scholarly journals Baicalin Attenuates High Fat Diet-Induced Obesity and Liver Dysfunction: Dose-Response and Potential Role of CaMKKβ/AMPK/ACC Pathway

2015 ◽  
Vol 35 (6) ◽  
pp. 2349-2359 ◽  
Author(s):  
Youli Xi ◽  
Miaozong Wu ◽  
Hongxia Li ◽  
Siqi Dong ◽  
Erfei Luo ◽  
...  

Background/Aims: Obesity-associated fatty liver disease affects millions of individuals. This study aimed to evaluate the therapeutic effects of baicalin to treat obesity and fatty liver in high fat diet-induced obese mice, and to study the potential molecular mechanisms. Methods: High fat diet-induced obese animals were treated with different doses of baicalin (100, 200 and 400 mg/kg/d). Whole body, fat pad and liver were weighed. Hyperlipidemia, liver steatosis, liver function, and hepatic Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ) / AMP-activated protein kinase (AMPK) / acetyl-CoA carboxylase (ACC) were further evaluated. Results: Baicalin significantly decreased liver, epididymal fat and body weights in high fat diet-fed mice, which were associated with decreased serum levels of triglycerides, total cholesterol, LDL, alanine transaminase and aspartate transaminase, but increased serum HDL level. Pathological analysis revealed baicalin dose-dependently decreased the degree of hepatic steatosis, with predominantly diminished macrovesicular steatosis at lower dose but both macrovesicular and microvesicular steatoses at higher dose of baicalin. Baicalin dose-dependently inhibited hepatic CaMKKβ/AMPK/ACC pathway. Conclusion: These data suggest that baicalin up to 400 mg/kg/d is safe and able to decrease the degree of obesity and fatty liver diseases. Hepatic CaMKKβ/AMPK/ACC pathway may mediate the therapeutic effects of baicalin in high fat diet animal model.

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1440
Author(s):  
Hong Yang ◽  
Jordi Mayneris-Perxachs ◽  
Noemí Boqué ◽  
Josep M. del Bas ◽  
Lluís Arola ◽  
...  

Although the prevalence of non-alcoholic fatty liver disease (NAFLD) continues to increase, there is no effective treatment approved for this condition. We previously showed, in high-fat diet (HFD)-fed mice, that the supplementation of combined metabolic activators (CMA), including nicotinamide riboside (NAD+ precursor) and the potent glutathione precursors serine and N-acetyl-l-cysteine (NAC), significantly decreased fatty liver by promoting fat oxidation in mitochondria. Afterwards, in a one-day proof-of-concept human supplementation study, we observed that this CMA, including also L-carnitine tartrate (LCT), resulted in increased fatty acid oxidation and de novo glutathione synthesis. However, the underlying molecular mechanisms associated with supplementation of CMA have not been fully elucidated. Here, we demonstrated in hamsters that the chronic supplementation of this CMA (changing serine for betaine) at two doses significantly decreased hepatic steatosis. We further generated liver transcriptomics data and integrated these data using a liver-specific genome-scale metabolic model of liver tissue. We systemically determined the molecular changes after the supplementation of CMA and found that it activates mitochondria in the liver tissue by modulating global lipid, amino acid, antioxidant and folate metabolism. Our findings provide extra evidence about the beneficial effects of a treatment based on this CMA against NAFLD.


2015 ◽  
Vol 16 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Nemanja Jovicic ◽  
Ilija Jeftic ◽  
Marina Miletic Kovacevic ◽  
Irena Tanaskovic ◽  
Nebojsa Arsenijevic ◽  
...  

ABSTRACTNon-alcoholic fatty liver disease (NAFLD) is strongly associated with obesity, but the molecular mechanisms of liver steatosis and its progression to non-alcoholic steatohepatitis and fibrosis are incompletely understood. Immune reactivity plays an important role in the pathogenesis of NAFLD. The IL-33/ST2 axis has a protective role in adiposity and atherosclerosis, but its role in obesity-associated metabolic disorders requires further clarification. To investigate the unresolved role of IL-33/ST2 signalling in NAFLD, we used ST2-deficient (ST2-/-) and wild type (WT) BALB/c mice maintained on a high-fat diet (HFD) for 24 weeks. HFD-fed ST2-/- mice exhibited increased weight gain, visceral adipose tissue weight and triglyceridaemia and decreased liver weight compared with diet-matched WT mice. Compared with WT mice on an HFD, ST2 deletion significantly reduced hepatic steatosis, liver inflammation and fibrosis and downregulated the expression of genes related to lipid metabolism in the liver. The frequency of innate immune cells in the liver, including CD68+ macrophages and CD11c+ dendritic cells, was lower in HFD-fed ST2-/- mice, accompanied by lower TNFα serum levels compared with diet-matched WT mice. Less collagen deposition in the livers of ST2-/- mice on an HFD was associated with lower numbers of profibrotic CD11b+Ly6clow monocytes and CD4+IL-17+ T cells in the liver, lower hepatic gene expression of procollagen, IL-33 and IL-13, and lower serum levels of IL-33 and IL-13 compared with diet-matched WT mice.Our findings suggest that the IL-33/ST2 axis may have a complex role in obesity-associated metabolic disorders. Although it is protective in HFD-induced adiposity, the IL-33/ST2 pathway promotes hepatic steatosis, inflammation and fibrosis.


2021 ◽  
Vol 22 (18) ◽  
pp. 9969
Author(s):  
Mariano Schiffrin ◽  
Carine Winkler ◽  
Laure Quignodon ◽  
Aurélien Naldi ◽  
Martin Trötzmüller ◽  
...  

Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargFΔ/Δ) and whole-body PPARγ-null (PpargΔ/Δ) mice. We identified a clear sex dimorphism occurring only in PpargΔ/Δ mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized PpargΔ/Δ mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans.


2019 ◽  
Vol 150 (2) ◽  
pp. 294-302
Author(s):  
Ya-nan Sun ◽  
Jia-qiang Huang ◽  
Zhong-zhou Chen ◽  
Min Du ◽  
Fa-zheng Ren ◽  
...  

ABSTRACT Background Ectopic fat accumulation in skeletal muscle results in dysfunction and atrophy, but the underlying molecular mechanisms remain unclear. Objective The aim of this study was to investigate the effects of a high-fat diet (HFD) in modulating the structure and energy metabolism of skeletal muscle and the underlying mechanisms in mice. Methods Four-week-old male C57BL/6 J mice (n = 30) were allowed 1 wk for acclimatization. After 6 mice with low body weight were removed from the study, the remaining 24 mice were fed with a normal-fat diet (NFD; 10% energy from fat, n = 12) or an HFD (60% energy from fat, n = 12) for 24 wk. At the end of the experiment, serum glucose and lipid concentrations were measured, and skeletal muscle was collected for atrophy analysis, inflammation measurements, and phosphoproteomic analysis. Results Compared with the NFD, the HFD increased (P < 0.05) body weight (35.8%), serum glucose (64.5%), and lipid (27.3%) concentrations, along with elevated (P < 0.05) expressions of the atrophy-related proteins muscle ring finger 1 (MURF1; 27.6%) and muscle atrophy F-box (MAFBX; 44.5%) in skeletal muscle. Phosphoproteomic analysis illustrated 64 proteins with differential degrees of phosphorylation between the HFD and NFD groups. These proteins were mainly involved in modulating cytoskeleton [adenylyl cyclase-associated protein 2 (CAP2) and actin-α skeletal muscle (ACTA1)], inflammation [NF-κB-activating protein (NKAP) and serine/threonine-protein kinase RIO3 (RIOK3)], glucose metabolism [Cdc42-interacting protein 4 (TRIP10); protein kinase C, and casein kinase II substrate protein 3 (PACSIN3)], and protein degradation [heat shock protein 90 kDa (HSP90AA1)]. The HFD-induced inhibitions of the insulin signaling pathway and activations of inflammation in skeletal muscle were verified by Western blot analysis. Conclusions Quantitative phosphoproteomic analysis in C57BL/6 J mice fed an NFD or HFD for 24 wk revealed that the phosphorylation of inflammatory proteins and proteins associated with glucose metabolism at specific serine residues may play critical roles in the regulation of skeletal muscle atrophy induced by an HFD. This work provides information regarding underlying molecular mechanisms for inflammation-induced dysfunction and atrophy in skeletal muscle.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jiayao Yang ◽  
Dongqing Tao ◽  
Wei Ma ◽  
Song Liu ◽  
Yan Liao ◽  
...  

Objective. Sijunzi, Lizhong, and Fuzilizhong decoction were traditional Chinese classic formulations, which are widely used in clinical treatment, and the underlying mechanism is unclear. In this study, we aim to investigate the molecular mechanisms underlying the protective effects of Sijunzi, Lizhong, and Fuzilizhong on nonalcoholic fatty liver disease (NAFLD). Methods. Male Wistar rats were fed a high-fat diet for four weeks to induce NAFLD and were thereafter administered Sijunzi (8 g/kg/d), Lizhong (10 g/kg/d), or Fuzilizhong (10 g/kg/d) by gavage for four weeks. Hepatic damage, lipid accumulation, inflammation, autophagy, and peroxisome proliferator-activated receptor-α signaling were evaluated. Results. The high-fat diet-fed rats showed typical symptoms of NAFLD, including elevated levels of hepatic damage indicators, increased hepatic lipid deposition and fibrosis, severe liver inflammation, and prominent autophagy. Upon administration of Sijunzi, Lizhong, and Fuzilizhong, liver health was improved remarkably, along with ameliorated symptoms of NAFLD. In addition, NAFLD-suppressed peroxisome proliferator-activated receptor-α signaling was reactivated after treatment with the three types of decoctions. Conclusions. The results collectively signify the effective therapeutic and protective functions of Sijunzi, Lizhong, and Fuzilizhong against NAFLD and demonstrate the potential of Chinese herbal medication in mitigating the symptoms of liver diseases. Novelty of the Work. Traditional Chinese herbal medicine has been used for centuries to treat various diseases, but the molecular mechanisms of individual ingredients have rarely been studied. The novelty of our work lies in elucidating the specific signaling pathways involved in the control of NAFLD using three common Chinese herbal decoctions. We suggest that natural herbal formulations can be effective therapeutic agents to combat against NAFLD.


2017 ◽  
Vol 45 (04) ◽  
pp. 813-832 ◽  
Author(s):  
Hyeon-Jeong Kim ◽  
Sanghwa Kim ◽  
Ah Young Lee ◽  
Yoonjeong Jang ◽  
Orkhonselenge Davaadamdin ◽  
...  

This study used an integrated approach to investigate the effects of Gymnema sylvestre (GS) extract as a functional dietary supplement with a high-fat diet. This approach examined insulin resistance, the dysfunction of adipose tissue, and liver steatosis. Male C57BL/6J mice were fed a normal chow or high-fat diet (HFD) for the acute and chronic study, in addition to GS in different doses (100, 250 and 500[Formula: see text]mg/kg body weight). Their body composition changes, serum lipid and glucose parameters, adipose and liver tissue histology, and gene expression were measured. It was found that GS significantly suppressed the increase of body weight, serum levels of lipid, insulin and leptin, and adipose tissue, and liver inflammation. GS also demonstrated hypoglycemic effects due to the amylase inhibition activity. Our results support the existence of a relationship between the HFD induced insulin resistance, adipose dysfunction and liver steatosis. In conclusion, GS works as a functional dietary supplement with preventative effects against metabolic disorder.


2020 ◽  
Author(s):  
Ada Admin ◽  
Chenghui Yan ◽  
Xiaoxiang Tian ◽  
Jiayin Li ◽  
Dan Liu ◽  
...  

Exosomes are important for intercellular communication, but the role of exosomes in the communication between adipose tissue (<a>AT</a>) and the liver remains unknown. The aim of this study is to determine the contribution of AT-derived exosomes in nonalcoholic fatty liver disease (<a>NAFLD</a>). Exosome components, liver fat content, and liver function were monitored in AT in mice fed a <a>high-fat diet </a>(<a>HFD</a>) or treated with metformin- or GW4869 and with AMP-activated protein kinase (AMPKα1)<i> </i>floxed<i> (Prkaα1</i><sup>fl/fl</sup>/WT), <a><i>Prkaα1</i><sup>-/-</sup></a>, liver tissue-specific <i>Prkaα1</i><sup>-/-</sup>, or AT-specific <i>Prkaα1</i><sup>-/-</sup> modification. In cultured adipocytes and white adipose tissue (WAT), the absence of <a><i>AMPKα1</i></a> increased exosome release and exosomal proteins by elevating <a>tumor susceptibility gene 101 (<i>TSG101</i></a>)-mediated exosome biogenesis. In adipocytes treated with palmitic acid, TSG101 facilitated scavenger receptor class B (CD36) sorting into exosomes. CD36-containing exosomes were then endocytosed by hepatocytes to induce lipid accumulation and inflammation. Consistently, an HFD induced more severe lipid accumulation and cell death in <a><i>Prkaα1</i><sup>-/-</sup> </a>and adipose tissue-specific <i>Prkaα1</i><sup>-/-</sup> mice than in WT and liver-specific <i>Prkaα1</i><sup>-/-</sup> mice. AMPK activation by metformin reduced adipocyte-mediated exosome release and mitigated fatty liver development in WT and liver specific <i>Prkaα1</i><sup>-/-</sup> mice. Moreover, administration of the exosome inhibitor GW4869 blocked exosome secretion and alleviated HFD-induced fatty livers in <i>Prkaα1</i><sup>-/-</sup> and adipocyte-specific <i>Prkaα1</i><sup>-/-</sup> mice. We conclude that HFD-mediated AMPKα1 inhibition promotes NAFLD by increasing numbers of AT C<a>D36</a>-containing exosomes.


2019 ◽  
Vol 150 (4) ◽  
pp. 672-684 ◽  
Author(s):  
Lingyan Ye ◽  
Zheng Cao ◽  
Xiangru Lai ◽  
Ying Shi ◽  
Naiming Zhou

ABSTRACT Background Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. Hepatic de novo lipogenesis (DNL) has been suggested to contribute to the pathogenesis of NAFLD. Recent studies have demonstrated that niacin (NA) modulates hepatic DNL through GPR109A. However, the underlying mechanism remains largely unknown. Objectives This study aims to elucidate the potential molecular mechanism by which GPR109A inhibits hepatic DNL. Methods C57BL/6 wild-type (WT) and Gpr109a knockout (KO) mice (male, 5 wk old) were fed a high-fat diet (60% energy from fat) firstly for 6 wk to generate a diet-induced obese model. Subsequently, they were randomly divided into 4 groups for the next 8–9 wk: WT mice with oral water [WT + vehile (VE)], WT mice with oral NA (50 mM, dissolved in water) (WT + NA), KO mice with oral water (KO + VE), and KO mice with oral NA (50 mM) (KO + NA). Mechanisms were examined in HepG2 cells. Body composition, liver histology, biomarkers of hepatic function, lipid accumulation, and lipid synthesis signals in HepG2 cells were measured. Results Upon activation, GPR109A apparently protected against obesity and hepatic steatosis (P &lt; 0.05). The concentrations of hepatic Tnf-α in the WT + NA group were about 50% of those in the WT + VE group (P &lt; 0.05). The activities of serum alanine transaminase and aspartate transaminase were 26.7% and 53.5% lower in the WT + NA group than in the WT + VE group, respectively (P &lt; 0.05). In HepG2 cells, activation of GPR109A resulted in remarkable inhibition of oleic acid–induced lipid accumulation via a protein kinase C–extracellular signal-regulated kinase-1/2–AMP-activated protein kinase signaling pathway. Conclusions NA inhibits hepatic lipogenesis in C57BL/6 mice through a GPR109A-mediated signaling pathway, consistent with the mechanistic studies in HepG2 cells, suggesting its potential for treatment of NAFLD and other fatty liver diseases.


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