The effects of metformin administration on liver enzymes and body composition in non-diabetic patients with non-alcoholic fatty liver disease and/or non-alcoholic steatohepatitis: An up-to date systematic review and meta-analysis of randomized controlled trials

Steatotic Liver Disease: Pathophysiology and Emerging Pharmacotherapies

Steatotic liver disease (SLD) displays a dynamic and complex disease phenotype. Consequently, the metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH) therapeutic pipeline is expanding rapidly and in multiple directions. In parallel, noninvasive tools for diagnosing and monitoring responses to therapeutic interventions are being studied, and clinically feasible findings are being explored as primary outcomes in interventional trials. The realization that distinct subgroups exist under the umbrella of SLD should guide more precise and personalized treatment recommendations and facilitate advancements in pharmacotherapeutics. This review summarizes recent updates of pathophysiology-based nomenclature and outlines both effective pharmacotherapeutics and those in the pipeline for MASLD/MASH, detailing their mode of action and the current status of phase 2 and 3 clinical trials. Of the extensive arsenal of pharmacotherapeutics in the MASLD/MASH pipeline, several have been rejected, whereas other, mainly monotherapy options, have shown only marginal benefits and are now being tested as part of combination therapies, yet others are still in development as monotherapies. Although the Food and Drug Administration (FDA) has recently approved resmetirom, additional therapeutic approaches in development will ideally target MASH and fibrosis while improving cardiometabolic risk factors. Due to the urgent need for the development of novel therapeutic strategies and the potential availability of safety and tolerability data, repurposing existing and approved drugs is an appealing option. Finally, it is essential to highlight that SLD and, by extension, MASLD should be recognized and approached as a systemic disease affecting multiple organs, with the vigorous implementation of interdisciplinary and coordinated action plans. SIGNIFICANCE STATEMENT: Steatotic liver disease (SLD), including metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis, is the most prevalent chronic liver condition, affecting more than one-fourth of the global population. This review aims to provide the most recent information regarding SLD pathophysiology, diagnosis, and management according to the latest advancements in the guidelines and clinical trials. Collectively, it is hoped that the information provided furthers the understanding of the current state of SLD with direct clinical implications and stimulates research initiatives.

The impact of metformin on weight and metabolic parameters in patients with obesity: A systematic review and meta-analysis of randomized controlled trials

There are conflicting data on the weight-reducing potential of metformin (MTF) in nondiabetic patients with obesity. The purpose of this systematic review and meta-analysis was to evaluate the effect of MTF on weight and cardiometabolic parameters in adults with overweight/obesity with or without nonalcoholic fatty liver disease (NAFLD) (CRD42018085512). We included randomized controlled trials (RCTs) in adults without diabetes mellitus, with mean body mass index (BMI) ≥ 25 kg/m2, with or without NAFLD, comparing MTF to placebo/control, lifestyle modification (LSM) or a US Food and Drug Administration-approved anti-obesity drug, reporting on weight or metabolic parameters, and extending over at least 3 months. We conducted a systematic search in MEDLINE, EMBASE, PubMed and the Cochrane Library without time limitation (until March 2022). We screened and selected eligible articles, abstracted relevant data, and assessed the risk of bias. All steps were in duplicate and independently. We conducted a random-effects model meta-analysis using Review Manager version 5.3, with prespecified subgroup analyses in case of heterogeneity. We identified 2650 citations and included 49 trials (55 publications). Compared to placebo, MTF was associated with a significant reduction in BMI (mean difference [MD] -0.56 [-0.74, -0.37] kg/m2; p < 0.0001), at doses ranging from 500 to 2550 mg/day, and with a significant percentage change in BMI of -2.53% (-2.90, -2.17) at the dose 1700 mg/day. There was no interaction by baseline BMI, MTF dose or duration, nor presence or absence of NAFLD. There was no significant difference between MTF and LSM. Orlistat was more effective than MTF (at doses of 1000-1700 mg/day) in terms of weight loss, with an MD in BMI of -3.17 (-5.88; -0.47) kg/m2, favouring the former. Compared to placebo/control, MTF improved insulin parameters, while no effect was detected when compared to LSM. A few small trials showed heterogenous effects on liver parameters in patients with NAFLD treated with MTF compared to placebo/control. There was a large variability in the expression of outcome measures and RCTs were of low quality. In conclusion, MTF was associated with a modest weight reduction in obese nondiabetic patients. Further high-quality and better powered studies are needed to examine the impact of MTF in patients with insulin resistance and NAFLD.

The role of anti-diabetic drugs in NAFLD. Have we found the Holy Grail? A narrative review

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of liver disease, affecting 30% of the global population. NAFLD prevalence is particularly high in obese individuals and patients with type 2 diabetes mellitus (T2DM). NAFLD ranges from simple fat deposition in the liver to necroinflammation and fibrosis (non-alcoholic steatohepatitis (NASH)), NASH-cirrhosis, and/or hepatocellular carcinoma. Insulin resistance plays a key role in NAFLD pathogenesis, alongside dysregulation of adipocytes, mitochondrial dysfunction, genetic factors, and changes in gut microbiota. Since insulin resistance is also a major predisposing factor of T2DM, the administration of anti-diabetic drugs for the management of NAFLD seems reasonable.

METHODS

In this review we provide the NAFLD-associated mechanisms of action of some of the most widely used anti-diabetic drugs, namely metformin, pioglitazone, sodium-glucose transport protein-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor analogs (GLP1 RAs), and dipeptyl-peptidase-4 inhibitors (DPP4i) and present available data regarding their use in patients with NAFLD, with and without T2DM.

RESULTS

Both metformin and DPP4i have shown rather contradictory results, while pioglitazone seems to benefit patients with NASH and is thus the only drug approved for NASH with concomitant significant liver fibrosis by all major liver societies. On the other hand, SGLT2i and GLP1 RAs seem to be beneficiary in patients with NAFLD, showing both remarkable results, with SGLT2i proving to be more efficient in the only head-to-head study so far.

CONCLUSION

In patients with NAFLD and diabetes, pioglitazone, GLP1 RAs, and SGLT2i seem to be logical treatment options. Larger studies are needed before these drugs can be recommended for non-diabetic individuals.

Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity: A joint position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM), Brazilian Society of Hepatology (SBH), and Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso)

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Nonalcoholic fatty liver disease (NAFLD), is one of the most common hepatic diseases in individuals with overweight or obesity. In this context, a panel of experts from three medical societies was organized to develop an evidence-based guideline on the screening, diagnosis, treatment, and follow-up of MASLD.

Material and methods

A MEDLINE search was performed to identify randomized clinical trials, meta-analyses, cohort studies, observational studies, and other relevant studies on NAFLD. In the absence of studies on a certain topic or when the quality of the study was not adequate, the opinion of experts was adopted. Classes of Recommendation and Levels of Evidence were determined using prespecified criteria.

Results

Based on the literature review, 48 specific recommendations were elaborated, including 11 on screening and diagnosis, 9 on follow-up,14 on nonpharmacologic treatment, and 14 on pharmacologic and surgical treatment.

Conclusion

A literature search allowed the development of evidence-based guidelines on the screening, diagnosis, treatment, and follow-up of MASLD in individuals with overweight or obesity.

The benefit of metformin in the treatment of pediatric non-alcoholic fatty liver disease: a systematic review and meta-analysis of randomized controlled trials

This is the first meta-analysis of the available literature about the efficacy of metformin exclusively in pediatric patients with non-alcoholic fatty liver disease (NAFLD). We conducted a systematic literature search through major electronic databases till March 12, 2023, investigating the efficacy and safety of metformin in pediatric NAFLD. Weighted mean difference (WD) and standard deviation (SD) were used for continuous outcomes. In total, 4 randomized controlled trials (RCTs) with 309 pediatric patients with NAFLD were included in the meta-analysis. Metformin could not reach a statistically significant improvement in alanine aminotransferase (ALT) levels [(ALT: WMD =  - 1.55 IU/L, 95% CI: - 5.38 to 2.28, I2 = 16%, p = 0.43), but had a statistically significant impact (p < 0.05) in insulin and HOMA-IR regulation, triglycerides, and high-density lipoprotein level improvement.   Conclusion: According to the data of this meta-analysis, treatment with metformin failed to statistically improve liver enzymes but may be beneficial in the improvement of lipid parameters and insulin metabolism regulation in pediatric patients with NAFLD. As there are not enough available studies in the literature, the influence of metformin on liver ultrasonography or histology in pediatric NAFLD should be further analyzed in future studies. What is Known: • Lifestyle modification with weight loss through physical activity and dietary modification is the recommended treatment option for pediatric NAFLD. • Metformin may reduce steatosis on ultrasound and may have a beneficial role in liver histology collated with insulin resistance improvement. What is New: • Metformin may improve insulin sensitivity and lipid parameters in children with obesity and NAFLD. • Metformin does not have a significant effect on transaminase levels in children with obesity and NAFLD.

Why do some glucose-lowering agents improve non-alcoholic fatty liver disease whereas others do not? A narrative review in search of a unifying hypothesis

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) are metabolic disorders connected by common pathophysiological mechanisms. Since insulin resistance (IR) and metabolic alterations are common to both conditions, almost all glucose-lowering agents which improve IR have also been studied in patients with NAFLD. Some have shown great efficacy, others none. Thus, the mechanisms behind the efficacy of these drugs in improving hepatic steatosis, steatohepatitis, and eventually fibrosis remain controversial. Glycaemic control improves T2D, but probably has limited effects on NAFLD, as all glucose-lowering agents ameliorate glucose control but only a few improve NAFLD features. In contrast, drugs that either improve adipose tissue function, reduce lipid ingestion, or increase lipid oxidation are particularly effective in NAFLD. We therefore hypothesise that improved free fatty acid metabolism may be the unifying mechanism behind the efficacy of some glucose-lowering agents on NAFLD and may represent the key to NAFLD treatment.

Neuroprotective and Cardiometabolic Role of Vitamin E: Alleviating Neuroinflammation and Metabolic Disturbance Induced by AlCl3 in Rat Models

Cardiovascular diseases (CVDs) and neurodegenerative disorders, such as diabetes mellitus and Alzheimer's disease, share a common pathophysiological link involving insulin resistance (IR), inflammation, and hypertension. Aluminium chloride (AlCl3), a known neurotoxicant, has been associated with neurodegeneration, cognitive impairment, and various organ dysfunctions due to the production of reactive oxygen species (ROS) and oxidative stress. In this study, we aimed to investigate the potential protective effects of metformin and vitamin E against AlCl3-induced neuroinflammation and cardiometabolic disturbances in rat models. Rats were divided into five groups: a normal control group, an AlCl3-treated diseased group without any treatment, and three groups exposed to AlCl3 and subsequently administered with metformin (100 mg/kg/day) alone, vitamin E (150 mg/kg/day) orally alone, or a combination of metformin (100 mg/kg/day) and vitamin E (150 mg/kg/day) for 45 days. We analyzed serum biomarkers and histopathological changes in brain, heart, and pancreatic tissues using H&E and Masson's trichrome staining and immunohistochemistry (IHC). Electrocardiogram (ECG) patterns were observed for all groups. The AlCl3-treated group showed elevated levels of inflammatory biomarkers, MDA, and disturbances in glycemic and lipid profiles, along with reduced insulin levels. However, treatment with the combination of metformin and vitamin E resulted in significantly reduced glucose, cholesterol, LDL, and TG levels, accompanied by increased insulin and HDL levels compared to the individual treatment groups. Histopathological analyses revealed that combination therapy preserved neuronal structures, muscle cell nuclei, and normal morphology in the brain, heart, and pancreatic tissues. IHC demonstrated reduced amyloid plaques and neurofibrillary tangles in the combination-treated group compared to the AlCl3-treated group. Moreover, the combination group showed a normal ECG pattern, contrasting the altered pattern observed in the AlCl3-treated group. Overall, our findings suggest that metformin and vitamin E, in combination, possess neuroprotective and cardiometabolic effects, alleviating AlCl3-induced neuroinflammation and metabolic disturbances.

Evaluating the role of non-alcoholic fatty liver disease in cardiovascular diseases and type 2 diabetes: a Mendelian randomization study in Europeans and East Asians

BACKGROUND

Whether non-alcoholic fatty liver disease (NAFLD) causes cardiovascular disease (CVD) and type 2 diabetes (T2D) is unclear and possible differences between ethnicities have not been thoroughly explored. We used Mendelian randomization (MR) to assess the role of NAFLD in CVD and T2D risk in Europeans and East Asians.

METHODS

We conducted a MR study using genetic predictors of alanine aminotransferase (ALT), liability to NAFLD, aspartate transaminase (AST), liver magnetic resonance imaging corrected T1 and proton density fat fraction and combined them with genome-wide association studies (GWAS) summary statistics of CVD, T2D and glycaemic traits (sample size ranging from 14 400 to 977 320). Inverse-variance weighted analysis was used to assess the effect of NAFLD in these outcomes, with sensitivity analyses and replication in FinnGen. We conducted analyses in East Asians using ethnicity-specific genetic predictors of ALT and AST, and the respective outcome GWAS summary statistics.

RESULTS

In Europeans, higher ALT was associated with higher T2D risk (odds ratio: 1.77 per standard deviation, 95% CI 1.5 to 2.08), with similar results for other exposures, across sensitivity analyses and in FinnGen. Although NAFLD proxies were related to higher coronary artery disease (CAD) and stroke risk, sensitivity analyses suggested possible bias by horizontal pleiotropy. In East Asians, higher ALT was possibly associated with higher T2D risk, and ALT and AST were inversely associated with CAD.

CONCLUSIONS

NAFLD likely increases the risk of T2D in Europeans and East Asians. Potential differential effects on CAD between Europeans and East Asians require further investigation.

Association of De Ritis Ratio with Prognosis in Patients with Coronary Artery Disease and Aminotransferase Activity within and outside the Healthy Values of Reference Range

BACKGROUND

The aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (De Ritis ratio), obtained from AST and ALT activities in the healthy range, has not been studied in association with mortality.

METHODS

This study included 3392 patients with stable coronary heart disease and aminotransferase activity in the reference range. Patients are categorized into two groups: a group with AST and ALT activity in the healthy range (n = 1697), and a group with AST and/or ALT activity outside the healthy range but in the reference range (n = 1695). The primary endpoint was all-cause mortality at three years.

RESULTS

The De Ritis ratio (median 5th-95th percentile] was 0.94 [0.61-1.41] in patients with AST and ALT in the healthy range and 0.93 [0.45-1.96] in patients with AST and/or ALT outside the healthy range (p = 0.700). At three years, there were 86 deaths in patients with AST and ALT in the healthy range: 27 deaths (3.9%) in patients with a De Ritis ratio ≤median, and 59 deaths (8.2%) in patients with the De Ritis ratio >median (adjusted hazard ratio [HR] = 1.16, 95% confidence interval [CI] 0.94 to 1.42; p = 0.159); in patients with AST and/or ALT outside the healthy range, there were 148 deaths: 49 deaths (6.6%) in patients with a De Ritis ratio ≤median, and 99 deaths (14.1%) in patients with De Ritis ratio >median (adjusted HR = 1.27 [1.09-1.48], p = 0.002), with both HRs calculated per unit higher values of the De Ritis ratio.

CONCLUSIONS

The De Ritis ratio obtained from AST and ALT activity in the healthy range was not independently associated with higher risk of mortality. The De Ritis ratio obtained from aminotransferase activity outside the healthy range (but still in the reference range) was independently associated with the risk of mortality.

Prevalence of nonalcoholic fatty liver disease increased with type 2 diabetes mellitus in overweight/obese youth with polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) increases non-alcoholic fatty liver disease (NAFLD) risk and severity in adults, but data in adolescents with diverse backgrounds are limited. We evaluated NAFLD prevalence and characterized NAFLD risk factors in overweight/obese adolescents by PCOS status.

METHODS

Retrospective study of overweight (n=52)/obese (n=271) female adolescents (12-18 years old), evaluated clinically 2012-2020, was conducted comparing PCOS patients to age-matched non-PCOS controls. NAFLD was defined as ALT≥44U/L x2 and/or ≥80U/L x1, hepatic steatosis on imaging, or NAFLD on biopsy, in absence of other liver disease. Metabolic comorbidities were captured. Log-binomial regression models estimated prevalence risk ratios (PR).

RESULTS

NAFLD prevalence was 19.1 % in adolescents with PCOS (n=161), similar to those without (n=162) (16.8 %, p=0.6). Adolescents with PCOS were more likely to have insulin resistance, hypercholesterolemia, and higher triglycerides (p<0.05). Those with PCOS and concomitant type 2 diabetes (T2DM) did have increased NAFLD risk (PR 2.5, p=0.04), but those with PCOS without T2DM did not (PR 0.9, p=0.8). Adolescents with PCOS and NAFLD, compared to those with PCOS without NAFLD, had a higher prevalence of metabolic comorbidities including hypercholesterolemia (77 vs. 48 %), T2DM (29 vs. 8 %), and hypertriglyceridemia (65 vs. 37 %) (p<0.01).

CONCLUSIONS

Almost 1 in 5 overweight/obese female adolescents had NAFLD, but PCOS did not increase NAFLD risk in this diverse cohort. Among young women with PCOS, concomitant T2DM did increase the risk for NAFLD. Closer monitoring of obesity comorbidities in adolescents with PCOS is essential for optimizing health and merits updating current guidelines.

Recent updates on targeting the molecular mediators of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common disease worldwide in an era of rapid economic growth. NAFLD is a multifactorial disease, involving multiple genetic, metabolic, and environmental factors, and is closely associated with metabolic syndrome, obesity, and cardiovascular disease. NAFLD can be classified into nonalcoholic fatty liver disease (NAFL) and nonalcoholic steatohepatitis (NASH), which can both progress to cirrhosis and even hepatocellular carcinoma (HCC). Due to the enormous burden of NAFLD and its complications, no FDA-approved drugs for the treatment of NAFLD are on the market, and therapeutic targets and drug therapies are being actively investigated. In view of the various pathological mechanisms of NAFLD, numbers of preclinical studies and clinical trials have made rapid progress. This review mainly summarizes the most recently characterized mechanisms and therapeutic targets in each mechanism of NAFLD, focusing on the mechanism and application potential.

Gut microbiota modulation in patients with non-alcoholic fatty liver disease: Effects of current treatments and future strategies

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with metabolic disorders, being highly prevalent in obese and diabetic patients. Many concomitant factors that promote systemic and liver inflammation are involved in NAFLD pathogenesis, with a growing body of evidence highlighting the key role of the gut microbiota. Indeed, the gut-liver axis has a strong impact in the promotion of NAFLD and in the progression of the wide spectrum of its manifestations, claiming efforts to find effective strategies for gut microbiota modulation. Diet is among the most powerful tools; Western diet negatively affects intestinal permeability and the gut microbiota composition and function, selecting pathobionts, whereas Mediterranean diet fosters health-promoting bacteria, with a favorable impact on lipid and glucose metabolism and liver inflammation. Antibiotics and probiotics have been used to improve NAFLD features, with mixed results. More interestingly, medications used to treat NAFLD-associated comorbidities may also modulate the gut microbiota. Drugs for the treatment of type 2 diabetes mellitus (T2DM), such as metformin, glucagon-like peptide-1 (GLP-1) agonists, and sodium-glucose cotransporter (SGLT) inhibitors, are not only effective in the regulation of glucose homeostasis, but also in the reduction of liver fat content and inflammation, and they are associated with a shift in the gut microbiota composition towards a healthy phenotype. Even bariatric surgery significantly changes the gut microbiota, mostly due to the modification of the gastrointestinal anatomy, with a parallel improvement in histological features of NAFLD. Other options with promising effects in reprogramming the gut-liver axis, such as fecal microbial transplantation (FMT) and next-generation probiotics deserve further investigation for future inclusion in the therapeutic armamentarium of NAFLD.

Drugs in Clinical Development to Treat Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation that ultimately leads to kidney failure in most patients. Approximately 10% of patients who receive kidney replacement therapy suffer from ADPKD. To date, a vasopressin V2 receptor antagonist (V2RA) is the only drug that has been proven to attenuate disease progression. However, aquaresis-related adverse events limit its widespread use. Data on the renoprotective effects of somatostatin analogues differ largely between studies and medications. This review discusses new drugs that are investigated in clinical trials to treat ADPKD, such as cystic fibrosis transmembrane conductance regulator (CFTR) modulators and micro RNA inhibitors, and drugs already marketed for other indications that are being investigated for off-label use in ADPKD, such as metformin. In addition, potential methods to improve the tolerability of V2RAs are discussed, as well as methods to select patients with (likely) rapid disease progression and issues regarding the translation of preclinical data into clinical practice. Since ADPKD is a complex disease with a high degree of interindividual heterogeneity, and the mechanisms involved in cyst growth also have important functions in various physiological processes, it may prove difficult to develop drugs that target cyst growth without causing major adverse events. This is especially important since long-standing treatment is necessary in this chronic disease. This review therefore also discusses approaches to targeted therapy to minimize systemic side effects. Hopefully, these developments will advance the treatment of ADPKD.

Nonalcoholic fatty liver disease and obstructive sleep apnea in women with polycystic ovary syndrome

Nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea are frequently associated with polycystic ovary syndrome (PCOS) but remain underrecognized. Women with PCOS have a 2-4 times higher risk of NAFLD independent of body mass index than healthy weight-matched controls. Insulin resistance and hyperandrogenemia together play a central role in the pathogenesis of NAFLD. Timely diagnosis of NAFLD is important because its progression can lead to nonalcoholic steatohepatitis and/or advanced liver fibrosis that can eventually result in liver-related mortality. The presence of NAFLD has also been associated with increased risks of type 2 diabetes, cardiovascular events, overall mortality, and extrahepatic cancers. The treatment of NAFLD in PCOS should include lifestyle interventions. Glucagon-like peptide 1 receptor agonists have shown promising results in patients with PCOS and NAFLD, but future randomized trails are needed to confirm this benefit. Likewise, the use of combined oral estrogen-progestin contraceptives may provide a benefit by decreasing hyperandrogenemia. Sleep disordered breathing is common among women with PCOS and is responsible for a number of cardiometabolic derangements. Obstructive sleep apnea is most often found in overweight and obese women with PCOS, but as is the case with NAFLD, its prevalence exceeds that of women who are of similar weight without PCOS. Left untreated, obstructive sleep apnea can precipitate or exacerbate insulin resistance, glucose intolerance, and hypertension.

Pharmacological systemic analysis of gardenia fructus against non-alcoholic fatty liver disease and validation of animal models

[Purpose]

We aimed to investigate the systemic pharmacological analysis of gardenia fructus (GF) and the proof of concepts. We examined the antioxidant and anti-inflammatory effects in high-fat (HF) diet mice.

[Methods]

The active compounds of GF and the target genes were identified using the Traditional Chinese Medicine Database and Analysis Platform (oral bioavailability ≥ 30%, Caco-2 permeability ≥ -0.4, and drug-likeness ≥ 0.18). The rats were divided into four groups: untreated group, HF group, HF and metformin (17 mg/kg) treated group, and HF and treated with GF (28 mg/kg) for 8 weeks group. Hepatic lesion changes and markers were analyzed using hematoxylin and eosin staining and immunohistochemistry assay.

[Results]

In the systemic analysis, we identified 14 active compounds including A, B, and C. From these 14 compounds, 242 biological target genes were identified. The top 10 Gene Ontology were analyzed using GO-biological process analysis: removal of superoxide radicals, regulation of endothelial cell apoptotic process, and cellular response to lipopolysaccharide. GF extracts in high-fat diet-induced non-alcoholic fatty liver disease (NAFLD) mice models significantly regulated hepatic lesion markers, such as mTOR, 8-Hydroxy-2'-deoxyguanosine as well as oxidative stress activities, TGF-β, and phosphorylation of ERK1/2.

[Conclusion]

These results suggest that GF, as an exercise supplement, can alleviate NAFLD disease or fatty liver inflammation. Further studies are required to verify the synergistic effect of GF treatment combined with exercise, which is known to alleviate NAFLD and fatty liver inflammation.

Therapeutic developments in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) has become one of the most prevalent chronic liver diseases worldwide, bringing risk of multiorgan disfunctions including cardiovascular events, complications of cirrhosis, and even malignance. In terms of health burden management, screening patients with high risk of MAFLD and providing individual comprehensive treatment is critical. Although there are numerous agents entering clinical trials for MAFLD treatment every year, there is still no effective approved drug. The nomenclature of MAFLD highlighted the concomitant metabolic disorders and obesity. MAFLD patients with type 2 diabetes had higher risk of developing liver cirrhosis and cancer, and would benefit from anti-hyperglycemic agents; overweight and obese patients may benefit more from weight loss therapies; for patients with metabolic syndrome, individual comprehensive management is needed to reduce the risk of adverse outcomes. In this review, we introduced the current status and advances of the treatment of MAFLD based on weight loss, improving insulin resistance, and management of cardiometabolic disorders, in order to provide individualized therapy approaches for patients with MAFLD.

Posttranslational modifications in pathogenesis of PCOS

Polycystic ovary syndrome (PCOS) is a lifelong reproductive, metabolic, and psychiatric disorder that affects 5-18% of women, which is associated with a significantly increased lifetime risk of concomitant diseases, including type 2 diabetes, psychiatric disorders, and gynecological cancers. Posttranslational modifications (PTMs) play an important role in changes in protein function and are necessary to maintain cellular viability and biological processes, thus their maladjustment can lead to disease. Growing evidence suggests the association between PCOS and posttranslational modifications. This article mainly reviews the research status of phosphorylation, methylation, acetylation, and ubiquitination, as well as their roles and molecular mechanisms in the development of PCOS. In addition, we briefly summarize research and clinical trials of PCOS therapy to advance our understanding of agents that can be used to target phosphorylated, methylated, acetylated, and ubiquitinated PTM types. It provides not only ideas for future research on the mechanism of PCOS but also ideas for PCOS treatments with therapeutic potential.

Clinical spectrum transition and prediction model of nonalcoholic fatty liver disease in children with obesity

OBJECTIVE

This study aims to outline the clinical characteristics of pediatric NAFLD, as well as establish and validate a prediction model for the disease.

MATERIALS AND METHODS

The retrospective study enrolled 3216 children with obesity from January 2003 to May 2021. They were divided into obese without NAFLD, nonalcoholic fatty liver (NAFL), and nonalcoholic steatohepatitis (NASH) groups. Clinical data were retrieved, and gender and chronologic characteristics were compared between groups. Data from the training set (3036) were assessed using univariate analyses and stepwise multivariate logistic regression, by which a nomogram was developed to estimate the probability of NAFLD. Another 180 cases received additional liver hydrogen proton magnetic resonance spectroscopy (1H-MRS) as a validation set.

RESULTS

The prevalence of NAFLD was higher in males than in females and has increased over the last 19 years. In total, 1915 cases were NAFLD, and the peak onset age was 10-12 years old. Hyperuricemia ranked first in childhood NAFLD comorbidities, followed by dyslipidemia, hypertension, metabolic syndrome (MetS), and dysglycemia. The AUROC of the eight-parameter nomogram, including waist-to-height ratio (WHtR), hip circumference (HC), triglyceride glucose-waist circumference (TyG-WC), alanine aminotransferase (ALT), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1(ApoA1), insulin sensitivity index [ISI (composite)], and gender, for predicting NAFLD was 0.913 (sensitivity 80.70%, specificity 90.10%). Calibration curves demonstrated a great calibration ability of the model.

CONCLUSION AND RELEVANCE

NAFLD is the most common complication in children with obesity. The nomogram based on anthropometric and laboratory indicators performed well in predicting NAFLD. This can be used as a quick screening tool to assess pediatric NAFLD in children with obesity.

Management of Cardiometabolic Complications in Patients With Nonalcoholic Fatty Liver Disease: A Review of the Literature With Recommendations

Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of liver conditions characterized by significant lipid deposition within hepatocytes. As an overarching diagnosis, NAFLD contains a continuum of progressive liver diseases ranging from isolated liver steatosis to necroinflammatory states leading to end-stage liver disease. Nonalcoholic fatty liver and nonalcoholic steatohepatitis are distinguished by their histologic patterns, with the former exhibiting steatosis without fibrosis or inflammation. This important distinction provides clinicians a timeline within the NAFLD staging to target appropriate interventions against modifiable risk factors. NAFLD is likely formed in response to metabolic imbalances that damage the livers adaptive capacity. Metabolic conditions leading to steatosis mirror common cardiovascular risk factors, including dyslipidemia, diabetes mellitus, and obesity. Acknowledging the common risk factors for development and progression of NAFLD, it is unsurprising the first-line management focuses on the treatment of metabolic syndrome with an emphasis on weight reduction in obese populations. The purpose of this review is to provide a detailed summary of the literature as well as outline the current treatment recommendations for patients with NAFLD with a detailed focus on pharmacologic antiobesity interventions.

Alcohol's Impact on the Gut and Liver

Alcohol is inextricably linked with the digestive system. It is absorbed through the gut and metabolised by hepatocytes within the liver. Excessive alcohol use results in alterations to the gut microbiome and gut epithelial integrity. It contributes to important micronutrient deficiencies including short-chain fatty acids and trace elements that can influence immune function and lead to liver damage. In some people, long-term alcohol misuse results in liver disease progressing from fatty liver to cirrhosis and hepatocellular carcinoma, and results in over half of all deaths from chronic liver disease, over half a million globally per year. In this review, we will describe the effect of alcohol on the gut, the gut microbiome and liver function and structure, with a specific focus on micronutrients and areas for future research.

Metformin attenuates silica-induced pulmonary fibrosis via AMPK signaling

Background

Silicosis is one of the most common occupational pulmonary fibrosis caused by respirable silica-based particle exposure, with no ideal drugs at present. Metformin, a commonly used biguanide antidiabetic agent, could activate AMP-activated protein kinase (AMPK) to exert its pharmacological action. Therefore, we sought to investigate the role of metformin in silica-induced lung fibrosis.

Methods

The anti-fibrotic role of metformin was assessed in 50 mg/kg silica-induced lung fibrosis model. Silicon dioxide (SiO₂)-stimulated lung epithelial cells/macrophages and transforming growth factor-beta 1 (TGF-β1)-induced differentiated lung fibroblasts were used for in vitro models.

Results

At the concentration of 300 mg/kg in the mouse model, metformin significantly reduced lung inflammation and fibrosis in SiO₂-instilled mice at the early and late fibrotic stages. Besides, metformin (range 2–10 mM) reversed SiO₂-induced cell toxicity, oxidative stress, and epithelial-mesenchymal transition process in epithelial cells (A549 and HBE), inhibited inflammation response in macrophages (THP-1), and alleviated TGF-β1-stimulated fibroblast activation in lung fibroblasts (MRC-5) via an AMPK-dependent pathway.

Conclusions

In this study, we identified that metformin might be a potential drug for silicosis treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03036-5.

Endoplasmic Reticulum Stress and Autophagy in the Pathogenesis of Non-alcoholic Fatty Liver Disease (NAFLD): Current Evidence and Perspectives

PURPOSE OF REVIEW

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease with rising prevalence worldwide. Herein, we provide a comprehensive overview of the current knowledge supporting the role of ER stress and autophagy processes in NAFLD pathogenesis and progression. We also highlight the interrelation between these two pathways and the impact of ER stress and autophagy modulators on NAFLD treatment.

RECENT FINDINGS

The pathophysiological mechanisms involved in NAFLD progression are currently under investigation. The endoplasmic reticulum (ER) stress and the concomitant unfolded protein response (UPR) seem to contribute to its pathogenesis mainly due to high ER content in the liver which exerts significant metabolic functions and can be dysregulated. Furthermore, disruption of autophagy processes has also been identified in NAFLD. The crucial role of these two pathways in NAFLD is underlined by the fact that they have recently emerged as promising targets of therapeutic interventions. There is a greater need for finding the natural/chemical compounds and drugs which can modulate the ER stress pathway and autophagy for the treatment of NAFLD. Clarifying the inter-relation between these two pathways and their interaction with inflammatory and apoptotic mechanisms will allow the development of additional therapeutic options which can better target and reprogram the underlying pathophysiological pathways, aiming to attenuate NAFLD progression.

The Evaluation of Drug Delivery Nanocarrier Development and Pharmacological Briefing for Metabolic-Associated Fatty Liver Disease (MAFLD): An Update

Current research indicates that the next silent epidemic will be linked to chronic liver diseases, specifically non-alcoholic fatty liver disease (NAFLD), which was renamed as metabolic-associated fatty liver disease (MAFLD) in 2020. Globally, MAFLD mortality is on the rise. The etiology of MAFLD is multifactorial and still incompletely understood, but includes the accumulation of intrahepatic lipids, alterations in energy metabolism, insulin resistance, and inflammatory processes. The available MAFLD treatment, therefore, relies on improving the patient's lifestyle and multidisciplinary pharmacotherapeutic options, whereas the option of surgery is useless without managing the comorbidities of the MAFLD. Nanotechnology is an emerging approach addressing MAFLD, where nanoformulations are suggested to improve the safety and physicochemical properties of conventional drugs/herbal medicines, physical, chemical, and physiological stability, and liver-targeting properties. A wide variety of liver nanosystems were constructed and delivered to the liver, only those that addressed the MAFLD were discussed in this review in terms of the nanocarrier classes, particle size, shape, zeta potential and offered dissolution rate(s), the suitable preparation method(s), excipients (with synergistic effects), and the suitable drug/compound for loading. The advantages and challenges of each nanocarrier and the focus on potential promising perspectives in the production of MAFLD nanomedicine were also highlighted.

The effects of metformin on autophagy

Metformin is the first-line option for treating newly diagnosed diabetic patients and also involved in other pharmacological actions, including antitumor effect, anti-aging effect, polycystic ovarian syndrome prevention, cardiovascular action, and neuroprotective effect, etc. However, the mechanisms of metformin actions were not fully illuminated. Recently, increasing researches showed that autophagy is a vital medium of metformin playing pharmacological actions. Nevertheless, results on the effects of metformin on autophagy were inconsistent. Apart from few clinical evidences, more data focused on kinds of no-clinical models. First, many studies showed that metformin could induce autophagy via a number of signaling pathways, including AMPK-related signaling pathways (e.g. AMPK/mTOR, AMPK/CEBPD, MiTF/TFE, AMPK/ULK1, and AMPK/miR-221), Redd1/mTOR, STAT, SIRT, Na⁺/H⁺ exchangers, MAPK/ERK, PK2/PKR/AKT/ GSK3β, and TRIB3. Secondly, some signaling pathways were involved in the process of metformin inhibiting autophagy, such as AMPK-related signaling pathways (AMPK/NF-κB and other undetermined AMPK-related signaling pathways), Hedgehog, miR-570-3p, miR-142-3p, and MiR-3127-5p. Thirdly, two types of signaling pathways including PI3K/AKT/mTOR and endoplasmic reticulum (ER) stress could bidirectionally impact the effectiveness of metformin on autophagy. Finally, multiple signal pathways were reviewed collectively in terms of affecting the effectiveness of metformin on autophagy. The pharmacological effects of metformin combining its actions on autophagy were also discussed. It would help better apply metformin to treat diseases in term of mediating autophagy.

Effect of sodium-glucose co-transporter 2 inhibitors on hepatic parameters: A systematic review and meta-analysis of randomized controlled trials

Previous studies have suggested that sodium-glucose co-transporter-2 (SGLT2) inhibitors may improve hepatic function; however, the evidence is scarce. Hence, we performed a meta-analysis of randomized controlled trials to evaluate the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors on hepatic parameters. PubMed, Web of Science, Scopus, and Google Scholar databases were searched to identify randomized controlled trials examining the effect of SGLT2 inhibitors on hepatic parameters. Meta-analysis was performed using a random-effects model and sensitivity analysis. Meta-analysis revealed that SGLT2 inhibitors therapy significantly lowered alanine aminotransferase (ALT) (WMD: -4.79 U/L, 95 % CI: -6.10, -3.47, I² = 62 %, p < 0.00001), aspartate aminotransferase (AST) (WMD: -2.49 U/L, 95 % CI: -3.30, -1.68, I² = 54 %, p < 0.00001), alkaline phosphatase (AP) (WMD: -1.13 U/L, 95 % CI: -2.03, -0.22, I² = 23 %, p = 0.02), and gamma-glutamyl transferase (GGT) (WMD: -7.77 U/L, 95 % CI: -9.33, -6.21, I² = 5 %, p < 0.00001). Additionally, SGLT2 inhibitors showed a significant increase in bilirubin levels (WMD: 0.64 U/L, 95 % CI: 0.27, 1.00, I² = 53 %, p < 0.0006. Finally, no significant changes were found on albumin levels (WMD: 0.13 U/L, 95 % CI: -0.06, 0.32, I² = 53 %, p < 0.0006) after SGLT2 inhibitors treatment. In conclusion, our results suggest that treatment with SGLT2 inhibitors exerts a beneficial effect on liver function tests through decreased ALT, AST, AP, and GGT concentrations.

The clinical application of metformin in children and adolescents: A short update

Metformin is a widely used drug that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The global increase in the prevalence of obesity among children and adolescents is accompanied by the appearance and increasing prevalence of insulin resistance, prediabetes, and type 2 diabetes mellitus (T2DM). In addition, children, and adolescents with premature pubarche and polycystic ovary have considerable degree of insulin resistance. The insulin sensitizing actions of metformin encouraged many investigators and physician to use it as the key drug in these conditions for both prevention and treatment. However, long term-controlled studies are still required to assess the degree and duration of effectiveness and safety of using metformin. This review tries to update physicians about the main and the new therapeutic perspectives of this drug.

Herbal formulation MIT ameliorates high-fat diet-induced non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases and is caused by obesity, diabetes, high blood pressure, and insulin resistance. Many studies have explored novel candidates to treat NAFLD using herbal medicines owing to their fewer side effects. In this study, we examined the effect of MIT, an herbal formula comprising Ephedra sinica, Panax ginseng, and Alisma orientale, on the murine model of NAFLD.

Methods

To evaluate the effect of MIT on NAFLD, we used the high-fat diet (HFD)-induced NAFLD mice model. The mice were divided into four groups: control, HFD, HFD with metformin administration, and HFD with MIT administration. Freeze-dried MIT was dissolved in phosphate buffered saline and orally administered for 8 weeks to MIT-treated mice (60 mg/kg) after feeding them with HFD for 16 weeks.

Results

MIT treatment significantly attenuated fat accumulation, serum glucose levels, and excessive cholesterol. It also reduced the activation of NF-κB, JNK, ERK, mammalian target of rapamycin, and peroxisome proliferator-activated receptor γ in the HFD-induced NAFLD mice. The expression level of enzymes involved in the synthesis and oxidation of fatty acids, acetyl-coA carboxylase and CYP2E1, were clearly reduced by MIT treatment. Reactive oxygen species (ROS) production and subsequent liver damage were effectively reduced by MIT treatment.

Conclusion

We suggest that MIT is a potent herbal formula that can be used for the prevention and treatment of obesity-related NAFLD via regulating the levels of serum glucose and free fatty acids, inflammation, lipid accumulation, and ROS-mediated liver damage.