Comparative review of diets for the metabolic syndrome: implications for nonalcoholic fatty liver disease

Gut microbes, diet, and genetics as drivers of metabolic liver disease: a narrative review outlining implications for precision medicine

Metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing in prevalence, impacting over a third of the global population. The advanced form of MASLD, Metabolic dysfunction-associated steatohepatitis (MASH), is on track to become the number one indication for liver transplant. FDA-approved pharmacological agents are limited for MASH, despite over 400 ongoing clinical trials, with only a single drug (resmetirom) currently on the market. This is likely due to the heterogeneous nature of disease pathophysiology, which involves interactions between highly individualized genetic and environmental factors. To apply precision medicine approaches that overcome interpersonal variability, in-depth insights into interactions between genetics, nutrition, and the gut microbiome are needed, given that each have emerged as dynamic contributors to MASLD and MASH pathogenesis. Here, we discuss the associations and molecular underpinnings of several of these factors individually and outline their interactions in the context of both patient-based studies and preclinical animal model systems. Finally, we highlight gaps in knowledge that will require further investigation to aid in successfully implementing precision medicine to prevent and alleviate MASLD and MASH.

Relative Recovery of Non-Alcoholic Fatty Liver Disease (NAFLD) in Diet-Induced Obese Rats

Consumption of a high-carbohydrate diet has a critical role in the induction of weight gain and obesity-related pathologies. This study tested the hypothesis that a carbohydrate-rich diet induces weight gain, ectopic fat deposition, associated metabolic risks and development of non-alcoholic fatty liver disease (NAFLD), which are partially reversible following carbohydrate reduction. Sprague Dawley (SD) rats were fed a carbohydrate-enriched cafeteria diet (CAF) or normal chow (NC) ad libitum for 16-18 weeks. In the reversible group (REV), the CAF was replaced with NC for a further 3 weeks (18-21 weeks). Animals fed the CAF diet showed significantly increased body weight compared to those fed NC, accompanied by abnormal changes in their systemic insulin and triglycerides, elevation of hepatic triglyceride and hepatic steatosis. In the REV group, when the CAF diet was stopped, a modest, non-significant weight loss was associated with improvement in systemic insulin and appearance of the liver, with lower gross fatty deposits and hepatic triglyceride. In conclusion, a carbohydrate-enriched diet led to many features of metabolic syndrome, including hyperinsulinemia, while a dietary reduction in this macronutrient, even for a short period, was able to restore normoinsulinemia, and reversed some of the obesity-related hepatic abnormalities, without significant weight loss.

Divergent pathways of liver fat accumulation, oxidation, and secretion in lipodystrophy versus obesity-associated NAFLD

BACKGROUND AND AIMS

Fatty liver is common in obesity as well as in partial lipodystrophy (PL) syndromes, characterized by deficient adipose tissue. Insulin resistance is key to fatty liver pathogenesis in both entities. We aimed to compare the contributions of insulin resistance and adipose tissue to hepatic steatosis in PL and non-syndromic, obesity-associated non-alcoholic fatty liver disease (NS-NAFLD).

METHODS

In a cross-sectional comparison of people with NS-NAFLD (N = 73) and PL (N = 27), liver fat was measured by FibroScan® controlled attenuation parameter (CAP) and insulin resistance by HOMA-IR, Adipo-IR, and NMR-based LP-IR.

RESULTS

Insulin resistance was greater in PL versus NS-NAFLD by HOMA-IR (p = 0.005), Adipo-IR (p = 0.01) and LP-IR (p = 0.05) while liver fat was comparable (304 vs. 324 dB/m, p = 0.12). Liver fat correlated with HOMA-IR in both groups, but CAP values were lower by 32 dB/m in PL compared with NS-NAFLD for any given HOMA-IR. In contrast, Adipo-IR and LP-IR correlated with CAP only in the NS-NAFLD group, suggesting different pathways for fat accumulation. Plasma free fatty acids, reflecting substrate input from the adipose tissue, were comparable between groups. However, the levels of β-hydroxybutyrate, a marker of β-oxidation, and large triglyceride-rich lipoprotein particles, a marker of VLDL secretion, were both higher in PL (p < 0.001 for both).

CONCLUSION

Liver fat content was comparable in subjects with PL-associated NAFLD and NS-NAFLD, despite worse insulin resistance in partial lipodystrophy. Our data demonstrate higher triglyceride oxidation and export in PL, suggesting a compensatory shift of fat from liver storage into the circulation that does not occur in NS-NAFLD.

Management of metabolic syndrome by nutraceuticals prepared from chitosan and ferulic acid with or without beta-sitosterol and their nanoforms

Dyslipidemia, steatohepatitis and insulin resistance are among the components of metabolic syndrome (MS). Nutraceuticals containing chitosan, beta-sitosterol and/or ferulic acid and their nanostructures could have a potential role for management of MS. The aim of the present study was to assess the efficacy of the aforementioned nutraceuticals in treatment of MS in rat and their interaction with atorvastatin, a hypolipidemic drug. The two nutraceuticals and their nanostructures were prepared and the nanostructures were assessed by transmission electron microscope and Fourier-Transform Infra-red Spectrometry. MS was induced in rats by feeding high fructose-high fat diet (HFFD). Different groups of rats fed HFFD and treated with the different nutraceuticals, atorvastatin and atorvastatin in combination with different nutraceuticals, control fed on balanced diet and control consumed HFFD without treatments were run. Plasma glucose, lipid profile, aminotransferases activity, total antioxidant capacity, malondialdehyde, urea, creatinine, insulin, high sensitivity C-reactive protein, and adiponectin were assessed along with calculation of insulin resistance. Liver fat and histopathology were investigated. All nutraceuticals in original and nanostructures showed beneficial effects in the treatment of MS, superiority was ascribed to nutraceuticals composed of chitosan and ferulic acid in both forms. A more promising treatment of MS belonged to atorvastatin administered with the different nutraceuticals.

Vitamin D3 alleviates nonalcoholic fatty liver disease in rats by inhibiting hepatic oxidative stress and inflammation via the SREBP-1-c/ PPARα-NF-κB/IR-S2 signaling pathway

Introduction: Nonalcoholic fatty liver disease (NAFLD) is a chronic disease characterized by fat deposits in liver cells, which can lead to hepatitis and fibrosis. This study attempted to explore the protective effect of vitamin D3 (VitD) against NAFLD. Methods: Adult male albino rats were randomized into four separate groups: the negative control group was fed a standard rat chow; the positive group received a high-fat diet (20%) and 25% fructose water (NAFLD); the VitD control group was intramuscularly treated with VitD (1,000 IU/kg BW) 3 days per week for 10 weeks; and the NAFLD group was treated with VitD therapy. Biochemical and hepatic histological analyses were performed. Hepatic oxidative stress and inflammatory conditions were also studied. Hepatic expression of sterol regulatory element-binding protein 1-c (SREBP-1-c), peroxisome proliferator-activated receptor alpha (PPAR-α), and insulin receptor substrate-2 was analyzed by quantitative real-time polymerase chain reaction. Results and discussion: The NAFLD rats exhibited elevated terminal body weight, hepatic injury markers, dyslipidemia, glucose intolerance, and insulin resistance. Moreover, the NAFLD rats had increased SREBP-1-c expression and reduced PPAR-α and IRS-2 expressions. Histological analysis showed hepatic steatosis and inflammation in the NAFLD group. In contrast, VitD administration improved the serum biochemical parameters and hepatic redox status in NAFLD rats. Also, VitD treatment ameliorated hepatic inflammation and steatosis in the NAFLD group by decreasing the expression of SREBP-1-c and increasing the expression of PPAR-α. Overall, these results suggest that VitD could have a protective effect against NAFLD and its associated complication.

Hepatic Transcriptomics Reveals Reduced Lipogenesis in High-Salt Diet Mice

It has been demonstrated that a high salt diet (HSD) increases the risk of cardiovascular disease and metabolic dysfunction. In particular, the impact and molecular mechanisms of long-term HSD on hepatic metabolism remain largely unknown. To identify differentially expressed genes (DEGs) affecting the metabolism of liver tissues from HSD and control groups, a transcriptome analysis of liver tissues was performed in this study. As a result of the transcriptome analysis, the expression of genes related to lipid and steroid biosynthesis (such as Fasn, Scd1, and Cyp7a1) was significantly reduced in the livers of HSD mice. Additionally, several gene ontology (GO) terms have been identified as associated with metabolic processes in the liver, including the lipid metabolic process (GO: 0006629) and the steroid metabolic process (GO: 0008202). An additional quantitative RT-qPCR analysis was conducted to confirm six down-regulated genes and two up-regulated genes. Our findings provide a theoretical basis for further investigation of HSD-induced metabolic disorders.

Thermodynamic Assessment of the Effects of Intermittent Fasting and Fatty Liver Disease Diets on Longevity

Organisms uptake energy from their diet and maintain a highly organized structure by importing energy and exporting entropy. A fraction of the generated entropy is accumulated in their bodies, thus causing ageing. Hayflick's entropic age concept suggests that the lifespan of organisms is determined by the amount of entropy they generate. Organisms die after reaching their lifespan entropy generation limit. On the basis of the lifespan entropy generation concept, this study suggests that an intermittent fasting diet, which means skipping some meals without increasing the calories uptake in the other courses, may increase longevity. More than 1.32 million people died in 2017 because of chronic liver diseases, and a quarter of the world's population has non-alcoholic fatty liver disease. There are no specific dietary guidelines available for the treatment of non-alcoholic fatty liver diseases but shifting to a healthier diet is recommended as the primary treatment. A healthy obese person may generate 119.9 kJ/kg K per year of entropy and generate a total of 4796 kJ/kg K entropy in the first 40 years of life. If obese persons continue to consume the same diet, they may have 94 years of life expectancy. After age 40, Child-Pugh Score A, B, and C NAFLD patients may generate 126.2, 149.9, and 272.5 kJ/kg K year of entropy and have 92, 84, and 64 years of life expectancy, respectively. If they were to make a major recommended shift in their diet, the life expectancy of Child-Pugh Score A, B, and C patients may increase by 29, 32, and 43 years, respectively.

Omega-3 polyunsaturated fatty acids in the treatment of non-alcoholic fatty liver disease: An umbrella systematic review and meta-analysis

There has been conflicting evidence from meta-analyses on the effect of polyunsaturated fatty acids (PUFA) on non-alcoholic fatty liver disease (NAFLD). Therefore, in this umbrella meta-analysis, we are evaluating whether omega-3 PUFA supplementation has any benefit in treating NAFLD. Electronic databases such as PubMed, Web of Science, Scopus, Embase and Google Scholar were assessed to October 2022. This meta-analysis included all meta-analyses that examined the effect of PUFAs on liver fat and liver function tests [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT)]. Meta-analysis was conducted using a random effects model. Subgroup analyses and sensitivity analyses were also performed. In total, eight articles involving 6,561 participants met the eligibility criteria. Advantageous impacts PUFA supplementation were observed on ALT (ES_WMD  = -6.72 IU/L; 95% CI: -8.61, -4.84; p < 0.001, and ES_SMD  = -0.52 IU/L; 95% CI: -0.84, -0.20, p < 0.001), AST (ES_WMD  = -3.73 IU/L, 95% CI: -5.93, -1.53, p < 0.001, and ES_SMD  = -0.65 IU/L; 95% CI: -1.08, -0.22, p = 0.003), GGT levels (ES_WMD  = -4.20 IU/L, 95% CI: -6.85, -1.55, p = 0.002), and liver fat (ES_WMD  = -5.16; 95% CI: -8.49, -1.82, p < 0.001). Intervention with omega-3 PUFAs improves ALT, AST, GGT, and liver fat in patients with NAFLD. Thus, omega-3 PUFAs could be considered as a therapeutic option in the treatment of NAFLD.

Intermittent Protein Diets Alter Hepatic Lipid Accumulation by Changing Tryptophan Metabolism in a Fast-Response Manner

In modern life, the fluctuation of dietary protein levels is common, in particular, for low-income populations. However, its effect on human health is little known. Alternating changes of low and high casein or pork protein were used to simulate the fluctuation of dietary protein content in mice. Hepatic lipid accumulation showed a fast response to alternating changes of low- and high-protein diets. Correspondingly, some gut microbiota and tryptophan metabolite composition also showed a fast response to dietary protein changes. The fast response of 3-hydroxykynurenine (3-HK) was proven to inhibit hepatic lipid accumulation in vitro. Therefore, intermittent protein diets modulated hepatic lipid accumulation through 3-HK. These findings highlighted the sensitivity of hepatic lipid accumulation to dietary protein levels.

Uncovering the effect and mechanism of Panax notoginseng saponins on metabolic syndrome by network pharmacology strategy

ETHNOPHARMACOLOGICAL RELEVANCE

Metabolic syndrome (MetS) is a cluster of disease centered on obesity, which is the result of stagnation of liver qi according to traditional Chinese medicine. Panax notoginseng is a traditional Chinese herbal medicine, entering liver and stomach meridians and dissipating blood stasis, in which panax notoginseng saponins (PNS) are the main active components. However, its effects and mechanism on metabolic syndrome has not been revealed yet.

AIM OF STUDY

To evaluate the anti-MetS effect of PNS, including body weight and adiposity, glucose metabolism and non-alcoholic fatty liver disease (NAFLD), as well as to explore the mechanism and signaling pathway of PNS on MetS effect.

MATERIALS AND METHODS

HPLC was utilized to affirm the percentages of saponins in PNS. In vivo, normal C57BL/6J mice and high-fat diet (HFD)-induced MetS mice were used to evaluate anti-MetS effect of PNS. Body weight, food and water intake were recorded. NMR imager was used for NMR imaging and lipid-water analysis. Blood glucose detection, glucose and insulin tolerance test were performed to evaluate glucose metabolism. Biochemical indexes analysis and histopathological staining were used to evaluate the effect on NAFLD. The expressions of mRNA and proteins related to thermogenesis in adipose tissue were determined using real-time PCR and Western blot. In silico, network pharmacology was utilized to predict potential mechanism. In vitro, matured 3T3-L1 adipocyte was used as subject to confirm the signaling pathway by Western blot.

RESULTS

We determined the content of PNS component by HPLC. In vivo, PNS could improve metabolic syndrome with weight loss, reduction of adiposity, improvement of adipose distribution, correction of glucose metabolism disorder and attenuation of NAFLD. Mechanismly, PNS boosted energy exhaustion and dramatically enhanced thermogenesis in brown adipose tissue (BAT), induced white adipose tissue (WAT) browning. In silico, utilizing network pharmacology strategy, we identified 307 candidate targets which were enriched in MAPK signaling pathway specifically in liver tissue and adipocyte. In vitro validation confirmed ERK and p38MAPK mediated anti-MetS effects of PNS, not JNK signaling pathway.

CONCLUSION

PNS exerted protective effect on metabolic syndrome through MAPK-mediated adipose thermogenic activation, which may serve as a prospective therapeutic drug for metabolic syndrome.

Non-pharmacological management options for MAFLD: a practical guide

Lifestyle changes should be the main basis for any treatment for metabolic dysfunction-associated fatty liver disease (MAFLD), aiming to increase energy expenditure, reduce energy intake and improve the quality of nutrients consumed. As it is a multifactorial disease, approaches such as physical exercise, a better dietary pattern, and possible pharmacological intervention are shown to be more efficient when used simultaneously to the detriment of their applications. The main treatment for MAFLD is a lifestyle change consisting of diet, activity, exercise, and weight loss. The variables for training prescription such as type of physical exercise (aerobic or strength training), the weekly frequency, and the intensity most indicated for the treatment of MAFLD remain uncertain, that is, the recommendations must be adapted to the clinical conditions comorbidities, and preferences of each subject in a way individual. This review addresses recent management options for MAFLD including diet, nutrients, gut microbiota, and physical exercise.

Higher carbohydrate intake in relation to non-alcoholic fatty liver disease in patients with type 2 diabetes

Background

Non-alcoholic fatty liver disease (NAFLD) is an overlooked complication of type 2 diabetes (T2D). Current recommendations for the management of NAFLD are mainly focused on weight reduction, overlooking the role of macronutrient composition. Although dietary carbohydrates play a major role in intrahepatic fat synthesis, their association with the progression of liver steatosis has not been fully investigated in patients with T2D.

Aim

To investigate the association between higher carbohydrate intake and the presence of liver steatosis in patients with T2D.

Methods

This cross-sectional study included men and women aged 18-60 years diagnosed with T2D. Anthropometric measurements, hepatic steatosis assessment using the controlled attenuation parameter (CAP), blood samples, and dietary data were analyzed. Participants were divided into two groups: NAFLD and NAFLD-free. A two-sample t-test was used to evaluate the differences between the two groups. Stepwise multiple linear regression models adjusted for potential confounders were used to determine the association between CAP values and higher carbohydrate intake.

Results

In total, 358 participants were included. NAFLD was present in 79.3% of the participants. Body mass index, waist circumference, ALT, HbA1c, and triglycerides showed direct, while HDL-Cholesterol revealed inverse associations with CAP values. No significant relationship was found between carbohydrate intake and steatosis in the total study sample; however, multiple linear regression analysis revealed a significant relationship between carbohydrate intake and CAP values in patients aged ≤50 years.

Conclusion

In patients with T2D, higher carbohydrate intake was associated with liver steatosis in those aged 50 years and below. Further studies are required to confirm the causality between carbohydrate intake and liver steatosis.

Dihydroquercetin Supplementation Improved Hepatic Lipid Dysmetabolism Mediated by Gut Microbiota in High-Fat Diet (HFD)-Fed Mice

Dihydroquercetin (DHQ) is a natural flavonoid with multiple bioactivities, including hepatoprotective effects. This study aimed to investigate whether DHQ improved lipid dysmetabolism in the body, especially in the liver, and whether there is a relationship between hepatic metabolism and altered gut flora in high-fat diet (HFD)-induced mice. HFD-induced mice were given 50 mg/kg body weight DHQ intragastrically for 10 weeks. The data showed that DHQ reduced body weight, the weight of the liver and white adipose tissue as well as serum leptin, LPS, triglyceride and cholesterol levels. RNA-seq results indicated that DHQ down-regulated lipogenesis-related genes and up-regulated fatty acid oxidation-related genes, including MOGAT1 and CPT1A. Furthermore, DHQ had a tendency to decrease hepatic cholesterol contents by reducing the mRNA levels of cholesterol synthesis genes such as FDPS and HMGCS1. 16S rRNA sequencing analysis indicated that DHQ significantly decreased the richness of Lactococcus, Lachnoclostridium, and Eubacterium_xylanophilum_group. Correlation analysis further demonstrated that these bacteria, Lactococcus and Eubacterium_xylanophilum_group in particular, had significantly positive correlation with lipid and cholesterol synthesis genes, and negative correlation with fatty acid oxidation genes. In conclusion, DHQ could improve hepatic lipid dysmetabolism potentially by improved gut microbial community, which may be used as an intervention strategy in hepatic metabolism diseases.

Developmental modeling of hepatogenesis using obese iPSCs-hepatocyte differentiation uncovers pathological features

Obesity is a multigene disorder. However, in addition to genetic factors, environmental determinants also participate in developing obesity and related pathologies. Thus, obesity could be best described as a combination of genetic and environmental perturbations often having its origin during the early developmental period. Environmental factors such as energy-dense food and sedentary lifestyle are known to be associated with obesogenicity. However, the combinatorial effects of gene-environment interactions are not well understood. Understanding the role of multiple genetic variations leading to subtle gene expression changes is not practically possible in monogenic or high-fat-fed animal models of obesity. In contrast, human induced pluripotent stem cells (hiPSCs) from individuals with familial obesity or an obesogenic genotype could serve as a good model system. Herein, we have used hiPSCs generated from normal and genetically obese subjects and differentiated them into hepatocytes in cell culture. We show that hepatocytes from obese iPSCs store more lipids and show increased cell death than normal iPSCs. Whole transcriptome analyses in both normal and obese iPSCs treated with palmitate compared to control revealed LXR-RXR and hepatic fibrosis pathways were enriched among other pathways in obese iPSCs compared to normal iPSCs. Among other genes, increased CD36 and CAV1 expression and decreased expression of CES1 in obese iPSCs could have been responsible for excess lipid accumulation, resulting in differential expression of genes associated with hepatic fibrosis, a key feature of non-alcoholic fatty liver disease (NAFLD). Our results demonstrate that iPSCs derived from genetically obese subjects could serve as an excellent model to understand the effects of this multigene disorder on organ development and may uncover pathologies of NAFLD, which is highly associated with obesity.

The Association of Salt Intake and Non-alcoholic Fatty Liver Disease in People With Type 2 Diabetes: A Cross-Sectional Study

Objectives

Non-alcoholic fatty liver disease (NAFLD), which has a close relationship with type 2 diabetes (T2D), is related to salt intake in the general population. In contrast, the relationship between salt intake and the presence of NAFLD in patients with T2D has not been clarified.

Methods

Salt intake (g/day) was assessed using urinary sodium excretion, and a high salt intake was defined as an intake greater than the median amount of 9.5 g/day. Hepatic steatosis index (HSI) ≥ 36 points was used to diagnosed NAFLD. Odds ratios of high salt intake to the presence of NAFLD were evaluated by logistic regression analysis.

Results

The frequency of NAFLD was 36.5% in 310 patients with T2D (66.7 ± 10.7 years old and 148 men). The patients with high salt intake had a higher body mass index (25.0 ± 4.0 vs. 23.4 ± 3.8 kg/m², p < 0.001) than those with low salt intake. HSI in patients with high salt intake was higher than that in patients with low salt intake (36.2 ± 6.2 vs. 34.3 ± 5.5 points, p = 0.005). In addition, the presence of NALFD in patients with high salt intake was higher than that in patients with low salt intake (44.5% vs. 28.4%, p = 0.005). High salt intake was associated with the prevalence of NAFLD [adjusted odds ratio, 1.76 (95% confidence interval: 1.02–3.03), p = 0.043].

Conclusion

This cross-sectional study revealed that salt intake is related to the prevalence of NAFLD in patients with T2D.

The Advent of Nutrigenomics: A Narrative Review with an Emphasis on Psychological Disorders

A new research field is emerging that combines nutrition and genetics at the molecular level, namely nutrigenomics. Several aspects of nutrigenomics are examined in this review, with a particular focus on psychological disorders. The origin of this field in the 20th century and its modern developments have been investigated. Various studies have reported the impact of genetic factors and diet on various chronic disorders, elucidating how the deficiency of several macronutrients results in significant ailments, including diabetes, cancer, cardiovascular disorders, and others. Furthermore, the application of nutrigenomics to diet and its impact on the global disease rate and quality of life have been discussed. The relationship between diet and gene expression can facilitate the classification of diet-gene interactions and the diagnosis of polymorphisms and anomalies. Numerous databases and research tools for the study of nutrigenomics are essential to the medical application of this field. The nutrition-gene interrelationships can be utilized to study brain development, impairment, and diseases, which could be a significant medical breakthrough. It has also been observed that psychological conditions are exacerbated by the interaction between gut microbes and the prevalence of malnutrition. This article focuses on the impact of nutrition on genes involved in various psychological disorders and the potential application of nutrigenomics as a revolutionary treatment method.

Relation of Dietary Patterns and Nutritional Profile to Hepatic Fibrosis in a Sample of Lebanese Non-Alcoholic Fatty Liver Disease Patients

Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver injury worldwide. NAFLD can evolve into non-alcoholic steatohepatitis (NASH) with or without fibrosis. The objectives of this study were to determine the nutritional profile and dietary patterns of NAFLD Lebanese patients and to report the type of diet-related to the presence of hepatic fibrosis. We hypothesized that the traditional pattern was related to a low risk of fibrosis. This cross-sectional study included 320 eligible Lebanese NAFLD patients. Three dietary patterns were identified: the Traditional diet, the High Fruit diet, and the Westernized diet. Multivariate analysis showed a significant relationship between high adherence to the traditional diet and absence of hepatic fibrosis with a decreased risk of 82%, p = 0.031 after adjusting for its covariables. Fruits were absent from this dietary pattern. Although our results pointed to a possible relationship between fibrosis in NAFLD patients and fruit intake, experimental studies are needed to show whether this is a causal relationship. However, the results obtained in this study may contribute to the planning of dietary interventions and recommendations and enable a better follow-up for NAFLD patients with fibrosis.

Tilapia-Head Chondroitin Sulfate Protects against Nonalcoholic Fatty Liver Disease via Modulating the Gut-Liver Axis in High-Fat-Diet-Fed C57BL/6 Mice

We isolated and characterized tilapia-head chondroitin sulfate (TH-CS) and explored its biological activity and mechanisms of action as an oral supplement for nonalcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD) in mice. The results showed that treatment with TH-CS for 8 weeks alleviated the development of NAFLD, as evidenced by the notable improvement in liver damage, blood lipid accumulation and insulin resistance (IR). Meanwhile, TH-CS treatment reduced the expression of proinflammatory cytokines and normalized oxidative stress. Additionally, the analysis of 16S rDNA sequencing revealed that TH-CS could restore gut microbiota balance and increase the relative abundance of short-chain fatty acid (SCFA)-producing bacteria. Furthermore, SCFAs produced by related bacteria can further improve lipid metabolism and IR by regulating lipid synthesis signals. In conclusion, TH-CS is an effective dietary supplement for the prevention of NAFLD, and may serve as a potential supplementary treatment for lipid-related metabolic syndrome.

The role of Resolvin D1 in liver diseases

The liver is a parenchymatous organ closely related to immunity, detoxification and metabolism of the three major nutrients. The inflammatory response is a protective mechanism of the body to eliminate harmful stimuli. However, continuous inflammatory stimulation leads to occurrence of many liver diseases and brings great social burden. Resolvin D1, a member of the specialized pro-resolving lipid mediators family, exerts anti-inflammatory, anti-oxidant stress, anti-fibrosis, anti-apoptotic, and anti-tumor effects by binding to ALX/FPR2 or GPR32. RvD1 plays an important role and has great therapeutic potential in liver diseases, which has been validated in multiple models of preclinical disease. This review will provide a detailed summary of the role of RvD1 in different liver diseases, including acute liver injury, liver ischemia/reperfusion injury, non-alcoholic fatty liver disease, liver fibrosis, and liver cancer, so as to help people have a more comprehensive understanding of RvD1 and promote its further research.

Enhanced alleviation of insulin resistance via the IRS-1/Akt/FOXO1 pathway by combining quercetin and EGCG and involving miR-27a-3p and miR-96-5p

Quercetin and EGCG exhibit anti-diabetic and anti-obesity activities, however, their interactive effects in anti-diabetic/anti-obesity actions and underlying mechanisms remain unclear. This study aimed to fill these knowledge gaps. Quercetin, EGCG or their combination attenuated insulin resistance and decreased hepatic gluconeogenesis in high-fat-high-fructose diet (HFFD)-fed C57BL/6 mice and in palmitic acid (PA)-treated HepG2 cells. In mice, supplementation with quercetin (0.05%w/w), EGCG (0.05%w/w) and their combination (quercetin 0.05%+EGCG 0.05%w/w) reduced weight gain and fasting blood glucose and improved serum biochemical parameters. Compare with quercetin/EGCG alone, the quercetin-EGCG combination reduced gluconeogenesis to a greater extent via IRS-1/Akt/FOXO1-mediated down-regulation of downstream PEPCK and G-6-pase. In HepG2 cells, the quercetin (5 μM)-EGCG (5 μM) co-treatment exerted greater suppression on PA-induced changes in glucose and glycogen contents and hexokinase and G-6-pase activities than quercetin/EGCG alone (each 10 μM). The quercetin-EGCG co-treatment reduced glucose production through targeting FOXO1 and inhibiting the transcription of gluconeogenic enzymes. MiR-27a-3p and miR-96-5p regulated directly FOXO1 expression and function, and co-inhibition of miR-27a-3p and miR-96-5p weakened greatly the protective effect of quercetin-EGCG combination. This is the first report on the contributions of miR-27a-3p and miR-96-5p to the synergistic and protective effect of the quercetin-EGCG co-treatment against PA-induced insulin resistance through inhibiting FOXO1 expression.

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.

The interplay between non-alcoholic fatty liver disease and innate immunity in hepatitis B virus patients

Background

Non-alcoholic fatty liver disease (NAFLD) is the most epidemic liver disorder worldwide as a result of rapid lifestyle transformation over the past few decades and is expected to elevate in the next few years as well as it is ranging from plain hepatic steatosis via non-alcoholic steatohepatitis (NASH) to liver cirrhosis and hepatocellular carcinoma (HCC).

Main text

NAFLD can also stimulate the diseases progression as diabetes and cardiovascular. Therefore, understanding the NAFLD pathogenesis is of vital clinical interest additionally is a crucial for disease treatment and prevention. After analyzing NAFLD and liver diseases prevalence, it has been a belief regarding the interaction between NAFLD and chronic hepatitis B (CHB).

Conclusion

The liver is an essential innate immune organ with large numbers of innate immune cells that contribute in NAFLD pathogenesis, additionally play the influential role that control NAFLD progression in the hepatitis B patients. Here, we summarized the recent advances in understanding and managing the NAFLD patients with chronic hepatitis B infection and interplay with innate immunity.

The Myristic Acid:Docosahexaenoic Acid Ratio Versus the n-6 Polyunsaturated Fatty Acid:n-3 Polyunsaturated Fatty Acid Ratio as Nonalcoholic Fatty Liver Disease Biomarkers

It is well established that diets containing an increased omega-6 polyunsaturated fatty acid (n-6 PUFA) to omega-3 polyunsaturated fatty acid (n-3 PUFA) ratios are linked to inflammation and chronic diseases such as nonalcoholic fatty liver disease (NAFLD). However, the influence of an elevated n-6 PUFA:n-3 PUFA ratio in the tissues requires clarification. Herein, we identified primary experimental and clinical studies where it is possible to compare the performance of the myristic acid (Myr):docosahexaenoic acid (DHA) and n-6 PUFA:n-3 PUFA ratios in the liver and/or serum as potential NAFLD biomarkers. Articles were included if quantitative values of n-6 PUFA, n-3 PUFA, Myr, DHA, and information about liver inflammation or liver disease progression parameters were provided. Overall, most experimental (91.6%) and clinical studies (87.5%) reported higher Myr:DHA ratios associated with inflammation and/or NAFLD progression than the n-6 PUFA:n-3 PUFA ratio. We conclude that the Myr:DHA ratio represents a better biomarker of NAFLD than the n-6 PUFA:n-3 PUFA ratio. Future studies are necessary for verifying this observation.

Hepatic Glucose Metabolism and Its Disorders in Fish

Carbohydrate, which is the most abundant nutrient in plant-sourced feedstuffs, is an economically indispensable component in commercial compound feeds for fish. This nutrient can enhance the physical quality of diets and allow for pellet expansion during extrusion. There is compelling evidence that an excess dietary intake of starch causes hepatic disorders, thereby further reducing the overall food consumption and growth performance of fish species. Among the severe metabolic disturbances are glycogenic hepatopathy (hepatomegaly caused by the excessive accumulation of glycogen in hepatocytes) and hepatic steatosis (the accumulation of large vacuoles of triacylglycerols in hepatocytes). The development of those disorders is mainly due to the limited ability of fish to oxidize glucose and control blood glucose concentration. The prolonged elevations of blood glucose increase glucose intake by the liver, and excess glucose is stored either as glycogen through glycogenesis in hepatocytes or as triglycerides via lipogenesis in tissues, depending on the species. In some fish species (e.g., largemouth bass), the liver has a low ability to regulate glycolysis, gluconeogenesis, and glycogen breakdown in response to high starch intake. For most species of fish, the liver size increases with lipid or glycogen accumulation when they have a high starch intake. It is a challenge to develop the same set of diagnostic criteria for all fish species as their physiology or metabolic patterns differ. Although glycogenic hepatopathy appears to be a common disease in carnivorous fish, it has been under-recognized in many studies. As a result, understanding these diseases and their pathogeneses in different fish species is crucial for manufacturing cost-effective pellet diets to promote the health, growth, survival, and feed efficiency of fish in future.

Dietary and Physical Activity Habits in Adolescent Girls with Polycystic Ovary Syndrome (PCOS)-HAstudy

The role of inappropriate lifestyle in the etiology of polycystic ovary syndrome (PCOS) and its metabolic and reproductive complications has attracted much attention in recent years; however, most studies involve adult patients. Thus, the study aimed to compare dietary patterns, physical activity, metabolic, anthropometric and inflammatory markers of 14-18-year-old girls with and without PCOS (n = 61 and n = 35, respectively) as well as to assess correlations between concentrations of metabolic and inflammatory markers and macronutrient intake and to identify the independent predictors of PCOS, related to diet and physical activity (PA). Compared to the control group, PCOS girls consumed significantly more total fat (p = 0.0005), including both saturated (SFA) (p = 0.03), monounsaturated (MUFA) (p = 0.0003) and polyunsaturated fatty acids (PUFA) (p = 0.01). A significantly higher percentage of PCOS patients consumed high and medium glycemic index (GI) foods (p = 0.03) and represented a low level of PA, both during school and in leisure time (41.67 vs. 6.06%; p = 0.0001 and 32.79 vs. 5.71%; p = 0.003, respectively). The PCOS group had also significantly higher waist circumference (WC), C-reactive protein (CRP) (p = 0.01), LDL cholesterol (p = 0.01), fasting insulin (p = 0.002) and HOMA-IR (p = 0.006) levels. There was an inverse correlation between fiber intake and fasting insulin, (p = 0.0002, r = -0.37), HOMA-IR (p = 0.0004, r = -0.35), WC (p = 0.029; r = -0.222) and a positive relationship between high and medium GI diet and insulin concentration (p = 0.003; r = 0.3). An increase of 10 g/day in total fat intake per day increases the probability of PCOS by 1.4 times. If the SFA or MUFA intakes increase by 10 g, the probability of PCOS increase 1.7-fold and 2.5-fold, respectively. The consumption of foods with a medium GI raises the probability of PCOS by more than 3 times, after adjusting for age. The odds ratio decreased for the moderate and high PA at school/work and in leisure time. Further research in girls with PCOS is needed to test whether low GI and dietary fatty acid reduction combined with increased PA is effective in the nonpharmacological treatment and prevention of PCOS complications. ClinicalTrial.gov Identifier: NCT04738409.

Alteration of serum amino acid profiles by dietary adenine supplementation inhibits fatty liver development in rats

Studies on animal models have demonstrated that feeding a low-arginine diet inhibits triacylglycerol (TAG) secretion from the liver, resulting in marked fatty liver development in rats. Here, we first showed that culturing hepatocytes in the medium mimicking the serum amino acid profile of low-arginine diet-fed rats induced TAG accumulation in the cells, indicating that the specific amino acid profile caused TAG accumulation in hepatocytes. Dietary adenine supplementation completely recovered hepatic TAG secretion and abolished hepatic TAG accumulation in rats. A comprehensive non-linear analysis revealed that inhibition of hepatic TAG accumulation by dietary adenine supplementation could be predicted using only serum amino acid concentration data. Comparison of serum amino acid concentrations indicated that histidine, methionine, and branched-chain amino acid (BCAA) concentrations were altered by adenine supplementation. Furthermore, when the serum amino acid profiles of low-arginine diet-fed rats were altered by modifying methionine or BCAA concentrations in their diets, their hepatic TAG accumulation was abolished. Altogether, these results suggest that an increase in methionine and BCAA levels in the serum in response to dietary arginine deficiency is a key causative factor for hepatic TAG accumulation, and dietary adenine supplementation could disrupt this phenomenon by altering serum amino acid profiles.

Sasa quelpaertensis Leaf Extract Ameliorates Dyslipidemia, Insulin Resistance, and Hepatic Lipid Accumulation in High-Fructose-Diet-Fed Rats

Background: Increased dietary fructose consumption is closely associated with lipid and glucose metabolic disorders. Sasa quelpaertensis Nakai possesses various health-promoting properties, but there has been no research on its protective effect against fructose-induced metabolic dysfunction. In this study, we investigated the effects of S. quelpaertensis leaf extract (SQE) on metabolic dysfunction in high-fructose-diet-fed rats. Methods: Animals were fed a 46% carbohydrate diet, a 60% high-fructose diet, or a 60% high-fructose diet with SQE (500 mg/kg of body weight (BW)/day) in drinking water for 16 weeks. Serum biochemical parameters were measured and the effects of SQE on hepatic histology, protein expression, and transcriptome profiles were investigated. Results: SQE improved dyslipidemia and insulin resistance induced in high-fructose-diet-fed rats. SQE ameliorated the lipid accumulation and inflammatory response in liver tissues by modulating the expressions of key proteins related to lipid metabolism and antioxidant response. SQE significantly enriched the genes related to the metabolic pathway, namely, the tumor necrosis factor (TNF) signaling pathway and the PI3K-Akt signaling pathway. Conclusions: SQE could effectively prevent dyslipidemia, insulin resistance, and hepatic lipid accumulation by regulation of metabolism-related gene expressions, suggesting its role as a functional ingredient to prevent lifestyle-related metabolic disorders.

Impact of the Analytical Approach on the Reliability of MRI-Based Assessment of Hepatic Fat Content

MRI is a popular noninvasive method for the assessment of liver fat content. After MRI scan acquisition, there is currently no standardized image analysis procedure for the most accurate estimate of liver fat content. We determined intraindividual reliability of MRI-based liver fat measurement using 10 different MRI slice analysis methods in normal-weight, overweight, and obese individuals who underwent 2 same-day abdominal MRI scans. We also compared the agreement in liver fat content between analytical methods and assessed the variability in fat content across the entire liver. Our results indicate that liver fat content varies across the liver, with some slices averaging 54% lower and others 75% higher fat content than the mean of all slices (gold standard). Our data suggest that the entire liver should be contoured on at least every 10th slice to achieve close agreement with the gold standard.

Targeting n-3 Polyunsaturated Fatty Acids in Non-Alcoholic Fatty Liver Disease

BACKGROUND

Non-Alcoholic Fatty Liver Disease (NAFLD) is characterized by abnormal hepatic accumulation of triacylglycerides in the absence of alcohol consumption, in association with Oxidative Stress (OS), a pro-inflammatory state and Insulin Resistance (IR), which are attenuated by n-3 long-chain polyunsaturated Fatty Acids (FAs) C20-C22 (LCPUFAs) supplementation. Main causes of NAFLD comprise high caloric intake and a sedentary lifestyle, with high intakes of saturated FAs.

METHODS

The review includes several searches considering the effects of n-3 LCPUFAs in NAFLD in vivo and in vitro models, using the PubMed database from the National Library of Medicine- National Institutes of Health.

RESULT

The LCPUFAs eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n- 3, DHA) have a positive effect in diminishing liver steatosis, OS, and the levels of aspartate aminotransferase, alanine aminotransferase and pro-inflammatory cytokines, with improvement of insulin sensitivity and adiponectin levels. The molecular pathways described for n-3 LCPUFAs in cellular and animal models and humans include peroxisome proliferator-activated receptor-α activation favouring FA oxidation, diminution of lipogenesis due to sterol responsive element binding protein-1c downregulation and inflammation resolution. Besides, nuclear factor erythroid-2-related factor-2 activation is elicited by n-3 LCPUFA-derived oxidation products producing direct and indirect antioxidant responses, with concomitant anti-fibrogenic action.

CONCLUSION

The discussed effects of n-3 LCPUFA supplementation support its use in NAFLD, although having a limited value in NASH, a contention that may involve n-3 LCPUFA oxygenated derivatives. Clinical trials establishing optimal dosages, intervention times, type of patients and possible synergies with other natural products are needed in future studies.

Rescue of Hepatic Phospholipid Remodeling Defectin iPLA2β-Null Mice Attenuates Obese but Not Non-Obese Fatty Liver

Polymorphisms of group VIA calcium-independent phospholipase A2 (iPLA₂β or PLA2G6) are positively associated with adiposity, blood lipids, and Type-2 diabetes. The ubiquitously expressed iPLA₂β catalyzes the hydrolysis of phospholipids (PLs) to generate a fatty acid and a lysoPL. We studied the role of iPLA₂β on PL metabolism in non-alcoholic fatty liver disease (NAFLD). By using global deletion iPLA₂β-null mice, we investigated three NAFLD mouse models; genetic Ob/Ob and long-term high-fat-diet (HFD) feeding (representing obese NAFLD) as well as feeding with methionine- and choline-deficient (MCD) diet (representing non-obese NAFLD). A decrease of hepatic PLs containing monounsaturated- and polyunsaturated fatty acids and a decrease of the ratio between PLs and cholesterol esters were observed in all three NAFLD models. iPLA₂β deficiency rescued these decreases in obese, but not in non-obese, NAFLD models. iPLA₂β deficiency elicited protection against fatty liver and obesity in the order of Ob/Ob › HFD » MCD. Liver inflammation was not protected in HFD NAFLD, and that liver fibrosis was even exaggerated in non-obese MCD model. Thus, the rescue of hepatic PL remodeling defect observed in iPLA₂β-null mice was critical for the protection against NAFLD and obesity. However, iPLA₂β deletion in specific cell types such as macrophages may render liver inflammation and fibrosis, independent of steatosis protection.

Effects of Omega-3 Polyunsaturated Fatty Acid Supplementation on Non-Alcoholic Fatty Liver: A Systematic Review and Meta-Analysis

(1) Aim: Non-alcoholic fatty liver disease (NAFLD) is a prevalent disease worldwide. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) bear anti-inflammatory action and can ameliorate hyperlipidemia. We wish to appraise the effects of n-3 PUFAs supplement on NAFLD. (2) Methods: We searched CENTRAL, Embase, and MEDLINE on 29 March 2020 for randomized control trials (RCTs) on the effects of n-3 PUFAs supplementation in treating NAFLD. The Cochrane Collaboration's tool was used to assess the risk of bias of included RCTs. (3) Results: We included 22 RCTs with 1366 participants. The risk of bias of included RCTs was generally low or unclear. n-3 PUFAs supplementation significantly reduced liver fat compared with placebo (pooled risk ratio 1.52; 95% confidence interval (CI) 1.09 to 2.13). n-3 PUFAs supplementation also significantly improved the levels of triglyceride, total cholesterol, high-density lipoprotein, and body-mass index, with pooled mean difference and 95% CI being -28.57 (-40.81 to -16.33), -7.82 (-14.86 to -0.79), 3.55 (1.38 to 5.73), and -0.46 (-0.84 to -0.08), respectively. (4) Conclusions: The current evidence supports the effects of n-3 PUFAs supplementation in improving fatty liver. n-3 PUFAs supplementation may also improve blood lipid levels and obesity.

Arachidonic acid induces ER stress and apoptosis in HT-29 human colon cancer cells

Polyunsaturated fatty acids (PUFAs) have important functions in biological systems. The beneficial effects of dietary PUFAs against inflammatory diseases, cardiovascular diseases, and metabolic disorders have been shown. Studies using cancer cells have presented the anti-tumorigenic effects of docosahexaenoic acid (DHA), an n-3 PUFA, while arachidonic acid (AA), an n-6 PUFA, has been shown to elicit both pro- and anti-tumorigenic effects. In the current study, the anti-tumorigenic effects of AA were evaluated in HT-29 human colon cancer cells. Upon adding AA in the media, more than 90% of HT-29 cells died, while the MCF7 cells showed good proliferation. AA inhibited the expression of SREBP-1 and its target genes that encode enzymes involved in fatty acid synthesis. As HT-29 cells contained lower basal levels of fatty acid synthase, a target gene of SREBP-1, than that in MCF7 cells, the inhibitory effects of AA on the fatty acid synthase levels in HT-29 cells were much stronger than those in MCF-7 cells. When oleic acid (OA), a monounsaturated fatty acid that can be synthesized endogenously, was added along with AA, the HT-29 cells were able to proliferate. These results suggested that HT-29 cells could not synthesize enough fatty acids for cell division in the presence of AA because of the suppression of lipogenesis. HT-29 cells may incorporate more AA into their membrane phospholipids to proliferate, which resulted in ER stress, thereby inducing apoptosis. AA could be used as an anti-tumorigenic agent against cancer cells in which the basal fatty acid synthase levels are low.

Nonalcoholic Fatty Liver Disease (NAFLD) and Hepatic Cytochrome P450 (CYP) Enzymes

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive fat in the liver. An international consensus panel has recently proposed to rename the disease to metabolic dysfunction associated with fatty liver disease (MAFLD). The disease can range from simple steatosis (fat accumulation) to nonalcoholic steatohepatitis (NASH) which represents a severe form of NAFLD and is accompanied by inflammation, fibrosis, and hepatocyte damage in addition to significant steatosis. This review collates current knowledge of changes in human hepatic cytochrome P450 enzymes in NAFLD. While the expression of these enzymes is well studied in healthy volunteers, our understanding of the alterations of these proteins in NAFLD is limited. Much of the existing knowledge on the subject is derived from preclinical studies, and clinical translation of these findings is poor. Wherever available, the effect of NAFLD on these proteins in humans is debatable and currently lacks a consensus among different reports. Protein expression is an important in vitro physiological parameter controlling the pharmacokinetics of drugs and the last decade has seen a rise in the accurate estimation of these proteins for use with physiologically based pharmacokinetic (PBPK) modeling to predict drug pharmacokinetics in special populations. The application of label-free, mass spectrometry-based quantitative proteomics as a promising tool to study NAFLD-associated changes has also been discussed.

The Protective Effect of Myristica fragrans Houtt. Extracts Against Obesity and Inflammation by Regulating Free Fatty Acids Metabolism in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a disorder characterized by the excess accumulation of fat in the hepatocytes. It is commonly associated with severe obesity and inflammation. Free fatty acids (FFAs) are the key to regulate lipid metabolism and immune response in hepatocyte cells. This study examined the effects of AEN (alcohol extract of nutmeg, the seed of Myristica fragrans Houtt.) on the inhibition of lipid synthesis and inflammation in vitro and in vivo and on high-fat diet-induced obesity in NAFLD mice. Our results showed that AEN treatment could downregulate the expression of lipid synthesis-related genes fatty acid synthase (FASN) and sterol regulatory element-binding protein 1c (SREBP-1c) and lower the lipid content of cells. AEN also inhibited FFAs-mediated inflammation-related cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) expression in cells. In a mouse model, AEN reduced the bodyweight of obese mice and improved NAFLD without affecting food intake. Further analysis revealed that AEN significantly reduced inflammation level, cholesterol and lipid accumulation, blood glucose, and other liver function indexes in mice fed with a high-fat diet. In conclusion, AEN inhibited the aggravation of obesity and inflammation by downregulating lipid-gene expression in the liver to ameliorate NAFLD.

A non-pharmacological therapeutic approach in the gut triggers distal metabolic rewiring capable of ameliorating diet-induced dysfunctions encompassed by metabolic syndrome

Metabolic syndrome has increased at a worrisome level. Lifestyle changes are not sufficient to prevent and improve the adverse effects of obesity, thus novel interventions are necessary. The aim of this study was to investigate the use and metabolic outcomes of a non-pharmacological intervention in a high-fat diet (HFD) fed mouse model, capable of recapitulating key aspects of metabolic syndrome. We show that Policaptil Gel Retard has remarkable, beneficial effects on metabolic dysfunction caused by consumption of HFD. We describe the mechanism by which such effects are obtained, highlighting the fact that the amelioration of metabolic function observed upon Policaptil Gel Retard administration is profound and of systemic nature, despite being originated by sequestering, therefore non-pharmacological events elicited in the gut lumen.

Animal Models of Fibrosis in Nonalcoholic Steatohepatitis: Do They Reflect Human Disease?

Nonalcoholic steatohepatitis (NASH) is one of the most common chronic liver diseases in the world, yet no pharmacotherapies are available. The lack of translational animal models is a major barrier impeding elucidation of disease mechanisms and drug development. Multiple preclinical models of NASH have been proposed and can broadly be characterized as diet-induced, deficiency-induced, toxin-induced, genetically induced, or a combination of these. However, very few models develop advanced fibrosis while still reflecting human disease etiology or pathology, which is problematic since fibrosis stage is considered the best prognostic marker in patients and an important endpoint in clinical trials of NASH. While mice and rats predominate the NASH research, several other species have emerged as promising models. This review critically evaluates animal models of NASH, focusing on their ability to develop advanced fibrosis while maintaining their relevance to the human condition.

Virgin Coconut Oil Associated with High-Fat Diet Induces Metabolic Dysfunctions, Adipose Inflammation, and Hepatic Lipid Accumulation

Obesity reaches an epidemic level worldwide, and this condition is associated with chronic low-grade inflammation and secondary comorbidities, largely driven by global changes in lifestyle and diet. Various dietary approaches are proposed for the obesity treatment and its associated metabolic disorders. Good taste, antioxidant functions, and vitamins have been attributed to virgin coconut oil (VCO). However, VCO contains a large amount of saturated fatty acids, and the consumption of this fat is associated with a number of secondary diseases. We evaluate the effects of VCO supplementation on biochemical, inflammatory, and oxidative stress parameters in rats fed with high-fat diet (HFD). After feeding with HFD for 12 weeks, the animals were supplemented with VCO for 30 days. HFD+VCO group increased in diet intake, weight gain, low-density lipoprotein cholesterol level, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. These findings were accompanied by increased in hepatic lipid profile and fat deposition in the liver. Adipocyte hypertrophy was observed in the HFD+VCO group, which was associated with elevated expression of tumor necrosis factor alpha (TNF-α) in adipose tissue. These results revealed that VCO associated with HFD induced important metabolic alterations, adipose inflammation, and hepatic lipid accumulation in rats.

Association of the dietary patterns with the risk of non-alcoholic fatty liver disease among Iranian population: a case-control study

BACKGROUND

Diet-based recommendations can be developed for preventing and treating non-alcoholic fatty liver disease (NAFLD) after investigating the effects of whole diets on NAFLD. The aim of this study was to identify major dietary patterns and their association with the risk of NAFLD.

METHODS

A total of 244 individuals (122 NAFLD patients and 122 controls) participated in this case-control study. The patients with NAFLD were diagnosed by a gastroenterologist. The participants' dietary intake data were collected using a 147-item semi-quantitive food frequency questionnaire and major dietary patterns were identified by principal component analysis. Adherence to dietary patterns was divided into tertiles and its association with odds of NAFLD was investigated by multivariate logistic regression.

RESULTS

The results showed four major dietary patterns, among which adherence to the "ordinary pattern" was positively associated with NAFLD risk. After adjusting for all confounding factors, individuals in the highest tertile of "ordinary pattern" exhibited a significantly elevated risk of NAFLD compared to the lowest tertile (OR = 3.74, 95%CI = 1.23-11.42, P trend< 0.001). As well as, Individuals in the second and third tertiles of the "traditional pattern" were associated with the risk of NAFLD compared to the lowest tertile (medium vs. lowest tertile OR = 2.37, 95%CI = 1.02-5.53; highest vs. lowest tertile OR = 3.58, 95% CI = 1.48-8.68, P trend< 0.001). The highest tertile of "vegetable and dairy pattern" compared to the lowest tertile was inversely associated with NAFLD risk (OR = 0.23, 95%CI = 0.09-0.58, P trend = 0.02). No significant association was found between "fast food type pattern" and the risk of NAFLD.

CONCLUSION

A significant association was observed between different dietary patterns and the risk of NAFLD. These results can potentially serve as a dietary strategy for preventing NAFLD in individuals who are at a high risk for progression of NAFLD.

The Effect of Laparoscopic Sleeve Gastrectomy on Nonalcoholic Fatty Liver Disease

Obesity is associated with nonalcoholic fatty liver disease which is one of the most common causes of chronic liver disease. FibroScan is a noninvasive tool for liver stiffness measurement and controlled attenuation parameter to evaluate liver steatosis and fibrosis. We aimed to demonstrate the effect of laparoscopic sleeve gastrectomy on liver steatosis and fibrosis. Of the 120 consecutive patients screened, 72 were enrolled in this study. FibroScan M probe and XL probe were used for the evaluation of liver steatosis and fibrosis. Fifty-two patients (72.2%) were female individuals and 20 (27.8%) were male individuals; the mean age was 37.9±10.4 years. Percentage of excess weight loss was significant at the third and sixth months: 57.2±18.3 (P<0.05) and 81.4±24.6 (P<0.05), respectively. Mean preoperative controlled attenuation parameter and liver stiffness measurement values were 309.2±68.7 dB/m and 7.5±5.0 kPa, respectively, and significantly declined to 217.4±56.4 dB/m and 5.6±2.5 kPa, respectively, at sixth postoperative month (P<0.001 and <0.01, respectively). These results suggest that laparoscopic sleeve gastrectomy is associated with significant improvement in liver steatosis and fibrosis. Bariatric surgery has a beneficial effect on nonalcoholic fatty liver disease in morbidly obese patients.

Effect of Supplementation with Hydroethanolic Extract of Campomanesia xanthocarpa (Berg.) Leaves and Two Isolated Substances from the Extract on Metabolic Parameters of Mice Fed a High-Fat Diet

There are still controversies regarding the correlation between the beneficial effects for health and the administration of isolated compounds or crude extracts in therapeutic applications. Campomanesia xanthocarpa, found in the Brazilian Cerrado, demonstrated beneficial effects in metabolic disorders associated with obesity. We investigated the effects of Campomanesia xanthocarpa hydroethanolic extract and two isolated substances from the extract (S1 and S2) in a diet-induced obesity (DIO) model. Male Swiss mice were divided into five groups: (1) American Institute of Nutrition (AIN-93M) diet, (2) high-fat diet (HF), (3) HF supplemented with C. xanthocarpa hydroethanolic leaf extract at 100 mg/kg (HFE), (4) HF supplemented with S1 at 1 mg/kg (HFS1) and (5) HF supplemented with S2 at 1 mg/kg (HFS2). The HFS1, HFS2 and HFE groups did not present decreasing body weight or visceral adiposity gain. No differences in glycemic and lipid parameters, or in the expression of protein content in two cytokines, interleukin-6 (IL-6) and anti-inflammatory (IL-10), were observed. Only the HFS1 group displayed decreased food intake. Even though substantial effects such as an improvement in obesity features or the metabolic and histological parameters promoted by S1, S2 and the extract were not observed, further investigations are necessary to evaluate the principal genes and protein expressions involved in regulating food behavior promoted by S1.

S. Ferreira KC, Neto JCR. Pharmacological Strategies for Insulin Sensitivity in Obesity and Cancer: Thiazolidinediones and Metformin

Background:

Chronic diseases, such as obesity and cancer, have high prevalence rates. Both diseases have hyperinsulinemia, hyperglycemia, high levels of IGF-1 and inflammatory cytokines in common. Therefore, these can be considered triggers for cancer development and growth. In addition, low-grade inflammation that modulates the activation of immune cells, cellular metabolism, and production of cytokines and chemokines are common in obesity, cancer, and insulin resistance. Pharmacological strategies are necessary when a change in lifestyle does not improve glycemic homeostasis. In this regard, thiazolidinediones (TZD) possess multiple molecular targets and regulate PPARγ in obesity and cancer related to insulin resistance, while metformin acts through the AMPK pathway.

Objective:

The aim of this study was to review TZD and metformin as pharmacological treatments for insulin resistance associated with obesity and cancer.

Conclusions:

Thiazolidinediones restored adiponectin secretion and leptin sensitivity, reduced lipid droplets in hepatocytes and orexigen peptides in the hypothalamus. In cancer cells, TZD reduced proliferation, production of reactive oxygen species, and inflammation by acting through the mTOR and NFκB pathways. Metformin has similar effects, though these are AMPK-dependent. In addition, both drugs can be efficient against certain side effects caused by chemotherapy.

IMPACT OF CURRENT DIET AT THE RISK OF NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD)

The nonalcoholic fatty liver disease (NAFLD) affects approximately 20%-30% of general population and is even more prevalent among obese individuals. The risk factors mainly associated with NAFLD are diseases related to the metabolic syndrome, genetics and environment. In this review, we provide a literature compilation evaluating the evidence behind dietary components, including calories intake, fat, protein, fibers and carbohydrate, especially fructose which could be a trigger to development and progression of the NAFLD. In fact, it has been demonstrated that diet is an important factor for the development of NAFLD and its association is complex and extends beyond total energy intake.

Kukoamine B Ameliorate Insulin Resistance, Oxidative Stress, Inflammation and Other Metabolic Abnormalities in High-Fat/High-Fructose-Fed Rats

BACKGROUND

Obesity is characterized by excessive body fat, insulin resistance and dyslipidemia, which increases the chances of developing chronic diseases like type 2 diabetes, cardiovascular diseases, hypertension, nonalcoholic fatty liver diseases, some types of cancers and neurodegenerative diseases. Kukoamine B (Kuk B) is a spermine alkaloid obtained from Lycium chinense, and it has been shown to possess antidiabetic, antioxidant and anti-inflammatory properties. In this study, we evaluated the therapeutic effect of Kuk B on high-fat diet/high-fructose (HFDFr)-induced insulin resistance and obesity in experimental rats.

MATERIALS AND METHODS

Rats were fed with either normal rat diet or HFDFr for 10 consecutive weeks. The groups that were fed with HFDFr received Kuk B (25 and 50 mg/kg) from the beginning of the 6th week to the 10th week. After treatment, the effect of Kuk B on body weight, food, water intake, insulin, blood glucose, serum biochemical parameters, hepatic oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and proinflammatory cytokine (interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α)) levels was determined. Histopathological analysis of the liver tissues was also performed.

RESULTS

HFDFr-fed rats showed a significant increase in body weight, fasting blood glucose, insulin, lipid accumulation and liver function enzymes. In addition, HFDFr diet increased hepatic MDA, TNF-α, IL-1β and IL-6 and decreased hepatic SOD, CAT and GSH-Px activities. On the other hand, Kuk B significantly attenuated body weight, insulin resistance, lipid accumulation, oxidative stress and inflammation.

CONCLUSION

These results indicated that Kuk B showed protective effect against HFDFr-induced metabolic disorders by downregulating lipid accumulation, oxidative stress and inflammatory factors.

Prospective study of perceived dietary salt intake and the risk of non-alcoholic fatty liver disease

BACKGROUND

A high sodium intake is associated with obesity and metabolic syndrome. However, little is known regarding whether greater salt intake is a potential risk factor for non-alcoholic fatty liver disease (NAFLD). We thus prospectively investigated whether individuals with higher perceived dietary salt intake had a higher risk of developing NAFLD.

METHODS

The present study included 35 023 participants (22 629 men and 12 394 women) from the Kailuan study who were free of NAFLD at baseline (2006) and who did not drink alcohol at baseline and during follow-up (2006-2014; follow-rate 95.2%). NAFLD was defined as a participant who had been diagnosed with fatty liver at least twice by ultrasound tests conducted every 2 years during follow-up. Dietary salt intake was determined by a self-report question and was classified into three categories: low (<6 g day^-1 ), medium (6-9 g day^-1 ) or high (≥10 g day^-1 ). Cox proportional models were used to estimate the risk of NAFLD, adjusting for potential confounders, such as age, sex, education, physical activity, smoking, income, occupation, marriage, body mass index, waist circumference and blood pressure, as well as serum concentrations of glutamic-pyruvic transaminase, glucose, total cholesterol and triglyceride.

RESULTS

During 8 years of follow-up, we identified 5102 incident NAFLD cases. After adjusting for potential confounders, the hazard ratio (95% conference interval) for NAFLD was 1.12 (1.00, 1.26) for medium salt intake and 1.19 (1.02,1.39) for high salt consumption (P trend = 0.03) relative to the low salt consumption group.

CONCLUSIONS

A perceived high salt intake was associated with a higher future risk of NAFLD.

Development of nonalcoholic fatty liver disease model by high-fat diet in rats

Background Nonalcoholic fatty liver disease (NAFLD) is indicated by liver steatosis without excessive alcohol use or other liver disease. Several studies have reported that metabolic syndromes such as obesity, type 2 diabetes mellitus, and dyslipidemia have a linear correlation associated with NAFLD pathophysiology. One of the characteristics of dyslipidemia in NAFLD is increase in serum triglycerides. This study aimed to develop a model of NAFLD characterized by an increase in serum triglyceride levels and histological profile of liver steatosis by high-fat diet in rats. Methods Twelve Wistar rats were fed with pellets enriched with 60% fat. They were housed individually, and the remaining pellets were weighted every day for intake evaluation. Blood samples were collected at day 0 and at the end of each trial period at days 7, 14, 21, and 28 for the measurement of triglyceride levels. Every animal from each group was also sacrificed for liver histopathological examination. Results This study has established developing the NAFLD animal model by induction of a high-fat diet. The levels of serum triglycerides were increased from baseline 80.41 ± 12.82 to 1152.00 ± 73.62, 493.66 ± 159.98, 556.00 ± 120.79, and 489.00 ± 156.75 mg/dL at days 7, 14, 21, and 28, respectively. Liver histology also showed liver steatosis development, inflammation, and hepatocellular ballooning, which were associated with the NAFLD state. Conclusions High-fat diet in rats induced hypertriglyceridemia along with NAFLD-like liver histopathology.

The effect of a Mediterranean diet on metabolic parameters in patients with non-alcoholic fatty liver disease: A systematic review of randomized controlled trials

BACKGROUND

Dietary habit can play a key role in the prevention and treatment of fatty liver disease (NAFLD). Although many studies have investigated the effect of Mediterranean diet on NAFLD, findings are inconsistent and there is no systematic review on this topic. Therefore, the aim of this systematic review is to summarize the effect of Mediterranean diet on serum metabolic indices and anthropometric measures among NAFLD patients.

METHODS

We searched titles, abstracts, and keywords of articles indexed in Science Direct, MEDLINE, and Google Scholar databases up to October 2018 to identify eligible RCT studies. Randomized clinical trials assessing the effects of MD on NAFLD were included.

RESULTS

The present study included 10 randomized controlled trials, which involved a total of 856 adults with NAFLD. According to the result, MD may improve anthropometric measures, lipid profile, glycemic indices, liver enzyme, and NAFLD severity indices among patients with NAFLD.

CONCLUSION

We found that MD could alleviate NAFLD severity parameters but differences between studies should be taken into account. Finally, in order to draw a firm link between MD and NAFLD, more clinical trials with adequate sample size and better methodology should be done.

N-3 fatty acids as preventive and therapeutic agents in attenuating PCOS complications

To our knowledge, in spite of several trials exploring the beneficial effect of n-3 polyunsaturated fatty acids (PUFA) on polycystic ovary syndrome (PCOS), no comprehensive evidence has investigated the effects of n-3 PUFA consumption on PCOS complications. Therefore, our aim was to conduct a review to investigate the possible effect and related mechanisms. A comprehensive systematic search was conducted in Embase, MEDLINE/PubMed, Google Scholar, and SCOPUS, to identify studies investigating n-3 fatty acids as a preventative or therapeutic agent for the attenuation of PCOS complications. Subsequently, the impact of omega-3 on PCOS, omega-3 and inflammation, omega-3 and insulin resistance, omega-3 and adipokines, omega-3 and lipid metabolism, omega-3 and endothelial function and omega-3 and hormonal factors were discussed. There are multiple mechanisms by which n-3 PUFAs may exert their beneficial effects on PCOS, including anti-obesity, glycemic and hormonal hemostasis, anti-inflammatory, regulation of adipokine production and enhancement of endothelial function.N-3 PUFAs are a promising agent in relieving complications associated with PCOS. Although most of the studies in patients with PCOS reported an improvement in most complications after administration of omega-3 supplements, there is a distinct dearth of studies investigating the dietary intake of these types of fatty acids. Moreover, favorable effects regarding the improvement of dyslipidemia, regulation of adipokines, regulation of hormonal factors and enhancement of endothelial function are limited. Therefore, more trials are warranted to investigate palatable mechanisms for clarifying the metabolic and hormonal effects of these agents in PCOS.

CARDIO-RENAL METABOLIC SYNDROME AND PRO-INFLAMMATORY FACTORS: THE DIFFERENTIAL EFFECTS OF DIETARY CARBOHYDRATE AND FAT

BACKGROUND

We aimed to evaluate whether a high carbohydrate or a high fat diet differs in alteration of the inflammatory and metabolic risk factors in cardio-renal metabolic syndrome in rats.

METHODS

Twelve male Wister rats were randomly divided into two groups: one received diet 1 standard pellet rat diet (D1) containing 10% fat, 50% carbohydrate, 25% protein and another group received diet 2 (D2) containing 59% fat, 30% carbohydrate and 11% protein for 16 weeks. Weight was recorded weekly. FSG and insulin levels were measured using an enzymatic spectrophotometric and a standard ELISA kit respectively. Inflammatory parameters including TGF-β, MCP-1, TNF-α, IL-1β, IL-6 in the renal and cardiac tissues of rats were evaluated by ELISA technique.

RESULT

Food intake in D1 and D2 groups increased in the study period, however food intake in D2 group was significantly higher compared with D1 group. FSG, HOMA and TG concentrations in D2 group were significantly higher compared to D1 group. Moreover, TGF-β and MCP-1 concentrations in the renal tissues of D2 group and TNF-α in the cardiac tissues of D1 group were significantly higher compared with D1 group (P<0.05). Positive associations between IL-1β and TG and between HOMA, FSG with TGF-β and MCP-1 in the renal tissue of animals were also identified.

Cardiovascular Risk in Fatty Liver Disease: The Liver-Heart Axis-Literature Review

According to the World Health Organization, cardiovascular disease (CVD) remains the leading cause of death worldwide, accounting for approximately 18 million deaths per year. Nevertheless, the worldwide prevalence of metabolic diseases, such as type 2 diabetes mellitus, obesity, and non-alcoholic fatty liver disease (NAFLD), also known to be common risk factors for CVD, have dramatically increased over the last decades. Chronic alcohol consumption is a major cause of chronic liver diseases (CLD) as well as being a major health care cost expenditure accounting for the spending of tremendous amounts of money annually. NAFLD has become one of the major diseases plaguing the world while standing as the most common cause of liver disease in the Western countries by representing about 75% of all CLD. Currently, the most common cause of death in NAFLD remains to be CVD. Several mechanisms have been suggested to be responsible for associating FLD with CVD through several mechanisms including low-grade systemic inflammation, oxidative stress, adipokines, endoplasmic reticulum stress, lipotoxicity and microbiota dysbiosis which may also be influenced by other factors such as genetic and epigenetic variations. Despite of all this evidence, the exact mechanisms of how FLD can causally contribute to CVD are not fully elucidated and much remains unknown. Moreover, the current literature supports the increasing evidence associating FLD with several cardiovascular (CV) adverse events including coronary artery disease, increased subclinical atherosclerosis risk, structural alterations mainly left ventricular hypertrophy, increased epicardial fat thickness, valvular calcifications including aortic valve sclerosis and mitral annular calcification and functional cardiac modifications mainly diastolic dysfunction in addition to cardiac arrhythmias such as atrial fibrillation and ventricular arrythmias and conduction defects including atrioventricular blocks and bundle branch blocks. Patients with FLD should be evaluated and managed accordingly in order to prevent further complications. Possible management methods include non-pharmacological strategies including life style modifications, pharmacological therapies as well as surgical management. This review aims to summarize the current state of knowledge regarding the pathophysiological mechanisms linking FLD with an increased CV risk, in addition to associated CV adverse events and current management modalities.