• Molecules and Cells
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• v.44 no.2
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• pp.116-125
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• 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.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.1
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• pp.22-27
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• 2013

The prevalence of obesity is increasing worldwide. Obesity can cause hyperlipidemia, hypertension, cardiovascular diseases, metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Many environmental or genetic factors have been suggested to contribute to the development of obesity, but there is no satisfactory explanation for its increased prevalence. This review discusses the latest updates on the role of the gut microbiota in obesity and NAFLD.

• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.253-263
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• 2023

The biogenesis and biological roles of extracellular vesicles (EVs) in the progression of liver diseases have attracted considerable attention in recent years. EVs are membrane-bound nanosized vesicles found in different types of body fluids and contain various bioactive materials, including proteins, lipids, nucleic acids, and mitochondrial DNA. Based on their origin and biogenesis, EVs can be classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are the smallest EVs (30-150 nm in diameter), which play a significant role in cell-to-cell communication and epigenetic regulation. Moreover, exosomal content analysis can reveal the functional state of the parental cell. Therefore, exosomes can be applied to various purposes, including disease diagnosis and treatment, drug delivery, cell-free vaccines, and regenerative medicine. However, exosome-related research faces two major limitations: isolation of exosomes with high yield and purity and distinction of exosomes from other EVs (especially microvesicles). No standardized exosome isolation method has been established to date; however, various exosome isolation strategies have been proposed to investigate their biological roles. Exosome-mediated intercellular communications are known to be involved in alcoholic liver disease and nonalcoholic fatty liver disease development. Damaged hepatocytes or nonparenchymal cells release large numbers of exosomes that promote the progression of inflammation and fibrogenesis through interactions with neighboring cells. Exosomes are expected to provide insight on the progression of liver disease. Here, we review the biogenesis of exosomes, exosome isolation techniques, and biological roles of exosomes in alcoholic liver disease and nonalcoholic fatty liver disease.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.419-428
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• 2018

Background: Despite the large number of studies on ginseng, pharmacological activities of ginseng seed oil (GSO) have not been established. GSO is rich in unsaturated fatty acids, mostly oleic and linoleic acids. Unsaturated fatty acids are known to exert a therapeutic effect in nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effect and underlying mechanisms of GSO against NAFLD using in vitro and in vivo models. Methods: In vitro lipid accumulation was induced by free fatty acid mixture in HepG2 cells and by 3 wk of high fat diet (HFD)-feeding in Sprague-Dawley rats prior to hepatocyte isolation. The effects of GSO against diet-induced hepatic steatosis were further examined in C57BL/6J mice fed a HFD for 12 wk. Results: Oil Red O staining and intracellular triglyceride levels showed marked accumulation of lipid droplets in both HepG2 cells and rat hepatocytes, and these were attenuated by GSO treatment. In HFD-fed mice, GSO improved HFD-induced dyslipidemia and hepatic insulin resistance. Increased hepatic lipid contents were observed in HFD-fed mice and it was lowered in GSO (500 mg/kg)-treated mice by 26.4% which was evident in histological analysis. Pathway analysis of hepatic global gene expression indicated that GSO increased the expression of genes associated with ${\beta}$-oxidation (Ppara, Ppargc1a, Sirt1, and Cpt1a) and decreased the expression of lipogenic genes (Srebf1 and Mlxipl), and these were confirmed with reverse transcription and quantitative polymerase-chain reaction. Conclusion: These findings suggest that GSO has a beneficial effect on NAFLD through the suppression of lipogenesis and stimulation of fatty acid degradation pathway.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.5-5
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• 2021

Alcoholic and nonalcoholic steaohepatitis is a leading form of chronic liver disease with few biomakers ad treatment options currently available. a progressive disease of NAFLD may lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Recently, we extracted HIMH0021, which is an active flavonoid component in the Acer tegmentosum extract, has been shown to protect against liver damage caused by hepatic dysfunction. Therefore, in this study, we aimed to investigate whether HIMH0021 could regulate steatohepatitis and liver fibrosis during alcoholic or nonalcoholic metabolic process. HIMH0021, which was isolated from the active methanol extract of A. tegmentosum, inhibited alcohol-induced steatosis and attenuated the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) during hepatocellular alcohol metabolism, both of which promote lipogenesis as well as liver inflammation. Treatment with HIMH0021 conferred protection against lipogenesis and liver injury, inhibited the expression of cytochrome P4502E1, and increased serum adiponectin levels in the mice subjected to chronic-plus-binge feeding. Furthermore, in hepatocytes, HIMH0021 activated fatty acid oxidation by activating pAMPK, which comprises pACC and CPT1a. These findings suggested that HIMH0021 could be used to target a TNFα-related pathway for treating patients with alcoholic hepatitis.

• Journal of Nutrition and Health
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• v.42 no.8
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• pp.732-739
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• 2009

Metabolic syndrome has been strongly associated with elevated alanine aminotransferase (ALT), a surrogate of nonalcoholic fatty liver disease. We investigated the relationship between metabolic syndrome and elevated ALT in the general Korean population. The study sample was comprised of 4,781 Korean adults who had participated in the 2005 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined by National Cholesterol Education Program for Adult Treatment Panel III. Elevated ALT was defined as an enzyme activity > 40 IU/L for men, and > 31 IU/L for women. ALT was measured by enzymatic methods. Among participants, 425 (8.9%) subjects displayed elevated ALT. The odds ratios (ORs) for elevated ALT increased in subjects with obesity or one of components of metabolic syndrome such as abdominal obesity, high blood pressure, high fasting glucose, high triglyceride, and low HDL cholesterol after adjusting for age and sex. The unadjusted OR for elevated ALT increased according to the number of components of metabolic syndrome (OR = 1.5, 95% CI: 0.96-2.32 for 1 component; OR = 3.0, 95% CI: 1.98-4.61 for 2 components; OR = 6.3, 95% CI: 4.29-9.35 for ${\geq}3$ components; p for trend < 0.0001). This trend did not differ after adjustments for putative risk factors including age, sex, BMI, smoking status, and alcohol intake. Metabolic syndrome is implicated as a strong risk factor of elevated ALT in Korean adults.

• Journal of Life Science
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• v.22 no.9
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• pp.1261-1267
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• 2012

The aim of the present study was to investigate effects of a 12-week aerobic exercise training program and a gym-ball exercise training program on body composition, aspartate aminotransferase (AST), alanine aminotransferase (ALT), adipokines, and cardiovascular risk factors in obese children with nonalcoholic fatty liver disease. The subjects were separated into two groups, an aerobic exercise group (n=10), which practiced moderate aerobic exercise training for 12 weeks, and a gym-ball exercise group (n=13), which practiced resistance exercise training for 12 weeks. The results of the analyses are as follows: Weight, body mass index, and body fat were significantly lower (p<0.01, respectively), whereas the $VO_2$ max was higher in both groups (p<0.01). Fasting glucose, insulin and HOMA-IR levels were significantly decreased in the gym-ball exercise group (p<0.05), whereas adiponectin, AST, and ALT levels were significantly increased (p<0.05, p<0.001, p<0.001, respectively) in both groups after the 12-week exercise training program. In addition, our results showed that HOMA-IR, insulin, and concentrations of C-reactive protein (CRP) were significantly lower in both groups. They demonstrate that a 12-week program of regular aerobic exercise or gym-ball exercise yields beneficial effects such as an amelioration of cardiovascular risk factors, body indices, and liver function in obese children with nonalcoholic fatty liver disease.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.5
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• pp.455-469
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• 2021

Purpose: The rs641738 C>T in membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) is implicated, along with the rs738409 C>G polymorphism in patatin-like phospholipase domain-containing protein 3 (PNPLA3), in nonalcoholic fatty liver disease (NAFLD). The association of these polymorphisms and NAFLD are investigated in Hispanic children with obesity. Methods: Obese children with and without NAFLD were enrolled at a pediatric tertiary care health system and genotyped for MBOAT7 rs641738 C>T and PNPLA3 rs738409 C>G. NAFLD was characterized by the ultrasonographic presence of hepatic steatosis along with persistently elevated liver enzymes. Genetic variants and demographic and biochemical data were analyzed for the effects on NAFLD. Results: Among 126 enrolled subjects, 84 in the case group had NAFLD and 42 in the control group did not. The two groups had similar demographic distribution. NAFLD was associated with abnormal liver enzymes and elevated triglycerides and cholesterol (p<0.05). Children with NAFLD had higher percentage of PNPLA3 GG genotype at 70.2% versus 31.0% in non-NAFLD, and lower MBOAT7 TT genotype at 4.8% versus 16.7% in non-NAFLD (p<0.05). PNPLA3 rs738409 C>G had an additive effect in NAFLD; however, MBOAT7 rs641738 C>T had no effects alone or synergistically with PNPLA3 polymorphism. NAFLD risk increased 3.7-fold in subjects carrying PNPLA3 GG genotype and decreased in MBOAT7 TT genotype. Conclusion: In Hispanic children with obesity, PNPLA3 rs738409 C>G polymorphism increased the risk for NAFLD. The role of MBOAT7 rs641738 variant in NAFLD is less evident.

• The Journal of Pediatrics of Korean Medicine
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• v.33 no.2
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• pp.12-21
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• 2019

Objectives Coptidis Rhizoma and Glycyrrhiza Uralensis are herbs that treat obesity and dampness-phlegm. The aim of this study is to investigate the efficacy of Coptidis Rhizoma and Glycyrrhiza Uralensis on lipid deposition with nonalcoholic fatty liver disease (NAFLD). Methods Male 6-week-old C57BL/6 male mice were divided into three groups: control group (Ctrl), high fat diet group (HFF), and high fat diet with Coptidis Rhizoma and Glycyrrhiza Uralensis extract administration group (CGT). Each 10 mice were allocated to each group (total of 30 mice). All mice were allowed to eat fat rich diet freely throughout the experiment. To examine the effect of Coptidis Rhizoma and Glycyrrhiza Uralensis, we observed weight changes, total cholesterol and glucose levels, lipid blot distributions, PGC-1, p-$I{\kappa}B$, and p-JNK. Results Body weights for all mice were measured and analyzed the difference between the groups. Weight gain was significantly lower in CGT group than the HFF group. Total cholesterol and glucose levels were significantly lower in CGT group. The distribution of lipid blots and positive reaction of PGC-1 were significantly lower in CGT group. The positive reaction of p-$I{\kappa}B$ in hepatic tissues was significantly lower in CGT group. The positive reaction of p-JNK in hepatic tissues was significantly lower in CGT group. Conclusions Coptidis Rhizoma and Glycyrrhiza Uralensis have the effect of improving non - alcoholic fatty liver induced insulin resistance through regulation of lipid metabolism.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.6
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• pp.459-466
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• 2019

Dipeptidyl peptidase (DPP)-4 inhibitors, or gliptins, are a class of oral hypoglycemic drugs that have been widely used as a second-line treatment for type 2 diabetes. Gliptins, which were introduced for clinical use a decade ago, have been shown to be beneficial against nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) in animals and humans. Cenicriviroc (CVC), a dual antagonist of C-C chemokine receptor type 2 and 5, is currently under investigation against NASH and fibrosis. It was previously discovered that evogliptin (EVO) reduces hepatic steatosis in diet-induced obese animals but the effectiveness of EVO on NASH remains unexplored. Here, we compared the effectiveness of EVO and CVC against NASH and fibrosis in mice fed a high-fat and high-fructose diet (HFHF). Biochemical and histological analyses showed that mice fed a HFHF for 20 weeks developed severe hepatic steatosis and inflammation with mild fibrosis. Administration of EVO (0.2% wt/wt) for the last 8 weeks of HFHF feeding significantly reduced hepatic triglyceride accumulation, inflammation, and fibrosis as well as restored insulin sensitivity, as evidenced by lowered plasma insulin levels and the improvement in insulin tolerance test curves. Treatment of mice with CVC (0.1% wt/wt) inhibited hepatic inflammation and fibrogenesis with similar efficacy to that of EVO, without affecting hepatic steatosis. CVC treatment also reduced plasma insulin concentrations, despite no improvement in insulin tolerance. In conclusion, EVO administration efficiently ameliorated the development of NASH and fibrosis in HFHF-fed mice, corroborating its therapeutic potential.