• Journal of Life Science
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• v.22 no.1
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• pp.49-54
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• 2012

The effects of genistein on cell proliferation and adipogenesis were examined in mouse 3T3-L1 preadipocyte cells. Genistein decreased viability of 3T3-L1 pre-adipocytes in a dose-dependent manner. Oil Red O staining of these cells also indicated that adipogenesis was inhibited by 50 ${\mu}M$ genistein treatment. We investigated the molecular mechanisms involved in the decrease in cell viability in genistein-treated 3T3-L1 cells by conducting an oligo DNA microarray analysis. We selected the sirtuin-1 gene, one of the upregulated genes, for further experimentation because sirtuin-1 belongs to the sirtuin family, which is associated with anti-obesity and anti-inflammation activities. We found that four phytochemicals (resveratrol, capsaicin, daidzein, and genistein) could increase sirtuin-1 expression. Genistein was the strongest inducer of sirtuin-1 among the tested phytochemicals. The inhibition of adipogenesis by genistein was recovered by surtuin-1 siRNA transfection. Overall, these results may further our understanding of the molecular mechanisms underlying the inhibition of proliferation and adipogenesis by genistein in mouse 3T3-L1 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1293-1299
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• 2017

Obesity contributes to the development of diseases, such as type II diabetes, hypertension, coronary heart disease, and cancer. In addition, oxidative stress caused by reactive oxygen species (ROS) is recognized widely as a contributing factor in the development of chronic diseases. This study was examined the antioxidant and anti-adipogenic activities of epigallocatechin-3-gallate (EGCG) in 3T3-L1 preadipocytes. 3T3-L1 cells were differentiated with or without EGCG for 6 days. The production of glutathione (GSH) and the activities of the antioxidant enzymes, such as glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were measured. EGCG inhibited significantly the lipid accumulation and the expression of adipogenic specific proteins including CCAAT/enhancer binding protein ${\alpha}$ and adipocyte fatty acid binding protein. The production of intracellular ROS was decreased significantly by EGCG in 3T3-L1 cells. EGCG increased the GSH production and the activities of GPx, GR, CAT, and SOD. Moreover, EGCG increased the protein expression of glutamate-cysteine ligase and heme oxygenase-1 in 3T3-L1 cells. These results suggest that EGCG increased the activity and expression of antioxidant enzymes and suppressed the lipid accumulation in 3T3-L1 cells. Therefore, the use of phytochemicals that can maintain the GSH redox balance in adipose tissue could be promising for reducing obesity.

• Journal of Life Science
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• v.32 no.10
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• pp.762-770
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• 2022

Hyperglycemia in type 2 diabetes can be alleviated by promoting cellular glucose uptake. Betulinic acid (3β,-3-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic lupane-type triterpenoid compound. Although there have been studies on the antidiabetic activity of betulinic acid, studies on cellular glucose uptake are lacking. We investigated the effects of betulinic acid on glucose uptake and its mechanism of action in 3T3-L1 adipocytes. Betulinic acid significantly stimulated glucose uptake in 3T3-L1 adipocytes by increasing the phosphorylation of the insulin receptor substrate 1-tyrosine (IRS-1tyr) in the insulin signaling pathway, which in turn stimulated the activation of phosphoinositide 3-kinase (PI3K) and the phosphorylation of protein kinase B (Akt). The activation of PI3K and Akt by betulinic acid translocated glucose transporter 4 to the plasma membrane (PM-GLUT4), thereby increasing the expression of PM-GLUT4 and thus stimulating cellular glucose uptake. Betulinic acid also significantly increased the phosphorylation/activation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. The activation of PI3K and AMPK by betulinic acid was confirmed using the PI3K inhibitor wortmannin and the AMPK inhibitor compound C. The increase in glucose uptake induced by betulinic acid was significantly decreased by wortmannin and compound C in the 3T3-L1 adipocytes. These results suggest that betulinic acid stimulates glucose uptake by activating PI3K and AMPK in 3T3-L1 adipocytes.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.369-378
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• 2023

Smilax sieboldii is one of the Smilax species. A number of Smilax plants have multiple physiologically-active components and anti-inflammatory/anti-oxidant effects. Antiobesity effects induced by Smilax sieboldii have not been reported. In this study, we investigated the effects and molecular mechanisms of anti-obesity activity of 70% ethanol Smilax sieboldii extract (SSE). The anti-obesity effect of SSE was determined using 3T3-L1 adipocytes. We confirmed that SSE was not cytotoxic to murine 3T3-L1 preadipocytes, we evaluated SSE dose-dependently decreased the accumulation of lipids via an Oil Red O assay and triglyceride assay. These anti-obesity activities of SSE were mediated by the inhibition of adipogenesis-related marker genes (peroxisome proliferator activated receptor-γ, CCAAT-enhancer-binding protein α, and SREBP1c) and lipogenesis-related marker genes (fatty acid synthase and aP2). These results suggest that SSE has the potential to exert anti-obesity and anti-hyperlipidemia effects by regulating adipogenic transcription factors and inhibiting the expression of adipogenic markers.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.99-110
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• 2015

The purpose of this study was to evaluate the inhibitory effects of commonly consumed vegetables in Korea on lipid accumulation and production of pro-inflammatory cytokines related to obesity/metabolic syndrome. Using KNHANES (Korea National Health and Nutrition Examination Survey) raw data ($1^{st}$; 1998, $5^{th}$; 2010, 2011) and a literature search, we selected vegetables for study. Edible portions of samples were prepared, ethanol-extracted, and then freeze-dried. 3T3-L1 adipocytes and HepG2 hepatocytes cells were used as in vitro models. Lipid accumulation determined by Oil-red O staining showed that all samples except bracken had inhibitory effects on lipid accumulation in 3T3-L1 adipocytes. Especially, crown daisy and mugwort effectively reduced accumulation of lipids, and their inhibition rates were more than 60% of the control group. Young pumpkin, leeks, crown daisy, and mugwort showed significantly decreased MCP-1 levels compared to the control group. However, adiponectin protein level did not increase in the vegetables experimental group. In HepG2 hepatocytes, all samples showed inhibitory effects on lipid accumulation at one of the two concentrations. Although adiponectin protein levels did not increase, MCP-1 protein levels decreased in adipocytes. Further, lipid accumulation in adipocytes and hepatocytes decreased. In conclusion, all samples showed one or more improved obesity/metabolic syndrome indicators. Among them, young pumpkin, leeks, crown daisy, and mugwort were selected as the most effective portions of vegetables based on improvement of obesity/metabolic syndrome-related indicators.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.127-133
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• 2019

The ami of our study was on the anti-obesity effect of ethanol extract from Trichosanthes kirilowii Maxim root (TKM) in murine adipocytes, 3T3-L1 cells. This study focused on anti-adipogenic activity through inhibition of cell differentiation in 3T3-L1 cells treated TKM. 100 ug/ml of non-cytotoxic TEM remarkablely inhibited content of triglycerol and suppressed expressions of $C/EBP{\alpha}$, $PPAR{\gamma}a$ and SREBP-1c related with lipogenic transcription factors in theres 3T3-L1 cells compared to (-)control cells. As phosphorylations of AMPK and ACC were incerased, HSL and CPT-1 mRNA expression increased upon TKM treatment, which involved in inhibition of fatty acid synthase expression. In conclusion, these results indicate that TKM can inhibit mRNA and protein expression of lipogenic genes in 3T3-L1 adipocytes. Our study suggests that TKM has potential anti-obesity effects and is a convergence therapeutic functional agent with anti-adipogenic activity via hypolipogenesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.161-167
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• 2012

To evaluate the anti-obesity effect of Agrimonia pilosa L., this study investigated that ethyl acetate extract from A. pilosa L. (EAAP) suppresses lipid accumulation and inhibits expression of adipogenic marker genes, such as peroxisome proliferator activated receptor ${\gamma}$ (PPAR${\gamma}$), CCAAT-enhancer-binding protein ${\alpha}$ (C/EBP${\alpha}$), glucose transporter 4 (GLUT4), and adiponectin in 3T3-L1 preadipocytes. We demonstrated that EAAP inhibited adipocyte differentiation and expression of PPAR${\gamma}$ and C/EBP${\alpha}$ mRNA levels in a dose-dependent manner. In addition, EAAP reduced the PPAR${\gamma}$ transcriptional activity stimulated by rosiglitazone in HEK 293T cells and decreased the expression of GLUT4 and adiponectin in 3T3-L1 cells. These results suggest that EAAP inhibits preadipocyte differentiation and adipogenesis by blocking of PPAR${\gamma}$ and C/EBP${\alpha}$ gene expression in 3T3-L1 cells.

• Journal of Life Science
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• v.24 no.7
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• pp.798-803
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• 2014

Cathepsin D (CtsD), an aspartyl peptidase, is involved in apoptosis, resulting in the release of cytochrome C from mitochondria in cells. Here, we investigated microRNA regulation of CtsD expression in 3T3-L1 cells First, we observed the expression of CtsD in cells in response to doxorubicin (Dox). As expected, the level of CtsD mRNA was increased in 3T3-L1 cells exposed to Dox in a dose-dependent manner. Cellular viability of ectopically expressed CtsD cells was also decreased. Next, we used the miRanda program to search for particular microRNA targeting CtsD. MiR-145 was selected as a putative controller for CtsD because miR-145 had a high mirSVR score. In a reporter assay, the luciferase activity of cells containing the CtsD 3'-UTR region was decreased in cells transfected with miR-145 mimic compared to that of a control. The level of CtsD expression was down-regulated in preadipocytes ectopically expressing miR-145 and up-regulated by an miR-145 inhibitor. Cells also suppressed miR-145 expression when exposed to Dox. The miR-145 inhibitor reduced the cellular viability of 3T3-L1 cells. Taken together, these data suggest that miR-145 regulates CtsD-mediated cell death in adipocytes. These findings may have valuable implications concerning the molecular mechanism of CtsD-mediated cell death in obesity, suggesting that CtaD could be a useful therapeutic tool for the prevention and treatment of obesity by regulating fat cell numbers.

• Journal of Life Science
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• v.30 no.6
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• pp.532-541
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• 2020

In this study, we describe the inhibition of adipocyte differentiation by the lactic acid bacteria (LAB) fermentation product of Chrysanthemum indicum L. (CI) extract to control obesity. Preparation of LAB-fermented products was performed to overcome the cytotoxicity of CI extract. During fermentation and 3T3-L1 cell line experiment, cytotoxicity was not induced in the CI fermentation products over 1 day in culture. Fermented materials from highly proliferative cultures were selected for treatment of 3T3-L1 cells and for comparison with unfermented control groups. Cell survival and undifferentiated cell populations were decreased differentiation population in all experimental groups compared with controls, as measured using fluorescence-activated cell sorting analysis. Akt pathway activity increased upon treatment with these fermented extracts in 3T3-L1 cells. Gli2 depleted at the protein level in association with adipocyte differentiation. LAB KCTC 3115- and 3109-fermented extract treatment caused controlled Gli2 protein accumulation. Moreover, KCTC 3115 and 3109 were found to reduce C/EBPα and FAS was depleted, whereas pACC was increased at the protein level upon treatment with the fermentation products of each of the four LAB used in this study. With Lactococcus lactis subsp. lactis KCTC 3115 fermentation, the regulation of adipose differentiation and hedgehog signaling were also suppressed, thereby inhibiting the differentiation of progenitor cells. The basis for the activation of hedgehog signaling may provide insights into the treatment of obesity and the inhibition of adipocyte differentiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.31-35
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• 2010

This study was designed to evaluate anti-diabetes effect of Helianthus tuberosus extract (HT) in HIT-T15 cells. There were 5 experimental groups according to treatment NC (0 ${\muL/mL$), HT2 (1.1 ${\muL/mL$), HT3 (1.5 ${\muL/mL$), IN2 (1.8 ${\muL/mL$), IN3 (2.5 ${\muL/mL$). Inulin (IN) was used as a positive control for the Helianthus tuberosus extract groups. Cell viability was significantly increased in the HT3 (1.5 ${\muL/mL$), IN2 (1.8 ${\muL/mL$), IN3 (2.5 ${\muL/mL$) groups, compared with the NC group. There was no significant difference in cytotoxicity among all groups. Cell survival by MTT assay with alloxan was significantly increased in the HT2 (1.1 ${\muL/mL$), HT3 (1.5 ${\muL/mL$) groups, compared with the NC group. Insulin secretion and NAD+/NADH ratio were significantly increased in the HT3 group, compared with the NC group. We found that Helianthus tuberosus extract increased cell viability, had a protective effect on $\beta$-cells, and increased insulin secretion level and $NAD^+$/NADH ratio in HIT-T15 cells. These results suggest that Helianthus tuberosus extract improves the diabetes-related factors.