• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.1
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• pp.54-60
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• 2016

Amomum cadamomum Linne (ACL) has long been utilized against the inhibited qi movement related diseases such as dyspepsia, acute gastroenteritis, vomiting and diarrhea in Korean medicine. We speculated that ACL could improve the metabolic disorders such as obesity and type 2 diabetes through removing the phlegm-dampness and promoting the qi movement or stagnation. This study was designed to investigate effects and molecular mechanisms of ACL extract on the improvement of adipocyte dysfunction induced by TNF-α in 3T3-L1 adipocytes. Potential roles of ACL extract in the lipogenesis, inhibition of inflammatory cytokines and insulin resistance, were investigated in this study. Also, we examined the adipose genes and signaling molecules related to insulin resistance and glucose uptake to elucidate its mechanism. Our data demonstrated that TNF-α significantly incresed the release of lipid droplets and the production of MCP-1 and IL-6 from adipocytes. In gene expression, TNF-α reduced the expression of aP2, PPARγ, C/EBPα, GLUT4, and IRS-1 related to lipogenesis and insulin sesitivity, while TNF-α increased the expression of MCP-1 related to inflammation. In addition, TNF-α down-regulated the PPARγ and IRS-1 protein and up-regulated the IRS-1 Ser307 phosphorylation. These alterations induced by TNF-α were prevented by the treatment of ACL extract. Thus, our results indicate that ACL extract can be used to prevent from the TNF-α-induced adipocyte dysfunction through insulin and PPARγ pathways.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.115-123
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• 1991

Molecular association of glucose transporters with the other proteins in the plasma membrane was assessed by gel electrophoresis and immunoblot techniques. Approximately $31.5{\pm}5.1%$ of GLUT-4, $64.8{\pm}2.7%$ of clathrin, 48.7% of total protein in the plasma membrane (PM) were found insoluble upon extraction with 1% Tx-100. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the Tx-100 insoluble PM fraction contained about 4 major polypeptides with apparent molecular weight of above 200, 100-120, 80 and 30-35 KDa that were readily removed upon wash with a high pH buffer which is known to remove clathrin and 0.5 M Tris-buffer which is known to remove assembly proteins (AP). Immunoblotting of GLUT4 and clathrin against specific antibodies showed that GLUT-4 and clathrin were co-solubilized up to 84.6% and 82.7% respectively by wash with a high pH buffer and 1% Tx-100. When the membrane was pre-washed with a high pH buffer and 0.5 M Tris solution, GLUT4 and clathrin were not solubilized further suggesting that GLUT4 molecules are in molecular association with clathrin, AP and/or other extrinsic membrane proteins in plasma membrane and the formation of clathrin-coated structures might be involved in insulin stimulated glucose transporter translocation mechanism.

• Journal of Life Science
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• v.21 no.9
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• pp.1346-1353
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• 2011

Sophora tonkinensis Gapnep has been used as a traditional herbal medicine in oriental regions since ancient times. In this study, the effect and mechanism of the MeOH extract of Sophora tonkinensis Gapnep (STME) on adipocite differentiation and adipogenesis in 3T3-L1 preadipocites were investigated. Treatment with STME in the concentration range of 0-200 ${\mu}g$/ml significantly inhibited the differentiation of 3T3-L1 preadipocites in a dose-dependent manner, as determined by a decrease in intracellular lipid droplets and lipid contents measured by Oil Red O staining. In association with the inhibitory effect of lipid accumulation, the expressions of the proteins concerned with adipogenesis in 3T3-L1 preadipocites were also investigated. Treatment with STME reduced the expressions of peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ and ${\beta}$ (C/EBP${\alpha}$ and C/EBP${\beta}$) and sterol regulatory element binding protein (SREBP), which are adipocyte specific markers. In flow cytometry analysis, the inhibitory effect of differentiation was caused by G1 arrest and following mitotic clonal expansion cease. Therefore, we also investigated the alteration of G1 phase arrest-related proteins. As a result, the expression of p21 protein was significantly increased, while the expressions of Cdk2, E2F-1 and phospho-Rb were reduced in a dose-dependent manner in STME treated 3T3-L1 cells. According to these results, STME might inhibit differentiation through G1 arrest in 3T3-L1 preadipocytes adipogenesis, and further studies, which are in progress, have to be completed to identify the active compounds.

• Nutrition Research and Practice
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• v.18 no.1
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• pp.1-18
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• 2024

BACKGROUND/OBJECTIVES: Endoplasmic reticulum (ER) stress in adipose tissue causes an inflammatory response and leads to metabolic diseases. However, the association between vitamin D and adipose ER stress remains poorly understood. In this study, we investigated whether 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) alleviates ER stress in adipocytes. MATERIALS/METHODS: 3T3-L1 cells were treated with different concentrations (i.e., 10-100 nM) of 1,25(OH)₂D₃ after or during differentiation (i.e., on day 0-7, 3-7, or 7). They were then incubated with thapsigargin (TG, 500 nM) for an additional 24 h to induce ER stress. Next, we measured the mRNA and protein levels of genes involved in unfold protein response (UPR) and adipogenesis using real-time polymerase chain reaction and western blotting and quantified the secreted protein levels of pro-inflammatory cytokines. Finally, the mRNA levels of UPR pathway genes were measured in adipocytes transfected with siRNA-targeting Vdr. RESULTS: Treatment with 1,25(OH)₂D₃ during various stages of adipocyte differentiation significantly inhibited ER stress induced by TG. In fully differentiated 3T3-L1 adipocytes, 1,25(OH)₂D₃ treatment suppressed mRNA levels of Ddit3, sXbp1, and Atf4 and decreased the secretion of monocyte chemoattractant protein-1, interleukin-6, and tumor necrosis factor-α. However, downregulation of the mRNA levels of Ddit3, sXbp1, and Atf4 following 1,25(OH)₂D₃ administration was not observed in Vdr-knockdown adipocytes. In addition, exposure of 3T3-L1 preadipocytes to 1,25(OH)₂D₃ inhibited transcription of Ddit3, sXbp1, Atf4, Bip, and Atf6 and reduced the p-alpha subunit of translation initiation factor 2 (eIF2α)/eIF2α and p-protein kinase RNA-like ER kinase (PERK)/PERK protein ratios. Furthermore, 1,25(OH)₂D₃ treatment before adipocyte differentiation reduced adipogenesis and the mRNA levels of adipogenic genes. CONCLUSIONS: Our data suggest that 1,25(OH)₂D₃ prevents TG-induced ER stress and inflammatory responses in mature adipocytes by downregulating UPR signaling via binding with Vdr. In addition, the inhibition of adipogenesis by vitamin D may contribute to the reduction of ER stress in adipocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1079-1085
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• 2012

Obesity is an important issue worldwide as it may associated with increased prevalence of metabolic diseases. Mung bean is known as a functional food for decreasing the glycemic index and lipid profile of plasma. The purpose of this study was to investigate the anti-obesity effects of vitexin from mung bean on the regulation of adipocyte differentiation and adipocytokine secretion. When 3T3-L1 adipocytes were treated with vitexin from days 0 to 14 at various levels of 25, 50, 100, and $200{\mu}M$, there was no change in cell viability. Vitexin treatment at 50, 100, and $200{\mu}M$ decreased triacylglycerol levels in cells, but only $100{\mu}M$ vitexin induced lipolysis. At $200{\mu}M$ of vitexin, phosphorylation of p38 and ERK, which causes secretion of inflammatory adipocytokines, was depressed, whereas there was an increase in expression of $PPAR{\gamma}$, the key regulator of adipocyte differentiation. Phosphorylation of AMPK increased at $100{\mu}M$ vitexin. TNF-${\alpha}$ and aP2 mRNA expression increased at $25{\mu}M$ vitexin, whereas only TNF-${\alpha}$ mRNA expression increased at $200{\mu}M$ vitexin. Further, the mRNA levels of TNF-${\alpha}$ and aP2 decreased at other concentrations in a dose-dependent manner. Since we observed that mRNA expression of C/EBP, SREBP1, and $PPAR{\gamma}$ did not change upon vitexin treatment, our future studies will investigate other genes such as mTOR, which is related with apoptosis signaling, or SIRT1, which is associated with inhibition of adipogenesis. Our results indicate that vitexin at concentrations between 100 and $200{\mu}M$ is suitable in vivo for the development of mung bean as an anti-obesity therapy or functional food.

• BMB Reports
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• v.53 no.3
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• pp.142-147
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• 2020

Lipid accumulation in white adipose tissue is the key contributor to the obesity and orchestrates numerous metabolic health problems such as type 2 diabetes, hypertension, atherosclerosis, and cancer. Nonetheless, the prevention and treatment of obesity are still inadequate. Recently, scientists found that brown adipose tissue (BAT) in adult humans has functions that are diametrically opposite to those of white adipose tissue and that BAT holds promise for a new strategy to counteract obesity. In this study, we evaluated the potential of sinapic acid (SA) to promote the thermogenic program and lipolysis in BAT. SA treatment of brown adipocytes induced the expression of brown-adipocyte activation-related genes such as Ucp1, Pgc-1α, and Prdm16. Furthermore, structural analysis and western blot revealed that SA upregulates protein kinase A (PKA) phosphorylation with competitive inhibition by a pan-PKA inhibitor, H89. SA binds to the adenosine triphosphate (ATP) site on the PKA catalytic subunit where H89 binds specifically. PKA-cat-α1 gene-silencing experiments confirmed that SA activates the thermogenic program via a mechanism involving PKA and cyclic AMP response element-binding protein (CREB) signaling. Moreover, SA treatment promoted lipolysis via a PKA/p38-mediated pathway. Our findings may allow us to open a new avenue of strategies against obesity and need further investigation.

• Nutrition Research and Practice
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• v.6 no.3
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• pp.221-225
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• 2012

Zinc deficiency is known to be associated with insulin resistance in obese individuals. This study was performed to evaluate the effect of zinc supplementation on insulin resistance and metabolic risk factors in obese Korean women. Forty obese women (body mass index (BMI) ${\geq}25kg/m^2$) aged 19-28 years were recruited for this study. Twenty women of the study group took 30 mg/day of supplemental zinc as zinc gluconate for 8 weeks and 20 women of control group took placebo. Usual dietary zinc intake was estimated from 3-day diet records. Insulin resistances were measured using Homeostasis model assessment (HOMA) indices, and insulin sensitivities Matsuda indices, which were calculated using oral glucose tolerance test data. Metabolic risk factors, such as waist circumference, blood pressure, fasting glucose, triglyceride, high density lipoprotein (HDL) cholesterol, and adipocyte hormones such as leptin, and adiponectin were also measured. At the beginning of study, dietary zinc averaged 7.31 mg/day and serum zinc averaged $12.98{\mu}mol/L$ in the study group. Zinc supplementation increased serum zinc by 15% and urinary zinc by 56% (P < 0.05). HOMA values tended to decrease and insulin sensitivity increased slightly in the study group, but not significantly so. BMI, waist circumference, blood pressure, blood glucose, triglyceride, HDL cholesterol, and adipocyte hormones did not change in either the study or control group. These results suggest that zinc status may not affect insulin resistance and metabolic risk factors in obese Korean women. Further research is required on a larger cohort with a longer follow-up to determine the effects of zinc status on insulin resistance and metabolic variables.

• Food Science and Preservation
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• v.24 no.4
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• pp.524-528
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• 2017

Ricinus communis, belongs to the family Euphorbiaceae, has been known as medicinal plants for treatment of inflammation, tumors, antidiabetic, hepatoprotective and laxative. Compared to many pharmacological studies, the effect of R. communis extract on regulating adipogenesis as therapeutic drug for treating obesity has not been reported. R. communis extract (RCE) was investigated to determine its effects on the adipogenesis by monitoring the status of $Wnt/{\beta}-catenin$ signaling and factors involving the differentiation of adipocytes. The differentiation of 3T3-L1 cells monitored by Oil Red O staining was inhibited in concentration dependent manner by RCE. The luciferase activity of HEK 293-TOP cells containing pTOPFlash with Tcf4 response element-luciferase gene was increased approximately 2-folds by the treatment of RCE at concentrations of $100{\mu}g/mL$ compared to the control. Activation of the $Wnt/{\beta}-catenin$ pathway by RCE was further confirmed by immunocytochemical analysis which shows an increment of nuclear localization of ${\beta}-catenin$. In addition, safety of RCE was verified through performing neural stem cell morphology assay. Among the identified flavonoids in RCE, isoquercitrin was the most abundant. Therefore, these results indicate that the adipocyte differentiation was significantly reduced by isoquercitrin in R. communis. In this study, RCE suppresses the adipogenesis of 3T3-L1 cells via the activation of $Wnt/{\beta}-catenin$ signaling.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.267-273
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• 2008

Water-soluble fraction (WSF) from edible mushroom hinmogi (Tremella fuciformis) were obtained by water extraction, and polysaccharides in the WSF were separated by ethanol precipitation. The inhibitory effects of the polysaccharides on 3T3-L1 adipocyte differentiation were evaluated by the reduction of peroxisome proliferators-activated receptor ${\gamma}$ ($PPAR{\gamma}$) translation, triglyceride accumulation, Oil Red-O staining, and expression levels of $PPAR{\gamma}$, CCAAT/enhancer binding protein a (C/$EBP{\alpha}$), and leptin. The $PPAR{\gamma}$ translation in 3T3-L1 cells was inhibited by the treatment with polysaccharide precipitated by 80% ethanol (P80) which showed highest inhibitory activity among polysaccharides tested. In addition, treatment of P80 to 3T3-L1 cells significantly inhibited the triglyceride accumulation, Oil Red-O staining, and mRNA expression of $PPAR{\gamma}$, C/$EBP{\alpha}$, and leptin in a dose-dependent manner. Based upon these results, P80 from edible mushroom hinmogi shows the inhibitory activity on the differentiation of 3T3-L1 adipocytes. Therefore, it might be employed as a potential anti-obesity material.

• Journal of Acupuncture Research
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• v.27 no.6
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• pp.31-42
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• 2010

Objectives : The aim of this study was to investigate the anti-obesity potential and mechanisms of action of Rhizoma Atractylodis(RA) herbal acupuncture in high fat diet- induced obese ICR mice. Methods : Sample solutions for herbal acupuncture were prepared from the Rhizoma Atractylodis water extract powder at concentration of 150mg/kg and 300mg/kg with distilled water. Five week-old ICR mice acclimatized to the laboratory environment for 1 week were allocated into four groups: regular diet group (RD), high fat diet group(HFD), groups fed HFD with 150mg/kg RA herbal acupuncture treatment (RAE 150) and with 300mg/kg RA herbal acupuncture treatment(RAE 300). Herbal acupuncture groups were injected with either 150mg/kg or 300mg/kg of Rhizoma Atractylodis(RA) subcutaneously onto both Sinsu($BL_{23}$) alternately on the same time everyday for 30days. Body weight, gross appearance of epididymal fat area, blood glucose, insulin, insulin resistance(HOMA-IR), non-esterified fatty acid, cholesterol, triglyceride, AST, ALT, histological analysis of white adipose tissue, gene expression responsible for adipocyte differentiation and AMPK activation were analyzed. Results : RA herbal acupuncture inhibited the development of weight gain, hyperglycemia, hyperinsulinemia, hyperlipidemia, increases of AST and ALT, and the enlargement of fat cell size induced by HFD. Also, RA herbal acupuncture inhibited the expression of PPAR-${\gamma}$, C/$EBP{\alpha}$, aP2, LPL, FAS, SCD-1 and enhanced the activation of AMP-activated protein kinase. Conclusions : The results of this study demonstrate that RA herbal acupuncture can exert the anti-obesity effect and it is partially mediated by activation of AMPK and inhibition of the gene expressions responsible for adipocyte differentiation. Further studies will be required to ascertain the nti-obesity effect and mechanisms of action of RA herbal acupuncture in animal models and human for aclinical application.