Treatment of non-alcoholic fatty liver disease - Current perspectives

Resveratrol attenuates against high-fat-diet-promoted non-alcoholic fatty liver disease in rats mainly by targeting the miR-34a/SIRT1 axis

This study evaluated if miR-34a/SIRT1 signalling mediates the anti-hepatosteatotic effect of resveratrol (RSV) in high-fat-diet (HFD)-fed rats. Rats were divided into seven groups (n = 6/each) as control, control + miR-34a agomir negative control, HFD, HFD + miR-34a, HFD + RSV, HFD + RSV + Ex-527 (a SIRT1 inhibitor), and HFD + RSV + miR-34a agomir. After 8 weeks, RSV suppressed dyslipidemia, lowered fasting glucose and insulin levels, improved insulin sensitivity, and prevented hepatic lipid accumulation. These effects were associated with hepatic downregulation of SREBP1 and SREBP2, upregulation of PPARα, and acetylation of Nrf2 (activation) and NF-κβ p65 (inhibition). Also, RSV reduced the transcription of miR-34a and increased the nuclear localisation of SIRT1 in the livers, muscles, and adipose tissues of HFD-fed rats. All these effects were prevented by EX-527 and miR-34a agmir. In conclusion, RSV prevents HFD-induced insulin resistance and hepatic steatosis by suppressing miR-34a-induced activation of SIRT1.

Compensated Advanced Chronic Liver Disease in Nonalcoholic Fatty Liver Disease: Two-Step Strategy is Better than Baveno Criteria

BACKGROUND

Advanced fibrosis and cirrhosis (compensated advanced chronic liver disease [cACLD]) are clinically indistinguishable and increase risk of developing clinically significant portal hypertension. Baveno VII recommends using elastography to rule out and diagnose cACLD with liver stiffness measurement (LSM) cut-offs of 10/15 kPa.

METHODS

In a retrospective analysis of 330 nonalcoholic fatty liver disease (NAFLD) patients, performance of the Baveno VII cut-offs for diagnosing cACLD was compared with newly suggested lower cut-offs (8/12 kPa). A model for detecting cACLD among those with LSM between 8 and 12 kPa was developed and compared with recently published models.

RESULTS

Seventy (21.2%) of the 330 NAFLD patients had biopsy-proven cACLD. The Baveno VII cut-offs (10/15 kPa) had a lower sensitivity of 72.8% (60.9-82.8%) and a specificity of 93.4% (89.7-96.1%). Sensitivity and specificity of lower cut-offs (8/12 kPa) were 91.4% (82.3-96.8%) and 88.5% (83.9-92.1%), respectively. Modeling based on the presence of diabetes (odds ratio [OR] 3.625[1.161-11.320], p = 0.027) and serum aspartate aminotransferase (AST) levels (OR 1.636[1.098-2.436], p = 0.015) correctly identified 75.7% of patients with LSM between 8 and 12 kPa. Our model performed best with an area under receiver operator curve (AUROC) of 0.725 (95%CI 0.609-0.822), compared to Papatheodoridi (AUROC 0.626, CI 0.506-.736) and Zhou (AUROC 0.523, CI 0.403-0.640) models. A two-step strategy comprising application of lower LSM cut-offs followed by the predictive model correctly identified the presence of cACLD in 83% of the patients as compared to 75% by the Baveno VII cut-offs.

CONCLUSION

A two-step strategy employing lower LSM cut-offs and modeling based on diabetes and AST levels outperforms Baveno VII cut-offs for identifying cACLD in NAFLD patients.

Liraglutide on type 2 diabetes mellitus with nonalcoholic fatty liver disease: A systematic review and meta-analysis of 16 RCTs

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common comorbidity of type 2 diabetes mellitus (T2DM). Our aim is to investigate the effects of liraglutide on T2DM with NAFLD.

METHODS

Relevant articles published from the earliest publication to March 2022 were selected from several databases. The Cochrane Collaboration's RevMan software was used for the analysis.

RESULTS

Sixteen studies are selected for this meta-analysis, which includes totally 634 patients in the treatment group and 630 patients in the control group. As a result, 14 studies show that fasting plasma glucose levels of the experimental group are lower than that of the control group; 15 studies show that glycosylated hemoglobin A1c levels of the experimental group are lower than that of the control group; 13 studies show that triglyceride levels of the experimental group are lower than that of the control group; twelve studies show that total cholesterol levels of the experimental group are lower than that of the control group; 10 studies show that alanine aminotransferase levels of the experimental group is lower than that of the control group; 10 studies show that no significant difference in changes in aspartate transaminase between 2 groups; 13 studies show that low density lipoprotein cholesterol levels of the experimental group is lower than that of the control group; 9 studies show that no significant difference in changes in high density lipoprotein cholesterol between 2 groups; 7 studies mentioned adverse effects and the difference is significant.

CONCLUSION

Liraglutide is potentially curative for T2DM with NAFLD.

Comparison of efficacy of anti-diabetics on non-diabetic NAFLD: A network meta-analysis

Objective: This study aimed to assess the efficacy of currently used anti-diabetic medications in the treatment of non-alcoholic fatty liver disease (NAFLD) without diabetes.

DESIGN

The efficacy of various anti-diabetic medicines on non-alcoholic fatty liver disease in the absence of diabetes was evaluated by searching Pubmed, Embase, Cochrane Library, and Web of Science for randomized controlled trials (RCT) only. The methodological quality was evaluated using the Revised Cochrane risk-of-bias tool for randomized trials (RoB2), and the data were analyzed using Stata software (version 15.1).

RESULTS

All papers published between the time of the pooling and September 2022 were searched. There were a total of 18 randomized controlled studies with a total sample size of 1141 cases. The outcomes of interest included variations in alanine transaminase (ALT) and aspartate transaminase (AST). Rosiglitazone (SUCRA: 100%) and vildagliptin (SUCRA: 99.9%) were the best anti-diabetic medicines to improve ALT and AST, respectively, in patients with NAFLD without diabetes, according to the findings of this network meta-analysis.

CONCLUSION

In accordance with the Network Ranking plot, Rosiglitazone was the best anti-diabetic medicine for improving ALT, and vildagliptin was the best for improving AST in patients with non-diabetic NAFLD.

A Multidisciplinary Approach and Current Perspective of Nonalcoholic Fatty Liver Disease: A Systematic Review

In recent times, nonalcoholic fatty liver disease (NAFLD) has been considered one of the major causes of liver disease across the world. NAFLD is defined as the deposition of triglycerides in the liver and is associated with obesity and metabolic syndrome. Hyperinsulinemia, insulin resistance (IR), fatty liver, hepatocyte injury, unbalanced proinflammatory cytokines, mitochondrial dysfunction, oxidative stress, liver inflammation, and fibrosis are the main pathogenesis in NAFLD. Recent studies suggest that the action of intestinal microbiota through chronic inflammation, increased intestinal permeability, and energy uptake plays a vital role in NAFLD. Moreover, polycystic ovarian syndrome also causes NAFLD development through IR. Age, gender, race, ethnicity, sleep, diet, sedentary lifestyle, and genetic and epigenetic pathways are some contributing factors of NAFLD that can exacerbate the risk of liver cirrhosis and hepatocellular carcinoma (HCC) and eventually lead to death. NAFLD has various presentations, including fatigue, unexplained weight loss, bloating, upper abdominal pain, decreased appetite, headache, anxiety, poor sleep, increased thirst, palpitation, and a feeling of warmth. Some studies have shown that NAFLD with severe coronavirus disease 2019 (COVID-19) has poor outcomes. The gold standard for NAFLD diagnosis is liver biopsy. Other diagnostic tools are imaging tests, serum biomarkers, microbiota markers, and tests for extrahepatic complications. There are no specific treatments for NAFLD. Therefore, the main concern for NAFLD is treating the comorbid conditions such as anti-diabetic agents for type 2 diabetes mellitus, statins to reduce HCC progression, antioxidants to prevent hepatocellular damage, and bariatric surgery for patients with a BMI of >40 kg/m² and >35 kg/m² with comorbidities. Lifestyle and dietary changes are considered preventive strategies against NAFLD advancement. Inadequate treatment of NAFLD further leads to cardiac consequences, sleep apnea, chronic kidney disease, and inflammatory bowel disease. In this systematic review, we have briefly discussed the risk factors, pathogenesis, clinical features, and numerous consequences of NAFLD. We have also reviewed various guidelines for NAFLD diagnosis along with existing therapeutic strategies for the management and prevention of the disease.

Croton urucurana Baill. Ameliorates Metabolic Associated Fatty Liver Disease in Rats

Background: Metabolic associated fatty liver disease (MAFLD) affects a quarter of the worldwide population, but no drug therapies have yet been developed. Croton urucurana Baill. (Euphorbiaceae) is a medicinal species, that is, widely distributed in Brazil. It is used in popular medicine to treat gastrointestinal, cardiovascular, and endocrine system diseases. However, its hepatoprotective and lipid-lowering effects have not yet been scientifically investigated.

Aim of the study: The present study investigated the effects of an extract of C. urucurana in a rat model of MAFLD that was associated with multiple risk factors, including hypertension, smoking, and dyslipidemia.

Material and Methods: The phytochemical composition of C. urucurana was evaluated by liquid chromatography-mass spectrometry. Spontaneously hypertensive rats received a 0.5% cholesterol-enriched diet and were exposed to cigarette smoke (9 cigarettes/day for 10 weeks). During the last 5 weeks, the animals were orally treated with vehicle (negative control [C-] group), C. urucurana extract (30, 100, and 300 mg/kg), or simvastatin + enalapril (two standard reference drugs that are commonly used to treat dyslipidemia and hypertension, respectively). One group of rats that were not exposed to these risk factors was also evaluated (basal group). Blood was collected for the analysis of cholesterol, triglyceride, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels. The liver and feces were collected for lipid quantification. The liver was also processed for antioxidant and histopathological analysis.

Results: The main constituents of the C. urucurana extract were flavonoids, glycosides, and alkaloids. The model successfully induced MAFLD, reflected by increases in AST and ALT levels, and induced oxidative stress in the C- group. Treatment with the C. urucurana extract (300 mg/kg) and simvastatin + enalapril decreased plasma and hepatic lipid levels. In contrast to simvastatin + enalapril treatment, C. urucurana reduced AST and ALT levels. Massive lesions were observed in the liver in the C- group, which were reversed by treatment with the C. urucurana extract (300 mg/kg).

Conclusion:C. urucurana extract exerted promising hepatoprotective and lipid-lowering effects in a preclinical rat model of MAFLD.

The Ameliorating Effects of Apple Polyphenol Extract on High-Fat-Diet-Induced Hepatic Steatosis Are SIRT1-Dependent: Evidence from Hepatic-Specific SIRT1 Heterozygous Mutant C57BL/6 Mice

Apple polyphenol extract (APE) has been reported to possess protective effects against hepatic steatosis. To explore whether APE-induced alleviation of hepatic steatosis is SIRT1-dependent, the present study was carried out using wild-type and hepatic SIRT1 heterozygous mutant (Sirt1^+/-) C57BL/6 mice. On consideration of the sex disparity related to hepatic steatosis morbidity, both male and female mice were included in the study. Six to eight week old mice were fed a high-fat diet (HFD) and randomly assigned to one of the following groups: (1) wild-type mice (wt+HFD), (2) Sirt1^+/- mice (Sirt1^+/-+HFD), and (3) Sirt1^+/- mice with 500 mg/(kg·bw·d) APE intragastric administration (Sirt1^+/-+HAP). HFD-induced weight gain and triglyceride accumulation was more prominent in Sirt1^+/- mice in comparison to wild-type mice. Following APE treatment, these effects were significantly reduced along with the alleviation of hepatic steatosis via upregulated expression of SIRT1 at the protein and mRNA levels in both male and female mice. However, APE differentially regulated the genes related to lipid metabolism (Lkb1, Ampk, Hsl, Srebp-1c, Abcg1, and Cd36) in a sex-specific manner. Moreover, APE treatment altered gut microbiota composition, with an increased relative abundance of Akkermansia and a decreased Firmicutes/Bacterodetes ratio. Thus, our study provided new evidence supporting our hypothesis that APE-induced alleviation of hepatic steatosis is SIRT1-dependent.

Fasting, Nutrition and Weight Loss: An Approach to Refine Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is considered as one of the most common causes of chronic liver disease. It includes a group of conditions associated with fat deposition in liver cells. Also, NAFLD is strongly associated with obesity and insulin resistance (IR). Until now, there is no pharmacological treatment validated for this disease. Fasting, nutritional intervention, and weight loss can be considered the first line in treating hepatic steatosis. This review is based on the scientific evidence showing the results of these interventions in the past years. The results include fasting and nutritional support for NAFLD treatment in humans. In clinical trials and cohort studies, an increase in hepatic fat content was correlated with a weight loss of at least 7% and a diet resembling the Mediterranean diet (MD) improving hepatic biomarkers and histological regression of NAFLD. Fasting is a dietary approach known to improve the lipid profile in healthy and obese populations by decreasing overall cholesterol, triglycerides, LDL, and increasing HDL. Bariatric surgery helps improve liver fat content in patients with serious health problems due to overweight.

A Current Understanding of Bile Acids in Chronic Liver Disease

Chronic liver disease (CLD) is one of the leading causes of disability-adjusted life years in many countries. A recent understanding of nuclear bile acid receptor pathways has increased focus on the impact of crosstalk between the gut, bile acids, and liver on liver pathology. While conventionally used in cholestatic disorders and to dissolve gallstones, the discovery of bile acids' influence on the gut microbiome and human metabolism offers a unique potential for their utility in early and advanced liver diseases because of diverse etiologies. Based on these findings, preclinical studies using bile acid-based molecules have shown encouraging results at addressing liver inflammation and fibrosis. Emerging data also suggest that bile acid profiles change distinctively across various causes of liver disease. We summarize the current knowledge and evidence related to bile acids in health and disease and discuss culminated and ongoing therapeutic trials of bile acid derivatives in CLD. In the near future, further evidence in this area might help clinicians better detect and manage liver diseases.

Prevalence of Non-alcoholic Fatty Liver Disease in India: A Systematic Review and Meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) contributes to a large proportion of liver disease burden in the world. Several groups have studied the prevalence of NAFLD in the Indian population.

AIM

A systematic review of the published literature and meta-analysis was carried out to estimate the prevalence of NAFLD in the Indian population.

METHODS

English language literature published until April 2021 was searched from electronic databases. Original data published in any form which had reported NAFLD prevalence in the Indian population were included. The subgroup analysis of prevalence was done based on the age (adults or children) and risk category, i.e., average-risk group (community population, participants of control arm, unselected participants, hypothyroidic individuals, athletes, aviation crew, and army personnel) and high-risk group (obesity or overweight, diabetes mellitus, coronary artery disease, etc.). The prevalence estimates were pooled using the random-effects model. Heterogeneity was assessed with I².

RESULTS

Sixty-two datasets (children 8 and adults 54) from 50 studies were included. The pooled prevalence of NAFLD was estimated from 2903 children and 23,581 adult participants. Among adults, the estimated pooled prevalence was 38.6% (95% CI 32-45.5). The NAFLD prevalence in average-risk and high-risk subgroups was estimated to be 28.1% (95% CI 20.8-36) and 52.8% (95% CI 46.5-59.1), respectively. The estimated NAFLD prevalence was higher in hospital-based data (40.8% [95% CI 32.6-49.3%]) than community-based data (28.2% [95% CI 16.9-41%]). Among children, the estimated pooled prevalence was 35.4% (95% CI 18.2-54.7). The prevalence among non-obese and obese children was 12.4 (95% CI 4.4-23.5) and 63.4 (95% CI 59.4-67.3), respectively.

CONCLUSION

Available data suggest that approximately one in three adults or children have NAFLD in India.

Investigating pharmacological mechanisms of andrographolide on non-alcoholic steatohepatitis (NASH): A bioinformatics approach of network pharmacology

Objective

To investigate the mechanisms of andrographolide against non-alcoholic steatohepatitis (NASH) based on network pharmacology, so as to provide a reference for further study of andrographolide in the treatment of NASH and other metabolic diseases.

Methods

The methionine- and choline-deficient (MCD) diet-induced NASH mice were treated by administration of andrographolide, and serum transaminase and pathological changes were analyzed. The network pharmacology-based bioinformatic strategy was then used to search the potential targets, construct protein–protein interaction (PPI) network, analyze gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment, and conduct molecular docking to explore the molecular mechanisms.

Results

The predicted core targets TNF, MAPK8, IL6, IL1B and AKT1 were enriched in non-alcoholic fatty liver disease (NAFLD) signaling pathway and against NASH by regulation of de novo fatty acids synthesis, anti-inflammation and anti-oxidation.

Conclusion

This work provides a scientific basis for further demonstration of the anti-NASH mechanisms of andrographolide.

Epigenetics in NAFLD/NASH: Targets and therapy

Recently non-alcoholic fatty liver disease (NAFLD) has grabbed considerable scientific attention, owing to its rapid increase in prevalence worldwide and growing burden on end-stage liver diseases. Metabolic syndrome including obesity, diabetes, and hypertension poses a grave risk to NAFLD etiology and progression. With no drugs available, the mainstay of NAFLD management remains lifestyle changes with exercise and dietary modifications. Nonselective drugs such as metformin, thiazolidinediones (TZDs), ursodeoxycholic acid (UDCA), silymarin, etc., are also being used to target the interrelated pathways for treating NAFLD. Considering the enormous disease burden and the unmet need for drugs, fresh insights into pathogenesis and drug discovery are required. The emergence of the field of epigenetics offers a convincing explanation for the basis of lifestyle, environmental, and other risk factors to influence NAFLD pathogenesis. Therefore, understanding these epigenetic modifications to target the primary cause of the disease might prove a rational strategy to prevent the disease and develop novel therapeutic interventions. Apart from describing the role of epigenetics in the pathogenesis of NAFLD as in other reviews, this review additionally provides an elaborate discussion on exploiting the high plasticity of epigenetic modifications in response to environmental cues, for developing novel therapeutics for NAFLD. Besides, this extensive review provides evidence for epigenetic mechanisms utilized by several potential drugs for NAFLD.

A Systematic Review of Newer Antidiabetic Agents in the Treatment of Nonalcoholic Fatty Liver Disease

OBJECTIVE

To evaluate glucagon-like peptide 1 receptor agonists (GLP-1 RAs), dipeptidyl-peptidase IV (DPP-4) inhibitors, and sodium-glucose cotransporter 2 (SGLT) inhibitors to treat nondiabetic and type 2 diabetes mellitus (T2DM) nonalcoholic fatty liver disease (NAFLD) as it relates to improvement in hepatosteatosis (HS) or steatohepatitis (SH).

DATA SOURCES

MEDLINE and CINAHL were searched from inception through May 1, 2020. Search terms included nonalcoholic steatohepatitis, nonalcoholic fatty liver disease, fatty liver, dipeptidyl-peptidase IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose transporter 2 inhibitors.

STUDY SELECTION AND DATA EXTRACTION

Full-text observational and randomized controlled studies in English were included. Patients diagnosed with NAFLD, treated with GLP-1 RAs, DPP-4 inhibitors, and SGLT2 inhibitors, with measures to evaluate HS or SH were evaluated.

DATA SYNTHESIS

Eight GLP-1 RA trials were reviewed; 7 GLP-1 RA trials showed improvement in HS. Two studies demonstrated improvement in liver histology in patients with SH. Seven SGLT2 inhibitor studies were reviewed; 6 studies demonstrated improvements in NAFLD. Five studies showed improvements in HS, whereas 1 displayed improvement in liver histology in NASH. Six studies that included DPP-4 inhibitors were evaluated, and only 2 demonstrated improvement in NASH.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Based on evidence reviewed, GLP-1 RAs and SGLT2 inhibitors decreased HS and SH in NAFLD patients, whereas DPP-4 inhibitor therapy was not effective for patients with HS.

CONCLUSIONS

Based on study data utilizing imaging studies and biopsy results, GLP-1 RAs or SGLT2 inhibitors can benefit NAFLD T2DM patients. Clinical trials with larger patient populations may augment these results.