• 한국응용과학기술학회지
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• 제13권3호
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• pp.15-24
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• 1996

Essentiality was proposed in the field of lipid by Burr and Burr in 1929. When rats were raised on the fat-free diet, their growth retarded and their skin and tails showed the characteristic deficient symptoms, which were relieved by the addition of ${\omega}6(n-6)$ polyunsaturated fatty acids as linoleic(LA) and arachidonic(AA) acids to the basal diet. LA is dehydrogenated to ${\gamma}-linolenic$ acid(GLNA) by ${\Delta}6$ desaturase, then GLNA is 2 carbon chain elongated by elongase to $dihomo-{\gamma}-linolenic$ acid(DGLNA), which is desaturated by ${\Delta}5$ desaturase to AA. These acids are called LA family or ${\omega}6(n-6)$ polyunsaturated fatty acids(PUFA). ${\alpha}-Linolenic$ acid(ALNA) is converted through the series of desaturation and elongation steps to docosahexaenic acid(DHA) via eicosapentaenoic acid(EPA). These acids belong to ALNA family or ${\omega}3(n-3)$PUFA. Human who consume large amounts of EPA and DHA, which are present in fatty fish and fish oils, have increased levels of these two fatty acids in their plasma and tissue lipids at the expense of LA and AA. Alternately, vegetarians, whose intake of LA in high, have more elevated levels of LA and AA and lower levels of EPA and DHA in plasma lipids and in cell membranes than omnivores. AA and EPA are metabolized to substances called eicosanoids. Those derived form AA are known as prostanocids(prostaglandins and prostacyclins) of the 2-types and leukotrienes of the 4-series, whereas those derived from EPA are known as prostanoids of the 3-types and leukotrienes of the 5-series. DGLNA is a precursor of the 1-types of prostaglandins. The metabolites of AA and EPA have competitive functions. Ingestion of EPA from fish or fish oil replaces AA from membrane phospholipids in practically all cells. So this leads to a more physiological state characterized by the production of proatanoids and leukotrienes that have antithrombic, antichemotactic, antivasoconstrictive and antiinflammatory properties. It is evident that ${\omega}3$ fatty acids can affect a number of chronic diseases through eicosanoids alone.

• Preventive Nutrition and Food Science
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• 제18권3호
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• pp.175-180
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• 2013

The purpose of this study was to determine the effects of a pre-exercise meal on the plasma human growth hormone (hGH) response and fat oxidation during walking. Subjects (n=8) were randomly provided with either 1 g/kg body weight of glucose in 200 mL water (CHO) or 200 mL water alone (CON) 30 min prior to exercise and subsequently walked on a treadmill at 50% of VO2max for 60 min. Plasma hGH concentrations were significantly higher in subjects who received CHO compared to those who received CON at 15 and 30 min. The fat oxidation rate in the CHO was significantly lower than the CON while walking for 5~15, 25~35 and 45~55 min. Plasma FFA levels were also significantly lower in the CHO compared to the CON at 30, 45 and 60 min. Plasma glucose levels in the CHO were significantly lower while plasma insulin levels were significantly higher than in the CON at 15 and 30 min. Therefore, the results of this study suggest that the elevation of plasma hGH levels due to the intake of a pre-exercise meal may not be strongly related to fat oxidation and plasma free fatty acid (FFA) levels during low-intensity exercise.

• Molecules and Cells
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• 제44권2호
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• pp.116-125
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• 2021

Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMG-CoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.

• Journal of Nutrition and Health
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• 제34권6호
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• pp.619-625
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• 2001

Diabetes mellitus was induced in male Sprague-Dawley rats weighing 200-245g by injection of streptozotocin(STZ) into the tail vein at a dose of 45mg/kg and were divided into seven groups ; normal, diabetic control, and five experimental groups(fractions of hexane, chloroform(CHCl$_3$), ethylacetate(EtOAc), butanol(BuOH) and water($H_2O$)). The rats of all groups were fed on AIN-93 diet and the five experimental groups were orally administered each fraction for 14 days. The body weight and diet intake were monitored daily. The plasma levels of glucose, insulin, cholesterol, triglyceride, HDL-cholesterol, free fatty acid and aspartate and alanine aminotransferase activities were analyzed. Diabetic rats showed the lower weight gain compared to the normal rats. The plasma glucose levels of the CHCl$_3$, and $H_2O$ fraction groups were significantly lower than the other experimental groups. The plasma insulin level of the CHCl$_3$ fraction group was much higher than that of diabetic control group. The plasma cholesterol levels were increased in all the experimental groups. The groups of hexane, BuOH and H2() fractions showed the lower plasma triglyceride levels compared to diabetic control group. The plasma free fatty acid levels were not significantly different in all groups. HDL-cholesterol levels were definitely higher in hexane, CHCl$_3$ and EtOAc fraction groups than that of diabetic control group. In conclusion, administration of CHCl$_3$ and $H_2O$ fractions of methanol extract of Alisma canaliculatum exhibited hypoglycemic effects in STZ induced diabetic rats, showing the possibility of therapeutic use of Alisma canaliculatum to the diabetes mellitus.

• 한국식품조리과학회지
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• 제13권5호
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• pp.639-647
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• 1997

The hypoglycemic effects of five Korean wild vegetables, Aralia continentalis (A. con.), Castanea crenata (C. cre.), Xanthium strumarium (K, str.), Alisma canaliculatum (A. can,) and Eupatorium chinense var. simplicifolium for tripartium (E. tri) which have been utilized for the traditional remedies were investigated in this study. Diabetes mellitus was induced in male Sprague-Dawley rats by injections of streptozotocin (STZ) into the tail veins at a dose of 45 mg/kg. Five groups of STZ-induced diabetic rats were fed one of each experimental diet containing 10% of the Korean wild vegetable powder and normal and STZ-control rats were fed the control diet for five weeks. The body weight change, feed efficiency ratio (FER) and organ weights were compared. The plasma levels of glucose, protein, cholesterol, HDL-cholesterol, triglyceride, free fatty acid, and aminotransferase activity were determined. Mineral (Ca, K, Mg, Na, Cu, Fe, Mn and Zn) contents of the Korean wild vegetables were analyzed. The body weight gain was higher in normal, C. cre., A. can. and E. tri. groups than in the diabetic control group. The FER of C. cre., A. can. and E. tri. groups was significantly higher (p.＜0.05) than that of diabetic control group. Liver weight was heavier in A. con., X. str. and A. can. groups compared with the diabetic control group. The weights of kidney were lighter in all five Korean wild vegetable groups than in the diabetic control group. After five weeks, the plasma glucose level tends to be decreased in A. con., A. can. and E. tri. groups. Plasma cholesterol level was decreased the Korean wild vegetables except for X. str. group. Plasma HDL- cholesterol level was significantly higher in A. con., A. can. and E. tri. groups compared with the diabetic control group. Plasma triglyceride and free fatty acid levels were significantly higher in X. str. group compared with the diabetic control group. Mineral contents were higher in E. tri. (Ca, K, Na and Fe). The results suggest that the intakes of A. con., A. can. and E. tri. have a hypoglycemic effect in diabetic rats showing the possibility as the valuable food resources for the prevention of diabetic mellitus.

• Journal of Nutrition and Health
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• 제34권4호
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• pp.367-374
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• 2001

Conjugated linoleic acid(CLA) is a naturally occuring group of derivatives of linoleic acid found in beef and dairy products. CLA has reported to reduce body fat. This study was designed to observe the effect of CLA supplementation on fat accumulation and degradation in male Sprague Dawley rats. Seventy two rats, weighing 150-180g, were divided into 2 groups according to the types of dietary fat(beef tallow or fish oil) and then each group was divided into 2 groups depending on CLA supplementation, i.e., BT, BT-CLA, FO, FO-CLA. All rats were fed experimental diet containing total fat at 12%(w/w) including CLA at 1% for 30 weeks. At 30 weeks, rats were sacrificed to measure TG, free fatty acid level in plasma, TG, lipogenic enzymes in lever and fat cell size, LPL and HSL activities in epididymal fat fad. Fish oil supplemented with CLA diet showed significant reduction in the food efficiency and weight in 30 weeks-fed rats. CLA supplement did not effect on plasma TG, hepatic TG levels and lipogenic enzymes activities in rats, but, fish oil significantly reduced, The LPL and HSL activities did not affected by CLA supplement and n-3 fatty acid rich fish oil. In conclusion, the results suggest that CLA supplement was not a proper way to reduce the fat accumulation in Sprague Dawley rats. Fish oil supplemented with CLA might better way to reduce the body fatness than fish oil itself. Therefore, It is recommended that further study be performed related to physiological and biochemical effects of CLA supplementation and n-3 fatty acid in rats for the reduction of body fatness.(Korean J Nutrition 34(4) : 367∼374, 2001)

• Journal of Nutrition and Health
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• 제27권4호
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• pp.323-335
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• 1994

The present study was carried out in normocholesterolemic New Zealand white(NZW) rabbit, to evaluate the effect of dietary supplementation with Korean pinenut oil, on plasma lipids, plasma lipoproteins, liver lipids and platelet aggregation. NZW rabbits were fed for 80 days on a commercial chow diet supplemented with 5% of energy as fats(soybean oil or pinenut oil) or 10% of energy as fats(soybean oil or pinenut oil). A control group was fed a commercial stock diet. There were no significant effects of pinenut oil on plasma free cholesterol, HDL-cholesterol, triglycerides, glucose and lecithin-cholesterol acyltransferase, as compared with those obtained from rabbits fed the soybean oil diet. After 80 days, the concentration of plasma free fatty acid in only the pinenut oil group was significantly decreased by about 50% relative to the control diet. At the end of the dietary treatment, liver triglycerides and phospholipids were significantly decreased in the pinenut oil group, compared to the how diet, whereas the soybean oil-consuming rabbits had only significantly decreased phospholipid levels. Cholesterol contents of liver were unaffected by type of dietary fat. At the end of 80 days, a diet containing pinenut oil resulted in a decrease in apolipoprotein B and the apo B/apo AI ratio as compared with the stock diet or soybean oil diet. Platelet aggregation induced by collagen or arachidonic acid was depressed significantily in pinenut oil diet.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1253-1261
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• 1998

Effects of dietary cholesterol and taurine supplementation on hepatic total and phospholipid fatty acid compositions were evaluated in rats fed one of the following semisynthetic diets for 5 weeks : control diet(CD, cholesterol free and taurine free diet); high cholesterol diet(HCD, CD＋1.5% cho lesterol); high cholesterol, high taurine diet(HCHTD, HCD＋1.5% taurine). Diet induced changes in hepatic total fatty acid compositions were very similar to those in hepatic phospholipid fatty acid compositions. The HCD significantly decreased the percentage of total saturated fatty acids(SFA), and increased the percentage of total monounsaturated fatty acids(MUFA) of hepatic total lipids and phospholipids as compared to the values for the control rats(p<0.001). HCHTD significantly elevated the percentage of $\Sigma$SFA and lowered the percentage of $\Sigma$MUFA compared to the values for the HCD(p<0.001). Percentages of hepatic total and phospholipid 18:3$\omega$3, 20:5$\omega$3, 18:2$\omega$6 and 20:3$\omega$6 were significantly higher in rats fed the HCD than the values for the control rats, and the percentages of their elongation and desaturation products(22:5$\omega$3, 22:6$\omega$3, 20:4$\omega$6, 22l:4$\omega$6 and 22: 5$\omega$6) were significantly lower in rats fed the HCD compared to those for the control rats. HCD significantly lowered the Δ5 desaturation(20:3$\omega$6⇒20:4$\omega$6) and Δ4 desaturation(22:4$\omega$6⇒22:5$\omega$6) indices, and the elongation index of $\omega$3 fatty acid(20:5 $\omega$3⇒22:5$\omega$3) in rat liver. HCHTD reversed the cholesterol induced changes in the compositions of $\omega$3 and $\omega$6 fatty acids. These results suggest the possibility that dietary cholesterol and taurine supplementations affect plasma and liver lipid levels, at least in part, by changing the hepatic phospholipid fatty acid compositions and thereby modulating the physical characteristics of the membrane and the activities of microsomal enzymes involved in lipid metabolism.

• Clinical and Experimental Pediatrics
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• 제45권9호
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• pp.1075-1082
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• 2002

목 적: L-carnitine은 carnitine acyltransferase 효소에 의해 장쇄(long chain)지방산을 세포질에서 미토콘드리아로 이동시킬 때 필요한 효소로 미토콘드리아 내로 이동된 장쇄 지방산은 ${\beta}$-산화를 거쳐 신체의 에너지원으로 사용된다. 비만 치료 방법의 하나로 L-carnitine을 투여하여 간과 근육세포의 산화를 증가시켜 혈청 지방을 감소시키려는 시도가 있으며, 실제로 L-carnitine이 혈청 지방산을 낮추는지를 알아보기 위해 본 연구를 실시하였다. 방 법: 250 g 내외의 Sprague Dawley 쥐를 두 군으로 나누어 실험하였다. A군은 정상 대조군, B군에서 L-carnitine을 200 mg/kg씩 매일 복강 내로 투여하였다. Hitachi 기기를 이용하여 총 콜레스테롤, 중성지방, 고분자량 콜레스테롤, 저분자량 콜레스테롤을 측정하였고, 혈청 C6-C18 지방산은 GC/MS 분석에 의해 1일, 1주, 2주에 측정하였다. Cycling 기법을 이용하여 총 carnitine, 유리 carnitine, 아실 carnitine을 정량 분석하였다. 결 과 : 1) 혈청 총 콜레스테롤, 고분자량 콜레스테롤, 저분자량 콜레스테롤은 두 군 사이에 유의한 차이가 없었으나, 중성지방은 1주일째에 A군은 $131.3{\pm}31.3mg/dL$인데 반하여 B군은 $90.0{\pm}7.0mg/dL$로 의미있는 감소를 보였다. 2) 혈청 총 지방산은 A군에 비해 B군에서 1주에만 약간의 감소를 보였으나 통계학적 유의성은 없었다. 1주일째 장쇄 지방산인 리놀레인 산(linoleic acid)이 B군에서 A군에 비해 유의하게 감소하였다. 3) L-carnitine투여 후 carnitine(total, free, acyl) 치는 1일째, 1주일째 및 2주일째에 모두 B군이 A군보다 유의하게 높았으나, 유리 carnitine 만이 투여 누적 용량에 따라서 유의한 증가를 보였다. 결 론 : L-carnitine 투여 후 1주일째에 혈중 중성 지방의 농도가 감소하였고, 리놀레인 산이 미토콘드리아 내로 이동함으로 혈중 농도의 감소를 보였다.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3374-3382
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• 2013

이 연구의 목적은 운동기능 및 신체활동에 제약이 있는 뇌성마비 아동들을 대상으로, 12주간의 수영운동프로그램이 렙틴과 지질성분에 어떠한 영향을 미치는 지를 연구하였다. 수영프로그램은 일일 60분씩, 주당 4회 이상 12주간의 수영프로그램을 실시하였으며, 물과 영법에 적응하게 되면 점진적으로 보다 높은 단계의 수준으로 프로그램이 향상 조정되었다. 이 연구의 결과에서 뇌성마비 아동들의 체중 및 BMI와 혈중 총콜레스테롤, LDL, 렙틴의 농도는 감소되는 경향을 보였으나 통계적으로 유의한 차이를 보이지 않았으며 HDL의 농도는 변화가 없었다. 그러나 혈중 중성지방의 농도는 유의하게 증가되었으며(p<.05), 혈중 유리지방산의 농도는 유의하게 감소되었다(p<.001). 이러한 결과는 12주간의 규칙적 수영운동프로그램이 뇌성마비 아동들의 혈중 지질성분과 렙틴 농도의 개선에 효과가 있는 것으로 생각되며 이는 신체활동이 부족한 뇌성마비 아동들의 비만관련 대사적질환의 예방을 위한 효과적 방법이라 사료된다.