• BMB Reports
• /
• 제35권5호
• /
• pp.494-497
• /
• 2002

The present study explored the short-term effects of dietary conjugated-linoleic acid (CLA) on liver lipid metabolism in starved/refed Otsuka Long Evans Tokushima Fatty (OLETF) rats. Male OLETF rats (12 weeks old) were starved for 24 hours, then refed for 48 hours with either a CLA diet [7.5% CLA and 7.5% Safflower oil (SAF)] or a SAF control diet (15% SAF). The results demonstrated a 30% reduction of hepatic triglyceride (TG) concentration in the CLA group when compared to the control group. Liver cholesterol concentration was also 26% lower in the CLA fed rats. The activity of mitochondrial carnitine palmitoyltransferase, the rate-limiting enzyme of fatty acid oxidation, was moderately elevated by 1.2-fold in the livers of the CLA group when compared to the control. In contrast, phosphatidate phosphohydrolase, the rate-limiting enzyme for TG synthesis, was found to be 20% lower in the livers of the CLA-fed rats. Therefore, dietary CLA evidently lowers liver lipid concentrations through a reduced TG synthesis and enhanced fatty acid oxidation in starved/refed OLETF rats.

• Journal of Nutrition and Health
• /
• 제30권2호
• /
• pp.123-131
• /
• 1997

The influence of (-0-Hydroxycitrate(HCA), shown to be a competitive inhibitor of adenosine 5-triphosphate(ATP) citrate lyase, on food intake and body weight, serum triglyceride and cholosterol level, in vivo rates of fatty acid and cholesterol synthesis, and fat cell number and size was investigated. 3 groups of female, 5 weeks old Sprague Dawley rats, 8 animals each, were ad libitum meal-fed or pair-fed(3 hours from 10 : 00 to 13 : 00) AIN based high glucose diet for a total period of 8 weeks. Providing normolipidemic rats orally with 400mg of HCA formula containing approximately 20mg of HCA 1 hour prior to daily feeding schedule significantly depressed in vivo hepatic rates of fatty acid and cholesterol synthesis in the liver and adipose tissue. Serum triglyceride and cholesterol levels were significantly reduced by HCA. At the end of treatment period, the rats administered with HCA resulted in a significantly reduction in body weight gain. The reduction in weights was attributable to a significant decrease in fat cell size with a smaller extent, but not significant, reduction in fat cell number. Rats receiving HCA demonstrated less food intake than the controls ; however, this decreased caloric intake was not fully responsible for the HCA induced depression of hepatic and adipocytic lipogenesis, since experiment using pair-fed cojntrol rats showed, less magnitude but similar results. Both a anorectic and an antilipogenic properties of HCA seem to be responsible for this weight reduction activity of HCA. The outcome of this study suggest that metabolic regulation may be a feasible approach to the control of obesity and hyperlipidemia.

• Journal of Nutrition and Health
• /
• 제56권6호
• /
• pp.641-654
• /
• 2023

Purpose: Sour cherry (Prunus cerasus L.) contains abounding phytochemicals, such as polyphenols and anthocyanins, and has antioxidative effects. Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator in enhancing the lipid metabolism. This study hypothesized that the intake of sour cherry affects AMPK signaling. Therefore, this study examined whether sour cherry regulates AMPK to balance the hepatic lipid metabolism and exert ameliorating effects. Methods: Male C57BL/6J mice had obesity induced with a 45% fat diet. The mice were divided into four groups: control (CON), high-fat diet (HFD), low percentage sour cherry powder (LSC), and high percentage sour cherry powder (HSC). The mice in the sour cherry groups were fed 1% sour cherry or 5% sour cherry in their respective diets for 12 weeks. Results: The body weight, visceral fat weight, and lipid droplet size significantly decreased in the treatment groups. The serum and hepatic triglyceride and total cholesterol levels improved significantly in the HSC group. The low-density lipoprotein cholesterol levels were also reduced significantly, whereas the high-density lipoprotein cholesterol levels were increased significantly in both treatment groups. The sterol regulator binding protein-1c and fatty acid synthase expression levels as fatty acid synthesis-related enzymes were significantly lower in the treatment groups than in the high-fat diet group. Furthermore, the adipose triglyceride lipase and hormone-sensitive lipase expression levels as lipolytic enzyme activity and AMPK/acetyl-CoA carboxylase/carnitine palmitoyltransferase-1 as fatty acid β-oxidation-related pathway were upregulated significantly in both sour cherry groups. Conclusions: These results show that sour cherry intake improves hepatic lipid synthesis and chronic diseases by activating AMPK signaling. Therefore, this study suggests that phytochemical-rich sour cherry can be developed as a healthy functional food.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
• /
• pp.267.1-267.1
• /
• 2003

Diacylglycerol acyltransferase (DGAT) is a microsomal enzyme that plays a central role in the metabolism of cellular glycerolipid. Recently, the generation of DGA T-deficient mice has provided a better understanding of triglyceride synthesis and its relationship to obesity. Therefore DGAT is an attractive target for treatments of triglyceride metabolism disorders, such as obesity or hypertriglyceridemia. (omitted)

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권6호
• /
• pp.865-870
• /
• 2009

In this study, we have attempted to understand the effects of taurine on serum and liver concentrations of cholesterol and triglycerides in broiler chickens and mice in the post-absorptive state, and on in vitro protein synthesis in the livers of broiler chickens and laying hens, as well as the effects of taurine on in vivo protein synthesis in the liver of mice. The experimental animals were subjected to 24 h of starvation in order to perpetuate a post-absorptive state. Serum concentrations of high density lipoprotein cholesterol and triglycerides were significantly (p<0.05) higher in the taurine groups than in the controls in both the broilers and the mice. However, taurine resulted in a significant (p<0.05) reduction in liver concentrations of total cholesterol and triglycerides, relative to what was seen in the control groups of both animals. Taurine stimulated the in vitro synthesis of 57-kDa, 40-kDa and 23-kDa proteins in the liver of broilers, but inhibited the in vitro synthesis of 54-kDa, 37-kDa and 24-kDa proteins. Taurine in the liver of laying hens exerted effects on in vitro protein synthesis, with the exception of the 26-kDa protein which was not detected in broiler liver, but was inhibited by taurine in the liver of laying hens. Unlike the findings regarding in vitro protein synthesis in the liver of broilers or laying hens, taurine appeared to stimulate the synthesis of only two proteins, a 47-kDa and a 40-kDa protein, in the liver of mice. Overall, theses findings indicate that taurine treatment results in a reduction in cholesterol and triglyceride concentrations, and also affects protein synthesis in the livers of broilers, laying hens, and mice.

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

• Asian-Australasian Journal of Animal Sciences
• /
• 제26권8호
• /
• pp.1080-1088
• /
• 2013

Our previous results showed that kisspeptin-10 (Kp-10) injections via intraperitoneal (i.p.) once daily for three weeks notably promoted the egg laying rate in quails. In order to investigate the mechanism behind the effects of Kp-10 on enhancing the egg laying rate in birds, this study focused on the alternations of lipids synthesis in liver after Kp-10 injections. 75 female quails (22 d of age) were allocated to three groups randomly, and subjected to 0 (control, Con), 10 nmol (low dosage, L) and 100 nmol (high dosage, H) Kp-10 injections via i.p. once daily for three weeks, respectively. At d 52, quails were sacrificed and sampled for further analyses. Serum $E_2$ concentration was increased by Kp-10 injections, and reached statistical significance in H group. Serum triglyceride (TG) concentrations were increased by 46.7% in L group and 36.8% in H group, respectively, but did not reach statistical significance, and TG contents in liver were significantly elevated by Kp-10 injections in a dose-dependent manner. Serum total cholesterol (Tch) concentrations significantly decreased in H group, while in H group the hepatic Tch content was markedly increased. The level of non-esterified fatty acid (NEFA), apolipoprotein A1 and B (apoA1 and apoB) were not altered by Kp-10 injections. The genes expression of sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FAS), apolipoprotein VLDL-II (apoVLDL-II), cholesterol $7{\alpha}$-hydroxylase (CYP7A1) and vitellogenin II (VTG-II) were significantly up-regulated by high but not low dosage of Kp-10 injection compared to the control group. However, the expression of SREBP-2, acetyl-CoA carboxylase ($ACC_{\alpha}$), malic enzyme (ME), stearoyl-CoA (${\Delta}9$) desaturase 1 (SCD1), apolipoprotein A1 (apoA1), fatty acid binding protein 2 (FABP2), 3-hydroxyl-3-methyl glutaryl-coenzyme A reductases (HMGCR), estrogen receptor ${\alpha}$, ${\beta}$($ER{\alpha}$ and ${\beta}$) mRNA were not affected by Kp-10 treatment. In line with hepatic mRNA abundance, hepatic SREBP1 protein content was significantly higher in H group. Although the mRNA expression was not altered, the content of $ER{\alpha}$ protein in liver was also significantly increased in H group. However, SREBP-2 protein content in liver was not changed by Kp-10 treatment. In conclusion, exogenous Kp-10 consecutive injections during juvenile stage significantly advanced the tempo of egg laying in quails, which was associated with the significant elevation in hepatic lipids synthesis and transport.

• 동의생리병리학회지
• /
• 제32권1호
• /
• pp.43-50
• /
• 2018

Korean Red Ginseng (RG) are used as a traditional treatment for improve blood circulation. This experimental study was designed to investigate the inhibitory effects of Korean red ginseng on lipid metabolism in high fat/cholesterol diet (HFCD)-induced hypertriglyceridemia. Sprague Dawley rats were fed the HFCD diet with/without fluvastatin (Flu, positive control) 3 mg/kg/day, and RG 125 or 250 mg/kg/day, respectively. All groups received regular diet or HFCD diet, respectively, for 13 weeks. The last three groups treatment of Flu and RG 125, and RG 250 orally for a period of 9 weeks. Group 1, reular diet; group 2, HFCD diet; group 3, Flu + HFCD diet; group 4, RG 125 + HFCD diet; group 5, RG 250 + HFCD diet. As a result, treatment with low or high doses of RG markedly attenuated plasma levels of triglycerides and augmented plasma levels of high-density lipoprotein (HDL) in HFCD-fed rats. RG and Flu also led to an increase in lipoprotein lipase activity in the HFCD group. On the other hand, RG and Flu led to an decrease in fatty acid synthase and free fatty acid activity in the HFCD group. Treatment with RG suppressed increased expressions of $PPAR-{\alpha}$ and AMPK in HFCD rat liver or muscle. In addition, the RG attenuated triglyceridemia by inhibition of $PPAR-{\gamma}$ and FABP protein expression levels and LXR and SREBP-1 gene expression in liver or muscle. The RG significantly prevented the development of the metabolic disturbances such as hypertriglyceridemia and hyperlipidemia. Taken together, the administration of RG improves hypertriglyceridemia through the alteration in suppression of triglyceride synthesis and accentuated of triglyceride decomposition. These results suggested that RG is useful in the prevention or treatment of hypertriglyceridemia.

• 생명과학회지
• /
• 제29권6호
• /
• pp.688-696
• /
• 2019

본 연구는 수분함유량이 많아 장기간의 보관이 어려운 아이스플랜트의 저장성을 높이기 위하여 발효하였을 경우, triglyceride, cholesterol 합성 및 tyrosinase 활성 등의 변화를 조사하였다. 유기산의 함량은 발효 후에는 lactic acid가 $23.672{\pm}3.74mg/g$으로 가장 많았으며 malic acid, acetic acid citric acid의 순이었다. 발효 전 후의 cyclitol 화합물의 변화를 보면, D-pinitol은 각각 $6.670{\pm}0.187mg/g$과 $5.541{\pm}0.088mg/g$으로 감소하였으나, myo-inositol은 $0.653{\pm}0.022mg/g$과 $3.848{\pm}0.216mg/g$, D-chiro-inositol은 $3.848{\pm}0.216mg/g$과 $4.945{\pm}0.098mg/g$으로 증가하였다. HepG2 세포 내 중성지방의 감소율은 발효 전 후에 각각 $3.04{\pm}1.70{\sim}35.73{\pm}5.06%$와 $5.13{\pm}0.90{\sim}53.32{\pm}1.79%$로서 발효 후 저해효과가 약간 높게 나타났으며, 대체로 극성이 큰 n-butanol과 aqueous 분획에서는 각각 $25.93{\pm}1.47{\sim}35.73{\pm}5.06%$과 $26.26{\pm}2.07{\sim}53.32{\pm}1.79%$로서 발효 후에 비교적 큰 폭으로 중성지방의 축적을 저해하였다. HepG2 세포 내 콜레스테롤의 감소율도 발효 전 후에 각각 $4.02{\pm}1.50{\sim}56.34{\pm}5.55%$와 $6.56{\pm}1.46{\sim}64.52{\pm}5.50%$ 정도로서 발효 후에 콜레스테롤의 합성 저해효과가 약간 크게 나타났다. 특히 처리농도가 $100{\mu}g/ml$ 이상에서 n-hexane, chloroform 및 ethylacetate 분획에서는 발효 전 후에 각각 $8.15{\pm}0.60{\sim}9.16{\pm}0.71%$와 $9.81{\pm}1.26{\sim}12.96{\pm}0.97%$로서 저해효과가 크지 않았으나, n-butanol과 aqueous 분획에서는 발효 전 후에 각각 $28.68{\pm}0.86{\sim}56.34{\pm}5.55%$와 $28.32{\pm}2.87{\sim}64.52{\pm}5.50%$로서 비교적 큰 폭으로 콜레스테롤의 합성을 저해하였다. Tyrosinase 활성억제효과도 발효 후에 약간 증가하는 경향이었다. 기질로서 L-tyrosine을 사용하였을 경우, 극성이 큰 aqueous 분획에서 발효 전 후에 각각 $60.58{\pm}4.035$와 $63.35{\pm}4.35%$로서 저해활성이 가장 높았으며, 양성대조군(arbutin, $100{\mu}g/ml$)의 72%에 달하는 활성이었다. 또한 기질로서 L-DOPA을 사용하였을 경우에도 aqueous 분획에서 발효 전 후에 각각 $56.85{\pm}1.57%$와 $59.38{\pm}1.74%$로서 저해활성이 가장 높았으며 양성대조군(kojic acid, $100{\mu}g/ml$)의 88% 이상의 높은 활성을 가지고 있었다. 전체적으로 발효 아이스플랜트의 중성지방 및 콜레스테롤 합성억제 효과, tyrosinase 활성억제효과는 대체로 발효 전에 비하여 다소 향상되었다. 특히 극성이 큰 용매의 분획추출물에서 높은 활성을 나타내었다. 이러한 결과를 바탕으로 발효 등의 다양한 가공방법이 개발되어 저장성과 활용도가 높아질 수 있는 계기가 되기를 기대한다.

• 동의생리병리학회지
• /
• 제20권6호
• /
• pp.1561-1566
• /
• 2006

Sebum is secreted due to the effect of androgen, which start to be secreted at puberty. Androgens have profound effects on the physiology of the sebaceous gland, Using the human sebocyte cell line SZ95, we investigated the inhibitory effect of Chelidonii Harba (CH) on the subum production. Our results showed that numerous cytoplasmic lipid droplets were examined by Oil red staining and lipid droplets were increased markedly by testosterone. Cell viability was dose-dependently decreased by CH as compared with untreated cells, while total lipid content and cholesterol slightly were increased by CH. Testosterone significantly stimulated the synthesis of total lipid and the synthesis of specific sebaceous lipids such as cholesterol and triglyceride. Combined treatment with CH and testosterone resulted in a lower lipid synthesis than with testosterone alone. Especially cholesteol content was reduced by combined treatment with CH and testosterone. These results indicate that CH inhibits the testosterone-induced lipid synthesis in SZ95 cells and acts antagonistically to androgen at the cellular level.