• Journal of Nutrition and Health
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• v.24 no.4
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• pp.314-325
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• 1991

To compare the hypolipidemic effects of n6 and n3 PUFA at different fat levels, male Sprague Dawley rats were fed either low fat (LF, 10% Cal) or high fat (HF, 40% Cal) diet which was different only in fatty acid composition for 6 weeks. Dietary fats were beef tallow, corn oil, perilla oil, and fish oil concentrate as a source of saturated fatty acid, n6 linoleic acid(LA). n3 ${\alpha}-linolenic$ acid(LL) and n3 eicosapentaenoic acid(EPA)+docosahexaenoic acid(DHA), respectively. VLDL fraction was separated by ultracentrifugation and chemical composition was determined by thin layer chromatography. Plasma cholesterol level was increased by n6 LA but decreased by n3 LL and n3 EPA in LF and HF diets, and the hypocholesterolemic effect of n3 EPA was most significant in HF diet. HDL-Chol level was raised by n6 LA in LF and HF diets, but significantly reduced by n3 EPA in HF. Plasma TG level was reduced by n6 LA n3 LL and EPA in LF and HF with the reduction of lipogenic enzyme activity only by n3 PUFAs. The proportion of TG in VLDL fraction was significantly lowered by n3 EPA in LF and HF. The proportion of apo-B in VLDL fraction was not changed in LF, but was significantly decreased in HF by n3 EPA. Therefore, the hypotriglyceridemic effect of n3 PUFA could be from the reduced lipogenesis in liver and resulted in the depressed secretion of TG as VLDL in LF and HF with significant lower production of apoB in HF diet.

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

• Journal of Nutrition and Health
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• v.24 no.5
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• pp.420-430
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• 1991

To compare the hypolipidemic effects of n6 linoleic acid. n3 $\alpha$-linolenic acid and n3 eicosapentaenoic acid in rats fed high carbohydrate(70% Cal) diet. male Sprague Dawley rats were fed different experimental diets for 6 weeks. which were different only in fatty acid composition. The dietary fats were beer tallow(BT) as a source of saturated fatty acid (SFA), corn oil(CO) for n6 linoleic acid(LA), perilla oil(PO) for n3 $\alpha$-linolenic acid(LL) and fish oil(FO) for n3 eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA) Plasma total cholesterol(Chol) level was increased by n6 LA but decreased by n3 LL and n3 EPA and most effectively reduced by n3 EPA. HDL-Chol level was raised by n6 LA, but there was no significant change in HDL-Chol levels by n3 LL and was lowered by n3 EPA. Plasma 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. Both lipogenic enzyme activity and liver TC level were also decreased by n3 PUFA. The relative proportions of TG in VLDL was significantly lowered by n3 EPA. but the proportions of Apo B in VLDL was not changed by n3 EPA. Overall. the hypolipidemic effect was in the order of EPA+ DHA(n3) >LL(n3) >LA(n6) and fish oil and perilla oil rich in n3 PUFA may have important nutritional applications in the prevention and treatment of hypertriglyceridemia.

• Journal of Nutrition and Health
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• v.27 no.6
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• pp.537-551
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• 1994

The dietry effects of marine n-3, plant n-3 and plant n-6 fatty acid on serum lipids levels, liver phospholipid fatty acid composition in rat were investigated. Four groups of male Sprague-Dawley rats, 30 weeks old, were fed on one of 4 different experimental diets for 4 weeks. The diets were composed of 15% fat(w/w) of either concentrated EPA oil(20:5, n-3 : 65%), fish oil(20:5, n-3 : 19%, 22:6, n-3 : 18%), perilla oil(18:3, n-3 : 60%) or corn oil(18:2, n-6 : 49%). Blood was initially taken before experimental feeding and also taken after 2 weeks and 4 weeks feeding the diet respectively and then examined for the levels of serum lipids. Rats were sacrificed at 4 weeks after the diet for the analysis of liver phospholipid fatty acid. EPA feeding remarkably decreased the serum levels of triglyceride, total cholesterol, HDL-cholesterol and total phospholipid than any other oil feeding. Fish oil feeding decreased serum HDL-cholesterol level comparable to the effect of EPA feeding and decreased total cholesterol and phospholipid less than but close to the effect of EPA feeding. Perilla oil feeding did not change serum levels of triglyceride and phospholipid, but it decreased serum total cholesterol a lot and HDL-cholesterol a little. Corn oil feeding did not affect triglyceride and total cholesterol while it increased serum level of HDL-cholesterol and total phospholipid. Serum HDL-cholesterol level was increased only in corn oil group. But contrary to the result of serum total phospholipid, liver phospholipid level found to be higher in fish oil and EPA groups than in perilla oil and corn groups. The fatty acid composition of liver phospholipid, phosphatidylcholine(PC) and phosphatidyl ethanolamine(PE) turned out to be affected by dietary fatty acid. 18:2 of liver PC was the lowest in FO group following CO group. The ratio of 20:4/18:2 was lower in PO group than in EPA group in consequence of higher 18:2 and lower 20:4 in PO group and vise versa in EPA group. In the liver PC and PE, similar trends in the ratios of n-6/n-3 and 20:4/18 were found showing higher ratios with CO and EPA group over FO and PO group. EPA group showed the lowest level of 20:5 and lower level of 20:6 than group. Fish oil was more efficient than EPA oil and PO in lowering the ratio of n-6/n-3 in consequence of the highest 22:6, and the lowest 18:2 in liver phospholipid. But PO lowers the ratio or 20:4/18 more than FO. In conclusion, EPA oil was more effective in lowering serum lipids than FO and PO. Reviewing the dietary effect of fatty acid on eicosanoids composition in rats, it is considered that more possibility was with FO than PO in the effectiveness of atherosclerosis prevention and more with PO than with EPA oil. It was also found that FO showed more effective than EPA oil for atherosclerosis prevention. It was hardly found that CO had any effect on lowering serum lipids and on eicosanoids composition in liver phospholipid for the prevention of atherosclerosis.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.414-420
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• 1998

We studied the difference effects of dietary ${\alpha}-linolenic\;acid\;({\alpha}-LA,\;18:3\;n-3)$, eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) on the lowering of triacylglycerol in the liver and serum on lipid metabolism in rats. Rats were fed semipurified diets containing 10% fat with constant polyunsaturated/monounsaturated/saturated fatty acids (1:1:1) and n-6/n-3 ratio (1:2). EPA (98%) and DHA (98%) were added in diets as the ethyl esters. The concentration of liver triacylglycerol was significantly lower in rats fed both EPA and DHA than in those fed ${\alpha}-LA$. The concentration of liver phospholipid was significantly higher in rats fed DHA than in those fed ${\alpha}-LA$ and EPA. Both EPA and DHA reduced serum triacylglycerol concentration compared with ${\alpha}-LA$, but this effect was more pronounced in the EPA diet. The activity of phophatidate phosphohydrolase in the liver microsome was significantly lower in rats fed both EPA and DHA than in those fed ${\alpha}-LA$. but, there was no significant difference on the activities of diacylglycerol acyltransferase among the three groups. The concentration of liver triacylglycerol were correlated with changes in the microsomal phosphatidate phosphohydrolase activity (r=0.84). Hepatic NADPH generating enzyme, glucose-6-phosphate dehydrogenase was more effective to reduce the activity in rats fed both EPA and DHA than in those fed ${\alpha}-LA$. In conclusion, EPA or DHA reduced the hepatic triacylglycerol concentration by inhibiting microsomal phosphatidate phosphohydrolase, thereby inhibiting synthesis of triacylglycerol in the liver.

• BMB Reports
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• v.32 no.1
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• pp.33-38
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• 1999

The effects of eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic acids (DHA, 22:6n-3) on the phospholipase $A_2$ ($PLA_2$)-mediated release of arachidonic acid (AA, 20:4n-6) were studied in kidney microsomes from rats fed diets containing sunflower oil (SO) or fish oil (FO) concentrate for 11 months. The amounts of AA released by the endogenous $PLA_2$ enzyme were significantly lower by 38% in the FO, compared to the SO-fed rats (23.2 nmol versus 60.7 nmol AA released/mg protein/h in the FO- and SO-treated groups, respectively). The FO-derived microsomes released less linoleic acid (LA, 18:2n-6) and adrenic acid (22:4n-6), but larger amounts of the n-3 fatty acids, including EPA, DHA, docosapentaenoic acid (DPA, 22:5n-3), and 20:4n-3 than the SO-derived microsomes. A similar replacement of the AA and adrenic acid with the n-3 fatty acids including EPA and DHA was also observed in the microsomal phospholipid fraction from the FO-fed rats relative to the SO-treated group. The results suggest that the $PLA_2$-mediated release of AA is reduced and that of EPA is increased in compensation for AA decline in kidney microsomes from FO-fed rats (0.7 nmol EPA/mg protein/h versus 22.7 nmol EPA/mg protein/h for the SO and FO-treated groups). Replacement of the n-6 with n-3 fatty acids may explain the reduced synthesis of the AA-derived prostaglandins and the concomitant rise in the EPA-derived prostaglandins observed in kidneys of FO-treated rats.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.1-8
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• 2012

To evaluate the effects of n-3 and n-9 fatty acid combination on broiler chicks, diets containing the combinations of five different fat sources including flaxseed oil, fish oil, EPA, DHA and olive oil were provided, and all chicks were processed at 4 weeks of growth. Liver, breast and thigh samples were collected and fatty acid composition and/or CIE $L^*$, $a^*$ and $b^*$ measurement were measured. Also, live chick and liver weights were weighed and the ratio was provided as an evidence of fat accumulation in liver. No significant difference was determined in both live and liver weight ratio and liver color. EPA was low in FHO as compared to livers from others. In contrast, DHA was significantly high in FHO. In broiler breasts derived from FDO, AA and n-3 fatty acid content was high, but only numerical differences of EPA and DHA were determined in breasts from FDO. The thighs from FHO showed high in EPA, DHA and n-3 fatty acid content but had low in AA and n-6 to n-3 ratio. Therefore, the results indicate that broiler chicken diets containing either FDO or FHO may be possible combination diets increasing n-3 polyunsaturated fatty acids in broiler chicks.

• Journal of Aquaculture
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• v.9 no.4
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• pp.353-361
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• 1996

The objective of this study was to investigate the essential fatty acids requirement and its optimal level in dietary for young of tiger puffer. The young puffer fish used in feeding trial were average body weight 3.45g. Fish were randomly divided into 11 groups containing 30 fish each in 200 ${\ell}$ tank and reared for 8 weeks at ambient temperature. In basal diets, defatted squid meal, casein-Na and activated gluten were used as the dietary protein source, dextrin and ${\alpha}$-starch (gelatinized starch) as the digestible carbohydrate source and beef tallow as the lipid source. Five fatty acids added to diet were linoleic acid (LNA), linolenic acid (LNA), eicosapentaenoic acid (EPA) ,docos-ahexaenoic acid (DHA) and n-3 HUFA. Among that, the supplement of LA and LNA were $1\%$ of total composition of diet, respectively, and EPA, DHA and n-3 HUFA ranged from $0.3\~1\%$ level. Growth and feed efficiency were measured to the interval of 2 weeks, and analyzed fatty acids composition of diet and liver by GCL. As a result of 8 weeks experiment, predominant growth were shown in $0.5\~1\%$ n-3 HUFA and $0.5\%$ DHA than others (P<0.05). In comparison of efficiency among EPA, DHA and n-3 HUFA groups, the most results were revealed in n-3 HUFA and the least in EPA. The adding effect was shown in EPA by increasing the fatty acids content from 0.5 to $1\%$ in diet. However, sudden decline and steady state in growth were observed in $1\%$ DHA and $1\%$ n-3 HUFA, respectively. The feeding efficiency and protein efficiency ratio were high in n-3 HUFA groups and $0.5\%$ DHA. Consequently, it is assumed that young puffer requires n-3 HUEA both EPA and DHA as essential fatty acids. The optimal content in diets are about $0.5\%$ of HUFA or DHA.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.47-56
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• 2022

This paper examines the process and evidence used to create the Dietary Reference Intake (DRI) of alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for Koreans. ALA (18:3n3) is an essential fatty acid, and EPA and DHA are known to have beneficial effects on cardiovascular disease risk and reduction of triglyceride levels. Various international organizations have suggested dietary recommendations for n-3 polyunsaturated fatty acids (PUFAs), including ALA, EPA, and DHA. A DRI for Koreans was established for the first time in 2020, specifically for the adequate intake (AI) of ALA and EPA + DHA. This recommendation was based on the average intake of ALA and EPA + DHA from the Korea National Health and Nutrition Examination Survey 2013-2017. For Korean infants, the AI of ALA and DHA was based on the fatty acid composition of maternal milk. Estimated average requirement and a tolerable upper intake level have not been set for n-3 PUFA due to insufficient evidence. In addition, the intake level of n-3 PUFA for prevention of chronic disease has also not been determined. Future studies and randomized controlled trials are required to establish the UL and to define the level for disease prevention.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.919-923
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• 1999

The edible portions of saury were cooked by pan frying, deep fat frying, steaming and microwave cooking to compare the compositions of fatty acids in cooked fish with those in raw fish. The total lipid in saury studied varied by each fish but ranged from 21.87% to 30.63%. The distribution of each fatty acid (average) was in order; $C_{22:1}\;(21.75%)>C_{20:1}\;(15.81%)>C_{16:0}\;(11.75%)>C_{22:6}\;(DHA,\;10.61%)>C_{14:0}\;(7.04%)>C_{20:5}\;(EPA,\;5.13%)$. The average ratio of PUFA (polyunsaturated fatty acids)/SFA (saturated fatty acids) in saury fillet was 1.07 and that of n-3/n-6 was 9.15, which showed saury might be a good source for PUFA including n-3 fatty acids. Comparing the effects of cooking on EPA and DHA, two of the most important n-3 PUFA, the decreasing rate of EPA were 6.98% (pan frying), 26.93% (deep fat frying), 1.16% (steaming) and 15.12% (microwave cooking), respectively. The decreasing rate of DHA ware 4.30% (pan frying), 15.99% (deep fat frying), 3.26% (steaming) and 9.56% (microwave cooking). This study showed that both EPA and DHA were reduced by steaming least, and pan frying, microwave cooking, deep fat frying most, in order.