• The Journal of Internal Korean Medicine
• /
• v.35 no.2
• /
• pp.175-183
• /
• 2014

Objectives : We tried to uncover the anti-lipogenic effect and underlying mechanism of Laminaria japonica on an experimental cellular model of non-alcoholic fatty liver disease. Methods : Ethanol extract of Laminaria japonica (LJ) was prepared. Intracellular lipid content of palmitate-treated HepG2 cells was evaluated with or without LJ treatment. We measured the effects of LJ on liver X receptor ${\alpha}$ ($LXR{\alpha}$) and sterol regulatory element-binding transcription factor-1c (SREBP-1c) expression, transcription level of lipogenic genes, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), and nuclear factor erythroid 2-related factor 2 (Nrf2) activation in HepG2 cells. Results : LJ markedly attenuated palmitate-induced intracellular lipid accumulation in HepG2 cells. LJ suppressed $LXR{\alpha}$-dependent SREBP-1c activation, and SREBP-1c mediated induction of ACC, FAS, and SCD-1. Furthermore, LJ activated Nrf2, which plays an important cytoprotective role in non-alcoholic fatty liver disease. Conclusions : Our study suggests that LJ has the potential to alleviate hepatic lipid accumulation, and this effect was mediated by inhibiting the $LXR{\alpha}$-SREBP-1c pathway that leads to hepatic steatosis. In addition, the anti-lipogenic potential may, at least in part, be associated with activation of Nrf2.

• Journal of Food Hygiene and Safety
• /
• v.35 no.1
• /
• pp.93-101
• /
• 2020

Seakso 1, a maize hybrid, was developed in 2008 by Gangwon Agricultural Research and Extension Services in Korea and registered in 2011. It is single-cross hybrid, semi-flint, deep-purple variety of corn, variety of are yellow, while the husks and cobs are purple. Due to the sensitivity of Seakso 1 to excess moisture after seeding, water supply should be carefully managed, and it should be harvested at a suitable time to obtain the highest anthocyanin content. This study investigated the hepatoprotective effect of Saekso 1 corn husk and cob extracts (EHCS) in oleic acid-induced non-alcoholic fatty liver disease (NAFLD) in HepG2 cells. EHCS showed a high level of lipid accumulation inhibiting effect. EHCS also suppressed triglyceride accumulation and inhibited expression of lipid marker genes, such as sterol regulatory element binding protein-1c (SREBP-1c) and sterol regulatory element binding protein-1a (SREBP-1a). Analysis by western blot of the expression of p-AMPK, p-SREBP1, PPARα, and FAS proteins showed that the incidence of SREBP1 protein, a major factor involved in lipid metabolism in the liver, has decreased significantly after treatment with the extracts. Moreover, the protein-induced expression of FAS, a major enzyme involved in the biosynthetic pathways of fatty acids, was decreased significantly in all concentrations. These results suggest that EHCS is a potent agent for the treatment of NAFLD.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.27 no.6
• /
• pp.802-808
• /
• 2013

Here we tried to uncover the potential anti-lipogenic effect and the underlying mechanism of Phaseolus angularis seed in a cellular model of nonalcoholic fatty liver disease (NAFLD) induced in HepG2 cells. Ethanol extract of Phaseolus angularis seed (JSD) was prepared. HepG2 cells were incubated in palmitate containing media to induce intracellular lipid accumulation, and co-treated with JSD for 16 hrs before examine intracellular lipid content. In control group, the cells were not co-treated with JSD. We measured the effects of JSD on liver X receptor ${\alpha}$ ($LXR{\alpha}$) and sterol regulatory element-binding transcription factor-1c (SREBP-1c) expression, transcription level of lipogenic genes, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), and AMP-activated protein kinase (AMPK) activation in HepG2 cells. JSD markedly reduced palmitate-induced intracellular lipid accumulation in HepG2 cells. JSD suppressed $LXR{\alpha}$/SREBP-1c expression, and SREBP-1c mediated induction of ACC, FAS, and SCD-1. Furthermore, JSD activated AMPK, which plays a major role in the control of hepatic lipid metabolism. Taken together, it is suggested that JSD has a potential to alleviate hepatic steatosis, at least in part, by suppressing $LXR{\alpha}$/SREBP-1c mediated induction of lipogenic genes. In addtion, the anti-lipogenic potential may be associated with activation of AMPK. Therefore, the Phaseolus angularis seed could be applied as a potential therapeutics for NAFLD with additional clinical studies.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.1
• /
• pp.101-112
• /
• 2014

The aim of this study was to evaluate the biological mechanism of orally administered ethanolic extract of fly maggot(EM) on hypocholesterolemic rats fed a high-cholesterol diet. Sprague Dawley male rats were divided into four groups (EM dose control=0, 5.0, 7.0, and 9.0 mg/100 g BW) and were treated for 6 weeks. EM groups revealed a significant reduction in serum triglyceride, total cholesterol, and LDL-C when compared with the control group(p<0.05). HMG-CoA reductase activity in EM groups were lower than those of the control group, but total sterol, neutral sterol, and bile acid excretion were increased in EM groups when compared with the control group(p<0.05). To identify the biological mechanism of EM towards the hypocholesterolemic effect, sterol response element binding proteins (SREBPs) and the peroxisome proliferator-activated receptors ($PPAR{\alpha}$ transcription system were determined in rats fed a high-cholesterol diet. It was discovered that EM suppress the expression of SREBP-$1{\alpha}$ and SREBP-2 mRNA in the liver tissues of high-cholesterol diet fed rats, while simultaneously increasing the expression of $PPAR{\alpha}$ mRNA(p<0.05). This finding indicates that EM may have hypocholesterolemic effects in rats fed a high-cholesterol diet, by regulating cholesterol metabolism-related biochemical parameters and SREBP-$1{\alpha}$ SREPB-2 and $PPAR{\alpha}$gene expression.

• The Journal of Internal Korean Medicine
• /
• v.35 no.1
• /
• pp.70-78
• /
• 2014

Objectives : Hoechunyanggyeok-san (HYS) is a traditional herbal medicine, which has been clinically used for treating febrile and inflammatory diseases. HYS has been reported to be a useful treatment for diabetes, atherosclerosis and hyperlipidemia in the type 1 diabetic model. However, the mechanism of the effects of HYS against hyperglycemia and hyperlipidemia is poorly understood. In the present study, we investigated the underlying mechanism of ameliorative effect of HYS on hyperglycemia and hyperlipidemia in vivo. Methods : HYS (10, 50 mg/kg/day, p.o.) was administered every day for 2 weeks to db/db mice and its effect was compared with vehicle-treated db/db mice. To confirm serum glucose and triglyceride (TG) changes, serological testing was performed. The levels of sterol regulatory element-binding protein-1 (SREBP-1) activity and Sirtuin1 (SIRT1), AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase ${\alpha}$ ($ACC{\alpha}$) expression were analyzed by western blot analysis. Results : The administration of HYS significantly decreased the elevated serum glucose and TG in db/db mice. HYS administration increased the levels of SIRT1 and AMPK expression compared with the vehicle-treated group. Moreover, HYS treatment significantly inhibited SREBP-1 activity and $ACC{\alpha}$ expression in the liver, while the vehicle-treated group exhibited their increase. Conclusions : In conclusion, HYS is suggested to have an improvement effect on hyperglycemia and hyperlipidemia by activating the SIRT1/AMPK signaling pathway and inhibiting SREBP-1.

• Journal of Life Science
• /
• v.22 no.10
• /
• pp.1316-1323
• /
• 2012

The present study was conducted to investigate whether myoblasts can be transdifferentiated into adipocytes by ectopic expression of adipogenic transcription factors, including peroxisome proliferator-activated receptor-${\gamma}$ ($PPAR{\gamma}$), CCAAT/enhancer-binding protein-${\alpha}$ (C/$EBP{\alpha}$), sterol regulatory element binding protein-1c (SREBP1c), and Krueppel-like factor 5 (KLF5), in primary bovine satellite cells. Transcription factors were transiently transfected into primary bovine myoblasts, and the cells were cultured with adipogenic differentiation medium for 2 days and then cultured on growth medium for an additional 8 days. Ectopic expression of $PPAR{\gamma}$ or C/$EBP{\alpha}$ alone was insufficient to induce adipogenesis in myoblasts. However, overexpression of both $PPAR{\gamma}$ and C/$EBP{\alpha}$ in myoblasts was able to induce adipogenic transdifferentiation as indicated by the appearance of mature adipocytes, the induction of adipogenic gene expressions, and the suppression of myogenic gene expressions. In addition, KLF5 and $PPAR{\gamma}$ co-transfected bovine myoblasts were converted to adipocytes but not in cells transfected with only KLF5 expression vector. Overexpression of SREBP1c alone was sufficient to induce transdifferentiation from myoblasts into adipocytes. These results demonstrate that primary bovine satellite cells can be transdifferentiated into adipocytes either by single ectopic expression or combined expression of adipogenic transcription factors in a culture system.

• Journal of Life Science
• /
• v.29 no.10
• /
• pp.1144-1151
• /
• 2019

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with various metabolic syndromes, such as obesity, dyslipidemia, hypertension, and diabetes. Cudrania tricuspidata is a medicinal plant distributed widely in Asia and has been used in clinical practice to treat various diseases. The aim of this study is to determine the lipid-lowering effects of C. tricuspidata fruit extract (CTE) using a cell model induced by free fatty acids (FFAs). HepG2 cells were exposed to 1mM FFAs (palmitic acid:oleic acid = 2:1) for 24 hr to simulate the conditions of NAFLD in vitro. CTE attenuated the increases of lipid accumulation, intracellular triglyceride, and cholesterol content and inhibited 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) activity in the HepG2 cells in a dose-dependent manner. Also, CTE inhibited the protein expression of lipogenesis-related genes, such as sterol regulatory element-binding protein-1/-2 (SREBP-1/-2), fatty acid synthase (FAS), and stearoyl CoA desaturase-1 (SCD-1) in FFAs-induced lipid accumulation in HepG2 cells. In addition, CTE-induced adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in HepG2 cells. These results suggest that CTE attenuates hepatic lipid accumulation by inhibiting lipogenesis through the modulation of the AMPK signaling pathway on FFAs-induced lipogenesis in HepG2 cells and may potentially prevent NAFLD.

• Preventive Nutrition and Food Science
• /
• v.13 no.2
• /
• pp.66-70
• /
• 2008

In order to develop a functionally improved kochujang with antiobesity effects, garlic-added kochujang was prepared with freeze-dried garlic powder and followed by fermentation for 60 days at $30^{\circ}C$. Antiobesity effect of the garlic-added kochujang was investigated by measuring the leptin secretions and mRNA expression levels of obesity-related gene such as TNF${\alpha}$, PPAR${\gamma}$, C/EBP${\alpha}$, and SREBP1c, in cultured 3T3-L1 adipocytes. Fermentation of garlic-added kochujang led to decreased levels of leptin secretions and reduced the mRNA expression levels of TNF${\alpha}$, PPAR${\gamma}$, C/EBP${\alpha}$, and SREBP1c in the 3T3-L1 adipocytes. Accordingly, these results suggest that the addition of garlic to kochujang has a potential as a valuable functional food for controlling obesity.

• Journal of Life Science
• /
• v.29 no.9
• /
• pp.964-971
• /
• 2019

Hepatic lipid accumulation and insulin resistance increases in patients with non-alcoholic fatty liver disease. Piperine is a major compound found in black pepper (Piper nigrum) and long pepper (P. longum). Piperine has been used in fine chemical for its anti-cancer, anti-obesity, anti-diabetic, anti-inflammatory and anti-oxidant properties. However, the signaling-based mechanism of piperine and its role as an inhibitor of lipogenesis and insulin resistance in human hepatocyte cells remains ill-defined. In the present study, we explored the effects of piperine on lipid accumulation and insulin resistance, and explored the potential underlying molecular mechanisms in palmitate-treated HepG2 cells. Piperine treatment resulted in a significant reduction of triglyceride content. Furthermore, piperine treatment decreased palmitate-treated intracellular lipid deposition by inhibiting the lipogenic target genes, sterol-regulatory-element-binding protein 1c (SREBP-1c) and fatty acid synthase (FAS); whereas the expression of carnitine palmitoyl transferase (CPT-1) and phosphorylation of acetyl coenzyme A carboxylase (ACC) gene involved in fatty acid oxidation was increased. Moreover, piperine also inhibited the phosphorylation of insulin receptor substrate (IRS)-1 (Ser307). Piperine treatment modulated palmitate-treated lipid accumulation and insulin resistance in HepG2 cells with concomitant reduction of lipogenic target genes, such as SREBP-1 and FAS, and induction of CPT-1-ACC and phosphorylation of IRS-1 (Tyr632)-Akt pathways. Therefore, piperine represents a promising treatment for the prevention of lipid accumulation and insulin resistance.

• Journal of Korean Medicine Rehabilitation
• /
• v.32 no.2
• /
• pp.19-36
• /
• 2022

Objectives This study is to investigate the effects and mechanisms of Imyo-san (IMS) on the obese mice model induced by high-fat diet. Methods Antioxidative capacity was measured by in vitro method. C57BL/6 mice were randomly assigned into 5 groups (n=7). Normal group was fed general diet (Normal). The other 4 groups were fed high fat diet (HFD) with water (Control), with Garcinia gummi-gutta (GG, Garcinia gummi-gutta 200 mg/kg), with low-dose IMS (IMSL, Imyo-san 0.54 g/kg) and with high-dose IMS (IMSH, Imyo-san 1.08 g/kg). Results IMS showed high radical scavenging activity. After 6 week experiment, body weight, food intake, food efficiency ratio (FER), epididymal fat and liver weight, triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, sterol regulatory element-binding protein-1 (SREBP-1), phospho-acetyl-CoA carboxylase (p-ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), SREBP-2, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), phospho-liver kinase B1 (p-LKB1), phospho-AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor 𝛼 (PPAR𝛼), peroxisome proliferator-activated receptor 𝛾 coactivator-1𝛼 (PGC-1𝛼), uncoupling protein-2 (UCP-2), carnitine palmitoyltransferase 1A (CPT-1A), and histology of liver and epididymal fat were measured and analysed. Body weight gain, FER, liver and epididymal fat weight of IMS groups were significantly decreased. There were significant improvements in blood lipids with less TG, TC, LDL-cholesterol, VLDL-cholesterol and more HDL-cholesterol. Proteins associated with lipid synthesis (SREBP-1, p-ACC, FAS, SCD-1) and cholesterol (SREBP-2, HMGCR) was improved. Factors regulating lipid synthesis and lipid catabolism (p-LKBI, p-AMPK, PPARα, PGC-1α, UCP-2, CPT-1A) were increased. In histological examinations, IMS group had smaller fat droplets than control group. All results increased depending on concentration. Conclusions It can be suggested that IMS has anti-obesity effects with improving lipid metabolism.