High-fat Diet-induced Fatty Liver Research Articles

Lack of adipocyte FAM20C improves whole body glucose homeostasis.

FAM20C, a member of the family with sequence similarity 20, is involved in many physiological functions. Obesity, characterized by excessive accumulation of adipose tissue, has attracted more and more attention as a worldwide health problem. Here we generated adipocyte-specific FAM20C knockout mice to investigate the role of FAM20C in adipose tissue expansion and obesity. Our results demonstrate that knockout mice are protected against high fat diet-induced obesity, adiposity, and fatty liver disease. Additionally, knockout mice exhibited improved metabolic phenotypes, including enhanced glucose tolerance and insulin sensitivity compared with control mice. Furthermore, we observed reduced inflammatory infiltration and collagen deposition in the adipose tissues of knockout mice. Taken together, our results indicate that targeting FAM20C in adipocytes may be a promising strategy for the treatment of obesity and associated metabolic disorders.

Curcumol ameliorates alcohol and high-fat diet-induced fatty liver disease via modulation of the Ceruloplasmin/iron overload/mtDNA signaling pathway.

Fatty liver disease (FLD), a chronic liver disease characterized by excessive lipid deposition, is affecting more and more people worldwide owing to the increasing global incidence of obesity and heavy alcohol consumption. However, there is still no effective strategy for prevention or treatment of alcohol and high-fat diet (HFD)-induced FLD. The purpose of this study was to investigate the effect of curcumol on alcohol and HFD-induced FLD and the underlying molecular mechanisms. The results showed that curcumol ameliorated alcohol and HFD-induced hepatocyte injury in vivo and in vitro, and the mechanism might be related to its up-regulation of ceruloplasmin and subsequent alleviation of iron overload. Moreover, curcumol inhibited alcohol and HFD-induced mitochondrial damage and mtDNA release in hepatocytes by modulating iron overload. Furthermore, curcumol's inhibition of mtDNA release could suppress the activation of cGAS-STING and subsequent inflammation, and this phenomenon could be reversed by cGAS overexpression. Notably, alcohol and HFD-induced mtDNA release from hepatocytes contributed to HSC activation and this effect could be weakened by curcumol. In conclusion, these findings elucidated that curcumol ameliorated alcohol and HFD-induced FLD via modulating ceruloplasmin/iron overload/mtDNA signaling pathway, which lead to the inhibition of inflammation and HSCs activation.

Ovothiol-A Mitigates High-Fat Diet-Induced Non-alcoholic Fatty Liver Disease in Rats

Background: Obesity is frequently linked to multiple comorbid and chronic illnesses, including non-alcoholic fatty liver disease, type 2 diabetes, cancer, and heart disease. Ovothiol-A is one of the most powerful natural antioxidants found in marine invertebrates like sea urchins. Objective: The current study aimed to investigate ovothiol-A's hypolipidemic and hypoglycemic potential in obese rats. Methods: All groups get a high-fat diet (HFD) for four weeks except for the control group. The control and HFD groups received distilled water, while the Ovothiol-A groups received two doses of Ovothiol-A (200 and 400 mg/kg orally) concurrent with HFD. Results: Weight gain, glucose, insulin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, total cholesterol, triglycerides, low-density lipoprotein, malondialdehyde, and nitric oxide were all decreased after oral administration of Ovo at either the 200 or 400 mg/kg dose, while levels of high-density lipoprotein (HDL), glutathionereduced, catalase and glutathione-S-transferase increased. Histopathological alterations were less noticeable in the liver tissue of Ovothiol-A groups, with only a few vacuolated or pyknotic nuclei amongst a few dispersed hepatocytes. Conclusion: The current findings indicate that ovothiol-A protects against high-fat diet-induced fatty liver in rats. The anti-obesity mechanism of Ovothiol-A is associated with its hypolipidemic, hypoglycemic, and antioxidant properties.

SENP1 prevents high fat diet-induced non-alcoholic fatty liver diseases by regulating mitochondrial dynamics

Mitochondrial dynamics plays a crucial role in the occurrence and development of non-alcoholic fatty liver diseases (NAFLD). SENP1, a SUMO-specific protease, catalyzes protein de-SUMOylation and involves in various physiological and pathological processes. However, the exact role of SENP1 in NAFLD remains unclear. Therefore, we investigated the regulatory role of SENP1 in mitochondrial dynamics during the progression of NAFLD. In the study, the NAFLD in vivo model induced by high fat diet (HFD) and in vitro model induced by free fatty acids (FFA) were established to investigate the role and underlying mechanism of SENP1 through detecting mitochondrial morphology and dynamics. Our results showed that the down-regulation of SENP1 expression and the mitochondrial dynamics dysregulation occurred in the NAFLD, evidenced as mitochondrial fragmentation, up-regulation of p-Drp1 ser616 and down-regulation of MFN2, OPA1. However, over-expression of SENP1 significantly alleviated the NAFLD, rectified the mitochondrial dynamics disorder, reduced Cyt-c release and ROS levels induced by FFA or HFD; moreover, the over-expression of SENP1 also reduced the SUMOylation levels of Drp1 and prevented the Drp1 translocation to mitochondria. Our findings suggest that the possible mechanisms of SENP1 were through rectifying the mitochondrial dynamics disorder, reducing Cyt-c release and ROS-mediated oxidative stress. The findings would provide a novel target for the prevention and treatment of NALFD.

TBHQ mitigates fatty liver ischemia–reperfusion injury by activating Nrf2 to attenuate hepatocyte mitochondrial damage and macrophage STING activation

BackgroundLiver ischemia–reperfusion (IR) injury is an inevitable pathophysiological process in various liver surgeries. Previous studies have found that IR injury is exacerbated in fatty liver due to significant hepatocellular damage and macrophage inflammatory activation, though the underlying mechanisms are not fully understood. In this study, we aim to explore the role and mechanism of Nrf2 (Nuclear factor erythroid 2-related factor 2) signaling in regulating hepatocellular damage and macrophage immune response in fatty liver IR injury. MethodsThe study used high-fat diet-induced fatty liver mice to establish an IR model, alongside an in vitro co-culture system of primary hepatocytes and macrophages. This approach was used to examine mitochondrial dysfunction, oxidative stress, mitochondrial DNA (mtDNA) release, and activation of macrophage STING (Stimulator of interferon genes) signaling. We also conducted recovery verification using H-151 (a STING inhibitor) and tBHQ (an Nrf2 activator). ResultsCompared to the control group, mice on a high-fat diet demonstrated more severe liver IR injury, as evidenced by increased histological damage, elevated liver enzyme levels, and heightened inflammatory markers. The HFD group showed significant oxidative stress and mitochondrial dysfunction and damage post-IR, as indicated by elevated levels of ROS and lipid peroxidation markers, and decreased antioxidant enzyme activity. Elevated mtDNA release from hepatocytes post-IR activated macrophage STING signaling, worsening inflammation and liver damage. However, STING signaling inhibition with H-151 in vivo or employing STING knockout macrophages significantly reduced these injuries. In-depth mechanism studies have found that the transfer of Nrf2 protein into the nucleus of liver cells after IR in fatty liver is reduced. Pre-treatment with tBHQ ameliorated liver oxidative stress, mitochondrial damage and suppressed the macrophage STING signaling activation. ConclusionsOur study reveals a novel mechanism where the interaction between hepatocellular damage and macrophage inflammation intensifies liver IR injury in fatty liver. Enhancing Nrf2 activation to protect mitochondrial from oxidative stress damage and inhibiting macrophage STING signaling activation emerge as promising strategies for clinical intervention in fatty liver IR injury.

Loss-of-function G6PD variant moderated high-fat diet-induced obesity, adipocyte hypertrophy, and fatty liver in male rats

Obesity is a major risk factor for liver and cardiovascular diseases. However, obesity-driven mechanisms that contribute to the pathogenesis of multiple organ diseases are still obscure and treatment is inadequate. We hypothesized that increased glucose-6-phosphate dehydrogenase (G6PD), the key rate-limiting enzyme in the pentose shunt, is critical in evoking metabolic reprogramming in multiple organs and is a significant contributor to the pathogenesis of liver and cardiovascular diseases. G6PD is induced by carbohydrate-rich diet and insulin. Long-term (8 months) high-fat diet (HFD) feeding increased body weight and elicited metabolic reprogramming in visceral fat, liver, and aorta, of the wild-type rats. In addition, HFD increased inflammatory chemokines in visceral fat. Interestingly, CRISPR-edited loss-of-function Mediterranean G6PD variant (G6PDS188F) rats, which mimic human polymorphism, moderated HFD-induced weight gain and metabolic reprogramming in visceral fat, liver, and aorta. The G6PDS188F variant prevented HFD-induced CCL7 and adipocyte hypertrophy. Furthermore, the G6PDS188F variant increased Magel2 – a gene encoding circadian clock-related protein that suppresses obesity associated with Prader-Willi syndrome – and reduced HFD-induced non-alcoholic fatty liver. Additionally, the G6PDS188F variant reduced aging-induced aortic stiffening. Our findings suggest G6PD is a regulator of HFD-induced obesity, adipocyte hypertrophy, and fatty liver.

Platycodi Radix Extract Prevents Hepatic Steatosis by Enhancing Bile Acid Synthesis in a High-Fat Diet-Induced Fatty Liver Mouse Model.

We aimed to identify the mechanism underlying the preventive effects of non-alcoholic fatty liver disease (NAFLD) through Platycodi Radix consumption using liver proteomic and bioinformatic analysis. C57BL/6J mice were categorized into three groups: those receiving a standard chow diet (NCD), those on a high-fat diet (HFD), and those on an HFD supplemented with 5% Platycodi Radix extract (PRE). After a 12-week period, PRE-fed mice exhibited a noteworthy prevention of hepatic steatosis. Protein identification and quantification in liver samples were conducted using LC-MS/MS. The identified proteins were analyzed through Ingenuity Pathway Analysis software, revealing a decrease in proteins associated with FXR/RXR activation and a concurrent increase in cholesterol biosynthesis proteins in the PRE-treated mouse liver. Subsequent network analysis predicted enhanced bile acid synthesis from these proteins. Indeed, the quantity of bile acids, which was reduced in HFD conditions, increased in the PRE group, accompanied by an elevation in the expression of synthesis-related proteins. Our findings suggest that the beneficial effects of PRE in preventing hepatic steatosis may be mediated, at least in part, through the modulation of FXR/RXR activation, cholesterol biosynthesis, and bile acid synthesis pathways.

Reducing brain Aβ burden ameliorates high-fat diet-induced fatty liver disease in APP/PS1 mice

High-fat diet (HFD)-induced fatty liver disease is a deteriorating risk factor for Alzheimer’s disease (AD). Mitigating fatty liver disease has been shown to attenuate AD-like pathology in animal models. However, it remains unclear whether enhancing Aβ clearance through immunotherapy would in turn attenuate HFD-induced fatty liver or whether its efficacy would be compromised by long-term exposure to HFD. Here, the therapeutic potentials of an anti-Aβ antibody, NP106, was investigated in APP/PS1 mice by HFD feeding for 44 weeks. The data demonstrate that NP106 treatment effectively reduced Aβ burden and pro-inflammatory cytokines in HFD-fed APP/PS1 mice and ameliorated HFD-aggravated cognitive impairments during the final 18 weeks of the study. The rejuvenating characteristics of microglia were evident in APP/PS1 mice with NP106 treatment, namely enhanced microglial Aβ phagocytosis and attenuated microglial lipid accumulation, which may explain the benefits of NP106. Surprisingly, NP106 also reduced HFD-induced hyperglycemia, fatty liver, liver fibrosis, and hepatic lipids, concomitant with modifications in the expressions of genes involved in hepatic lipogenesis and fatty acid oxidation. The data further reveal that brain Aβ burden and behavioral deficits were positively correlated with the severity of fatty liver disease and fasting serum glucose levels. In conclusion, our study shows for the first time that anti-Aβ immunotherapy using NP106, which alleviates AD-like disorders in APP/PS1 mice, ameliorates fatty liver disease. Minimizing AD-related pathology and symptoms may reduce the vicious interplay between central AD and peripheral fatty liver disease, thereby highlighting the importance of developing AD therapies from a systemic disease perspective.

The comparison of the effects of nano-silymarin and silymarin on high-fat diet-induced fatty liver of adult male rats.

Considering the high prevalence of non-alcoholic fatty liver disease and its complications, this study aims to determine and compare the effect of nano-silymarin and silymarin on non-alcoholic fatty liver in rats. Rats were divided into 5 groups: Control, high-fat diet, high-fat diet and atorvastatin, high-fat diet and silymarin, and high-fat diet and nano-silymarin. After 12 weeks, blood samples were taken to measure cholesterol, triglyceride, HDL, LDL, ALT and AST. The animals were killed and the liver tissue was removed to examine the histopathological changes. Feeding with a high-fat diet caused a significant increase in cholesterol, triglyceride and LDL-C in serum of rats compared to the control. Nano-silymarin and silymarin could significantly reduce serum triglyceride compared to negative group but the reduction of cholesterol, LDL-C, AST and ALT by nano-silymarin was not significant as compared to silymarin. The liver histology evaluation mainly showed that in the group receiving nano-silymarin, a significant decrease in the percentage of fat vacuoles and degree of steatosis was observed compared to the negative group. In the positive group, the percentage of fat vacuoles and the degree of steatosis showed a significant decrease compared to the negative group. Group receiving atorvastatin showed a greater protective effect than silymarin and nano-silymarin. The use of nano-silymarin similar to silymarin in rats treated with a high-fat diet led to a decrease in the percentage of fat vacuoles and the degree of hepatic steatosis mainly and can be used to prevent non-alcoholic fatty liver disease.

Escherichia coli NF73-1 disrupts the gut-vascular barrier and aggravates high-fat diet-induced fatty liver disease via inhibiting Wnt/β-catenin signalling pathway.

Gut-vascular barrier (GVB) dysfunction has been shown to be a prerequisite for nonalcoholic fatty liver disease (NAFLD) development. However, the causes of GVB disruption and the underlying mechanisms are still elusive. Here, we explored whether and how Escherichia coli (E. coli) NF73-1, a pathogenic E. coli strain isolated from nonalcoholic steatohepatitis patients, contributes to NAFLD by modulating the GVB. C57BL/6J mice were fed with high-fat diet (HFD) or normal diet in the presence or absence of E. coli NF73-1 for the indicated time periods. Intestinal barrier function and infiltration of immune cells were evaluated in these mice. Endothelial cells were exposed to E. coli NF73-1 for barrier integrity analysis. HFD-induced GVB disruption preceded the damage of intestinal epithelial barrier (IEB) as well as intestinal and hepatic inflammatory changes and can be reversed by vascular endothelial growth factor A blockade. Antibiotic treatment prevented mice from HFD-induced liver steatosis by restoration of the GVB. Notably, E. coli NF73-1 caused a more conspicuous damage of GVB than that of the IEB and contributed to NAFLD development. Mechanistically, E. coli NF73-1 dismantled the GVB by inhibiting the Wnt/β-catenin signalling pathway. Activation of Wnt/β-catenin improved the GVB and impeded the translocation of E. coli NF73-1 into the liver invitro and invivo. E. coli NF73-1 disrupts GVB and aggravates NAFLD via inhibiting the Wnt/β-catenin signalling pathway. Targeting E. coli NF73-1 or selectively enhancing the GVB may act as potential avenues for the prevention and treatment of NAFLD.

Knocking out Fkbp51 decreases CCl4-induced liver injury through enhancement of mitochondrial function and Parkin activity

Background and aimsPreviously, we found that FK506 binding protein 51 (Fkbp51) knockout (KO) mice resist high fat diet-induced fatty liver and alcohol-induced liver injury. The aim of this research is to identify the mechanism of Fkbp51 in liver injury.MethodsCarbon tetrachloride (CCl4)-induced liver injury was compared between Fkbp51 KO and wild type (WT) mice. Step-wise and in-depth analyses were applied, including liver histology, biochemistry, RNA-Seq, mitochondrial respiration, electron microscopy, and molecular assessments. The selective FKBP51 inhibitor (SAFit2) was tested as a potential treatment to ameliorate liver injury.ResultsFkbp51 knockout mice exhibited protection against liver injury, as evidenced by liver histology, reduced fibrosis-associated markers and lower serum liver enzyme levels. RNA-seq identified differentially expressed genes and involved pathways, such as fibrogenesis, inflammation, mitochondria, and oxidative metabolism pathways and predicted the interaction of FKBP51, Parkin, and HSP90. Cellular studies supported co-localization of Parkin and FKBP51 in the mitochondrial network, and Parkin was shown to be expressed higher in the liver of KO mice at baseline and after liver injury relative to WT. Further functional analysis identified that KO mice exhibited increased ATP production and enhanced mitochondrial respiration. KO mice have increased mitochondrial size, increased autophagy/mitophagy and mitochondrial-derived vesicles (MDV), and reduced reactive oxygen species (ROS) production, which supports enhancement of mitochondrial quality control (MQC). Application of SAFit2, an FKBP51 inhibitor, reduced the effects of CCl4-induced liver injury and was associated with increased Parkin, pAKT, and ATP production.ConclusionsDownregulation of FKBP51 represents a promising therapeutic target for liver disease treatment.Graphical

Kadukkai maathirai (Siddha herbal formulation) reverses liver pathology associated with metabolic dysfunction in high fat diet-induced fatty liver disease – a preclinical study

The study explores the hepatoprotective effect of Kadukkai maathirai (KM) in high fat diet (HFD) induced nonalcoholic fatty liver disease (NAFLD) in rats. Total 54 Sprague Dawley rats were used in the study, 9 groups: Group I – IV kept as normal and test drug control and group V - NAFLD disease model- received HFD for 40 weeks. Group VI – IX received HFD for 40 weeks and then test drugs: Group VI – VIII received KM in three different doses for 45 days. Metformin (standard) was administered to Group IX for 45 days. On day 46, the blood and liver tissue were collected for analysis. KM at 36, 144mg/kg and metformin showed a significant decrease in ALP level, all three doses of KM and metformin showed a significant reduction in direct bilirubin levels. A significant improvement in HDL was observed in all doses of KM and metformin-treated groups. Oral glucose tolerance test (OGTT) findings in KM treated test groups showed significantly reduced plasma glucose levels. The KM treated groups and metformin-treated groups showed a reduction in body weight at 47th week, and significantly reduced relative liver weight when compared with the HFD group. Histopathological evaluation of KM treated groups showed normal architecture of central vein and hepatic cords. Portal triads were also generally normal in their location and pattern. No indication of fatty liver. This study confirms the ability of phytoconstituents present in KM in reversing the metabolic dysfunction and liver pathology seen in NAFLD. Further studies are required to evaluate KM as a therapeutic agent.

Hepatoprotective Effect of Lactiplantibacillus plantarum DSR330 in Mice with High Fat Diet-Induced Nonalcoholic Fatty Liver Disease.

Lactiplantibacillus plantarum DSR330 (DSR330) has been examined for its antimicrobials production and probiotics. In this study, the hepatoprotective effects of DSR330 were examined against non-alcoholic fatty liver disease (NAFLD) in a high-fat diet (HFD)-fed C57BL/6 mouse model. To induce the development of fatty liver, a HFD was administered for five weeks, and then silymarin (positive control) or DSR330 (108 or 109 CFU/day) was administered along with the HFD for seven weeks. DSR330 significantly decreased body weight and altered serum and hepatic lipid profiles, including a reduction in triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels compared to those in the HFD group. DSR330 significantly alleviated HFD-related hepatic injury by inducing morphological changes and reducing the levels of biomarkers, including AST, ALT, and ALP. Additionally, DSR330 alleviated the expression of SREBP-1c, ACC1, FAS, ACO, PPARα, and CPT-1 in liver cells. Insulin and leptin levels were decreased by DSR330 compared to those observed in the HFD group. However, adiponectin levels were increased, similar to those observed in the ND group. These results demonstrate that L. plantarum DSR330 inhibited HFD-induced hepatic steatosis in mice with NAFLD by modulating various signaling pathways. Hence, the use of probiotics can lead to hepatoprotective effects.

Lusianthridin ameliorates high fat diet-induced metabolic dysfunction-associated fatty liver disease via activation of FXR signaling pathway.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common chronic liver disease, but there are few specific medications for it. Lusianthridin, a major phenanthrene component that originates from Dendrobium Sonia, has various in vitro biological functions. In this study, we aimed to evaluate the therapeutic effects of lusianthridin on high-fat diet (HFD)-induced MAFLD as well as to examine the mechanism of its effects. We fed male mice high-fat-diet for 12 weeks to induce MAFLD and then continued to feed them, either with or without lusianthridin, for another six weeks. We found that lusianthridin decreased serum triacylglycerol, hepatic triacylglycerol, and serum low density lipoprotein cholesterol. It also reduced hepatic lipid accumulation based on the results of morphology analysis. Besides, it improved hepatic inflammation as well, including a decrease in serum alanine aminotransferase and a reduction in macrophage and neutrophil infiltration. Mechanistically, surface plasmon resonance, cell thermal shift assay and dual-luciferase report system results suggested that lusianthridin combined with farnesoid X receptor (FXR) ligand binding region and activated its transcriptional activity. Lusianthridin also decreased de no lipogenesis though inhibiting Srebp1c and downstream Scd-1, Lpin1 and Dgat2 expression in a FXR-dependent manner in oleic acid treated L02 cells. Correspondingly, lusianthridin inhibited Srebp1c and downstream lipogenesis in MAFLD liver tissues of mice at both of genetic and protein levels. Finally, the protective effects of lusianthridin on hepatic steaotosis were abolished in Fxr−/− mice. Taken together, our results suggested that lusianthridin attenuated high-fat-diet induced MAFLD via activation the FXR signaling pathway.

Shenge Formula attenuates high-fat diet-induced obesity and fatty liver via inhibiting ACOX1

BackgroundNonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. Shenge Formula (SGF) is a traditional Chinese medicine that has been used in the clinical treatment of NAFLD, and its therapeutic potential in patients and NAFLD animal models has been demonstrated in numerous studies. However, its underlying mechanism for treating NAFLD remains unclear. PurposeThe aim of this study was to investigate the mechanism of SGF in the treatment of NAFLD using the proteomics strategy. MethodsUltra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to determine the main components of SGF. A mouse model of nonalcoholic fatty liver disease was constructed by feeding mice with a high-fat diet for 16 weeks. SGF was administered for an additional 8 weeks, and metformin was used as a positive control. Liver sections were subjected to histopathological assessments. LC-MS/MS was used for the label-free quantitative proteomic analysis of liver tissues. Candidate proteins and pathways were validated both in vivo and in vitro through qRT-PCR, western blot, and immunohistochemistry. The functions of the validated pathways were further investigated using the inhibition strategy. ResultsThirty-nine ingredients were identified in SGF extracts, which were considered to be key compounds in the treatment of NAFLD. SGF administration attenuated obesity and fatty liver by reducing the body weight and liver weight in HFD-fed mice. It also relieved HFD-induced insulin resistance. More importantly, hepatic steatosis was significantly attenuated by SGF administration both in vivo and in vitro. Proteomic profiling of mouse liver tissues identified 184 differential expressed proteins (DEPs) associated with SGF treatment. Bioinformatic analysis of DEPs revealed that regulating the lipid metabolism and energy consumption process of hepatocytes was the main role of SGF in NAFLD treatment. This also indicated that ACOX1 might be the potential target of SGF, which was subsequently verified both in vitro and in vivo. The results demonstrated that SGF inhibited ACOX1 activity, thereby activating PPARα and upregulating CPT1A expression. Increased CPT1A expression promoted mitochondrial β-oxidation, leading to reduced lipid accumulation in hepatocytes. ConclusionsOverall, our findings confirmed the protective effect of SGF against NAFLD and revealed the underlying molecular mechanism of regulating lipid metabolism.

Comparative analysis of the synergetic effects of Diwuyanggan prescription on high fat diet-induced non-alcoholic fatty liver disease using untargeted metabolomics

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders worldwide and had no approved pharmacological treatments. Diwuyanggan prescription (DWYG) is a traditional Chinese medicine preparation composed of 5 kinds of herbs, which has been used for treating chronic liver diseases in clinic. Whereas, the synergistic mechanism of this prescription for anti-NAFLD remains unclear. In this study, we aimed to demonstrate the synergetic effect of DWYG by using the disassembled prescriptions and untargeted metabolomics research strategies. The therapeutic effects of the whole prescription of DWYG and the individual herb were divided into six groups according to the strategy of disassembled prescriptions, including DWYG, Artemisia capillaris Thunb. (AC), Curcuma longa L. (CL), Schisandra chinensis Baill. (SC), Rehmannia glutinosa Libosch. (RG) and Glycyrrhiza uralensis Fisch. (GU) groups. The high fat diets-induced NAFLD mice model was constructed to evaluate the efficacy effects of DWYG. An untargeted metabolomics based on the UPLC-QTOF-MS/MS approach was carried out to make clear the synergetic effect on the regulation of metabolites dissecting the united mechanisms. Experimental results on animals revealed that the anti-NAFLD effect of DWYG prescription was better than the individual herb group in reducing liver lipid deposition and restoring the abnormality of lipidemia. In addition, further metabolomics analysis indicated that 23 differential metabolites associated with the progression of NAFLD were identified and 19 of them could be improved by DWYG. Compared with five single herbs, DWYG showed the most extensive regulatory effects on metabolites and their related pathways, which were related to lipid and amino acid metabolisms. Besides, each individual herb in DWYG was found to show different degrees of regulatory effects on NAFLD and metabolic pathways. SC and CL possessed the highest relationship in the regulation of NAFLD. Altogether, these results provided an insight into the synergetic mechanisms of DWYG from the metabolic perspective, and also supported a scientific basis for the rationality of clinical use of this prescription.

Bioactive dipeptides mitigate high-fat and high-fructose corn syrup diet-induced metabolic-associated fatty liver disease via upregulation of Nrf2/HO-1 expressions in C57BL/6J mice

Metabolic-associated fatty liver disease (MAFLD), formerly referred to as non-alcoholic fatty liver disease (NAFLD), is a common liver disease characterized by an abnormal buildup of fat in liver. This study aimed to investigate whether bioactive dipeptides mitigate high-fat and high-fructose corn syrup diet (HFFD)-induced MAFLD in C57BL/6J mice. Sixty male C57BL/6J mice were randomly divided into six groups. The naïve group (untreated) was fed a standard chow diet and other groups were fed with HFFD along with vehicle and bioactive dipeptides treatment throughout experiment period. The control group received vehicle, YF10 and YF50 groups received Tyr-Phe, 10 and 50 mg/kg/day, FY10 and FY50 groups received Phe-Tyr, 10 and 50 mg/kg/day. At the end of experiment, body weight was recorded, and glucose homeostasis was assessed. Mice were sacrificed and blood samples were collected to measure biochemical parameters. Further, liver, visceral fat pads, and other organs were acutely dissected, weighed, and processed. Histopathological and immunohistochemical changes were analyzed. Long-term HFFD feeding resulted in elevated body weight gain, liver weight, visceral adiposity, liver injury, fasting hyperglycemia, hyperinsulinemia, and hyperlipidemia. It also increased severe hepatic steatosis, chronic low-grade inflammation, oxidative stress, mitochondrial dysfunction, and lipid peroxidation. However, bioactive dipeptides dose-dependently alleviated these complications which are associated with MAFLD by modulating adipokines secretion and antioxidant defense system via upregulation of Nrf2/HO-1 expressions. This study highlights potential of bioactive dipeptides as a promising approach for prevention and/or treatment of MAFLD induced by HFFD, providing novel insights into alternative therapeutic strategies.

Oxymatrine relieves high-fructose/fat-induced obesity via reprogramming the activity of lipid metabolism-related enhancer.

Emerging evidence demonstrates that the high-fructose and high-fat diet (HFHF) induced obesity and fatty liver disease has become one of the most common metabolic disorders worldwide. Therefore, innovative investigations on compounds targeting obesity and fatty liver diseases are urgently needed. The high-throughput natural compounds screen was performed to screen the important compounds. A rat HFHF model was constructed, the regulatory function of Oxymatrine in HFHF-induced obesity was further explored. We identified Oxymatrine, a natural compound extracted from Sophora flavescens, showed a potential compacity in high-fat diet-induced fatty liver disease. We found that oxymatrine significantly inhibited HFHF-induced obesity using a rat HFHF model. Additionally, we found that oxymatrine altered the enhancer landscape of subcutaneous adipose tissues by ChIP-seq analysis using antibodies against the H3K27ac histone modification. Motif enrichment analysis showed the Smad motif was significantly enriched in enhancers altered post-oxymatrine treatment. Further chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) analysis and luciferase reporter assays showed oxymatrine alters the binding of Smad3 on the enhancer regions of B-cell lymphoma 2 (Bcl2) and the enhancer activity of Bcl2. Together, our study highlighted oxymatrine could suppress high-fructose and high-fat diet-induced obesity by inhibiting the suppressor of mothers against decapentaplegic 3 (Smad3) binding on obesity-related enhancers.

Therapeutic Effect of Prolyl Endopeptidase Inhibitor in High-fat Diet-induced Metabolic Dysfunction-associated Fatty Liver Disease.

Prolyl endopeptidase (PREP) is a serine endopeptidase that participates in many pathological processes including inflammation, oxidative stress, and autophagy. Our previous studies found that PREP knockout exhibited multiple benefits in high-fat diet (HFD) or methionine choline-deficient diet-induced metabolic dysfunction-associated fatty liver disease (MAFLD). However, cumulative studies have suggested that PREP performs complex functions during disease development. Therefore, further understanding the role of PREP in MAFLD development is the foundation of PREP intervention. In this study, an HFD-induced MAFLD model at different time points (4, 8, 12, and 16 weeks) was used to explore dynamic changes in the PREP proline-glycine-proline (PGP)/N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) system. To explore its potential value in MAFLD treatment, saline, or the PREP inhibitor, KYP-2047, was administered to HFD-induced MAFLD mice from the 10th to 16th weeks. PREP activity and expression were increased in HFD-mice compared with control mice from the 12th week onwards, and increased PREP mainly resulted in the activation of the matrix metalloproteinase 8/9 (MMP8/9)-PREP-PGP axis rather than the thymosin β4-meprin α/PREP-AcSDKP axis. In addition, KYP-2047 reduced HFD-induced liver injury and oxidative stress, improved lipid metabolism through the suppression of lipogenic genes and the induction of β-oxidation-related genes, and attenuated hepatic inflammation by decreasing MMP8/9 and PGP. Moreover, KYP2047 restored HFD-induced impaired autophagy and this was verified in HepG2 cells. These findings suggest that increased PREP activity/expression during MAFLD development might be a key factor in the transition from simple steatosis to steatohepatitis, and KYP-2047 might possess therapeutic potential for MAFLD treatment.

Liver-derived FGF21 is required for the effect of time-restricted feeding on high-fat diet-induced fatty liver in mice.

Nonalcoholic fatty liver disease (NAFLD), which leads to insulin resistance, steatosis, and even hepatocellular carcinoma, is the most common chronic liver disease worldwide, however, effective treatment is still lacking. This study determined the role of liver FGF21 and the mechanisms underlying the protective effects of time-restricted feeding (TRF) in NAFLD. FGF21 liver knockout (FGF21 LKO) mice and C57BL/6 wild-type (WT) mice were fed either a normal or a high-fat diet (HFD) for 16 weeks. Mice with diet-induced obesity (DIO) were also used. The mice were fed either ad libitum or in a time-restricted manner. Serum FGF21 levels were significantly increased after 16 weeks of TRF. TRF prevented body weight gain, improved glucose homeostasis, and protected against high-fat diet-induced hepatosteatosis and liver damage. The expression of genes related to liver lipogenesis and inflammation was reduced in TRF mice, but the expression of genes involved in fatty acid β-oxidation was increased. However, those beneficial effects of TRF were blunted in the FGF21 LKO mice. Moreover, TRF promoted improvements in insulin sensitivity and liver damage in DIO mice. Our data show that liver FGF21 signaling was involved in the effect of TRF on high-fat diet-induced fatty liver.