The Beneficial Additive Effect of Silymarin in Metformin Therapy of Liver Steatosis in a Pre-Diabetic Model

The combination of plant-derived compounds with anti-diabetic agents to manage hepatic steatosis closely associated with diabetes mellitus may be a new therapeutic approach. Silymarin, a complex of bioactive substances extracted from Silybum marianum, evinces an antioxidative, anti-inflammatory, and hepatoprotective activity. In this study, we investigated whether metformin (300 mg/kg/day for four weeks) supplemented with micronized silymarin (600 mg/kg/day) would be effective in mitigating fatty liver disturbances in a pre-diabetic model with dyslipidemia. Compared with metformin monotherapy, the metformin–silymarin combination reduced the content of neutral lipids (TAGs) and lipotoxic intermediates (DAGs). Hepatic gene expression of enzymes and transcription factors involved in lipogenesis (Scd-1, Srebp1, Pparγ, and Nr1h) and fatty acid oxidation (Pparα) were positively affected, with hepatic lipid accumulation reducing as a result. Combination therapy also positively influenced arachidonic acid metabolism, including its metabolites (14,15-EET and 20-HETE), mitigating inflammation and oxidative stress. Changes in the gene expression of cytochrome P450 enzymes, particularly Cyp4A, can improve hepatic lipid metabolism and moderate inflammation. All these effects play a significant role in ameliorating insulin resistance, a principal background of liver steatosis closely linked to T2DM. The additive effect of silymarin in metformin therapy can mitigate fatty liver development in the pre-diabetic state and before the onset of diabetes.

Download Full-text

Sex Dimorphism of Nonalcoholic Fatty Liver Disease (NAFLD) in Pparg-Null Mice

International Journal of Molecular Sciences ◽

10.3390/ijms22189969 ◽

2021 ◽

Vol 22 (18) ◽

pp. 9969

Author(s):

Mariano Schiffrin ◽

Carine Winkler ◽

Laure Quignodon ◽

Aurélien Naldi ◽

Martin Trötzmüller ◽

...

Keyword(s):

Gene Expression ◽

Liver Disease ◽

Fatty Liver ◽

Nonalcoholic Fatty Liver Disease ◽

Fatty Liver Disease ◽

Molecular Mechanisms ◽

Liver Steatosis ◽

Whole Body ◽

Sex Dimorphism ◽

Nonalcoholic Fatty Liver

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.

Download Full-text

Pharmacological management of nonalcoholic fatty liver disease: Limitations, challenges and new therapeutic opportunities

Journal of Atherosclerosis Prevention and Treatment ◽

10.53590/japt.02.1001 ◽

2019 ◽

pp. 28-37

Author(s):

Eleni A. Karavia ◽

Kyriakos E. Kypreos

Keyword(s):

Liver Disease ◽

Fatty Liver ◽

Nonalcoholic Fatty Liver Disease ◽

Hepatic Steatosis ◽

Fatty Liver Disease ◽

Lifestyle Changes ◽

Pharmacological Management ◽

Nonalcoholic Fatty Liver ◽

Hepatic Lipid ◽

Stress Changes

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of metabolic disorders ranging from a simple accumulation of excess triglycerides in the liver (hepatic steatosis) to hepatic steatosis with inflammation, fibrosis, and cirrhosis (steatohepatitis or non-alcoholic steatohepatitis (NASH)). Studies in humans and animal models suggested that alterations in hepatic lipid metabolism, increased generation of reactive oxygen species and consequently oxidative stress, changes in mitochondrial function, DNA damage, microbial infections and release of various cytokines may contribute to the pathogenesis of NAFLD and its progression to NASH. Recent data also suggest an important role of the lipoprotein transport system in hepatic lipid deposition. Currently, no drugs are approved for the treatment of NAFLD and NASH and existing pharmacotherapy aims at the management of intercurrent diseases such as obesity, hyperlipidemia, insulin resistance, and type 2 diabetes mellitus. All guidelines acknowledge that any medicines prescribed for NAFLD treatment should be considered as an off-label treatment and that their efficacy and safety should be carefully monitored. Although current pharmacotherapy may seem limited and of questionable efficacy, there is optimism that innovative safe and effective options for the management of the disease will be made available shortly since specialized drugs such as obeticholic acid, elafibranor and cenicriviroc, are presently tested in clinical trials. Given that patients with NAFLD without steatohepatitis or fibrosis have excellent prognosis if they adopt appropriate therapeutic lifestyle changes, it is generally accepted that pharmacological treatments should be limited to those with established NASH and fibrosis while subjects with early manifestations of NAFLD should resort to therapeutic lifestyle and nutritional changes.

Download Full-text

The Effects of Butyrate on Induced Metabolic-Associated Fatty Liver Disease in Precision-Cut Liver Slices

Nutrients ◽

10.3390/nu13124203 ◽

2021 ◽

Vol 13 (12) ◽

pp. 4203

Author(s):

Grietje H. Prins ◽

Melany Rios-Morales ◽

Albert Gerding ◽

Dirk-Jan Reijngoud ◽

Peter Olinga ◽

...

Keyword(s):

Liver Disease ◽

Fatty Liver ◽

Fatty Liver Disease ◽

Type I Collagen ◽

Smooth Muscle Actin ◽

Liver Steatosis ◽

Acid Oxidation ◽

Type I ◽

Triglyceride Accumulation ◽

Liver Slices

Metabolic-associated fatty liver disease (MAFLD) starts with hepatic triglyceride accumulation (steatosis) and can progress to more severe stages such as non-alcoholic steatohepatitis (NASH) and even cirrhosis. Butyrate, and butyrate-producing bacteria, have been suggested to reduce liver steatosis directly and systemically by increasing liver β-oxidation. This study aimed to examine the influence of butyrate directly on the liver in an ex vivo induced MAFLD model. To maintain essential intercellular interactions, precision-cut liver slices (PCLSs) were used. These PCLSs were prepared from male C57BL/6J mice and cultured in varying concentrations of fructose, insulin, palmitic acid and oleic acid, to mimic metabolic syndrome. Dose-dependent triglyceride accumulation was measured after 24 and 48 h of incubation with the different medium compositions. PCLSs viability, as indicated by ATP content, was not affected by medium composition or the butyrate concentration used. Under induced steatotic conditions, butyrate did not prevent triglyceride accumulation. Moreover, it lowered the expression of genes encoding for fatty acid oxidation and only increased C4 related carnitines, which indicate butyrate oxidation. Nevertheless, butyrate lowered the fibrotic response of PCLSs, as shown by reduced gene expression of fibronectin, alpha-smooth muscle actin and osteopontin, and protein levels of type I collagen. These results suggest that in the liver, butyrate alone does not increase lipid β-oxidation directly but might aid in the prevention of MAFLD progression to NASH and cirrhosis.

Download Full-text

Ruscogenin Ameliorates Experimental Nonalcoholic Steatohepatitis via Suppressing Lipogenesis and Inflammatory Pathway

BioMed Research International ◽

10.1155/2014/652680 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Hung-Jen Lu ◽

Thing-Fong Tzeng ◽

Shorong-Shii Liou ◽

Chia Ju Chang ◽

Cheng Yang ◽

...

Keyword(s):

Gene Expression ◽

Nonalcoholic Steatohepatitis ◽

Hepg2 Cells ◽

Inflammatory Responses ◽

Smooth Muscle Actin ◽

Liver Steatosis ◽

Acid Oxidation ◽

Mrna Levels ◽

Protective Effects ◽

Triglyceride Accumulation

The aim of the study was to investigate the protective effects of ruscogenin, a major steroid sapogenin in Ophiopogon japonicus, on experimental models of nonalcoholic steatohepatitis. HepG2 cells were exposed to 300 μmol/l palmitic acid (PA) for 24 h with the preincubation of ruscogenin for another 24 h. Ruscogenin (10.0 μmol/l) had inhibitory effects on PA-induced triglyceride accumulation and inflammatory markers in HepG2 cells. Male golden hamsters were randomly divided into five groups fed a normal diet, a high-fat diet (HFD), or a HFD supplemented with ruscogenin (0.3, 1.0, or 3.0 mg/kg/day) by gavage once daily for 8 weeks. Ruscogenin alleviated dyslipidemia, liver steatosis, and necroinflammation and reversed plasma markers of metabolic syndrome in HFD-fed hamsters. Hepatic mRNA levels involved in fatty acid oxidation were increased in ruscogenin-treated HFD-fed hamsters. Conversely, ruscogenin decreased expression of genes involved in hepatic lipogenesis. Gene expression of inflammatory cytokines, chemoattractive mediator, nuclear transcription factor-(NF-)κB, andα-smooth muscle actin were increased in the HFD group, which were attenuated by ruscogenin. Ruscogenin may attenuate HFD-induced steatohepatitis through downregulation of NF-κB-mediated inflammatory responses, reducing hepatic lipogenic gene expression, and upregulating proteins inβ-oxidation pathway.

Download Full-text

Ethanol administration exacerbates the abnormalities in hepatic lipid oxidation in genetically obese mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00309.2012 ◽

2013 ◽

Vol 304 (1) ◽

pp. G38-G47 ◽

Cited By ~ 34

Author(s):

Hannah Everitt ◽

Ming Hu ◽

Joanne M. Ajmo ◽

Christopher Q. Rogers ◽

Xiaomei Liang ◽

...

Keyword(s):

Fatty Liver ◽

Molecular Mechanisms ◽

Liver Steatosis ◽

Sirtuin 1 ◽

Ethanol Administration ◽

Peroxisome Proliferator ◽

Obese Mice ◽

Hepatic Lipid ◽

Ampk Signaling ◽

Ethanol Feeding

Alcohol consumption synergistically increases the risk and severity of liver damage in obese patients. To gain insight into cellular or molecular mechanisms underlying the development of fatty liver caused by ethanol-obesity synergism, we have carried out animal experiments that examine the effects of ethanol administration in genetically obese mice. Lean wild-type (WT) and obese (ob/ob) mice were subjected to ethanol feeding for 4 wk using a modified Lieber-DeCarli diet. After ethanol feeding, the ob/ob mice displayed much more pronounced changes in terms of liver steatosis and elevated plasma levels of alanine aminotransferase and aspartate aminotransferase, indicators of liver injury, compared with control mice. Mechanistic studies showed that ethanol feeding augmented the impairment of hepatic sirtuin 1 (SIRT1)-AMP-activated kinase (AMPK) signaling in the ob/ob mice. Moreover, the impairment of SIRT1-AMPK signaling was closely associated with altered hepatic functional activity of peroxisome proliferator-activated receptor γ coactivator-α and lipin-1, two vital downstream lipid regulators, which ultimately contributed to aggravated fatty liver observed in ethanol-fed ob/ob mice. Taken together, our novel findings suggest that ethanol administration to obese mice exacerbates fatty liver via impairment of the hepatic lipid metabolism pathways mediated largely by a central signaling system, the SIRT1-AMPK axis.

Download Full-text

Rice endosperm protein slows progression of fatty liver and diabetic nephropathy in Zucker diabetic fatty rats

British Journal Of Nutrition ◽

10.1017/s0007114516003512 ◽

2016 ◽

Vol 116 (8) ◽

pp. 1326-1335 ◽

Cited By ~ 10

Author(s):

Masatoshi Kubota ◽

Reiko Watanabe ◽

Miki Yamaguchi ◽

Michihiro Hosojima ◽

Akihiko Saito ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Fatty Liver ◽

Lipid Accumulation ◽

Fasting Blood Glucose ◽

Acid Oxidation ◽

Rice Endosperm ◽

Diabetic Model ◽

Endosperm Protein ◽

Zucker Diabetic Fatty Rats ◽

Zdf Rats

AbstractWe previously reported that rice endosperm protein (REP) has renoprotective effects in Goto–Kakizaki rats, a non-obese diabetic model. However, whether these effects occur in obese diabetes remains unclear. This study aimed to clarify the effects of REP on obese diabetes, especially on fatty liver and diabetic nephropathy, using the obese diabetic model Zucker diabetic fatty (ZDF) rats. In total, 7-week-old male ZDF rats were fed diets containing 20 % REP or casein (C) for 8 weeks. Changes in fasting blood glucose levels and urinary markers were monitored during the experimental period. Hepatic lipids and metabolites were measured and renal glomeruli were observed morphologically. HbA1c levels were significantly lower in rats fed REP, compared with C (P<0·05). Compared with C in the liver, REP prevented lipid accumulation (total lipid, TAG and total cholesterol, P<0·01). Liver metabolome analysis indicated that levels of metabolites associated with glycolysis, the pentose phosphate pathway and carnitine metabolism were significantly greater in the REP group than in the C group (P<0·05), suggesting activation of both glucose catabolism and fatty acid oxidation. The metabolite increases promoted by REP may contribute to suppression of liver lipid accumulation. Urinary excretion of albumin and N-acetyl-β-d-glucosaminidase was significantly reduced in rats fed REP for 8 weeks (P<0·01). In addition, there was a distinct suppression of mesangial matrix expansion and glomerular hypertrophy in response to REP (P<0·01). Thus, REP had preventive effects on obese diabetes, fatty liver and diabetic nephropathy.

Download Full-text

Supplementation with a Specific Combination of Metabolic Cofactors Ameliorates Non-Alcoholic Fatty Liver Disease and, Hepatic Fibrosis, and Insulin Resistance in Mice

Nutrients ◽

10.3390/nu13103532 ◽

2021 ◽

Vol 13 (10) ◽

pp. 3532

Author(s):

Sergio Quesada-Vázquez ◽

Marina Colom-Pellicer ◽

Èlia Navarro-Masip ◽

Gerard Aragonès ◽

Josep M. Del Bas ◽

...

Keyword(s):

Gene Expression ◽

Insulin Resistance ◽

Liver Disease ◽

Fatty Liver ◽

Hepatic Fibrosis ◽

Fatty Liver Disease ◽

Liver Steatosis ◽

Alcoholic Fatty Liver ◽

Specific Combination ◽

Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) have emerged as the leading causes of chronic liver disease in the world. Obesity, insulin resistance, and dyslipidemia are multifactorial risk factors strongly associated with NAFLD/NASH. Here, a specific combination of metabolic cofactors (a multi-ingredient; MI) containing precursors of glutathione (GSH) and nicotinamide adenine dinucleotide (NAD+) (betaine, N-acetyl-cysteine, L-carnitine and nicotinamide riboside) was evaluated as effective treatment for the NAFLD/NASH pathophysiology. Six-week-old male mice were randomly divided into control diet animals and animals exposed to a high fat and high fructose/sucrose diet to induce NAFLD. After 16 weeks, diet-induced NAFLD mice were distributed into two groups, treated with the vehicle (HFHFr group) or with a combination of metabolic cofactors (MI group) for 4 additional weeks, and blood and liver were obtained from all animals for biochemical, histological, and molecular analysis. The MI treatment reduced liver steatosis, decreasing liver weight and hepatic lipid content, and liver injury, as evidenced by a pronounced decrease in serum levels of liver transaminases. Moreover, animals supplemented with the MI cocktail showed a reduction in the gene expression of some proinflammatory cytokines when compared with their HFHFr counterparts. In addition, MI supplementation was effective in decreasing hepatic fibrosis and improving insulin sensitivity, as observed by histological analysis, as well as a reduction in fibrotic gene expression (Col1α1) and improved Akt activation, respectively. Taken together, supplementation with this specific combination of metabolic cofactors ameliorates several features of NAFLD, highlighting this treatment as a potential efficient therapy against this disease in humans.

Download Full-text

Effects of Long-Term DHA Supplementation and Physical Exercise on Non-Alcoholic Fatty Liver Development in Obese Aged Female Mice

Nutrients ◽

10.3390/nu13020501 ◽

2021 ◽

Vol 13 (2) ◽

pp. 501

Author(s):

Jinchunzi Yang ◽

Neira Sáinz ◽

Elisa Félix-Soriano ◽

Eva Gil-Iturbe ◽

Rosa Castilla-Madrigal ◽

...

Keyword(s):

Fatty Liver ◽

Liver Steatosis ◽

Dietary Lipids ◽

Treadmill Running ◽

Acid Oxidation ◽

Alcoholic Fatty Liver ◽

Lipogenic Genes ◽

Stress Related Genes ◽

Alcoholic Fatty Liver Disease

Obesity and aging are associated to non-alcoholic fatty liver disease (NAFLD) development. Here, we investigate whether long-term feeding with a docosahexaenoic acid (DHA)-enriched diet and aerobic exercise, alone or in combination, are effective in ameliorating NAFLD in aged obese mice. Two-month-old female C57BL/6J mice received control or high fat diet (HFD) for 4 months. Then, the diet-induced obese (DIO) mice were distributed into four groups: DIO, DIO + DHA (15% dietary lipids replaced by a DHA-rich concentrate), DIO + EX (treadmill running), and DIO + DHA + EX up to 18 months. The DHA-rich diet reduced liver steatosis in DIO mice, decreasing lipogenic genes (Dgat2, Scd1, Srebp1c), and upregulated lipid catabolism genes (Hsl/Acox) expression. A similar pattern was observed in the DIO + EX group. The combination of DHA + exercise potentiated an increase in Cpt1a and Ppara genes, and AMPK activation, key regulators of fatty acid oxidation. Exercise, alone or in combination with DHA, significantly reversed the induction of proinflammatory genes (Mcp1, Il6, Tnfα, Tlr4) in DIO mice. DHA supplementation was effective in preventing the alterations induced by the HFD in endoplasmic reticulum stress-related genes (Ern1/Xbp1) and autophagy markers (LC3II/I ratio, p62, Atg7). In summary, long-term DHA supplementation and/or exercise could be helpful to delay NAFLD progression during aging in obesity.

Download Full-text

Dysregulated H3K27 Acetylation Is Implicated in Fatty Liver Hemorrhagic Syndrome in Chickens

Frontiers in Genetics ◽

10.3389/fgene.2020.574167 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yaling Zhu ◽

Qingjie Zeng ◽

Fang Li ◽

Haoshu Fang ◽

Zhimin Zhou ◽

...

Keyword(s):

Gene Expression ◽

Fatty Liver ◽

Signaling Pathway ◽

High Throughput ◽

Liver Tissue ◽

Molecular Mechanisms ◽

Liver Steatosis ◽

Regulation Of Gene Expression ◽

High Energy ◽

Ppar Signaling

Epigenetic regulation of gene expression has been reported in the pathogenesis of metabolic disorders such as diabetes and liver steatosis in humans. However, the molecular mechanisms of fatty liver hemorrhagic syndrome (FLHS) in chickens have been rarely studied. H3K27ac chromatin immunoprecipitation coupled with high-throughput sequencing and high-throughput RNA sequencing was performed to compare genome-wide H3K27ac profiles and transcriptomes of liver tissue between healthy and FLHS chickens. In total, 1,321 differential H3K27ac regions and 443 differentially expressed genes were identified (| log2Fold change| ≥ 1 and P-value ≤ 0.05) between the two groups. Binding motifs for transcription factors involved in immune processes and metabolic homeostasis were enriched among those differential H3K27ac regions. Differential H3K27ac peaks were associated with multiple known FLHS risk genes, involved in lipid and energy metabolism (PCK1, APOA1, ANGPTL4, and FABP1) and the immune system (FGF7, PDGFRA, and KIT). Previous studies and our current results suggested that the high-energy, low-protein (HELP) diet might have an impact on histone modification and chromatin structure, leading to the dysregulation of candidate genes and the peroxisome proliferator-activated receptor (PPAR) signaling pathway, which causes excessive accumulation of fat in the liver tissue and induces the development of FLHS. These findings highlight that epigenetic modifications contribute to the regulation of gene expression and play a central regulatory role in FLHS. The PPAR signaling pathway and other genes implicated in FLHS are of great importance for the development of novel and specific therapies for FLHS-susceptible commercial laying hens.

Download Full-text

Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver

Molecular and Cellular Biology ◽

10.1128/mcb.00006-17 ◽

2017 ◽

Vol 37 (15) ◽

Cited By ~ 14

Author(s):

Sung E. Choi ◽

Sanghoon Kwon ◽

Sunmi Seok ◽

Zhen Xiao ◽

Kwan-Woo Lee ◽

...

Keyword(s):

Fatty Liver ◽

Nuclear Localization ◽

Liver Steatosis ◽

Phosphorylation Site ◽

Casein Kinase ◽

Casein Kinase 2 ◽

Serine Phosphorylation ◽

Acid Oxidation ◽

Specific Expression ◽

Nonalcoholic Fatty Liver

ABSTRACT Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases.

Download Full-text