Rhus verniciflua and Eucommia ulmoides Protects Against High-Fat Diet-Induced Hepatic Steatosis by Enhancing Anti-Oxidation and AMPK Activation

2019 ◽  
Vol 47 (06) ◽  
pp. 1253-1270
Author(s):  
Hwa-Young Lee ◽  
Geum-Hwa Lee ◽  
Young Yoon ◽  
Han-Jung Chae

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disorder associated with features of metabolic syndrome and oxidative stress. We examined the mechanism by which the combined extracts of Rhus verniciflua and Eucommia ulmoides extracts (ILF-RE) regulate hepatic dyslipidemia in an established NAFLD model, high-fat diet (HFD)-induced lipid dysmetabolism in rats. ILF-RE attenuated alanine aminotransferase (ALT) by 1.5% [Formula: see text], aspartate aminotransferase (AST) by 1.5% [Formula: see text], triglycerides by 1.5% [Formula: see text], cholesterol by 2.0% [Formula: see text], and lipid peroxidation by 1.5% [Formula: see text] in the NAFLD model. ILF-RE, recently shown to have anti-oxidant properties, also inhibited hepatic ROS accumulation by 1.68% [Formula: see text] and regulated ER-redox imbalance, a key phenomenon of ER stress. Due to nutrient overload stress-associated protein folding, ER stress and downstream SREBP-lipogenic transcription signaling were highly activated, and the mTORC1-AMPK axis was also disturbed, leading to hepatic steatosis. ILF-RE results in recovery from hepatic conditions induced by nutrient-based protein folding stress signaling and the ER stress-SREBP and AMPK-mTORC1-SREBP1 axes. Based on these results, ILF-RE is suggested to be a potential therapeutic strategy for hepatic steatosis and may represent a promising novel agent for the prevention and treatment of NAFLD.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Doo Jin Choi ◽  
Seong Cheol Kim ◽  
Gi Eun Park ◽  
Bo-Ram Choi ◽  
Dae Young Lee ◽  
...  

The present study aimed to evaluate the potential synergistic and protective effects of ALM16, a mixture of Astragalus membranaceus (AM) and Lithospermum erythrorhizon (LE) extract in a ratio of 7 : 3, against hepatic steatosis in high fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) mice. Forty-eight mice were randomly divided into eight groups and orally administered daily for 6 weeks with a normal diet (ND) or high fat diet alone (HFD), HFD with AM (HFD + 100 mg/kg AM extract), HFD with LE (HFD + 100 mg/kg LE extract), HFD with ALM16 (HFD + 50, 100, and 200 mg/kg ALM16), or HFD with MT (HFD + 100 mg/kg Milk thistle extract) as a positive control. ALM16 significantly decreased the body and liver weight, serum and hepatic lipid profiles, including triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL), and low-density lipoprotein-cholesterol (LDL), and serum glucose levels, compared to the HFD group. Moreover, ALM16 significantly ameliorated the HFD-induced increased hepatic injury markers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and gamma-glutamyltransferase (GGT)-1. Furthermore, as compared to the mice fed HFD alone, ALM16 increased the levels of phosphorylated AMP-activated protein kinase (p-AMPK) and acetyl-CoA carboxylase (p-ACC), thereby upregulating the expression of carnitine palmitoyltransferase (CPT)-1 and downregulating the expression of sterol regulatory element-binding protein (SREBP)-1c and fatty acid synthase (FAS). These results demonstrated that ALM16 markedly inhibited HFD-induced hepatic steatosis in NAFLD mice by modulating AMPK and ACC signaling pathways, and may be more effective than the single extracts of AM or LE.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Minjie Lin ◽  
Jungke Long ◽  
Wenbo Li ◽  
Chenxuan Yang ◽  
Patricia Loughran ◽  
...  

Abstract Background Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. Methods Wild type (WT) C57BL/6 and HC-HMGB1−/− mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. Results As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1−/− mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1−/− mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1−/− mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. Conclusions Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.


2016 ◽  
Vol 311 (4) ◽  
pp. G587-G598 ◽  
Author(s):  
Abdul Soofi ◽  
Katherine I. Wolf ◽  
Egon J. Ranghini ◽  
Mohammad A. Amin ◽  
Gregory R. Dressler

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease and is increasing with the rising rate of obesity in the developed world. Signaling pathways known to influence the rate of lipid deposition in liver, known as hepatic steatosis, include the transforming growth factor (TGF) superfamily, which function through the SMAD second messengers. The kielin/chordin-like protein (KCP) is a large secreted protein that can enhance bone morphogenetic protein signaling while suppressing TGF-β signaling in cells and in genetically modified mice. In this report, we show that aging KCP mutant ( Kcp −/−) mice are increasingly susceptible to developing hepatic steatosis and liver fibrosis. When young mice are put on a high-fat diet, Kcp −/− mice are also more susceptible to developing liver pathology, compared with their wild-type littermates. Furthermore, mice that express a Pepck-KCP transgene ( Kcp Tg) in the liver are resistant to developing liver pathology even when fed a high-fat diet. Analyses of liver tissues reveal a significant reduction of P-Smad3, consistent with a role for KCP in suppressing TGF-β signaling. Transcriptome analyses show that livers from Kcp −/− mice fed a normal diet are more like wild-type livers from mice fed a high-fat diet. However, the KCP transgene can suppress many of the changes in liver gene expression that are due to a high-fat diet. These data demonstrate that shifting the TGF-β signaling paradigm with the secreted regulatory protein KCP can significantly alter the liver pathology in aging mice and in diet-induced NAFLD.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Shasha Tao ◽  
Youjing Yang ◽  
Jianzhong Li ◽  
Hongyan Wang ◽  
Yu Ma

Nonalcoholic fatty liver disease is the most common liver disease worldwide. Hepatic steatosis and oxidative stress are the main characteristics of NAFLD (nonalcoholic fatty liver disease), which also affect its prognosis. Bixin acts as novel Nrf2 (NF-E2 p45-related factor 2) activator with the cytoprotection against oxidative stress and inflammation; this study mainly focused on the mechanism of Nrf2 activation by bixin and explored its potential feasibilities in long-term high-fat diet- (HFD-) caused hepatic steatosis and inflammatory response in vitro and in vivo. Bixin was found to activate Nrf2 signals by the modification of critical Keap1 (Kelch-like ECH-associated protein 1) cystine and competitive interaction with Keap1 with upregulating P62 mRNA and protein expression. In human liver cells exposed to FFA (free fatty acid), bixin displayed a pronounced cytoprotective activity with upregulation of Nrf2-mediated gene expression, such as PPARα and its targets related with fatty acid oxidation. In HFD-fed mice, systemic administration of bixin attenuated lipid accumulation, decreased oxidant inflammatory damage in the liver, and reduced circulating lipid levels through Nrf2. Different from most of other established inducers, bixin activated Nrf2 signals through two different mechanisms with safe administration for protection of oxidant inflammatory damage and attenuation of lipid accumulation in the in vivo long-term HFD-fed mice. Bixin represents a prototype Nrf2 activator that displays cytoprotective activity upon system administration targeting hepatic steatosis and oxidant inflammation originating from long-term HFD-fed mice. And bixin-based Nrf2-directed systemic intervention may also provide therapeutic benefit in protecting other organs in the process of metabolic syndrome.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ningjing Zhang ◽  
Junxian Tao ◽  
Lijun Gao ◽  
Yan Bi ◽  
Ping Li ◽  
...  

This study aimed to determine whether modulation of the gut microbiota structure by liraglutide helps improve nonalcoholic fatty liver disease (NAFLD) in rats on a high-fat diet (HFD). Rats were administered an HFD for 12 weeks to induce NAFLD and then administered liraglutide for 4 additional weeks. Next-generation sequencing and multivariate analysis were performed to assess structural changes in the gut microbiota. Liraglutide attenuated excessive hepatic ectopic fat deposition, maintained intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD rats. Liraglutide significantly altered the overall structure of the HFD-disrupted gut microbiota and gut microbial composition in HFD rats in comparison to those on a normal diet. An abundance of 100 operational taxonomic units (OTUs) were altered upon liraglutide administration, with 78 OTUs associated with weight gain or inflammation. Twenty-three OTUs positively correlated with hepatic steatosis-related parameters were decreased upon liraglutide intervention, while 5 OTUs negatively correlated with hepatic steatosis-related parameters were increased. These results suggest that liraglutide-mediated attenuation of NAFLD partly results from structural changes in gut microbiota associated with hepatic steatosis.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoqing Ma ◽  
Wenhua Du ◽  
Shanshan Shao ◽  
Chunxiao Yu ◽  
Lingyan Zhou ◽  
...  

Purpose. We investigated whether a DDP-4 inhibitor, vildagliptin, alleviated ER stress induced by a high fat diet and improved hepatic lipid deposition. Methods. C57BL/6 mice received standard chow diet (CD), high fat diet (HFD), and HFD administered with vildagliptin (50 mg/Kg) (V-HFD). After administration for 12 weeks, serum alanine aminotransferase, glucose, cholesterol, triglyceride, and insulin levels were analyzed. Samples of liver underwent histological examination and transmission electron microscopy, real-time PCR for gene expression levels, and western blots for protein expression levels. ER stress was induced in HepG2 cells with palmitic acid and the effects of vildagliptin were investigated. Results. HFD mice showed increased liver weight/body weight (20.27%) and liver triglycerides (314.75%) compared to CD mice, but these decreased by 9.27% and 21.83%, respectively, in V-HFD mice. In the liver, HFD induced the expression of ER stress indicators significantly, which were obviously decreased by vildagliptin. In vitro, the expressions of molecular indicators of ER stress were reduced in HepG2 when vildagliptin was administered. Conclusions. Vildagliptin alleviates hepatic ER stress in a mouse high fat diet model. In HepG2 cells, vildagliptin directly reduced ER stress. Therefore, vildagliptin may be a potential agent for nonalcoholic fatty liver disease.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2662 ◽  
Author(s):  
Su Ji Bae ◽  
Ji Eun Kim ◽  
Hyeon Jun Choi ◽  
Yun Ju Choi ◽  
Su Jin Lee ◽  
...  

Perilla oil has been considered to have excellent potential for treating various diseases due to its contents of beneficial fatty acids, such as α-linolenic acid, oleic acid and linoleic acid. The therapeutic effects and molecular mechanism of an α-linolenic acid-enriched cold-pressed perilla oil (LEP) on hepatic steatosis of an obesity model were investigated by analyzing alterations in fat accumulation and endoplasmic reticulum (ER) stress-mediated autophagy, in high-fat diet (HFD)-induced obesity C57BL/6N mice treated with LEP for 16 weeks. Although no significant alterations were detected in body weight and most organ weights, the liver weight and accumulation of lipid droplets in the liver section were significantly lower in HFD + LEP treated group as compared to the HFD + Vehicle treated group. Reduced mRNA expression levels of adipogenesis and lipogenesis regulating factors, including the peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein (C/EBP)α, fatty acid synthase (FAS), and adipocyte fatty acid-binding protein 2 (aP2) were observed after LEP treatment for 16 weeks, while the levels of lipolysis were remarkably increased in the same group. Moreover, the LEP-treated groups showed suppression of ER stress-regulating factors, such as the C/EBP homologous protein (CHOP), eukaryotic translation initiation factor 2α (eIF2α), inositol-requiring protein 1 (IRE1)α, and Jun-N-terminal kinase (JNK) during anti-hepatic steatosis effects. The expression level of the microtubule-associated protein 1A/1B-light chain 3 (LC3) protein and phosphatidylinositol-3-kinase (PI3K)/AKT/ mammalian target of rapamycin (mTOR) pathway for the autophagy response showed a significant decrease in the HFD+LEP-treated group. Furthermore, ER stress-mediated autophagy was accompanied with enhanced phosphorylation of extracellular signal-regulated kinase (ERK), JNK, and p38 protein in the mitogen-activated protein (MAP) kinase signaling pathway. Taken together, the results of the present study indicate that treatment with LEP inhibits hepatic steatosis in the HFD-induced obese model through regulation of adipogenesis and lipolysis. We believe our results are the first to show that the anti-hepatic steatosis activity of α-linolenic acid from cold-pressed perilla oil might be tightly correlated with the amelioration of ER stress-mediated autophagy.


2020 ◽  
Author(s):  
Minjie Lin ◽  
Jungke Long ◽  
Wenbo Li ◽  
Chenxuan Yang ◽  
Patricia Loughran ◽  
...  

Abstract Background: Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis.Methods: Wild type (WT) C57BL/6 and HC-HMGB1-/- mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks.Results: As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1-/- mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1-/- mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1-/- mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation.Conclusions: Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.


2020 ◽  
Author(s):  
Minjie Lin ◽  
Jungke Long ◽  
Wenbo Li ◽  
Chenxuan Yang ◽  
Patricia Loughran ◽  
...  

Abstract Background: Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. Methods: Wild type (WT) C57BL/6 and HC-HMGB1-/- mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. Results: As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1-/- mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1-/- mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1-/- mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. Conclusions: Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.


2020 ◽  
Author(s):  
Dan Zhang ◽  
Shan-zhuang Niu ◽  
Yi-cheng Ma ◽  
Bo Zhou ◽  
Yi Deng ◽  
...  

Abstract Background: Fenofibrate is a peroxisome proliferator-activated receptor alpha agonist, which is widely used in clinical practice to effectively ameliorates the development of NAFLD. However, the molecular mechanism remains largely unknown, the present study aimed to investigate the role and specific mechanism of fenofibrate on lipid metabolism disorders associated diseases.Methods: The male C57BL6/J mice were divided into 3 groups, the mice in control group (n=10) were fed with normal chow diet, and the mice in HFD-fed group (n =10) were fed with a high fat diet (HFD) for 14 weeks. For the fenofibrate +HFD-fed group (n =10), the mice fed HFD were orally gavaged with fenofibrate (40 mg/kg) daily for the last 4 weeks. Body weight and hip width were measured. Macrosteatosis and fat deposition in the liver were measured by H&E staining and Oil red O staining individually. The levels of serum and hepatic triglyceride were measured, and HOMA-IR, HOMA-ISI were analyzed. The levels of SCD-1, Bip, CHOP and SERCA2b were measured by western blotting. The expression of let-7 were analyzed by qPCR, and the complementarity between the 3′-UTR of SERCA2b gene and let-7 was measured by luciferase reporter assay.Results: Fenofibrate reduces hepatic steatosis and insulin resistance in HFD-fed mice. Fnofibrate alleviates endoplasmic reticulum stress (ER stress) of mice fed a high fat diet (HFD). Fenofibrate increases the levels of Sarco-endoplasmic reticulum Ca2+-ATPase 2b (SERCA2b) which serves as a regulator of ER stress. Further, the levels of let-7 microRNA is also regulated by fenofibrate, and let-7 directly targets 3’-UTR of SERCA2b. Conclusion: The present data suggests that fenofibrate alleviates ER stress through the let-7/SERCA2b axis to protect against excessive lipid accumulation in the liver of Non-alcoholic fatty liver disease (NAFLD) mice.


Sign in / Sign up

Export Citation Format

Share Document