• Applied Biological Chemistry
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• 제41권6호
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• pp.414-420
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• 1998

식이성지방 n-6/n-3비(1 : 2) 및 포화지방산:단순불포화지방산:다가불포화지방산비(1:1:1)를 일정하게 조정한 조건하에서 n-3계 지방산, ${\alpha}-LA(C_{18:3}),\;EPA(C_{20:5}),\;DHA(C_{22:6})$를 함유시킨 식이를 조제하여 성장기 SD-계 흰쥐 수컷에 2주간 급여하여 간장, 혈청의 Triacylglycerol(TG)농도 및 간장 TG 합성에 관여하는 효소 활성에 대하여 검토하였다. 본 실험에 사용한 EPA 및 DHA 는 순도 98%로서 고도로 정제한 ethyl ester 형태로 식이에 첨가하였다. 그 결과, ${\alpha}-LA$군에 비하여 EPA군 및 DHA군에서 간장 및 혈청 TG 농도는 유의적으로 감소하였으나, 총콜레스테롤 농도는 유의차가 인정되지 않았다. 간장의 인지질 농도는 DHA군에서만 유의적으로 증가하였다. 간장 막 결합성 phosphatidate phosphohydrolas(PAP)성은 간장TG 농도와 같은 경향으로서 EPA와 DHA군에서 유의하게 감소하였으며 Diacylglycerol acyltransferase(DGAT) 활성은 각 군간에는 변화가 없었다. 따라서, 간장TG 농도와 간장 막결합성 PAP활성과의 사이에 높은 상관관계(r=0.84)를 나타내어 간장TG 합성억제가 인정되었다. 지방산 합성계 효소의 활성도는 EPA및 DHA군에서 감소하였다. 이상의 결과로부터 n-3계 지방산, EPA 및 DHA에 의한 간장 및 혈청 TG 농도의 감소는 막 결합형 PAE 활성과 저해에 의한 간장TG 합성 및 지방산 합성 저해가 관여하는 것이 시사되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.768-774
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• 2007

To study the effect of dietary docosahexaenoic acid (DHA) enrichment on the expression of hepatic genes in pigs, weaned, crossbred pigs (30 d old) were fed diets supplemented with either 2% tallow or DHA oil for 18 d. Hepatic mRNA was extracted. Suppression subtractive hybridization was used to explore the hepatic genes that were specifically regulated by dietary DHA enrichment. After subtraction, we observed 288 cDNA fragments differentially expressed in livers from pigs fed either 2% DHA oil or 2% tallow for 18 d. After differential screening, 7 genes were found to be differentially expressed. Serum amyloid A protein 2 (SAA2) was further investigated because of its role in lipid metabolism. Northern analysis indicated that hepatic SAA2 was upregulated by dietary DHA enrichment (p<0.05). In a second experiment, feeding 10% DHA oil for 2d significantly increased the expression of SAA2 (compared to the 10% tallow group; p<0.05). The porcine SAA2 full length cDNA sequence was cloned and the sequence was compared to the human and mouse sequences. The homology of the SAA2 amino acid sequence between pig and human was 73% and between pig and mouse was 62%. There was a considerable difference in SAA2 sequences among these species. Of particular note was a deletion of 8 amino acids, in the pig compared to the human. This fragment is a specific characteristic for the SAA subtype that involved in acute inflammation reaction. Similar to human and mouse, porcine SAA2 was highly expressed in the liver of pigs. It was not detectable in the skeletal muscle, heart muscle, spleen, kidney, lung, and adipose tissue. These data suggest that SAA2 may be involved in mediation of the function of dietary DHA in the liver of the pig, however, the mechanism is not yet clear.

• Journal of Microbiology and Biotechnology
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• 제6권5호
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• pp.358-360
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• 1996

Solvent extraction, soxhlet method, and supercritical fluid extracion were considered, respectively, as the method of choice for the recovery of DHA from lyophilized Thraustochitrium sp., and the results of corresponding extraction were compared. Supercritical fluid extraction seems to be the most appropriate process with respect to time, process simplicity, and extractant intoxicity.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.95-103
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• 2014

This study was carried out to investigate the influences of dietary levels, ratios and sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the growth and fatty acid compositions of juvenile olive flounder Paralichthys olivaceus. Sixteen diets containing five levels of EPA (0.5%, 1.0%, 1.5%, 2.0%, and 4.0%), five levels of DHA (0.5%, 1.0%, 1.5%, 2.0% and 4.0%), three ratios of EPA/DHA (75/25, 50/50 and 25/75), two levels of squid liver oil (5% and 10%) and a control diet containing 5% soybean oil were hand-fed to triplicate groups of fish (average weight, $9.7{\pm}0.3g$) for 8 weeks. Survival, specific growth rate, feed efficiency and protein efficiency ratio of fish were not affected by dietary EPA and DHA levels or ratios. Also, the dietary treatment had no significant effect on the lipid and protein contents of muscle and whole body of fish. A corresponding increase in the EPA and DHA contents of fish occurred with increasing EPA and DHA levels in their diets. Our results suggest that juvenile olive flounder require a dietary EPA level of approximately 0.32% in the presence of 0.74% DHA for suitable survival and growth, and that EPA and DHA levels in fish muscle can increase to as much as 32% and 53%, respectively, of the total fatty acid content.

• 한국식품영양과학회지
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• 제31권2호
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• pp.351-354
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• 2002

본 연구에서는 황소개구리(Rana catesbeiana Shaw)가 불포화지방산의 주요 공급원이 될 수 있다는 점에 착안하여, 국내에서 서식하고 있는 황소개구리에서 지방을 추출하여 지방산 조성을 분석하였다. 황소개구리의 다리와 몸통에는 1%(w/w)이하의 지방이 함유되어 있었으며, 계절에 따른 변화를 관찰할 수 없었다. 황소개구리 다리에서 분리한 지방에는 26~31%(w/w) 포화지방산, 16~24% 모노엔산, 30~40% 고도불포화지방산이 함유되어 있었으며, 몸통에서 분리한 지방에는 23~28% 포화지방산, 29~44% 모노엔산, 16~30% 고도불포화지방산이 함유되어 있었다. 황소개구리에서 추출한 지방의 주요 지방산은 palmitic acid, oleic acid, linoleic acid이었다. 다리에서 분리한 지방에는 3~8% eicosapentaenoic acid(EPA)와 6~10% docosahexaenoic acid(DHA)가 함유되어 있었으며, 몸통에서 분리한 지방에는 1~3% EPA 와 DHA가 각각 함유되어 있었다.

• 한국수산과학회지
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• 제26권6호
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• pp.529-537
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• 1993

가다랭이 안와유로부터 docosahexaenoic acid(DHA)를 정제하기 위해 기존의 방법들을 적용하여 비교 검토하고, DHA의 효과적인 정제를 위해 조작방법을 개량하였다. 가다랭이 안와조직의 총지질은 $55.4\%$였으며, 이 중 DHA는 $23.7\%$였다. 저온분별결정법과 요소결정법을 적용한 결과 순도에서 각각 약 $46\%$ 및 $61\%$의 DHA가 얻어졌다. 이들 방법들은 순도면에서는 다소 떨어지나, 정제조작이 단순하여 다량의 DHA 분리에 적합하였다. 질산은 수용액법은 상기 2가지 방법에 비하여 순도면에서는 약간 개선되었으나, 회수율이 대단히 낮았다($10\%$ 이하). 질산은 함침 실리카 칼럼 크로마토그래피법은 고순도 DHA의 정제방법으로써 적합하였다(순도 $98\%$ 이상, 회수율 $90\%$ 이상). 결과적으로 저온분별결정법과 질산은 함침 실리카 칼럼 크로마토그래피법을 조합한 개량법(2단계 정제법)이 가다랭이 안와유로부터 고순도 DHA($99.9\%$)의 정제를 위한 가장 효과적인 방법으로 평가되었다.

• Journal of Cancer Prevention
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• 제22권1호
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• pp.1-5
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• 2017

Pancreatic cancer is a highly aggressive malignant tumor of the digestive system and radical resection, which is available to very few patients, might be the only possibility for cure. Since therapeutic choices are limited at the advanced stage, prevention is more important for reducing incidence in high-risk individuals with family history of pancreatic cancer. Epidemiological studies have shown that a high consumption of fish oil or ${\omega}3-polyunsaturated$ fatty acids reduces the risk of pancreatic cancers. Dietary fish oil supplementation has shown to suppress pancreatic cancer development in animal models. Previous experimental studies revealed that several hallmarks of cancer involved in the pathogenesis of pancreatic cancer, such as the resistance to apoptosis, hyper-proliferation with abnormal $Wnt/{\beta}-catenin$ signaling, expression of pro-angiogenic growth factors, and invasion. Docosahexaenoic acid (DHA) is a ${\omega}3-polyunsaturated$ fatty acid and rich in cold oceanic fish oil. DHA shows anti-cancer activity by inducing oxidative stress and apoptosis, inhibiting $Wnt/{\beta}-catenin$ signaling, and decreasing extracellular matrix degradation and expression of pro-angiogenic factors in pancreatic cancer cells. This review will summarize anti-cancer mechanism of DHA in pancreatic carcinogenesis based on the recent studies.

• 대한지역사회영양학회지
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• 제29권2호
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• pp.144-155
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• 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.

• ALGAE
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• 제32권1호
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• pp.67-74
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• 2017

The heterotrophic dinoflagellate Oxyrrhis marina is known to produce high levels of docosahexaenoic acid (DHA) when fed on diverse algal prey. However, large-scale culturing of algal prey species is not easy and requires a large amount of budget, and thus more easily cultivable and low-cost prey is required. Dried yeast was selected as a strong candidate for an alternative prey in our preliminary tests. Thus, we explored the fatty acid composition and DHA production of O. marina fed on dried yeast and compared these results to those of O. marina fed on two algal prey species: the phototrophic dinoflagellate Amphidinium carterae and chlorophyte Chlorella sp. powder. O. marina fed on dried yeast, which does not contain DHA, produced the same high level of DHA as those fed on DHA-containing A. carterae. This indicates that O. marina is likely to produce DHA by itself regardless of prey items. Furthermore, the DHA content (and portion of total fatty acid methyl esters) of O. marina satiated with dried yeast, 52.40 pg per cell(and 25.9%), was considerably greater than that of O. marina fed on A. carterae (26.91 pg per cell; 15.7%) or powder of Chlorella sp. powder (21.24 pg per cell; 16.7%). The cost of dried yeast (approximately 10 US dollars for 1 kg dried yeast) was much lower than that of obtaining the algal prey (approximately 160 US dollars for 1 kg A. carterae). Therefore, compared to conventional algal prey, dried yeast is a more easily obtainable and lower-cost prey for use in the production of DHA by O. marina.

• Journal of Nutrition and Health
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• 제29권3호
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• pp.267-277
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• 1996

Effect of DHA-rich fish oil on brain development and learning ability has been studied in Sprague Dawley rats. Female rats were fed experimental diets containing either corn oil fish oil at 10%(w/w) level throughout the gestation and lactation. Corn oil was added in fish oil diet to supply essential fatty acid at 2.3% of the calories. All male pups were weaned to the same diets of dams at 21-days after birth. Plasma fatty acid composition was analyzed for dams and pups at 21-days, 28-days and 22-weeks after birth. The analysis of DNA and fatty acid profile in the brain were undertaken at birth, 3, 7, 14, 21, 28 days and 22 weeks after birth and learning ability was tested at 18-20 weeks of age. Regardless of dietary fats, arachidonic acid(AA) and docosahexaenoic acid(DHA) were the principal polyunsaturated fatty acids in the brain. Rats fed CO diet showed a continouus increase of AA content in the brain from 10.9%(at birth) to maximum 15.3% level (14-days old), while the rars fed FO diet showed 78-79% of CO group throughout the period. Rats fed FO diet showed higher incorparation of DHA from 15.2% at birth to a maximum level of 18.5% at 140days, while the rats fed CO diet showed only 7.0% incorporation of DHA at birth and a maximum level of 11.1% at 21-days. Compared to CO group, FO group showed lower ratio of chol/PL and higher content of DHA in brain microsomal membrane, resulting in better membrane fluidity. Total amount of DNA per gram of brain was reached maximum level at 21 days in both groups. This would be a period of the cell proliferation during brain development. Overall, the rats fed fish oil diet showed a higher incorporation of DHA and membrane fluidity in the brain and better learning performances (p<0.05).