• The Korean Journal of Physiology and Pharmacology
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• v.18 no.4
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• pp.333-339
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• 2014

Exendin-4 (Ex-4), a glucagon-like peptide-1 receptor (GLP-1R) agonist, has been known to reverse hepatic steatosis in ob/ob mice. Although many studies have evaluated molecular targets of Ex-4, its mechanism of action on hepatic steatosis and fibrosis has not fully been determined. In the liver, glucose transporter 4 (GLUT4) is mainly expressed in hepatocytes, endothelial cells and hepatic stellate cells (HSCs). In the present study, the effects of Ex-4 on GLUT4 expression were determined in the liver of ob/ob mice. Ob/ob mice were treated with Ex-4 for 10 weeks. Serum metabolic parameters, hepatic triglyceride levels, and liver tissues were evaluated for hepatic steatosis. The weights of the whole body and liver in ob/ob mice were reduced by long-term Ex-4 treatment. Serum metabolic parameters, hepatic steatosis, and hepatic fibrosis in ob/ob mice were reduced by Ex-4. Particularly, Ex-4 improved hepatic steatosis by enhancing GLUT4 via GLP-1R activation in ob/ob mice. Ex-4 treatment also inhibited hepatic fibrosis by decreasing expression of connective tissue growth factor in HSCs of ob/ob mice. Our data suggest that GLP-1 agonists exert a protective effect on hepatic steatosis and fibrosis in obesity and type 2 diabetes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3879-3884
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• 2014

Background: In chronic hepatitis B (CHB), the presence of hepatic steatosis (HS) seems to be associated with known host and viral factors which may influence the long-term prognosis of chronic hepatitis B (CHB), probably leading to cirrhosis and hepatocellular carcinoma (HCC). Different from chronic hepatitis C (CHC), factors associated with HS in CHB are not clearly explored. Materials and Methods: 160 CHB patients were divided into two groups depending on the results of liver biopsy. Group I consisted of 71 patients with confirmed steatosis. Group II comprised 89 patients without steatosis. The groups were compared in terms of basal characteristics, body mass index (BMI), liver enzymes (ALT, AST, ALP), serum fasting blood sugar (FBS) and lipids, hepatitis B e antigen (HBeAg), viral load, and histological findings. Results: In terms of host factors, male gender, older age, BMI, high serum FBS and lipid levels were associated with HS. On the other hand, ALT levels, the HAI scores of necroinflammation and stage of fibrosis did not associate with HS. On multivariate analysis, parameters of sex, BMI, cholesterol and FBS levels were independently associated with HS. Regarding viral factors, HBeAg negativity was significantly associated with HS (81.7%, p value 0.006), but not HBV DNA level (p value 0.520). Conclusions: HS in CHB appears to be unrelated to the status of HBV replication. However, fibrosis progression in CHB is related to variable host factors. HS may be enhanced through these factors in HBV chronic patients.

• Nutrition Research and Practice
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• v.14 no.6
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• pp.568-579
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• 2020

BACKGROUD/OBJECTIVES: Hepatic steatosis is the most common liver disorder, particularly in postmenopausal women. This study investigated the protective effects of standardized rice bran extract (RBS) on ovariectomized (OVX)-induced hepatic steatosis in rats. MATERIALS/METHODS: HepG2 cells were incubated with 200 µM oleic acid to induce lipid accumulation with or without RBS and γ-oryzanol. OVX rats were separated into three groups and fed a normal diet (ND) or the ND containing 17β-estradiol (E2; 10 ㎍/kg) and RBS (500 mg/kg) for 16 weeks. RESULTS: RBS supplementation improved serum triglyceride and free fatty acid levels in OVX rats. Histological analysis showed that RBS significantly attenuated hepatic fat accumulation and decreased hepatic lipid, total cholesterol, and triglyceride levels. Additionally, RBS suppressed the estrogen deficiency-induced upregulation of lipogenic genes, such as sterol regulatory element-binding protein 1 (SREBP1), acetyl-CoA carboxylase 1, fatty acid synthase, glycerol-3-phosphate acyltransferase, and stearoyl-CoA desaturase 1. CONCLUSIONS: RBS and γ-oryzanol effectively reduced lipid accumulation in a HepG2 cell hepatic steatosis model. RBS improves OVX-induced hepatic steatosis by regulating the SREBP1-mediated activation of lipogenic genes, suggesting the benefits of RBS in preventing fatty liver in postmenopausal women.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.294-301
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• 2013

In this study, we examined the hepatic anti-steatosis activity of carnosic acid (CA), a phenolic compound of rosemary (Rosmarinus officinalis) leaves, as well as its possible mechanism of action, in a high-fat diet (HFD)-fed mice model. Mice were fed a HFD, or a HFD supplemented with 0.01% (w/w) CA or 0.02% (w/w) CA, for a period of 12 weeks, after which changes in body weight, blood lipid profiles, and fatty acid mechanism markers were evaluated. The 0.02% (w/w) CA diet resulted in a marked decline in steatosis grade, as well as in homeostasis model assessment of insulin resistance (HOMA-IR) index values, intraperitoneal glucose tolerance test (IGTT) results, body weight gain, liver weight, and blood lipid levels (P < 0.05). The expression level of hepatic lipogenic genes, such as sterol regulating element binding protein-1c (SREBP-1c), liver-fatty acid binding protein (L-FABP), stearoyl-CoA desaturase 1 (SCD1), and fatty acid synthase (FAS), was significantly lower in mice fed 0.01% (w/w) CA and 0.02% (w/w) CA diets than that in the HFD group; on the other hand, the expression level of ${\beta}$-oxidation-related genes, such as peroxisome proliferator-activated receptor ${\alpha}$ (PPAR-${\alpha}$), carnitine palmitoyltransferase 1 (CPT-1), and acyl-CoA oxidase (ACO), was higher in mice fed a 0.02% (w/w) CA diet, than that in the HFD group (P < 0.05). In addition, the hepatic content of palmitic acid (C16:0), palmitoleic acid (C16:1), and oleic acid (C18:1) was significantly lower in mice fed the 0.02% (w/w) CA diet than that in the HFD group (P < 0.05). These results suggest that orally administered CA suppressed HFD-induced hepatic steatosis and fatty liver-related metabolic disorders through decrease of de novo lipogenesis and fatty acid elongation and increase of fatty acid ${\beta}$-oxidation in mice.

• Natural Product Sciences
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• v.20 no.1
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• pp.65-70
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• 2014

This study was carried out to investigate the potential effects of Gardenia jasminoides (GJ) extracts, on hepatic steatosis and lipid metabolism in mice fed with high-fat diet (HFD). GJ extracts (100 mg/kg, ${\times}10$ weeks) fed mice showed reduced body weight, adipose tissue weight, reduced aminotransferase level in plasma and hepatic lipid (triglyceride, total cholesterol) content. These effects were accompanied by decreased expression of lipogenic genes, sterol regulatory element binding protein-1c (SREBP-1c), liver X receptor (LXR), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), cluster of differentiation 36 (CD36), lipoprotein lipase (LPL) and decreased lipogenic enzyme FAS and HMG-CoAR enzyme activities while elevating carnitine palmitoyltrasferase-1 (CPT) activity. Based on these results, we speculated that the inhibitory effect on hepatic steatosis of GJ extract containing geniposide is the result of suppression of lipid synthesis in mice fed with HFD, suggesting that GJ extract may be beneficial in preventing hepatic steatosis.

• Natural Product Sciences
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• v.27 no.3
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• pp.201-207
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• 2021

We have previously reported that Acer tegmentosum extract, which is traditionally used in Korea to reduce alcohol-related liver injury, suppresses liver inflammation caused by excessive alcohol consumption and might improve metabolism. The active ingredient, 6-O-galloylsalidroside (GAL), was isolated from A. tegmentosum, and we hypothesized that GAL could provide desirable pharmacological benefits by ameliorating physiological conditions caused by alcohol abuse. Therefore, this study focused on whether GAL could ameliorate alcoholic fat accumulation and repair liver injury in mice. During chronic alcohol consumption plus binge feeding in mice, GAL was administered orally once per day for 11 days. Intrahepatic lipid accumulation was measured in vivo using a noninvasive method, ¹H magnetic resonance imaging, and confirmed by staining with hematoxylin and eosin and Oil Red O. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using a Konelab system, and the triglyceride content was measured in liver homogenates using an enzymatic peroxide assay. The results suggested that GAL alleviated alcohol-induced steatosis,e as indicated by decreased hepatic and serum triglyceride levels in ethanol-fed mice. GAL treatment also correlated with a decrease in the Cd36 mRNA expression, thus potentially inhibiting the development of alcoholic steatosis via the hepatic de novo lipogenesis pathway. Furthermore, treatment with GAL inhibited the expression of cytochrome P450 2E1 and attenuated hepatocellular damage, as reflected by a reduction in ALT and AST levels. These findings suggest that GAL extracted from A. tegmentosum has the potential to serve as a bioactive agent for the treatment of alcoholic fatty liver and liver damage.

• Archives of Pharmacal Research
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• v.29 no.9
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• pp.768-776
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• 2006

Non-alcoholic fatty liver disease (NAFLD) is common in obesity. However, weight reduction alone does not prevent the progression of NAFLD to end-stage disease associated with the development of cirrhosis and liver disease. In a previous experiment, 50% ethanol extract of Acanthopanax senticosus stem bark (ASSB) was found to reduce body weight and insulin resistance in high fat diet-induced hyperglycemic and hyperlipidemic ICR mice. To evaluate the anti-steatosis action of ASSB, insulin-resistant ob/ob mice with fatty livers were treated with ASSB ethanol extract for an 8 week-period. ASSB ethanol extract reversed the hepatomegaly, as evident in reduction of % liver weight/body weight ratio. ASSB ethanol extract also specifically lowered circulating glucose and lipids, and enhanced insulin action in the liver. These changes culminated in inhibition of triglyceride synthesis in non-adipose tissues including liver and skeletal muscle. Gene expression studies confirmed reductions in glucose 6-phosphatase and lipogenic enzymes in the liver. These results demonstrate that ASSB ethanol extract is an effective treatment for insulin resistance and hepatic steatosis in ob/ob mice by decreasing hepatic lipid synthesis.

• Journal of Ginseng Research
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• v.46 no.4
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• pp.561-571
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• 2022

Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through its action on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liver steatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulin resistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectin expression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO) mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as well as insulin sensitivity was measured. The activation of AMPK was also detected in the liver and hepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium (CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partly attenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TG content, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulin sensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatment significantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise, the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosis and insulin resistance, which further elucidates a new mechanism underlying the beneficial effects of GRb1 on obesity.

• Toxicological Research
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• v.35 no.4
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• pp.403-410
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• 2019

Curcumin, a hydrophobic polyphenol isolated from the Curcuma longa L. plant, has many pharmacological properties, including antioxidant, anti-inflammatory, and chemo-preventive activities. Curcumin has been shown to have potential in preventing nonalcoholic fatty liver disease (NAFLD). However, the low bioavailability of curcumin has proven to be a major limiting factor in its clinical adoption. Theracurmin, a highly bioavailable curcumin that utilizes micronized technology showed improved biological absorbability in vivo. The aim of this study was to investigate the role of theracurmin in modulating hepatic lipid metabolism in vivo. A fatty liver mouse model was produced by feeding mice a high fat diet (HFD; 60% fat) for 12 weeks. We found that treatment for 12 weeks with theracurmin significantly lowered plasma triacylglycerol (TG) levels and reduced HFD-induced liver fat accumulation. Theracurmin treatment lowered hepatic TG and total cholesterol (T-CHO) levels in HFD-fed mice compared to controls. In addition, theracurmin administration significantly reduced lipid peroxidation and cellular damage caused by reactive oxygen species in HFD-fed mice. Overall, these results suggest that theracurmin has the ability to control lipid metabolism and can potentially serve as an effective therapeutic remedy for the prevention of fatty liver.

• Clinical and Molecular Hepatology
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• v.24 no.4
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• pp.392-401
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• 2018

Background/Aims: Leptin is associated with metabolic disorders, which predispose one to non-alcoholic fatty liver disease (NAFLD). The role of leptin in NAFLD pathogenesis is not fully understood. We aim to investigate the association between serum leptin level and severity of NAFLD using U.S. nationally representative data. Methods: Data were obtained from the United States Third National Health and Nutrition Examination Survey. NAFLD was defined by ultrasound detection and severity of hepatic steatosis in the absence of other liver diseases. The severity of hepatic fibrosis was determined by NAFLD fibrosis score (NFS). We used multivariate survey-weighted generalized logistic regression to evaluate the association between leptin level and the degree of NAFLD. We also performed subgroup analyses by body mass index (lean vs. classic NAFLD). Results: Among 4,571 people, 1,610 (35%) had NAFLD. By ultrasound findings, there were 621 people with mild, 664 with moderate, and 325 with severe steatosis. There were 885 people with low NFS (<-1.455, no significant fibrosis), 596 with intermediate NFS, and 129 with high NFS (>0.676, advanced fibrosis). Leptin levels for normal, mild, moderate and severe steatosis were $10.7{\pm}0.3ng/mL$, $12.1{\pm}0.7ng/mL$, $15.6{\pm}0.8ng/mL$, $16{\pm}1.0ng/mL$, respectively (trend P-value<0.001). Leptin levels for low, intermediate, and high NFS were $11.8{\pm}0.5ng/mL$, $15.6{\pm}0.8ng/mL$, $28.5{\pm}3.5ng/mL$, respectively (trend P-value<0.001). This association remained significant even after adjusting for known demographic and metabolic risk factors. In the subgroup analysis, this association was only prominent in classic NAFLD, but not in lean NAFLD. Conclusions: Serum leptin level is associated with the severity of NAFLD, especially in classic NAFLD patients.