• BMB Reports
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• 제46권4호
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• pp.207-212
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• 2013

The main purpose of this study is to examine the effect of caffeine on lipid accumulation in human hepatoma HepG2 cells. Significant decreases in the accumulation of hepatic lipids, such as triglyceride (TG), and cholesterol were observed when HepG2 cells were treated with caffeine as indicated. Caffeine decreased the mRNA level of lipogenesis-associated genes (SREBP1c, SREBP2, FAS, SCD1, HMGR and LDLR). In contrast, mRNA level of CD36, which is responsible for lipid uptake and catabolism, was increased. Next, the effect of caffeine on AMP-activated protein kinase (AMPK) signaling pathway was examined. Phosphorylation of AMPK and acetyl-CoA carboxylase were evidently increased when the cells were treated with caffeine as indicated for 24 h. These effects were all reversed in the presence of compound C, an AMPK inhibitor. In summary, these data indicate that caffeine effectively depleted TG and cholesterol levels by inhibition of lipogenesis and stimulation of lipolysis through modulating AMPK-SREBP signaling pathways.

• 한국식품과학회지
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• 제53권2호
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• pp.149-153
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• 2021

본 연구는 감귤 가공공정 중에 발생하는 가공부산물인 감귤피의 산업적 이용성 및 유용성을 증대시키고자 효소적 추출법을 적용하여 추출물을 제조하고 항비만 활성을 측정하였다. 감귤피 효소적 추출물(MPCE)의 폴리페놀 함량은 이전의 연구에서 보고한 유기용매 추출물보다 높은 함량을 나타내었다. MPCE의 항비만 활성을 알아보기 위해 지방세포 분화억제에 미치는 영향을 확인한 결과 MPCE는 농도 의존적으로 지방세포의 분화 및 지방축적을 감소시켰으며 이는 세포독성에 의한 것이 아님을 세포생존율 측정을 통해 확인하였다. 또한 MPCE는 adipogenesis 관련 전사인자인 C/EBPα, SREBP-1, PPARγ, FABP4의 단백질 발현을 감소시켰다. 이러한 결과들을 통해 MPCE는 adipogenesis 관련 전사인자의 단백질 발현 억제하여 지방세포의 분화 및 지방축적을 억제하였으며, 이를 통해 항비만 효과를 나타낸다는 것을 확인하였다. 따라서 MPCE는 비만 예방 효능을 가진 기능성 식품 소재로서의 활용 가치가 있는 것으로 판단되며, 보다 명확한 항비만 효능을 확인하기 위해 추후 동물 실험 등에 대한 연구가 필요할 것으로 생각된다.

• Nutrition Research and Practice
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• 제8권6호
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• pp.632-637
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• 2014

BACKGROUND/OBJECTIVES: The purpose of the current study was to investigate the effect of red pericarp glutinous rice rich in polyphenols (Jakwangchalbyeo, red rice) on serum and hepatic levels of cholesterol and hepatic protein expression linked to synthesis and degradation of cholesterol in a hypercholesterolemic mice diet as compared with brown rice. MATERIALS/METHODS: C57BL/6 male mice were randomly divided into four groups (n = 5 each), which were fed different diets for a period of 12 weeks: American Institute of Nutrition (AIN)-93G diet, AIN-93G diet with 2% cholesterol, brown rice with 2% cholesterol, or red rice with 2% cholesterol. RESULT: Consumption of red rice resulted in a significant decrease in serum level of low-density lipoprotein cholesterol and hepatic levels of triglyceride and total-cholesterol. Expression of acyl-coenzyme A cholesterol acyltransferase-2 (ACAT-2), sterol regulatory element binding protein-2 (SREBP-2), and 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase was decreased, while expression of phosphorylated adenosine monophosphate activated protein kinase (p-AMPK)/AMPK ratio, cholesterol 7-${\alpha}$-hydroxylase (CYP7a1), and sterol 12-${\alpha}$-hydroxylase (CYP8b1) was increased in mice fed red rice. Brown rice had similar effects on cholesterol metabolism, but the effect of red rice was significantly greater than that of brown rice. CONCLUSIONS: The current study suggested that red rice had a hypocholesterolemic effect by lowering hepatic cholesterol synthesis through ACAT-2, HMG-CoA reductase, and SREBP-2, and by enhancing hepatic cholesterol degradation through CYP7a1 and CYP8b1 in mice fed a hypercholesterolemic diet.

• Nutrition Research and Practice
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• 제17권6호
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• pp.1043-1055
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• 2023

BACKGROUND/OBJECTIVES: The fruit of Cydonia oblonga Miller (COM) is used traditionally in Mediterranean region medicine to prevent or treat obesity, but its mechanism of action is still unclear. Beyond a demonstrated anti-obesity effect, the fruit was tested for the mechanism of adipogenesis in 3T3-L1 preadipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were cultured for 8 days with COM fruit extract (COME) at different concentrations (0-600 ㎍/mL) with adipocyte differentiation medium. The cell viability was measured using an MTT assay; triglyceride (TG) was stained with Oil Red O. The expression levels of the adipogenesis-related genes and protein expression were analyzed by reverse transcription polymerase chain reaction and Western blotting, respectively. RESULTS: COME inhibited intracellular TG accumulation during adipogenesis. A COME treatment in 3T3-L1 cells induced upregulation of the adenosine monophosphate-activated protein kinase (AMPK)α phosphorylation and downregulation of the adipogenic transcription factors, such as sterol regulatory element-binding protein 1c, peroxisome proliferator-activated receptor γ, and CCAAT/enhancer binding protein α. The COME treatment reduced the mRNA expression of fatty acyl synthetase, adenosine triphosphate-citrate lyase, adipocyte protein 2, and lipoprotein lipase. It increased the mRNA expression of hormone-sensitive lipase and carnitine palmitoyltransferase I in 3T3-L1 cells. CONCLUSIONS: COME inhibits adipogenesis via the AMPK signaling pathways. COME may be used to prevent and treat obesity.

• Journal of Animal Science and Technology
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• 제64권6호
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• pp.1173-1183
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• 2022

Adipogenesis is a complex process comprising commitment and a differentiation stages. Through research, many different transcriptional factors were found to mediate preadipocyte commitment and differentiation. Lysine has a potential of regulating the commitment and differentiation of preadipocytes. In the present study, intramuscular stromal vascular cells (SVC) isolated from Hanwoo beef cattle were used to elucidate the effects of low lysine level on adipogenesis. SVC were isolated and incubated with various concentrations of lysine (0, 37.5, 75, 150 and 300 µg/mL). No significant difference were observed in the proliferation of SVC after 24 and 48 h of incubation with different concentration of lysine. On preadipocyte determination, reducing the level of lysine significantly increased the expression of preadipocyte commitment gene Zinc finger protein 423 and Preadipocyte factor-1. Upon differentiation, Oil Red O staining revealed that lipid accumulation and triglyceride content significantly increased with the decreasing lysine levels in the media. Expression levels of peroxisome proliferator-activated receptor-γ, CCAAT enhancer binding protein-α, sterol regulatory element binding protein-1c, Fatty Acid Binding Protein 4 and stearoyl CoA desaturase were upregulated by the decreased level of lysine. These data suggest the potential mechanism of action for the improved preadipocyte commitment and adipocyte differentiation in bovine intramuscular SVC upon treatment with low levels of lysine. These findings may be valuable in developing feed rations that promote deposition of intramuscular fat in beef cattle through lysine level modification.

• 동의생리병리학회지
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• 제36권5호
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• pp.181-186
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• 2022

Atractylodes macrocephala (AM) and Amomum villosum (AV) are the most common herbs in Korean Medicine to treat digestive diseases. In this study, we investigated the cholesterol lowering effects of mixtures of AM and AV extracts on high cholesterol diet (HCD) induced dyslipidemia mouse model. We classified animals into six different groups; Group 1: Normal diet, Group 2: HCD, Group 3: AV extracts : AM extracts (1:1) (200 mg/kg) + HCD, Group 4: AV extracts : AM extracts (1:2) (200 mg/kg) + HCD, Group 5: AV extracts : AM extracts (1:3) (200 mg/kg) + HCD, Group 6: Simvastatin 40 mg/kg + HCD. After 4 weeks of oral administration of respective drugs, we checked body, liver and epididymal fatweights along with liver and serum triacylglyceride (TG) concentration, total and low density lipoprotein (LDL) cholesterol in serum. Moreover, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (HMGCR), LDL receptor (LDLR), and sterol regulatory element-binding protein 2 (SREBP2) were detected by RT PCR or western blot analysis. The overall results showed that mixtures of AM and AV extracts inhibited HCD-induced increases of total cholesterol and LDL cholesterol in serum. Those effects seem to be caused by AM and AV extracts through inhibition of HMGCR expression. And thus blood cholesterol is induced into the liver by increasing LDLR expression, which is regulated by SREBP2 transcrption factor. The cholesterol lowering effects and mechanism of mixtures of AM and AV extracts was similar to the statin. We have identified the potential mixtures of AM and AV extracts as a new treatment for dyslipidemia.

• Toxicological Research
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• 제33권3호
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• pp.219-224
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• 2017

Lipin1 was identified as a phosphatidate phosphatase enzyme, and it plays a key role in lipid metabolism. Since free radicals contribute to metabolic diseases in the liver, this study investigated the effects of free radicals on the regulation of Lipin1 expression in Huh7 and AML12 cells. Hydrogen peroxide induced mRNA and protein expression of Lipin1 in Huh7 cells, which was assayed by quantitative RT-PCR and immunoblotting, respectively. Induction of Lipin1 by hydrogen peroxide was confirmed in AML12 cells. Hydrogen peroxide treatment significantly increased expression of sterol regulatory element-binding protein (SREBP)-2, but not SREBP-1. Moreover, nuclear translocation of SREBP-2 was detected after hydrogen peroxide treatment. Hydrogen peroxide-induced Lipin1 or SREBP-2 expression was significantly reduced by N-acetyl-$\small{L}$-cysteine treatment, indicating that reactive oxygen species (ROS) were implicated in Lipin1 expression. Next, we investigated whether the hypoxic environments that cause endogenous ROS production in mitochondria in metabolic diseases affect the expression of Lipin1. Exposure to hypoxia also increased Lipin1 expression. In contrast, pretreatment with antioxidants attenuated hypoxia-induced Lipin1 expression. Collectively, our results show that ROS activate SREBP-2, which induces Lipin1 expression.

• 대한한의학방제학회지
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• 제30권3호
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• pp.137-143
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• 2022

Objectives : Brain-Liver axis is an important target of the chronic human diseases. Hepatic steatosis is one of the most famous disorders in the chronic diseases. This study investigated the moderating effect of beneficial herbs on the fat accumulation, which is mediated by the LXR alpha-SREBP-1c signaling pathway. Methods : In order to confirm the SREBP-1c inhibitory effect, we performed immonoblotting ananlysis using HepG2 cells and Huh 7 cells treated by T0901317, the ligand of LXRα. Results : Forsythiae suspensa water extract (FSE) was not cytotoxicity in cell lines. FSE inhibited SREBP-1c protein expression in HepG2 and Huh7 cells induced by T0901317. In addition, FSE increased the phosphorylation of LKB1, which is associated with LXR-related pathway in HepG2 and Huh 7 cells. Conclusions : These results showed that FSE activated LKB1 to suppress SREBP-1c, which protects the cells against oxidative stress.

• 한국자원식물학회지
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• 제28권5호
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• pp.582-590
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• 2015

본 연구는 HRL의 3T3-L1 지방전구세포의 분화과정 중에 HRL이 지방의 축적에 미치는 영향을 확인하였다. MTT assay를 이용하여 세포 독성을 측정한 결과 100 ㎍/㎖의 농도에서도 세포증식에 영향을 미치지 않는 것을 확인하였고, 이와 같은 결과를 토대로 Oil Red O 염색법을 이용하여 지방세포 분화 억제능을 측정하였다. 그 결과, HRL의 경우 100 ㎍/㎖의 농도에서 82.25% 지방 축적 억제능을 나타내었다. 지방생성에 영향을 미치는 유전자 발현량을 측정하기 위해 RT-PCR법과 western blot법을 시행하였다. HRL은 SREBP-1c, PPARγ와 C/EBPα의 mRNA 발현을 억제시켰고, 지방생성에 영향을 미치는 효소인 FAS의 생성을 조절하는 것으로 나타났다. 또한, HRL 처리로 AMPKα의 단백질 발현이 증가하였으며, PPARγ의 발현량이 감소하는 것을 확인하였다. 이상의 결과들로부터 HRL은 AMPKα의 활성화를 통한 지방 합성을 억제를 보유하고 있는 바, 향후 항비만 기능성 소재로 활용될 수 있을 것으로 생각한다.

• 대한본초학회지
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• 제31권4호
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• pp.11-18
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• 2016

Objectives : The objective of this study was to investigate the effect of Myrrh 80% ethanol extract on adipocyte differentiation and adipogenesis in 3T3-L1 cell.Methods : Myrrh was prepared by extracting with 80% ethanol. Cell viability was assessed by MTT assay using 3T3-L1 cells. Anti-obesity activity was measured in lipid droplets and triglyceride (TG) accumulation in 3T3-L1 cells. We also analyzed the expression of C/EBPβ, C/EBPα, PPARγ, SREBP1c, and aP2 by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, we observed the production of fatty acid, acetyl-CoA carboxylase and Oil-red O stainingResults : No cytotoxicity from Myrrh 80% ethanol extracts was observed at the concentration of 1, 10, 100 (㎍/㎖) in 3T3-L1 cells. Treatment with Myrrh significantly suppressed the terminal differentiation of 3T3-L1 in a dose-dependent manner, as confirmed by a decrease in triglyceride and Fatty acid and Acetyl-CoA carboxylase. Also, Myrrh exhibited potential adipogenesis inhibition and downregulated the expression of pro-adipogenic transcription factors, such as sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα) and C/EBPβ, and adipocyte expressed genes, such as adipocyte fatty acid binding protein (aP2) and Fas. In addition, lipid accumulation determined by Oil-red O staining showed that Myrrh extract had inhibitory effects on lipid accumulation in 3T3-L1 cells.Conclusions : These results suggest that Myrrh suppresses obesity factors in 3T3-L1 cells. Myrrh may be a useful medical herbs for attenuating metabolic diseases such as obesity.