried out to investigate changes in biochemical composition of rotifer, Brachionus plicatilis, enriched with the commercial enrichments (Enhance, Advantage, Algamac-2000, DHA-Selco and Advantage ＋ Chlorella) at various durations of enrichment (0, 6, 12 and 24 hr) to improve the growth and survival of marine fish larvae. Total lipid content of rotifers enriched with various enrichments tended to increase with an increase in durations of enrichment up to 6 hr, but after that, was not significantly affected by enrichment materials. However, total protein content of rotifers enriched groups except for Advantage＋Chlorella decreased with the increase in duration of enrichment. The highest protein/lipid ratio showed 2.7 in rotifer enriched with the Advantage ＋Chlorella. The phospholipid/lipid ratio of rotifer enriched with the Enhance, Advantage and Advantage＋Chlorella groups was significantly higher than that of enriched rotifer with the Algamac-2000 and DHA-Selco groups. The highest DHA level, 2.5%, of rotifer enriched for 24 hr was obtained in the Advantage, but was not significantly different among other groups, except for Algamac-2000. No significant difference in DHA level of rotifer enriched with the DHA-Selco, Algamac-2000 and Advantage＋Chlorella groups was observed between l2h and 24hr of enrichment. The DHA/EPA ratio in the enriched rotifers varied among enrichment material groups, ranged from a high level of 11.1：1 in the Advantage＋Chlorella group to a low level of 4.1：1 in DHA-Selco group. The results from this study indicate that rotifers enriched with Enhance, Advantage and Advantage＋Chlorella seemed to be effective to improve nutritional value of rotifer for marine fish larvae because phospholipid, DHAJEPA and protein/lipid ratios of rotifer enriched with Enhance, Advantage＋Chlorella were higher than those of rotifer enriched with either DHA-Selco or Algamac-2000. Especially, supplementation of the Chlorella to these enrichments would appear to be effective for improvement of fish larval performance because of no reduction of protein level in rotifer, which is critical for growth of fish larvae.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.1
• /
• pp.31-38
• /
• 2014

Docosahexaenoic acid (DHA, 22:6n-3) and ecosapentaenoic acid (20:5n-3) have attracted increasing attention since the first epidemiological report on the importance of n-3 essential fatty acids. It is thought that DHA has important functions in brain and retinal tissues. Thraustochytrids, a group of marine protists, are capable of heterotrophic growth, and are potential omega-3 producers for industrial use, especially the members of the Schizochytrium and Thraustochytrium genera. The aims of this work were to isolate, identify and screen thraustochytrids from 17 different locations. Twenty-three isolates were screened for biomass, total fatty acid (TFA) and DHA content. Analysis of the fatty acid methyl esters revealed four distinct clusters biomass ranged from $8.68-9.36gL^{-1}$, and lipid and DHA contents ranged from $3.11-4.10gL^{-1}$ and $1.05-1.93gL^{-1}$ biomass, respectively. B-12 isolates were screened for biomass ($9.36gL^{-1}$), TFA ($4.10gL^{-1}$) and DHA (47.01%, w/w) content. C-6 isolates were also screened for biomass ($8.92gL^{-1}$), TFA ($3.30gL^{-1}$) and DHA (49.41%, w/w) content. The 18S rRNA gene sequencing results identified Schizochytrium mangrovei as B-12 and Crypthecodium cohnii as C-6.

• Korean Journal of Food Science and Technology
• /
• v.36 no.2
• /
• pp.361-364
• /
• 2004

EPA and DHA extracted from methyl esterified squid oil were purified by silver exchanged resin, silver nitrate-impregnated silica gel, silver exchanged zeolite, and silica gel column chromatography, among which column chromatography using mixture of silver exchanged resin and silica gel (10% by weight) showed the best result. By this simple purification method, EPA and DHA were concentrated from 12.5 to 27.9% (yield, 86,0%) and from 21.7 to 49.5% (yield, 87.3%), respectively. Silver exchanged resin had additional advantages of outstanding reusability and simple recovery of silver.

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

• BMB Reports
• /
• v.54 no.5
• /
• pp.278-283
• /
• 2021

Our understanding of the differential effects between specific omega-3 fatty acids is incomplete. Here, we aimed to evaluate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on T-helper type 1 (Th1) cell responses and identify the pathways associated with these responses. Naïve CD4⁺ T cells were co-cultured with bone marrow-derived dendritic cells (DCs) in the presence or absence of palmitate (PA), DHA, or EPA. DHA or EPA treatment lowered the number of differentiated IFN-γ-positive cells and inhibited the secretion of IFN-γ, whereas only DHA increased IL-2 and reduced TNF-α secretion. There was reduced expression of MHC II on DCs after DHA or EPA treatment. In the DC-independent model, DHA and EPA reduced Th1 cell differentiation and lowered the cell number. DHA and EPA markedly inhibited IFN-γ secretion, while only EPA reduced TNF-α secretion. Microarray analysis identified pathways involved in inflammation, immunity, metabolism, and cell proliferation. Moreover, DHA and EPA inhibited Th1 cells through the regulation of diverse pathways and genes, including Igf1 and Cpt1a. Our results showed that DHA and EPA had largely comparable inhibitory effects on Th1 cell differentiation. However, each of the fatty acids also had distinct effects on specific cytokine secretion, particularly according to the presence of DCs.

• Korean Journal of Community Nutrition
• /
• v.29 no.2
• /
• pp.144-155
• /
• 2024

Objectives: This study evaluated dietary intake and food sources of essential fatty acids in Korean adolescents. Methods: This study was comprised of 3,932 adolescents (9-18 years) who participated in the 2016-2021 Korea National Health and Nutrition Examination Surveys. Dietary intake and food sources of essential fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and linoleic acid (LA) were evaluated using data obtained from one-day 24-hour dietary recall. The proportions of adolescents consuming ALA, EPA + DHA, and LA above or below the adequate intake (AI) of the 2020 Dietary Reference Intakes for Koreans were calculated. All statistical analyses accounted for the complex sampling design effect and appropriate sample weights. Results: The mean intakes of ALA, EPA, DHA, and LA among Korean adolescents were 1.29 g/day, 69.6 mg/day, 166.0 mg/day, and 11.1 g/day, respectively. Boys had higher intakes of all essential fatty acids compared to girls. By age group, adolescents aged 15-18 years showed lower intakes of EPA and DHA compared to adolescents in younger age groups. The 9-11-year-old adolescents had lower intakes of ALA and LA than older adolescents. The proportions of adolescents who consumed more than AI were 35.7% for ALA, 30.4% for EPA + DHA, and 41.5% for LA. Adherence to the AI for ALA did not differ by sex or age group, although boys showed a lower adherence to the AI for EPA + DHA than girls. Major food sources for ALA and LA were plant-based oils, mayonnaise, pork, and eggs. Mackerel was the most significant contributor to EPA and DHA intake (EPA, 22.6%; DHA, 22.2%), followed by laver, squid, and anchovy. Conclusions: The proportion of Korean adolescents who consumed EPA + DHA more than AI was low. Our findings highlight that nutrition education emphasizing an intake of essential fatty acids from healthy food sources is needed among Korean adolescents.

• Biomedical Science Letters
• /
• v.14 no.3
• /
• pp.187-192
• /
• 2008

To clerify the protective effect of omega-3 of polyunsaturated fatty acid docosahexaenoic acid (DHA) on the cytotoxicity induced by organic mercury in cultured NIH3T3 fibroblasts. The measurement of cell viability on ogranic mercury wad done by XTT assay after NIH3T3 fibroblasts were cultured with various concentrations of methyl mercuric chloride (MMC). And also, the effect of DHA on the MMC-mediated cytotoxicity was examined by cell viability, and antioxidant effect of DHA was also assessed by superoxide dismutase (SOD)-like activity and the lipid peroxidation activity in cultured NIH3T3 fibroblasts. In this study, MMC decreased cell viability and $XTT_{50}$ value was determined at $50{\mu}M$ of MMC in these culture. In the effect of DHA against the cytotoxicity induced by MMC, DHA significantly increased the cell viability damaged by MMC in cultured NIH3T3 fibroblasts. And also, DHA showed the antioxidant effect by showing the increase of SOD-like activity and the decrease of lipid peroxidation activity. From these results, it is suggested that organic mercury such as MMC has highly toxic effect on cultured NIH3T3 fibroblasts, and also, omega-3 of polyunsaturated fatty acid, DHA showed the protection on MMC-induced cytotoxicity and antioxidant effect.

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

• The Korean Journal of Food And Nutrition
• /
• v.8 no.2
• /
• pp.59-69
• /
• 1995

This study designed to compare the hypolipidemic e(feats of n6 linoleic acid (LA), n3 w-linolenic acid(LL) and n3 eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) In rats fed high fat (40% Cal) diet. Male Sprague-Dawley rats fed experimental diets for 6 weeks, which were different only in fatty acid composition. The dietary fats were beef tallow (BT) as a source of saturated fatty acid (SFA), corn oil(CO) for n6 LA, perilla oil (PO) for n3 a-LL and fish oil (FO) for n3 EPA+DHA. Plasma total cholesterol (T-chol) level was increased by n6 LA but decreased by n3 LL and n3 EPA+DHA and most effectively reduced by n3 EPA+DHA. Plasma triglyceride(TG ) level was reduced by n6 LA, but lipogenesis in liver was not affected by n6 LA. However, plasma TG level was lowered by n3 LL and EPA+DHA. Both lipogenic enzyme activity and liver TG level were also decreased by n3 PUFA. PO and FO groups were significantly higher in the relative Proportions of C20:5 and C22:6 of plasma and liver and lower in those of C20:4/C20:5 ratio. Overall, the lipid-lowering effect was in the order of n3 EPA+DHA >n3 LL > n6 LA and fish oil and perilla oil rich in n3 PUFA may have important nutritional applications in the prevention and treatment of hyperlipidemia.