Animal models of steatohepatitis

Buckwheat resistant starch alleviates hyperlipidaemia in mice by inhibiting lipid accumulation and regulating gut microbiota

Hyperlipidemia, a prevalent metabolic disorder disease, has become a significant global health challenge. In this research, we looked into the effects of buckwheat resistant starch (BRS) supplementation on lipid metabolism and gut microbiota in hyperlipidemic mice. Results showed that HBRS intervention significantly inhibited weight gain in high-fat diet mice, reducing body weight by 2.91 g versus MC group. Serum TC, TG, and LDL-C decreased by 74.25 %, 76.79 %, and 56.25 % respectively, while HDL-C increased by 67.66 %. HBRS mitigated hepatic steatosis and epididymal adipocyte hypertrophy. HBRS downregulated TNF-α and IL-6 by 24.4 % and 18.25 %, respectively, and upregulated IL-10 by 15.35 %. It modulated lipid metabolism genes by suppressing SREBP2, FAS, SCD1 and activating PPARα/CPT1. Moreover, BRS improved gut microbiota composition by lowering the F/B ratio and enhancing populations of SCFA-producing bacteria (e.g., Akkermansia, Bifidobacterium, and Parabacteroides). BRS significantly increased the total levels of SCFAs in the gut. Compared to the MC group, HBRS resulted in increases of 40.2 %, 51.8 %, and 68.3 % in acetate, propionate, and butyrate, respectively. Collectively, these results demonstrate that BRS serves as a beneficial nutritional resource for the management of hyperlipidemia.

Carbon tetrachloride does not promote hepatic fibrosis in ob/ob mice via downregulation of lipocalin-2 protein

Although leptin-deficient ob/ob mice have been investigated to determine whether hepatic steatosis promotes susceptibility to hepatotoxic insults, carbon tetrachloride (CCl4)-induced hepatic fibrosis in ob/ob mice remains largely unknown. In this study, we evaluate the pathogenic mechanisms of hepatic fibrosis in CCl4-treated wild-type (WT) and ob/ob mice and analyze some parameters related to lipogenesis, inflammation, fibrosis, oxidative stress, apoptosis, and autophagy. CCl4 treatment attenuated liver weight and lipogenesis in ob/ob mice. Increased hepatic fibrosis-related proteins were reduced in CCl4-treated ob/ob mice compared with CCl4-treated WT mice. Specifically, the expression of lipocalin-2 (LCN2) was markedly reduced in CCl4-treated ob/ob mice versus CCl4-treated WT mice. Compared with CCl4-treated WT mice, CCl4-treated ob/ob mice had reduced expression of neutrophil-related inflammatory genes and proteins. Hepatic heme oxygenase-1 protein was reduced in CCl4-treated ob/ob mice compared with CCl4-treated WT mice. However, CCl4 did not promote hepatic apoptosis in ob/ob mice. Therefore, these findings highlight LCN2 as a key signaling factor in CCl4-induced hepatic fibrosis.

Modulation of liver cholesterol homeostasis by choline supplementation during fibrosis resolution

Liver fibrosis is a critical global health challenge, often leading to severe liver diseases without timely intervention. Choline deficiency has been linked to metabolic dysfunction associated steatohepatitis (MASH) and liver fibrosis, suggesting choline supplementation as a potential therapeutic approach. This study aimed to explore the therapeutic potential of choline supplementation in liver fibrosis resolution and its effects on cholesterol homeostasis using a mouse model with induced liver fibrosis. Our findings reveal that choline supplementation significantly decreases blood lactate dehydrogenase (LDH) and non-high-density lipoprotein cholesterol (non-HDL-C) levels. Transcriptome analysis showed that choline supplementation primarily induces genes related to cholesterol homeostasis, suggesting a significant impact on liver cholesterol synthesis. However, choline supplementation did not significantly alter the expression of fibrosis-related, choline metabolism-related, or epigenetics-related genes. This study provides novel insights into the role of choline in liver health and cholesterol metabolism, potentially informing treatments for liver fibrosis and related conditions.

Identification and validation of key biomarkers associated with macrophages in nonalcoholic fatty liver disease based on hdWGCNA and machine learning

BACKGROUND

NAFLD has attracted increasing attention because of its high prevalence and risk of progression to cirrhosis or even hepatocellular carcinoma. Therefore, research into the root causes and molecular indicators of NAFLD is crucial.

METHODS

We analyzed scRNA-seq data and RNA-seq data from normal and NAFLD liver samples. We utilized hdWGCNA to find module-related genes associated with the phenotype. Multiple machine learning algorithms were used to validate the model diagnostics and further screen for genes that are characteristic of NAFLD. The NAFLD mouse model was constructed using the MCD diet to validate the diagnostic effect of the genes.

RESULTS

We identified a specific macrophage population called NASH-macrophages by single-cell sequencing analysis. Cell communication analysis and Pseudo-time trajectory analysis revealed the specific role and temporal distribution of NASH-macrophages in NAFLD. The hdWGCNA screening yielded 30 genes associated with NASH-macrophages, and machine learning algorithms screened and obtained two genes characterizing NAFLD. The immune infiltration indicated that these genes were highly associated with macrophages. Notably, we verified by RT-qPCR, IHC, and WB that MAFB and CX3CR1 are highly expressed in the MCD mouse model and may play important roles.

CONCLUSIONS

Our study revealed a macrophage population that is closely associated with NAFLD. Using hdWGCNA analysis and multiple machine learning algorithms, we identified two NAFLD signature genes that are highly correlated with macrophages. Our findings may provide potential feature markers and therapeutic targets for NAFLD.

Sex difference in liver diseases: How preclinical models help to dissect the sex-related mechanisms sustaining NAFLD and hepatocellular carcinoma

Only a few preclinical findings are confirmed in the clinic, posing a critical issue for clinical development. Therefore, identifying the best preclinical models can help to dissect molecular and mechanistic insights into liver disease pathogenesis while being clinically relevant. In this context, the sex relevance of most preclinical models has been only partially considered. This is particularly significant in NAFLD and HCC, which have a higher prevalence in men when compared to pre-menopause women but not to those in post-menopausal status, suggesting a role for sex hormones in the pathogenesis of the diseases. This review gathers the sex-relevant findings and the available preclinical models focusing on both in vitro and in vivo studies and discusses the potential implications and perspectives of introducing the sex effect in the selection of the best preclinical model. This is a critical aspect that would help to tailor personalized therapies based on sex.

Ingesting retrograded rice (Oryza sativa) starch relieves high-fat diet induced hyperlipidemia in mice by altering intestinal bacteria

High-fat diet is a risk factor for many chronic diseases, whose symptoms are probably regulated by ingesting food ingredients such as resistant starch. For cooked rice stored in cold-chain, the starch component can retrograde to generate ordered structures (helices and crystallites) and become resistant. However, the role of retrograded starch in managing hyperlipidemia symptoms is insufficiently understood. Here, compared to the normal high-fat diet, ingesting retrograded starch reduced the triglyceride and low-density lipoprotein cholesterol levels of high-fat diet mice by 17.69% and 41.33%, respectively. This relieved hyperlipidemia could be linked to the changes in intestinal bacteria. Retrograded starch intervention increased the relative abundance of Bacteroides (2.30 times higher), which produces propionic acid (increased by 8.26%). Meanwhile, Bacteroides were positively correlated with butyric acid (increased by 98.4%) with strong anti-inflammatory functions. Hence, retrograded starch intervention may regulate the body's health by altering intestinal bacteria.

Hepatic oleate regulates one-carbon metabolism during high carbohydrate feeding

Obesity is a major risk factor for type 2 diabetes, coronary heart disease, and strok. These diseases are associated with profound alterations in gene expression in metabolic tissues. Epigenetic-mediated regulation of gene expression is one mechanism through which environmental factors, such as diet, modify gene expression and disease predisposition. However, epigenetic control of gene expression in obesity and insulin resistance is not fully characterized. We discovered that liver-specific stearoyl-CoA desaturase-1 (Scd1) knockout mice (LKO) fed a high-carbohydrate low-fat diet exhibit dramatic changes in hepatic gene expression and metabolites of the folate cycle and one-carbon metabolism respectively for the synthesis of S-adenosylmethionine (SAM). LKO mice show an increased ratio of S-adenosylmethionine to S-adenosylhomocysteine, a marker for increased cellular methylation capacity. Furthermore, expression of DNA and histone methyltransferase genes is up-regulated while the mRNA and protein levels of the non-DNA methyltransferases including phosphatidylethanolamine methyltransferase (PEMT), Betaine homocysteine methyltransferase (Bhmt), and the SAM-utilizing enzymes such as glycine-N-methyltransferase (Gnmt) and guanidinoacetate methyltransferase (Gamt) are generally down-regulated. Feeding LKO mice a high carbohydrate diet supplemented with triolein, but not tristearin, and increased endogenous hepatic synthesis of oleate but not palmitoleate in Scd1 global knockout mice normalized one carbon gene expression and metabolite levels. Additionally, changes in one carbon gene expression are independent of the PGC-1α-mediated ER stress response previously reported in the LKO mice. Together, these results highlight the important role of oleate in maintaining one-carbon cycle homeostasis and point to observed changes in one-carbon metabolism as a novel mediator of the Scd1 deficiency-induced liver phenotype.

Shedding light on non-alcoholic fatty liver disease: Pathogenesis, molecular mechanisms, models, and emerging therapeutics

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder globally impacting an estimated 25% of the population associated with severe consequences such as cirrhosis, hepatocellular carcinoma (HCC), and overall mortality. Fatty liver disease is triggered through multiple pathways, but the most prominent cause is either diabetes or obesity, or a combination of both. Therefore, hepatic glucose, insulin and fatty acid signaling becomes a dire need to understand which is well elaborated in this review. This review summarizes the popular two-hit pathogenesis of NAFLD, the molecular mechanisms underlying hepatic insulin resistance. As fatty liver disease gets advanced, it requires in-vitro as well as in-vivo models closer to disease progression in humans for better understanding the pathological state and identifying a novel therapeutic target. This review summarizes in-vitro (2D cell-culture/co-culture, 3D spheroid/organoid/liver-on-a-chip) models as well as in-vivo (genetically/dietary/chemically induced fatty liver disease) research models. Fatty liver disease research has gathered lots of attention recently since there is no FDA approved therapy available so far. However, there have been numerous promising targets to treat fatty liver disease including potential therapeutic targets under clinical trials are listed in this review.

Fenofibrate enhances lipid deposition via modulating PPARγ, SREBP-1c, and gut microbiota in ob/ob mice fed a high-fat diet

Obesity is characterized by lipid accumulation in distinct organs. Presently, fenofibrate is a commonly used triglyceride-lowering drug. This study is designed to investigate whether long-term fenofibrate intervention can attenuate lipid accumulation in ob/ob mouse, a typical model of obesity. Our data demonstrated that fenofibrate intervention significantly decreased plasma triglyceride level by 21.0%, increased liver index and hepatic triglyceride content by 31.7 and 52.1%, respectively, and elevated adipose index by 44.6% compared to the vehicle group. As a PPARα agonist, fenofibrate intervention significantly increased the expression of PPARα protein in the liver by 46.3% and enhanced the expression of LDLR protein by 3.7-fold. However, fenofibrate dramatically increased the expression of PPARγ and SREBP-1c proteins by ~2.1- and 0.9-fold in the liver, respectively. Fenofibrate showed no effects on the expression of genes-related to fatty acid β-oxidation. Of note, it significantly increased the gene expression of FAS and SCD-1. Furthermore, fenofibrate modulated the gut microbiota. Collectively, long-term fenofibrate induces lipid accumulation in liver and adipose tissues in ob/ob mice by enhancing the expression of adipogenesis-related proteins and gut microbiota. These data suggest that fenofibrate may have limited effects on attenuating lipid deposition in obese patients.

Angiotensin Converting Enzyme-2 Therapy Improves Liver Fibrosis and Glycemic Control in Diabetic Mice With Fatty Liver

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and is frequently associated with type 2 diabetes. However, there is no specific medical therapy to treat this condition. Angiotensin-converting enzyme 2 (ACE2) of the protective renin angiotensin system generates the antifibrotic peptide angiotensin-(1-7) from profibrotic angiotensin II peptide. In this study, we investigated the therapeutic potential of ACE2 in diabetic NAFLD mice fed a high-fat (20%), high-cholesterol (2%) diet for 40 weeks. Mice were given a single intraperitoneal injection of ACE2 using an adeno-associated viral vector at 30 weeks of high-fat, high-cholesterol diet (15 weeks after induction of diabetes) and sacrificed 10 weeks later. ACE2 significantly reduced liver injury and fibrosis in diabetic NAFLD mice compared with the control vector injected mice. This was accompanied by reductions in proinflammatory cytokine expressions, hepatic stellate cell activation, and collagen 1 expression. Moreover, ACE2 therapy significantly increased islet numbers, leading to an increased insulin protein content in β-cells and plasma insulin levels with subsequent reduction in plasma glucose levels compared with controls. Conclusion: We conclude that ACE2 gene therapy reduces liver fibrosis and hyperglycemia in diabetic NAFLD mice and has potential as a therapy for patients with NAFLD with diabetes.

Pathogenesis of sarcopenia and the relationship with fat mass: descriptive review

Age-associated obesity and muscle atrophy (sarcopenia) are intimately connected and are reciprocally regulated by adipose tissue and skeletal muscle dysfunction. During ageing, adipose inflammation leads to the redistribution of fat to the intra-abdominal area (visceral fat) and fatty infiltrations in skeletal muscles, resulting in decreased overall strength and functionality. Lipids and their derivatives accumulate both within and between muscle cells, inducing mitochondrial dysfunction, disturbing β-oxidation of fatty acids, and enhancing reactive oxygen species (ROS) production, leading to lipotoxicity and insulin resistance, as well as enhanced secretion of some pro-inflammatory cytokines. In turn, these muscle-secreted cytokines may exacerbate adipose tissue atrophy, support chronic low-grade inflammation, and establish a vicious cycle of local hyperlipidaemia, insulin resistance, and inflammation that spreads systemically, thus promoting the development of sarcopenic obesity (SO). We call this the metabaging cycle. Patients with SO show an increased risk of systemic insulin resistance, systemic inflammation, associated chronic diseases, and the subsequent progression to full-blown sarcopenia and even cachexia. Meanwhile in many cardiometabolic diseases, the ostensibly protective effect of obesity in extremely elderly subjects, also known as the 'obesity paradox', could possibly be explained by our theory that many elderly subjects with normal body mass index might actually harbour SO to various degrees, before it progresses to full-blown severe sarcopenia. Our review outlines current knowledge concerning the possible chain of causation between sarcopenia and obesity, proposes a solution to the obesity paradox, and the role of fat mass in ageing.

Pediatric nonalcoholic fatty liver disease and the microbiome: Mechanisms contributing to pathogenesis and progression

Nonalcoholic fatty liver disease (NAFLD) is the most common form of pediatric liver disease in the United States, and often associated with obesity and metabolic syndrome. NAFLD comprises a broad spectrum of liver diseases, from hepatic steatosis to steatohepatitis, fibrosis and cirrhosis. Disease progression is considered a multi-modal process of liver injury. The intestinal microbiome has been implicated in several aspects of NAFLD pathophysiology. Pediatric studies associating the intestinal microbiome with NAFLD have been limited in number and complicated by inconsistencies in study design and approach. Nevertheless, they provide support for involvement of the intestinal microbiome in NAFLD development and progression and point to common mechanisms shared by microbiome-associated inflammatory diseases with potential to inform future therapeutic intervention.

Zebrafish: An emerging model system to study liver diseases and related drug discovery

The zebrafish has emerged as a powerful vertebrate model for studying liver-associated disorders. Liver damage is a crucial problem in the process of drug development and zebrafish have proven to be an important tool for the high-throughput screening of drugs for hepatotoxicity. Although the structure of the zebrafish liver differs to that of mammals, the fundamental physiologic processes, genetic mutations and manifestations of pathogenic responses to environmental insults exhibit much similarity. The larval transparency of the zebrafish is a great advantage for real-time imaging in hepatic studies. The zebrafish has a broad spectrum of cytochrome P450 enzymes, which enable the biotransformation of drugs via similar pathways as mammals, including oxidation, reduction and hydrolysis reactions. In the present review, we appraise the various drugs, chemicals and toxins used to study liver toxicity in zebrafish and their similarities to the rodent models for liver-related studies. Interestingly, the zebrafish has also been effectively used to study the pathophysiology of nonalcoholic and alcoholic fatty liver disease. The genetic models of liver disorders and their easy manipulation provide great opportunity in the area of drug development. The zebrafish has proven to be an influential model for the hepatic system due to its invertebrate-like advantages coupled with its vertebrate biology. The present review highlights the pivotal role of zebrafish in bridging the gap between cell-based and mammalian models.

Animal Models: A Useful Tool to Unveil Metabolic Changes in Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) represents an important health problem. At the moment, systemic therapies offered only modest clinical benefits. Thus, HCC represents a cancer extremely difficult to treat, and therapeutic breakthroughs are urgently needed. Metabolic reprogramming of neoplastic cells has been recognized as one of the core hallmarks of cancer. Experimental animal models represent an important tool that allows to investigate metabolic changes underlying HCC development and progression. In the present review, we characterize available rodent models of hepatocarcinogenesis. Moreover, we discuss the possibility that pharmacological targeting of Warburg metabolism may represent an additional tool to improve already available therapeutic approaches for HCC.

Abstract

Hepatocellular carcinoma (HCC) is one the most frequent and lethal human cancers. At present, no effective treatment for advanced HCC exist; therefore, the overall prognosis for HCC patients remains dismal. In recent years, a better knowledge of the signaling pathways involved in the regulation of HCC development and progression, has led to the identification of novel potential targets for therapeutic strategies. However, the obtained benefits from current therapeutic options are disappointing. Altered cancer metabolism has become a topic of renewed interest in the last decades, and it has been included among the core hallmarks of cancer. In the light of growing evidence for metabolic reprogramming in cancer, a wide number of experimental animal models have been exploited to study metabolic changes characterizing HCC development and progression and to further expand our knowledge of this tumor. In the present review, we discuss several rodent models of hepatocarcinogenesis, that contributed to elucidate the metabolic profile of HCC and the implications of these changes in modulating the aggressiveness of neoplastic cells. We also highlight the apparently contrasting results stemming from different animal models. Finally, we analyze whether these observations could be exploited to improve current therapeutic strategies for HCC.

<i>In vitro</i> Anticancer Activity of Quinoa and Safflower Seeds and Their Preventive Effects on Non-alcoholic Fatty Liver

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is not only the most common cause of liver diseases in humans but also it may complicate and become a risk factor for liver cancer. The present work aimed to evaluate the anticancer activity (in vitro) of quinoa and safflower seeds powder and their beneficial effects against NAFLD (in vivo).

MATERIALS AND METHODS

Proximate analysis, fatty acids profile, total phenolic and phytic acid of quinoa and safflower seeds were assessed. Also their anticancer activities (in vitro) against liver cancer were evaluated. The preventive effect of both seeds on NAFLD was evaluated using twenty four male rats. NAFLD was induced in rats by high fructose diet (HFD) for 4 weeks. The effects of HFD and HFD supplemented with 20% quinoa or safflower powder on plasma and liver lipids, lipid peroxidation, total protein, albumin as well as liver and kidney functions were determined.

RESULTS

Quinoa seeds powder was promising in cytotoxicity against hepatocarcinoma cell line HEPG2 (IC50 was 14.6 μg). Feeding rats on HFD produced dyslipidemia and significant increase in liver functions and lipid peroxidation with significant elevation in liver triglycerides and total cholesterol. Quinoa and safflower seeds powder produced improvement in the biochemical parameters with different degrees.

CONCLUSION

Quinoa and safflower seeds powder possessed cytotoxicity against hepatocarcinoma cell line HEPG2 and afford hepato-protection against NAFLD.

Eicosapentaenoic acid-containing polar lipids from seaweed Susabinori (Pyropia yezoensis) alleviate hepatic steatosis in obese db/db mice

Nonalcoholic fatty liver disease (NAFLD) is emerging as the most common liver disease in industrialized countries. Because hepatic steatosis is an early pathogenesis of NAFLD, the discovery of food components that could ameliorate hepatic steatosis is of interest. Susabinori (Pyropia yezoensis) is recognized as one of the most delicious edible brown algae, and we prepared lipid component of susabinori (SNL), which is rich in eicosapentaenoic acid (EPA)-containing polar lipids. In this study, we tested whether feeding SNL to db/db mice protects them from developing obesity-induced hepatic steatosis. After four weeks of feeding, hepatomegaly, hepatic steatosis, and hepatic injury were markedly alleviated in SNL-fed db/db mice. These effects were partly attributable to the suppression of activities and mRNA expressions of lipogenic enzymes and enhanced levels of adiponectin due to the SNL diet. Additionally, mRNA expression of monocyte chemoattractant protein-1, an inflammatory chemokine, was markedly suppressed, and the mRNA levels of PPARδ, the anti-inflammatory transcription factor, were strongly enhanced in the livers of db/db mice by the SNL diet. We speculate that the development and progression of obesity-induced hepatic steatosis was prevented by the suppression of chronic inflammation due to the combination of bioactivities of EPA, phospholipids, and glycolipids in the SNL diet.

Siphonaxanthin, a carotenoid from green algae Codium cylindricum, protects Ob/Ob mice fed on a high-fat diet against lipotoxicity by ameliorating somatic stresses and restoring anti-oxidative capacity

Oxidative stress is implicated in the pathogenesis of many diseases including obesity, non-alcoholic fatty liver disease, and diabetes mellitus. Previously, we reported that siphonaxanthin, a carotenoid from green algae, elicited a potent inhibitory effect on hepatic de novo lipogenesis, and an anti-obesity effect in both 3T3L1 cells and KKAy mice. Thus, we hypothesized that consumption of siphonaxanthin could improve metabolic disorders including hepatic steatosis and systemic adiposity, as well as ameliorate somatic stress under obese conditions. Both the hepatocyte cell line HepG2 and a mouse model of severe obesity, produced by feeding Ob/Ob mice on a high-fat diet (HFD), were used to test this hypothesis. In obese mice, siphonaxanthin intake did not improve liver steatosis or systemic adiposity. However, intake did lower plasma glucose and alanine aminotransferase (ALT) levels and diminished hepatic lipid peroxidation products and antioxidant gene expression, which increased significantly in control group obese mice. Renal protein carbonyl content decreased significantly in the siphonaxanthin group, which might also indicate an ameliorated oxidative stress. Siphonaxanthin restored gene expression related to antioxidant signaling, lipid β-oxidation, and endoplasmic-reticulum-associated protein degradation in the kidney, which decreased significantly in obese mice. Liver and kidney responded to obesity-induced somatic stress in a divergent pattern. In addition, we confirmed that siphonaxanthin potently induced Nrf2-regulated antioxidant signaling in HepG2 cells. In conclusion, our results indicated that siphonaxanthin might protect obesity-leading somatic stress through restoration of Nrf2-regulated antioxidant signaling, and might be a promising nutritional supplement.

A simple method for inducing nonalcoholic steatohepatitis with fibrosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasingly occurring in sedentary people, and may progress to NASH and hepatocellular carcinoma. It is essential to design affordable animal models for the study of various diseases, including fatty liver, which was the aim of the study. In this study, a high-fat diet was devised that triggers NASH's animal model quickly and easily. High-fat diet (HFD) was used both with intra-mouth oral gavage and in combination with animal pellets.

METHODS

Twenty-four male C57BL/6J mice were divided into HFD and ND groups, which received a high-fat diet and a normal diet, respectively. At the end of the experiment (fourth week of treatment), body and liver weights, biochemical parameters, PPAR-α gene expression and histopathologic characteristics of the liver were evaluated.

RESULTS

During 4 weeks, body weight of mice did not show a significant increase in the HFD group compared to the ND group, while weight gain of the liver was significant. Histological assessment of the HFD group's liver confirmed NASH symptoms. In the HFD group, HDL-c, SOD, catalase, FRAP, adiponectin, and PPAR-α decreased significantly, and lipid profiles, hepatic enzymes, MDA, leptin, and TNF-α showed a significant increase compared to the ND group.

CONCLUSION

Our high-fat diet has successfully induced all aspects of NASH with fibrosis in 4 weeks, and with low cost.

Preparation and Evaluation of Functional Foods for Prevention of Non-alcoholic Fatty Liver Disease

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a public health problem presenting one of the most important common forms of liver diseases worldwide. This study was carried out to investigate the protective effect of two functional foods in form of bread containing purslane seeds meal and garden cress seeds against NAFLD.

MATERIALS AND METHODS

High fat and high cholesterol diet were used for induction of NAFLD in rats for 6 weeks. Plasma lipid profile (total cholesterol, triglycerides, high density lipoprotein-cholesterol and low-density lipoprotein-cholesterol, hepatic lipid profile (total fat, cholesterol, triglycerides), malondialdehyde (MDA), as well as liver (AST, ALT, total and direct bilirubin) and kidney (creatinine and urea) functions were assessed. Histological examination of liver tissue was carried out.

RESULTS

Results revealed that significant elevation in plasma and liver lipid profiles, MDA, liver enzymes (AST and ALT), bilirubin (total and direct) and kidney function (creatinine and urea) were observed in NAFLD control compared to normal control. Feeding rats on diet containing functional food I and II (purslane and garden cress bread, respectively) showed significant improvement in all the studied parameters with remarkable effect regards to functional food I (purslane bread).

CONCLUSION

Purslane bread and garden cress bread as functional foods prepared in the present study prevent weight gain, improve plasma lipid profile and prevent hepatic lipid accumulation effectively in NAFLD model in rats. Also decreased lipid peroxidation, improve liver and kidney functions and possess hypoglycemic effect. Purslane bread was superior in the prevention of hepatic lipid accumulation.

Mediterranean diet: The role of long-chain ω-3 fatty acids in fish; polyphenols in fruits, vegetables, cereals, coffee, tea, cacao and wine; probiotics and vitamins in prevention of stroke, age-related cognitive decline, and Alzheimer disease

The mechanisms of action of the dietary components of the Mediterranean diet are reviewed in prevention of cardiovascular disease, stroke, age-associated cognitive decline and Alzheimer disease. A companion article provides a comprehensive review of extra-virgin olive oil. The benefits of consumption of long-chain ω-3 fatty acids are described. Fresh fish provides eicosapentaenoic acid while α-linolenic acid is found in canola and soybean oils, purslane and nuts. These ω-3 fatty acids interact metabolically with ω-6 fatty acids mainly linoleic acid from corn oil, sunflower oil and peanut oil. Diets rich in ω-6 fatty acids inhibit the formation of healthier ω-3 fatty acids. The deleterious effects on lipid metabolism of excessive intake of carbohydrates, in particular high-fructose corn syrup and artificial sweeteners, are explained. The critical role of the ω-3 fatty acid docosahexaenoic acid in the developing and aging brain and in Alzheimer disease is addressed. Nutritional epidemiology studies, prospective population-based surveys, and clinical trials confirm the salutary effects of fish consumption on prevention of coronary artery disease, stroke and dementia. Recent recommendations on fish consumption by pregnant women and potential mercury toxicity are reviewed. The polyphenols and flavonoids of plant origin play a critical role in the Mediterranean diet, because of their antioxidant and anti-inflammatory properties of benefit in type-2 diabetes mellitus, cardiovascular disease, stroke and cancer prevention. Polyphenols from fruits and vegetables modulate tau hyperphosphorylation and beta amyloid aggregation in animal models of Alzheimer disease. From the public health viewpoint worldwide the daily consumption of fruits and vegetables has become the main tool for prevention of cardiovascular disease and stroke. We review the important dietary role of cereal grains in prevention of coronary disease and stroke. Polyphenols from grapes, wine and alcoholic beverages are discussed, in particular their effects on coagulation. The mechanisms of action of probiotics and vitamins are also included.

Hepatoprotective Role of Eclipta alba against High Fatty Diet Treated Experimental Models - A Histopathological Study

Background

The hepatic injury due to oxidative stress was ameliorated through administration of an aqueous extract of Eclipta alba leaves and suggested that wedelolactone and demethylwedelolactone were the possible components of Eclipta alba behind the protective effect on liver as well as against liver disorders.

Objective

To study the hepato-protective effects of Eclipta alba on high fatty diet treated experimental models.

Material and methods

A total of 30 adult albino rats of Wistar strain weighing 165-215 grams, from the animal house of the Basaveshwara Medical College, Hospital and Research Centre, Chitradurga, were used for the present study: group 1 included animals fed with normal diet (control); group 2, animals treated with hyperlipidemic diet for eight weeks; group 3, animals treated with hyperlipidemic diet for eight weeks, followed by one week post treatment of Eclipta alba with normal diet; group 4, animals treated with hyperlipidemic diet for eight weeks, followed by two weeks post-treatment of Eclipta alba with normal diet; and group 5, animals treated with hyperlipidemic diet for eight weeks, followed by three weeks posttreatment of Eclipta alba with normal diet.

Results

In animals with high fat diet (30%), we observed the deposition of fat in the form of fat lobules in and around the hepatocytes, mononuclear in filtration in the liver parenchyma, dilation of blood vessels, necrotic foci and damaged hepatocytes.

Conclusion

The components of Eclipta alba like wedelolactone, demethylwedelolactone and saponins reduced fat deposition, mononuclear infiltration, and necrotic foci, and stimulated hepatocyte regeneration in the liver.

Rapid Recapitulation of Nonalcoholic Steatohepatitis upon Loss of Host Cell Factor 1 Function in Mouse Hepatocytes

Host cell factor 1 (HCF-1), encoded by the ubiquitously expressed X-linked gene Hcfc1, is an epigenetic coregulator important for mouse development and cell proliferation, including during liver regeneration. We used a hepatocyte-specific inducible Hcfc1 knockout allele (called Hcfc1^hepKO) to induce HCF-1 loss in hepatocytes of hemizygous Hcfc1^hepKO/Y males by 4 days.

Host cell factor 1 (HCF-1), encoded by the ubiquitously expressed X-linked gene Hcfc1, is an epigenetic coregulator important for mouse development and cell proliferation, including during liver regeneration. We used a hepatocyte-specific inducible Hcfc1 knockout allele (called Hcfc1^hepKO) to induce HCF-1 loss in hepatocytes of hemizygous Hcfc1^hepKO/Y males by 4 days. In heterozygous Hcfc1^hepKO/+ females, owing to random X-chromosome inactivation, upon Hcfc1^hepKO allele induction, a 50/50 mix of HCF-1-positive and -negative hepatocyte clusters is engineered. The livers with Hcfc1^hepKO/Y hepatocytes displayed a 21- to 24-day terminal nonalcoholic fatty liver (NAFL), followed by nonalcoholic steatohepatitis (NASH) disease progression typical of severe NAFL disease (NAFLD). In contrast, in livers with heterozygous Hcfc1^hepKO/+ hepatocytes, HCF-1-positive hepatocytes replaced HCF-1-negative hepatocytes and revealed only mild NAFL development. Loss of HCF-1 led to loss of PGC1α protein, probably owing to its destabilization, and deregulation of gene expression, particularly of genes involved in mitochondrial structure and function, likely explaining the severe Hcfc1^hepKO/Y liver pathology. Thus, HCF-1 is essential for hepatocyte function, likely playing both transcriptional and nontranscriptional roles. These genetically engineered loss-of-HCF-1 mice can be used to study NASH as well as NAFLD resolution.

Disease Progression and Pharmacological Intervention in a Nutrient-Deficient Rat Model of Nonalcoholic Steatohepatitis

BACKGROUND

There is a marked need for improved animal models of nonalcoholic steatohepatitis (NASH) to facilitate the development of more efficacious drug therapies for the disease.

METHODS

Here, we investigated the development of fibrotic NASH in male Wistar rats fed a choline-deficient L-amino acid-defined (CDAA) diet with or without cholesterol supplementation for subsequent assessment of drug treatment efficacy in NASH biopsy-confirmed rats. The metabolic profile and liver histopathology were evaluated after 4, 8, and 12 weeks of dieting. Subsequently, rats with biopsy-confirmed NASH were selected for pharmacological intervention with vehicle, elafibranor (30 mg/kg/day) or obeticholic acid (OCA, 30 mg/kg/day) for 5 weeks.

RESULTS

The CDAA diet led to marked hepatomegaly and fibrosis already after 4 weeks of feeding, with further progression of collagen deposition and fibrogenesis-associated gene expression during the 12-week feeding period. Cholesterol supplementation enhanced the stimulatory effect of CDAA on gene transcripts associated with fibrogenesis without significantly increasing collagen deposition. Pharmacological intervention with elafibranor, but not OCA, significantly reduced steatohepatitis scores, and fibrosis-associated gene expression, however, was unable to prevent progression in fibrosis scores.

CONCLUSION

CDAA-fed rats develop early-onset progressive NASH, which offers the opportunity to probe anti-NASH compounds with potential disease-modifying properties.

GC-1: A Thyromimetic With Multiple Therapeutic Applications in Liver Disease

Thyroid hormones (THs), namely, 3,5,3'-triiodo-l-thyronine (T3) and 3,5,3',5'-tetraiodo-l-thyronine (thyroxine or T4), influence a variety of physiological processes that have important implications in fetal development, metabolism, cell growth, and proliferation. While THs elicit several beneficial effects on lipid metabolism and improve myocardial contractility, these therapeutically desirable effects are associated to a thyrotoxic state that severely limits the possible use of THs as therapeutic agents. Therefore, several efforts have been made to develop T3 analogs that could retain the beneficial actions (triglyceride, cholesterol, obesity, and body mass lowering) without the adverse TH-dependent side effects. This goal was achieved by the synthesis of TRβ-selective agonists. In this review, we summarize the current knowledge on the effects of one of the best characterized TH analogs, the TRβ1-selective thyromimetic, GC-1. In particular, we review some of the effects of GC-1 on different liver disorders, with reference to its possible clinical application. A brief comment on the possible therapeutic use of GC-1 in extrahepatic disorders is also included.

Aberrant hepatic lipid storage and metabolism in canine portosystemic shunts

Non-alcoholic fatty liver disease (NAFLD) is a poorly understood multifactorial pandemic disorder. One of the hallmarks of NAFLD, hepatic steatosis, is a common feature in canine congenital portosystemic shunts. The aim of this study was to gain detailed insight into the pathogenesis of steatosis in this large animal model. Hepatic lipid accumulation, gene-expression analysis and HPLC-MS of neutral lipids and phospholipids in extrahepatic (EHPSS) and intrahepatic portosystemic shunts (IHPSS) was compared to healthy control dogs. Liver organoids of diseased dogs and healthy control dogs were incubated with palmitic- and oleic-acid, and lipid accumulation was quantified using LD540. In histological slides of shunt livers, a 12-fold increase of lipid content was detected compared to the control dogs (EHPSS P<0.01; IHPSS P = 0.042). Involvement of lipid-related genes to steatosis in portosystemic shunting was corroborated using gene-expression profiling. Lipid analysis demonstrated different triglyceride composition and a shift towards short chain and omega-3 fatty acids in shunt versus healthy dogs, with no difference in lipid species composition between shunt types. All organoids showed a similar increase in triacylglycerols after free fatty acids enrichment. This study demonstrates that steatosis is probably secondary to canine portosystemic shunts. Unravelling the pathogenesis of this hepatic steatosis might contribute to a better understanding of steatosis in NAFLD.

Hyperpolarized 13C Spectroscopic Evaluation of Oxidative Stress in a Rodent Model of Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) has become highly prevalent, now considered the most common liver disease in the western world. Approximately one-third of patients with NASH develop non-alchoholic steatohepatitis (NASH), histologically defined by lobular and portal inflammation, and accompanied by marked oxidative stress. Patients with NASH are at increased risk for cirrhosis and hepatocellular carcinoma, and diagnosis currently requires invasive biopsy. In animal models of NASH, particularly the methionine-choline deficient (MCD) model, profound changes are seen in redox enzymes and key intracellular antioxidants. To study antioxidant status in NASH non-invasively, we applied the redox probe hyperpolarized [1-¹³C] dehydroascorbic acid (HP DHA), which is reduced to Vitamin C (VitC) rapidly in the normal liver. In MCD mice, we observed a significant decrease in HP DHA to VitC conversion that accompanied hepatic fat deposition. When these animals were subsequently placed on a normal diet, resonance ratios reverted to those seen in control mice. These findings suggest that HP DHA, a potentially clinically translatable imaging agent, holds special promise in imaging NASH and other metabolic syndromes, to monitor disease progression and response to targeted therapies.

Methotrexate Hepatotoxicity and the Impact of Nonalcoholic Fatty Liver Disease

Methotrexate (MTX) is commonly used to treat individuals with rheumatological and dermatologic disorders. Current American College of Rheumatology (ACR) and American Association of Dermatology (AAD) guidelines identify diabetes and obesity as risk factors for MTX-induced liver injury. Both diabetes and obesity are components of the metabolic syndrome, and are also risk factors for nonalcoholic fatty liver disease (NAFLD). NAFLD affects approximately 40% of the U.S. population, and those with more advanced NAFLD (i.e., nonalcoholic steatohepatitis with or without fibrosis) are likely to develop progressive liver disease. As such, individuals who are treated with MTX may need to be screened for advanced NAFLD, as this may put them at an increased risk of MTX-induced liver injury. In this mini-review, we review the current ACR and AAD guidelines on MTX hepatotoxicity, discuss the evidence (or lack thereof) of the impact of metabolic risk factors on MTX-induced liver injury and highlight the areas that need further research.

Administration of anti-receptor activator of nuclear factor-kappa B ligand (RANKL) antibody for the treatment of osteoporosis was associated with amelioration of hepatitis in a female patient with growth hormone deficiency: a case report

BACKGROUND

Growth hormone deficiency (GHD) is associated with non-alcoholic fatty liver disease (NAFLD). A recent animal study showed that hepatocyte-specific receptor activator of nuclear factor-kappa B (RANK) knockout mice had significantly lower liver fat content compared with control mice concomitant with a decrease in production of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) from hepatocytes and kupffer cells. The role of anti-RANK ligand (RANKL) antibody for osteoporosis on hepatitis in patients with aGHD is still unknown.

CASE PRESENTATION

A forty-seven-year-old female patient was referred to our hospital to investigate chronic hepatitis caused by unknown etiology. She had past history of craniopharyngioma treated with craniotomy and post-surgical radiotherapy. She was for the first time diagnosed as panhypopituitarism including growth hormone deficiency and osteoporosis by endocrine examinations and bone mineral densitometry, respectively. In addition, non-alcoholic steatohepatitis (NASH) was histologically confirmed by liver biopsy in this time. Sixty mg anti-RANKL antibody, which was subcutaneously injected to treat the osteoporosis every six months after replacement of 5 mg hydrocortisone and 30 μg oral desmopressin, rapidly decreased the levels of her liver enzymes (ALT and γGTP were 133 to 72 U/L and 284 to 99 U/L at 16 months after the beginning of the treatment, respectively). Additional amelioration of liver dysfunction was not observed after growth hormone replacement.

CONCLUSIONS

The clinical course of the present case suggested that RANKL-RANK signaling may be a key pathological mechanism in establishment or development of NAFLD or NASH in patients with panhypopituitarism including GHD.

Hepatoprotective Effect and Synergism of Bisdemethoycurcumin against MCD Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, has become one of the most common causes of chronic liver disease over the last decade in developed countries. NAFLD includes a spectrum of pathological hepatic changes, such as steatosis, steatohepatitis, advanced fibrosis, and cirrhosis. Bisdemethoxycurcumin (BDMC) is polyphenolic compounds with a diarylheptanoid skeleton, curcumin close analogues, which is derived from the Curcumae Longae Rhizoma. While the rich bioavailability research of curcumin, BDMC is the poor studies. We investigated whether BDMC has the hepatoprotective effect and combinatory preventive effect with silymarin on methionine choline deficient (MCD)-diet-induced NAFLD in C57BL/6J mice. C57BL/6J mice were divided into five groups of normal (normal diet without any treatment), MCD diet (MCD diet only), MCD + silymarin (SIL) 100 mg/kg group, MCD + BDMC 100 mg/kg group, MCD + SIL 50 mg/kg + BDMC 50 mg/kg group. Body weight, liver weight, liver function tests, histological changes were assessed and quantitative real-time polymerase chain reaction and Western blot analyses were conducted after 4 weeks. Mice lost body weight on the MCD-diet, but BDMC did not lose less than the MCD-diet group. Liver weights decreased from BDMC, but they increased significantly in the MCD-diet groups. All liver function test values decreased from the MCD-diet, whereas those from the BDMC increased significantly. The MCD- diet induced severe hepatic fatty accumulation, but the fatty change was reduced in the BDMC. The BDMC showed an inhibitory effect on liver lipogenesis by reducing associated gene expression caused by the MCD-diet. In all experiments, the combinations of BDMC with SIL had a synergistic effect against MCD-diet models. In conclusion, our findings indicate that BDMC has a potential suppressive effect on NAFLD. Therefore, our data suggest that BDMC may act as a novel and potent therapeutic agent against NAFLD.

In Situ Evaluation of Oxidative Stress in Rat Fatty Liver Induced by a Methionine- and Choline-Deficient Diet

Nonalcoholic fatty liver disease (NAFLD) is a serious health problem in developed countries. We documented the effects of feeding with a NAFLD-inducing, methionine- and choline-deficient (MCD) diet, for 1-4 weeks on rat liver oxidative stress, with respect to a control diet. Glycogen, neutral lipids, ROS, peroxidated proteins, and SOD2 were investigated using histochemical procedures; ATP, GSH, and TBARS concentrations were investigated by biochemical dosages, and SOD2 expression was investigated by Western Blotting. In the 4-week-diet period, glycogen stores decreased whereas lipid droplets, ROS, and peroxidated proteins expression (especially around lipid droplets of hepatocytes) increased. SOD2 immunostaining decreased in poorly steatotic hepatocytes but increased in the thin cytoplasm of macrosteatotic cells; a trend towards a quantitative decrease of SOD expression in homogenates occurred after 3 weeks. ATP and GSH values were significantly lower for rats fed with the MCD diet with respect to the controls. An increase of TBARS in the last period of the diet is in keeping with the high ROS production and low antioxidant defense; these TBARS may promote protein peroxidation around lipid droplets. Since these proteins play key roles in lipid mobilization, storage, and metabolism, this last information appears significant, as it points towards a previously misconsidered target of NAFLD-associated oxidative stress that might be responsible for lipid dysfunction.

Altered distribution of regulatory lymphocytes by oral administration of soy-extracts exerts a hepatoprotective effect alleviating immune mediated liver injury, non-alcoholic steatohepatitis and insulin resistance

AIM

To determine the immune-modulatory and the hepatoprotective effects of oral administration of two soy extracts in immune mediated liver injury and non-alcoholic steatohepatitis (NASH).

METHODS

Two soy extracts, M1 and OS, were orally administered to mice with concanavalin A (ConA) immune-mediated hepatitis, to high-fat diet (HFD) mice and to methionine and choline reduced diet combined with HFD mice. Animals were followed for disease and immune biomarkers.

RESULTS

Oral administration of OS and M1 had an additive effect in alleviating ConA hepatitis manifested by a decrease in alanine aminotransferase and aspartate aminotransferase serum levels. Oral administration of the OS and M1 soy derived fractions, ameliorated liver injury in the high fat diet model of NASH, manifested by a decrease in hepatic triglyceride levels, improvement in liver histology, decreased serum cholesterol and triglycerides and improved insulin resistance. In the methionine and choline reduced diet combined with the high fat diet model, we noted a decrease in hepatic triglycerides and improvement in blood glucose levels and liver histology. The effects were associated with reduced serum tumor necrosis factor alpha and alteration of regulatory T cell distribution.

CONCLUSION

Oral administration of the combination of OS and M1 soy derived extracts exerted an adjuvant effect in the gut-immune system, altering the distribution of regulatory T cells, and alleviating immune mediated liver injury, hyperlipidemia and insulin resistance.

Choline and Cystine Deficient Diets in Animal Models with Hepatocellular Injury: Evaluation of Oxidative Stress and Expression of RAGE, TNF-α, and IL-1β

This study aims to evaluate the effects of diets deficient in choline and/or cystine on hepatocellular injury in animal models (young male Wistar rats, aged 21 days), by monitoring some of the oxidative stress biomarkers and the expression of RAGE, TNF-α, and IL-1β. The animals were divided into 6 groups (n = 10) and submitted to different diets over 30 days: AIN-93 diet (standard, St), AIN-93 choline deficient (CD) diet and AIN-93 choline and cystine deficient (CCD) diet, in the pellet (pl) and powder (pw) diet forms. Independently of the diet form, AIN-93 diet already led to hepatic steatosis and CD/CCD diets provoked hepatic damage. The increase of lipid peroxidation, represented by the evaluation of thiobarbituric acid reactive species, associated with the decrease of levels of antioxidant enzymes, were the parameters with higher significance toward redox profile in this model of hepatic injury. Regarding inflammation, in relation to TNF-α, higher levels were evidenced in CD_(pl), while, for IL-1β, no significant alteration was detected. RAGE expression was practically the same in all groups, with exception of CCD_(pw) versus CCD_(pl). These results together confirm that AIN-93 causes hepatic steatosis and choline and/or cysteine deficiencies produce important hepatic injury associated with oxidative stress and inflammatory profiles.

6-gingerol protects against nutritional steatohepatitis by regulating key genes related to inflammation and lipid metabolism

Non-alcoholic fatty liver disease, including non-alcoholic steatohepatitis (NASH), appears to be increasingly common worldwide. The aim of the study was to investigate the effects of 6-gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone), a bioactive ingredient of plants belonging to the Zingiberaceae family, on experimental models of NASH. In HepG2 cells, 6-gingerol (100 μmol/L) treatment inhibited free fatty acids mixture (0.33 mmol/L palmitate and 0.66 mmol/L oleate)-induced triglyceride and inflammatory marker accumulations. Male C57BL/6 mice were fed with a methionine and choline-deficient (MCD) diet to induce steatohepatitis. After four weeks of MCD diet feeding, the mice were dosed orally with 6-gingerol (25, 50 or 100 mg/kg/day) once daily for another four weeks. 6-Gingerol (100 mg/kg/day) attenuated liver steatosis and necro-inflammation in MCD diet-fed mice. The expressions of inflammatory cytokine genes, including those for monocyte chemoattractant protein-1, tumor necrosis factor-α, and interleukin-6, and nuclear transcription factor (NF-κB), which were increased in the livers of MCD diet-fed mice, were attenuated by 6-gingerol. 6-Gingerol possesses a repressive property on hepatic steatosis, which is associated with induction of peroxisome proliferator-activated receptor α. Our study demonstrated the protective role of 6-gingerol in ameliorating nutritional steatohepatitis. The effect was mediated through regulating key genes related to lipid metabolism and inflammation.

Auricularia polytricha aqueous extract supplementation decreases hepatic lipid accumulation and improves antioxidative status in animal model of nonalcoholic fatty liver

Background: Amelioration effect of Auricularia polytricha water extract (AP) on hepatic injury in an animal model of NAFLD was investigated. Methods: Forty six-week-old Wistar rats were housed and thirty-two fed ten percent lard high-fat diet to induce NAFLD. After eight weeks of induction, animals were divided into five groups of eight rats each: normal control, high-fat diet, RN (reversion to a normal diet), 1× AP (normal diet plus 0.75% AP, w/w), and 2×AP (normal diet plus 1.5% AP). Animals were sacrificed four weeks later. Results: Rats receiving either 0.75% or 1.5% AP exhibited effective interruption of NAFLD progression, as evidenced by decreased lipid accumulation and elevated antioxidative status. Histological examination proved AP anti-inflammatory function and lower level of related markers for tumor necrosis factor-α and interleukin-6. Besides abundant polysaccharides against lipid accumulation, AP had a specific high level of phenolic compounds and tannins thus may be a potent anti-inflammatory and antioxidative agent. Conclusion: Findings suggest that under normal diet recovery, AP supplement may represent novel, protective material against NAFLD by attenuating inflammatory response, oxidative stress and lipid deposition.

RB tumor suppressive function in response to xenobiotic hepatocarcinogens

Diverse etiologic events are associated with the development of hepatocellular carcinoma. During hepatocarcinogenesis, genetic events likely occur that subsequently cooperate with long-term exposures to further drive the progression of hepatocellular carcinoma. In this study, the frequent loss of the retinoblastoma (RB) tumor suppressor in hepatocellular carcinoma was modeled in response to diverse hepatic stresses. Loss of RB did not significantly affect the response to a steatotic stress as driven by a methionine- and choline-deficient diet. In addition, RB status did not significantly influence the response to peroxisome proliferators that can drive hepatomegaly and tumor development in rodents. However, RB loss exhibited a highly significant effect on the response to the xenobiotic1,4-Bis-[2-(3,5-dichloropyridyloxy)] benzene. Loss of RB yielded a unique proliferative response to this agent, which was distinct from both regenerative stresses and genotoxic carcinogens. Long-term exposure to 1,4-Bis-[2-(3,5-dichloropyridyloxy)] benzene yielded profound tumor development in RB-deficient livers that was principally absent in RB-sufficient tissue. These data demonstrate the context specificity of RB and the key role RB plays in the suppression of hepatocellular carcinoma driven by xenobiotic stress.

Cordyceps militaris alleviates non-alcoholic fatty liver disease in ob/ob mice

BACKGROUND/OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is becoming an important public health problem as metabolic syndrome and type 2 diabetes have become epidemic. In this study we investigated the protective effect of Cordyceps militaris (C. militaris) against NAFLD in an obese mouse model.

MATERIALS/METHODS

Four-week-old male ob/ob mice were fed an AIN-93G diet or a diet containing 1% C. militaris water extract for 10 weeks after 1 week of adaptation. Serum glucose, insulin, free fatty acid (FFA), alanine transaminase (ALT), and proinflammatory cytokines were measured. Hepatic levels of lipids, glutathione (GSH), and lipid peroxide were determined.

RESULTS

Consumption of C. militaris significantly decreased serum glucose, as well as homeostasis model assessment for insulin resistance (HOMA-IR), in ob/ob mice. In addition to lowering serum FFA levels, C. militaris also significantly decreased hepatic total lipids and triglyceride contents. Serum ALT activities and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were reduced by C. militaris. Consumption of C. militaris increased hepatic GSH and reduced lipid peroxide levels.

CONCLUSIONS

These results indicate that C. militaris can exert protective effects against development of NAFLD, partly by reducing inflammatory cytokines and improving hepatic antioxidant status in ob/ob mice.

Hepatic fat during fasting and refeeding by MRI fat quantification

PURPOSE

To explore the sensitivity of high-field small animal magnetic resonance imaging to dynamic changes in fat content in the liver and to characterize the effect of prandial state on imaging studies of hepatic fat.

MATERIALS AND METHODS

A total of three timepoints were acquired using asymmetric spin-echo acquisitions for 12 mice with 24-hour spacing. After the first scan, half of the cohort was placed on a water-only diet. The second half of the cohort continued to have access to their high-fat chow. The scans were repeated after 24 hours. All animals were then returned to the high-fat diet, and the scans were again repeated after 24 hours. Fat fraction maps were computed using previously described methods. Regions of interests were manually drawn in the livers and the patterns of the two groups over time were compared.

RESULTS

Five out of six of the animals in the starved group showed an increase in hepatic fat fraction during the fasting period (average increase 0.54 ± 0.48), which decreased on refeeding. Analysis of variance indicated that the results significantly depended on both the group and the timepoint (P = 0.003).

CONCLUSION

Fat-water imaging methods are able to measure hepatic fat changes caused by short-term dietary perturbations.

miR-107 orchestrates ER stress induction and lipid accumulation by post-transcriptional regulation of fatty acid synthase in hepatocytes

MicroRNAs, a class of small non-coding RNAs, are believed to regulate several biological pathways and processes and are implicated in several diseases. They mostly regulate the levels of their target genes at the post transcriptional stage by primarily binding to the 3' UTR. Elevated hepatic levels of miR-107 are a consistent feature associated with several obese and diabetic models. Here, we show that miR-107 post-transcriptionally regulates fatty acid synthase (FASN) by binding to its 3' UTR and reduces its protein levels and the 3'UTR luciferase reporter activity, which are blunted by the miR-107 inhibitor and mutation in the miR-107 binding site in the 3' UTR. Knock-down of endogenous miR-107 levels increased FASN levels in a dose-dependent manner. Overexpression of miR-107 led to significant accumulation of malonyl CoA, accompanied by ER stress induction. All these events were prevented in the presence of the miR-107 inhibitor. While overexpression of FASN could attenuate miR-107 mediated ER stress markers' induction; the ER stress inhibitor, 4-phenyl-butyric acid did not rescue miR-107 induced FASN inhibition. This was followed by increased triglyceride formation and lipid accumulation in the presence of miR-107. These indicate that miR-107 inhibits FASN levels by binding to its 3' UTR and this interaction promotes ER stress induction and malonyl CoA and lipid accumulation in HepG2 cells and primary hepatocytes. Our results suggest that increased levels of miR-107 are critical in promoting lipid accumulation in hepatocytes and this might form the basis of diverse etiologies encountered in a fatty liver.

'The way to a man's heart is through his gut microbiota'--dietary pro- and prebiotics for the management of cardiovascular risk

The human gut microbiota has been identified as a possible novel CVD risk factor. This review aims to summarise recent insights connecting human gut microbiome activities with CVD and how such activities may be modulated by diet. Aberrant gut microbiota profiles have been associated with obesity, type 1 and type 2 diabetes and non-alcoholic fatty liver disease. Transfer of microbiota from obese animals induces metabolic disease and obesity in germ-free animals. Conversely, transfer of pathogen-free microbiota from lean healthy human donors to patients with metabolic disease can increase insulin sensitivity. Not only are aberrant microbiota profiles associated with metabolic disease, but the flux of metabolites derived from gut microbial metabolism of choline, phosphatidylcholine and l-carnitine has been shown to contribute directly to CVD pathology, providing one explanation for increased disease risk of eating too much red meat. Diet, especially high intake of fermentable fibres and plant polyphenols, appears to regulate microbial activities within the gut, supporting regulatory guidelines encouraging increased consumption of whole-plant foods (fruit, vegetables and whole-grain cereals), and providing the scientific rationale for the design of efficacious prebiotics. Similarly, recent human studies with carefully selected probiotic strains show that ingestion of viable microorganisms with the ability to hydrolyse bile salts can lower blood cholesterol, a recognised risk factor in CVD. Taken together such observations raise the intriguing possibility that gut microbiome modulation by whole-plant foods, probiotics and prebiotics may be at the base of healthy eating pyramids advised by regulatory agencies across the globe. In conclusion, dietary strategies which modulate the gut microbiota or their metabolic activities are emerging as efficacious tools for reducing CVD risk and indicate that indeed, the way to a healthy heart may be through a healthy gut microbiota.

Chunggan extract (CGX), methionine-and choline-deficient (MCD) diet-induced hepatosteatosis and oxidative stress in C57BL/6 mice

In the present study, we aimed to evaluate the hepatoprotective and antioxidant effects of Chunggan extract (CGX) in an animal model of hepatosteatosis. The C57BL/6N mice were fed either methionine- and choline-sufficient (MCS) diet (n = 10) or a methionine- and choline-deficient (MCD) diet (n = 50) for 4 weeks, and then they were treated orally with CGX (100 or 200 mg/kg), ursodeoxycholic acid (80 mg/kg, as a positive control), or distilled water (DW, MCS diet group, and MCD diet group) for the final 2 weeks (once per day). The MCD diet induced severe hepatic injury with the typical features of hepatosteatosis in both serum and hepatic tissues. CGX treatment significantly attenuated these alterations in the serum levels including triglyceride (TG), aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total bilirubin. Moreover, CGX also efficiently prevented from the hepatic TG accumulation in the hepatic tissue, evidenced by histopathological findings, compared with the MCD diet. In addition, CGX treatment significantly ameliorated the excessive oxidative stress and antioxidant markers in the serum as well as the hepatic levels of reactive oxygen species, the levels of malondialdehyde, the protein carbonyl, and total antioxidant capacity, and the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. In conclusion, our results indicate the experimental relevance of CGX for potential clinical application in patients with hepatosteatotic disorders and a possible mechanism related to its antioxidant properties.

Injury-dependent retention of intraportally administered mesenchymal stromal cells following partial hepatectomy of steatotic liver does not lead to improved liver recovery

The aim of this study was to evaluate the effect of bone marrow-derived mesenchymal stromal cell (BM-MSC) administration on liver function following partial hepatectomy (PHx) of methionine/choline-deficient (MCD) diet induced steatotic livers in rodents. Here we identified and validated serum cholinesterase (CHE) and triglyceride (TG) levels as non-invasive markers to longitudinally monitor rat liver function. Using in vivo bioluminescence imaging, retention of BM-MSC in the liver was observed following intraportal administration, but not after intravenous administration. Therefore, BM-MSC were intraportally delivered to investigate the effect on liver recovery and/or regeneration after PHx. However, despite recovery to normal body weight, liver weight and NAS score, both serum CHE and TG levels of non-treated and cell-treated rats with PHx after MCD diet remained significantly lower as compared to those of control rats. Importantly, serum CHE levels, but not TG levels, of cell-treated rats remained significantly lower as compared to those of non-treated rats, thereby warranting that certain caution should be considered for future clinical application of IP BM-MSC administration in order to promote liver regeneration and/or function.

Liver proteomics in progressive alcoholic steatosis

Fatty liver is an early stage of alcoholic and nonalcoholic liver disease (ALD and NALD) that progresses to steatohepatitis and other irreversible conditions. In this study, we identified proteins that were differentially expressed in the livers of rats fed 5% ethanol in a Lieber-DeCarli diet daily for 1 and 3 months by discovery proteomics (two-dimensional gel electrophoresis and mass spectrometry) and non-parametric modeling (Multivariate Adaptive Regression Splines). Hepatic fatty infiltration was significantly higher in ethanol-fed animals as compared to controls, and more pronounced at 3 months of ethanol feeding. Discovery proteomics identified changes in the expression of proteins involved in alcohol, lipid, and amino acid metabolism after ethanol feeding. At 1 and 3 months, 12 and 15 different proteins were differentially expressed. Of the identified proteins, down regulation of alcohol dehydrogenase (-1.6) at 1 month and up regulation of aldehyde dehydrogenase (2.1) at 3 months could be a protective/adaptive mechanism against ethanol toxicity. In addition, betaine-homocysteine S-methyltransferase 2 a protein responsible for methionine metabolism and previously implicated in fatty liver development was significantly up regulated (1.4) at ethanol-induced fatty liver stage (1 month) while peroxiredoxin-1 was down regulated (-1.5) at late fatty liver stage (3 months). Nonparametric analysis of the protein spots yielded fewer proteins and narrowed the list of possible markers and identified d-dopachrome tautomerase (-1.7, at 3 months) as a possible marker for ethanol-induced early steatohepatitis. The observed differential regulation of proteins have potential to serve as biomarker signature for the detection of steatosis and its progression to steatohepatitis once validated in plasma/serum.

Pharmacokinetic study of major bioactive components in rats after oral administration of extract of Ilex hainanensis by high-performance liquid chromatography/electrospray ionization mass spectrometry

Ilex hainanensis Merr. is commonly used as a folk remedy for treating hypertension, dyslipidemia and inflammation in Traditional Chinese Medicine (TCMs) and it also has great potential to treat non-alcoholic fatty liver disease (NAFLD). Chlorogenic acid, kaempferol-7-O-β-d-glucoside, and ilexgenin A are three major bioactive components in I. hainanensis extract. In this study, a rapid, sensitive and convenient LC-MS method was developed for their simultaneous determination in the plasma of normal and NAFLD rats. The method was validated in terms of selectivity, linearity and sensitivity, and shows advantages in monitoring the pharmacokinetic behaviors of these three compounds. Results revealed the pharmacokinetic behaviors of chlorogenic acid, kaempferol-7-O-β-d-glucoside, and ilexgenin A could be significantly changed in NAFLD rats after oral administration of I. hainanensis extract compared with normal rats. The areas under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax) of the three analytes were greatly decreased and the plasma clearance (CL) for kaempferol-7-O-β-d-glucoside, Ilexgenin A were greatly increased in NAFLD rats. Meanwhile, the mean residence time (MRT) of kaempferol-7-O-β-d-glucoside and Ilexgenin A were increased in the NAFLD rats. This is the first report on the determination of the major bioactive components in rat plasma after oral administration of I. hainanensis extract. These results provided a meaningful basis for evaluating the clinical application of this medicine.

Inhibitory effect of Ginkgo biloba extract on fatty liver: regulation of carnitine palmitoyltransferase 1a and fatty acid metabolism

OBJECTIVE

To investigate the potential effect of Ginkgo biloba extract (GBE) on the prevention and treatment of nonalcoholic fatty liver disease (NAFLD).

METHODS

Male Wistar rats were divided into 4 groups (the control group, GBE group, high-fat diet [HFD] group and HFD + GBE group). The human hepatocellular carcinoma cell line (HepG2) was treated with GBE and its flavonoid ingredients. The fatty acid composition of the rat liver was analyzed with gas chromatography/time-of-flight mass spectrometry (GC/TOFMS). Triglyceride contents of both the rat liver and HepG2 cells were measured by enzymatic colorimetric method. The expressions of fatty acid metabolism-related genes were analyzed with real-time reverse transcription-polymerase chain reaction (RT-PCR). The protein expression and enzymatic activity were subsequently measured.

RESULTS

In rat livers, GBE reduced the elevations of hepatic triglyceride contents caused by HFD and the increased hepatic fatty acids were differentially affected by GBE. Notably, the expression and total activity of the fatty acid β-oxidation rate-limiting enzyme, carnitine palmitoyltransferase 1a (CPT1A), were also promoted with GBE ingestion. In HepG2 cells, GBE and its ingredients, quercetin, kaempferol and isorhamnetin, could decrease the cellular triglyceride content and upregulate the expression and total activity of CPT1A, respectively.

CONCLUSIONS

The triglyceride-lowering effect of GBE on the HFD rat liver is closely associated with the increased expression and activity of CPT1A, and the flavonoid ingredients are the major contributors of GBE.

Measuring altered disposition of xenobiotics in experimental models of liver disease

Understanding the metabolic pathway and excretion mechanisms governing the disposition of a compound is essential to the safe use of pharmaceutical agents. Because the liver is the primary organ responsible for the metabolism and elimination of xenobiotics, chronic liver disease can have a significant effect on the disposition of many xenobiotics due to changes in the expression or function of drug metabolizing enzymes and transporters. Liver disease can result in increased retention of a xenobiotic within the body, causing greater exposure of the individual to a potentially harmful compound, which may lead to toxicity. On the other hand, liver disease may also up-regulate the elimination processes of a xenobiotic, accelerating its removal from the body. With regard to a pharmaceutical agent, enhanced elimination may result in a decreased pharmacologic effect. Such alterations may necessitate dosage adjustments to achieve the desired therapeutic outcome.