• Journal of Aquaculture
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• v.5 no.2
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• pp.157-165
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• 1992

Experiments were conducted to find out suitable dietary lipids in the practical feed for Nile tilapia, Oreochromis nilotius. Soybean oil, corn oil, fish oil or cuttlefish liver oil was mixed in the diet and tested. The best weight gain and feed efficiency were obtained from the fish fed soybean oil or corn oil, both rich in 18 : 2n-6. But the growth rate of fish fed diet with fish oil or cuttlefish liver oil were inferior. The levels of 20 : 3n-9 in the total lipid were not different in all tested lipids, but that in the polar lipid of the fish oil or cuttlefish liver oil were lower than that in the soybean oil or corn oil. Thus, vegetable oil such as soybean oil or corn oil, rich in 18 : 2 n-6, were suitable as dietary lipid for Nile tilapia. Unlike other fish species, fish oil or cuttlefish liver oil showed no essential dietary value for this species.

• Journal of Nutrition and Health
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• v.25 no.6
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• pp.468-475
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• 1992

This study was carried out to observe the effects of dietaryn-6, n-3 fatty acids and vitamin A levels on humoral immunity in rat. Sixty eight male Sprague-Dawley rats were fed 6 different experimental diets for 6 weeks. The diets were composed of 10% of either corn oil or fish oil with various levels of vitamin A ; deficient(12450 IU/kg diet) adequate(4000IU/kg diet) and excess(400,000 IU/kg diet) The weight of spleen from the excess vitamin A-fish oil group showed the lowest value of all the groups when spleen weight was expressed/100g body weight. The number of PFC to SRBC was not affected by dietary at type and vitamin A levels. Hemagglutination titers were significantly lower in fish oil groups compared to corn oil groups and the values of vitamin A deficient groups were lower than the ones of adequate and excess vitamin A groups. IgM contents is serum were significantly lower in fish oil groups than in corn oil groups. IgG contents were higher in fish oil groups than in corn oil groups and the highest levels was recorded in excess vitamin A-fish oil group which showed the smallest speen size. Light microscopical examination showed that spleen tissues of fish oil groups were well developed than those of the corn oil groups and vitamin A deficient and excessive groups showed poor development than the adequate groups. Therefore it is suggested that adequate amounts of vitamin A consumption is necessary for healthy individuals and fish oil intake along with excess vitamin A should be avoided in order to maintain immune function properly.

• 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.

• Journal of Nutrition and Health
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• v.27 no.6
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• pp.552-562
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• 1994

The study was designed to observe the effect of different dietary fats on the incidence of colorectal tumor and in vivo cell proliferation in colon carcinogenesis. Male Sprague Dawley rats were intrarectally infused with chemical carcinogen(methylnitrosourea, MNU) and fed 16%(w/w) fat diet containing one of dietary fats(beef tallow, corn oil, perilla oil) for 30 weeks. To measure in vivo cell proliferation, the incorporation of 5-bromo-2-deoxyuridine(BrdU) into DNA was localized using the monoclonal anti-BrdU antibody. Large number of tumors were found in the distal colon and tumor incidence was increased in the order of perilla oil(57.7%)$\alpha$-linolenic acid rich in perilla oil could have a protective effect against colon cancer compared to saturated fatty acid or n-6 linoleic acid.

• Journal of Nutrition and Health
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• v.24 no.3
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• pp.179-188
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• 1991

Twenty college women were led experimental diet which composed ot basal diet plus different kinds of dietary rats at 27% Cal. Equal amount of 13.5g of corn oil, perilla oil or fish oil was supplied for 2 weeks as a source of n6 linoleic acid(LA). n3 $\alpha$-linolenic acid (LL). or n3 EPA + DHA. respectively. Plasma total Chol level was reduced by perilla and fish oils, significantly only by fish oil. Plasma Chol level was rather increased by corn oil(P<0.05), but was decreased by double amount of corn oil supplement. Therefore, hypocholesterolemic effect of fatty acids was in the order of n3 EPA+DHA>n3 LL>n6 LA and influenced by the degree of fat unsaturation. Plasma TG level was also significantly decreased by n3 EPA+ DHA and increased by n6 LA. Hypotriglyceridemic effect of fatty acids was also in the order of n3 EPA + DHA> n3 LL>n6 LA and influenced by the unsaturation. However, the reduction of plasma TG was more influenced by the fatty acid structure rather than the fat unsaturation. There were no significant effects on lipoprotein pattern 3nd chemical compositions of lipoprotein by different dietary PUFAs. but fish oil diet significantly increased the relative proportion of HDL-Chol. In conclusion. cholesterol- lowering effect of dietary PUFAS seemed to be a function of total fat unsaturation but hypotriglyceridemic effect seemed to be more linked to the ratty acid structure rather than the degree of unsaturation. The hypolipidemic effect of n3 PUFAs was significant so that fish oil or perilla oil may have important nutritional applications in the prevention and treatment of atherosclerotic disease.

• Journal of Korean Biological Nursing Science
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• v.3 no.1
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• pp.41-52
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• 2001

This study was undertaken to investigate the effects of n-6(corn oil) & n-3(fish oil) fatty acids on infarction size and the cerebral activities of antioxidant enzyme in rat focal brain ischemia model. Weaning Sprague-Dawley rats were fed with either corn oil supplemented diet(COD, 14% corn oil) or fish oil supplemented diet(FOD, 14% menhaden oil) for 6 weeks. The right middle cerebral artery was occluded for 2 hours with a silicon rubber coated nylon surgical thread. After 24 hours of recirculation, the rats were sacrificed and brain sections were photographed using CCD camera after staining with 2, 3, 5-triphenyltetrazolium chloride for 60 minutes in room temperature. The infarcted area was measured and the volume of infarction was calculated. Catalase(CAT), superoxide dismutase(SOD) activities, and fatty acid composition in the brain were also measured. The total and corrected infarction volumes were not significantly different between FOD and COD group. The docosagexaenoic acid(DHA) and DHA content/arachidonic acid(AA) ratio of the cerebral cortex, an index of defense against lipid oxidation, were significantly increased in FOD group compared to those of COD group(p<0.05). In the left cortex(non-infarction side) as well as the right cortex(infarction side) of FOD group, CAT and Cu/Zn SOD activities were higher than those of the COD group(p<0.05). However, CAT and Cu/Zn SOD activities were not significantly different between the left cortex(non-infarction side) and the right cortex(infarction side) of both FOD and COD group. GPx activities were also not significantly different between two groups. Our results demonstrate that the brain infarction size in FOD and COD were not significantly different. However, cerebral lipid composition and antioxidant enzyme activities in FOD and COD group were different. Fish oil, a source of n-3 polyunsaturated fatty acid(PUFA) and corn oil, that of n-6(PUFA) may have a protective effect against oxidative stress induced via different mechanisms.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.375-386
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• 1995

This study was designed to investigate the changes in energy substrates, glucose and non-esterified fatty acid(NEFA), and fatty acid compositions in serum, following physiolgical stress in rats fed diets containing various fatty acids. Forty two Sprague-Dawley strain male rats, weighing 108$\pm$2.1g, were fed 3 different experimental diets for 4 weeks. The diets were composed of 105 fat(w/w) of either corn oil(CO;18:2 n6:57%), plant perilla oil(PO;18:3 n3:59%), or tuna fish oil(FO;20:5 n3:17%%, 22:6 n3:19%). After 4 weeks of feeding, each group wa subdiveided into (a) control, (b) 2 min swim in ice-cold water. Animals wer decapitated 20min after commencing the swim; trunk blood, brain, liver and epididymal fat pad were obtained. The levels of serum corticosterone, glucose, NEFA, triglyceride, fatty acid compositions, brain serotonin and 5-hydroxyindoleacetic acid were determined. Basal levels of corticosterone na NEFA of serum were significantly lower in fish oil fed animals than those of any other oil fed animals. Compared to either perilla oil-fed or corn oil-fed rats, cold swim stress in fish oil fed rats produced significantly smaller NEFA and larger corticosterone responses. However, there was no significant difference in basal levels of serum glucose. Stress increased serum glucose levels slightly, and the amount of increment was larger in fish oil rats than those of any other oil fed rats than those of any other oil fed rats, although all the values were normal level. Dietary fats and stress did not affect serotonin metabolism. In additions, the composition of fatty acids in serum was significantly affected by the dietary compostion of fatty acids and stress. Stress induced decreases in monounsaturated fatty acid and non-polyunsaturated fatty acid concentration in either perilla oil fed or fish group, but did not in corn oil fed group. Stress resulted in changes in fatty acid metabolism similar to that associated with essential fatty acid(EFA) dificiency, when feeding animals n-3 fatty acids in diet. In conclusion, feeding fish oil was more effective to decrease NEFA in serum than feeding perilla oil or corn oil and improved lipid metabolism, when the rats were maintained in normal or exposed to stressful environment. However, the fact that feeding diet containing n-3 fatty acids decreased EFA status under stress suggests that the requirement of n-6 PUFA should be increased in these groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.418-425
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• 1991

This study was designed to observe the effects of the fish oil and some seed oils on the improvement of the fatty acid compositions of liver and brain tissue in rats. In order to induce the hypertriglyceridemia in the rats of the Sprague-Dawley, 12% coconut oil and 3% each of olive oil, lard, fish oil, perilla oil, corn oil, red pepper seed oil and evening primrose oil were administered to the rats for 4 weeks. In the fatty acid composition of liver lipid, n-3 PUFA contents were most in the fish oil and perilla oil groups of phospholipid fraction, and n-6 PUFA contents were most in the corn oil, red pepper seed oil and evening primrose oil groups of triglyceride fractions. Fatty acid composition of liver lipid fractions were influenced from the fatty acid composition of the test lipids. In the fatty acid composition of brain phospholipid, n-3 PUFA contents (8.8~17.2%) were most in the fish oil group, and n-6 PUFA (34.6~38.2%), though it contains high percentage, showed little difference between groups.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.558-565
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• 1993

This study was carried out to observe the effects of dietary n-6, n-3 fatty acids and vitamin A levels on serum lipid contents and hepatic tissues in rats. Sixty eight male Sprague-Dawley rats were fed 6 different experimental diets for 6 weeks. The diets were composed of 10% of either corn oil or fish oil with three levels of vitamin A ; defient (1240IU/kg diet), adequate (4000IU/kg diet), excess(400,000IU/kg diet). It was observed that triglyceride content and lipoprotein ratio in serum were not affected by dietary fat types and vitamin A levels. However, total serum cholesterol contents were significantly lower in fish oil groups than in corn oil groups, which were not affected by vitamin A levels. Under light microscope, vitamin A excess groups showed pathological abnormalites, such as fatty change and inflammation of the hepatic tissues. There abnormalities were less severe in fish oil groups. These results suggested that fish oil could be a dietary factor lowering the serum lipid contents, and it seems to relieve the abnormal changes in liver induced by excess vitamin A.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.566-577
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• 1993

The study was to compare the effect of dietary fatty acids on fatty acid profile in tissue and the status of tocopherol and lipid peroxidation, and superoxide dismutase and glutathione peroxidase activities at two fat levels. Male Sprague Dawley rats weighing average 350g(17 weeks) were fed either low fat(LF, 4.3% w/w, 10% kcal) or high fat(HF, 20.8%, w/w, 40% kcal)diet for 6 weeks. The fats used were beef tallow as a source of saturated fatty acid, corn oil for n-6 linoleic acid, perilla oil for n-3 $\alpha$-linolenic acid and fish oil for n-3 eiocosapentatenoic acid(EPA) and n-3 docosahexaenoic acid(DHA). Palsma tocopherol was significantly reduced by fish oil compared to beef tallow at body fat level. However, there was no significant effect on the levels of plasma MDA, RBC MDA and tocopherol, and RBC hempolysis by the type and amount of dietary fat. The peroxidizibility index of fatty acid profile in plasma and liver was increased and liver MDA level was significantly increased by fish oil when dietary fat level was increased. The activities of SOD and GSHPx tended to be increased by perilla oil and fish oil at both fat oil significantly reduced the incorpration of c20:4 and increased the incorporation of c20:5 into liver compared to corn oil. The incorporation of n-3 fatty acids into tissue by perilla oil rich in $\alpha$-linolenic acid was significantly higher tan corn oil and its effect was improved with higher amount of perilla oil in diet by high fat diet. Overall, the lipid peroxidation of tissue could be prevented by tocopherol supplementation when dietary fat level was low in diet. However, at high fat diet, tocopherol supplementation might not be enough to prevent the lipid peroxidation in tissue since the potential for lipid peroxidation was tended to be increased with higher incorporation of higher unsaturated n-3 fatty acids into tissue. Therefore, it could not be recommended to consume large amount of fish oil even with excess amount of tocopherol supplemented to the high fat diet.