Effect of metformin on nonalcoholic fatty liver based on meta-analysis and network pharmacology

Metformin Treatment With or Without Mediterranean Diet for the Prevention of Age-Related Diseases in People With Metabolic Syndrome: The MeMeMe Randomized Trial

OBJECTIVE

The Metformin and Dietary Restriction to Prevent Age-Related Morbid Events in People With Metabolic Syndrome (MeMeMe) trial tested whether 1,700 mg/day metformin (MET) with or without a Mediterranean diet (MedDiet) intervention could reduce the cumulative incidence of major noncommunicable diseases in people with metabolic syndrome.

RESEARCH DESIGN AND METHODS

A total of 1,442 participants were randomly assigned to one of four interventions: 1) MET (1,700 mg/day) plus MedDiet intervention (MET+MedDiet); 2) placebo plus MedDiet intervention; 3) MET (1,700 mg/day) alone; and 4) placebo alone. Participants were followed up for 3 years on average. The primary outcome was the cumulative incidence of major noncommunicable diseases (including type 2 diabetes, cardiovascular diseases, and cancer). Secondary outcomes were the incidence of type 2 diabetes and the changing prevalence of metabolic syndrome.

RESULTS

The crude incidence of the major noncommunicable diseases was 6.7 cases per 100 person-years in the MET+MedDiet group, 6.9 in the MET alone group, 13.3 in the placebo plus MedDiet group, and 11.3 in the placebo group. The differences were fully explained by the reduction of type 2 diabetes, which was 80% and 92% lower in the MET and MET+MedDiet groups, respectively, compared with placebo.

CONCLUSIONS

The use of 1,700 mg/day MET is effective to prevent diabetes in people selected on the basis of metabolic syndrome.

The Triad of Risk: Linking MASLD, Cardiovascular Disease and Type 2 Diabetes; From Pathophysiology to Treatment

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an emerging global health concern, and it is not only the keystone precursor of eventual liver-related morbidity, but it also places patients at considerably higher cardiovascular risk, which is still a leading cause of death in these patients. The most important common underlying pathophysiological mechanisms in these diseases are primarily related to insulin resistance, chronic inflammation and oxidative stress. The presence of MASLD with cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) elevates the risk for poor outcomes, thus this review highlights a method to the therapeutic approaches. Given the intertwined nature of MASLD, T2DM, and CVD, there is an urgent need for therapeutic strategies that address all three conditions. Although lifestyle changes are important as treatment, medication plays a crucial role in managing hyperglycemia, enhancing liver function and lowering cardiovascular risk. The onset and progression of MASLD should be addressed through a multifaceted therapeutic approach, targeting inflammatory, immune, metabolic, oxidative stress, hormonal and gutaxis pathways, alongside the treatment strategies for T2DM. In this review, we discuss the effects of antidiabetic drugs with an impact on both liver outcomes and cardiovascular risk in patients affected by MASLD, T2DM and CDV.

Chitosan nanoparticles loaded with metformin and digoxin synergistically inhibit MCF-7 breast cancer cells through suppression of NOTCH-1 and HIF-1α gene expression

This study investigated the potential anticancer efficacy of co-treating the MCF-7 breast cancer cell line with chitosan nanoparticles (Cs NPs) loaded with metformin (Met) and digoxin (Dig). The Cs NPs had a size range of 90.6-148.7 nm and a zeta potential of +11.7 to +11.9 mV, indicating a positive surface charge. Notably, the Cs NPs demonstrated high encapsulation efficiencies, with values of 90.97 ± 5.14 % for Met and 92.12 ± 3.81 % for Dig, indicating effective loading of both drugs. The results revealed that the co-delivery of Met and Dig via Cs NPs significantly enhanced the anticancer efficacy, outperforming the treatment with individual free drugs or their combination, thereby demonstrating the potential benefits of nanoparticle-mediated co-administration. The drugs-loaded Cs NPs induced a marked increase in apoptosis in MCF-7 cells, with a cell death rate of 67.56 %, and significantly reduced mammosphere size by 48.08 %, thereby demonstrating a superior therapeutic efficacy compared to treatment with individual free drugs or their combination. Notably, the drug-loaded Cs NPs exhibited potent anti-migratory and anti-angiogenic effects, significantly inhibiting cell migration and new blood vessel formation, which may contribute to overcoming the inherent resistance of tumors to conventional therapies. Mechanistically, the co-treatment with drugs-loaded Cs NPs was found to downregulate the expression of NOTCH-1 and HIF-1α, two key transcription factors involved in tumor cell survival and adaptation, suggesting that their inhibition is a crucial component of the therapeutic efficacy of this treatment strategy. Collectively, the findings of this study suggest that the co-delivery of Met and Dig via chitosan Cs NPs represents a promising therapeutic strategy for breast cancer, as it effectively targets key pathways involved in tumor growth and progression, and underscores the potential of Cs NPs as a versatile platform for cancer therapy.

Exploring the mechanism of Pueraria lobata (Willd.) Ohwi in the regulation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Pueraria lobata (Willd.) Ohwi is a traditional medicinal and edible homologous plant rich in flavonoids, triterpenes, saponins, polysaccharides and other chemical components. At present, studies have shown that Pueraria lobata radix (PR) has the effect of lowering blood sugar, improving insulin sensitivity and inhibiting obesity. However, the specific mechanism of PR inhibits obesity is still unclear, and there are few researches on the anti-obesity effect of PR through the combination of network pharmacology and experiment.

AIM OF THE STUDY

Pharmacology, molecular docking technology and experimental verification through the network, revealing the PR the material basis of obesity and the potential mechanism.

METHODS AND RESULTS

The present study used network pharmacology techniques to investigate the therapeutic effect and mechanism of action of PR. Through relevant databases, a total of 6 main chemical components and 257 potential targets were screened. Protein interaction analysis shows that AKT1, AKR1B1, PPARG, MMP9, TNF, TP53, BAD, and BCL2 are core targets. Enrichment analysis shows that the pathway of PR in preventing obesity involves the cancer signaling pathway and the PI3K-Akt signaling pathway, which may be the main pathways of action. Further molecular docking verification indicates that its core target exhibits good binding activity with 4 compounds: formononectin, purerin, 7,8,4 '- trihydroxide and daidzein. Using the ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) technology to detected and confirmed these main compounds. Cell experiment results revealed that puerarin inhibits cell proliferation and differentiation in a concentration dependent manner, significantly promoting cell apoptosis and affecting cell migration. Animal experiments have shown that puerarin reduces food intake and weight gain in mice. It was found that puerarin can upregulate HDL and downregulate TC, TG, and LDL blood biochemical indicators. Western blot results showed that puerarin significantly inhibited the expression of AKT1, AKR1B1, MMP9, TNF, TP53, BCL2, PPARG, and significantly increased the expression of BAD protein at both cellular and animal levels.

CONCLUSION

The present study established a method for measuring PR content and predicted its active ingredients and their mechanisms of action in the treatment of obesity, providing a theoretical basis for further research.

Non-Alcoholic Fatty Liver Disease, Awareness of a Diagnostic Challenge—A Clinician’s Perspective

Non-alcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease globally. NAFLD is a complex pathology, considered to be the hepatic expression of metabolic syndrome (MetS). It is supposed to become the main indication for liver transplantation in the coming years and is estimated to affect 57.5–74.0% of obese people, 22.5% of children and 52.8% of obese children, with 50% of individuals with type 2 diabetes being diagnosed with NAFLD. Recent research has proved that an increase in adipose tissue insulin resistance index is an important marker of liver injury in patients with NAFLD. Despite being the main underlying cause of incidental liver damage and a growing worldwide health problem, NAFLD is mostly under-appreciated. Currently, NAFLD is considered a multifactorial disease, with various factors contributing to its pathogenesis, associated with insulin resistance and diabetes mellitus, but also with cardiovascular, kidney and endocrine disorders (polycystic ovary syndrome, hypothyroidism, growth hormone deficiency). Hepatitis B and hepatitis C, sleep apnea, inflammatory bowel diseases, cystic fibrosis, viral infections, autoimmune liver diseases and malnutrition are some other conditions in which NAFLD can be found. The aim of this review is to emphasize that, from the clinician’s perspective, NAFLD is an actual and valuable key diagnosis factor for multiple conditions; thus, efforts need to be made in order to increase recognition of the disease and its consequences. Although there is no global consensus, physicians should consider screening people who are at risk of NAFLD. A large dissemination of current concepts on NAFLD and an extensive collaboration between physicians, such as gastroenterologists, internists, cardiologists, diabetologists, nutritionists and endocrinologists, is equally needed to ensure we have the knowledge and resources to address this public health challenge.

Guideline for the Prevention and Treatment of Metabolic Dysfunction-associated Fatty Liver Disease (Version 2024)

With the rising epidemic of obesity, metabolic syndrome, and type 2 diabetes mellitus in China, metabolic dysfunction-associated non-alcoholic fatty liver disease has become the most prevalent chronic liver disease. This condition frequently occurs in Chinese patients with alcoholic liver disease and chronic hepatitis B. To address the impending public health crisis of non-alcoholic fatty liver disease and its underlying metabolic issues, the Chinese Society of Hepatology and the Chinese Medical Association convened a panel of clinical experts to revise and update the "Guideline of prevention and treatment of non-alcoholic fatty liver disease (2018, China)". The new edition, titled "Guideline for the prevention and treatment of metabolic dysfunction-associated fatty liver disease (Version 2024)", offers comprehensive recommendations on key clinical issues, including screening and monitoring, diagnosis and evaluation, treatment, and follow-up for metabolic dysfunction-associated fatty liver disease and metabolic dysfunction-associated steatotic liver disease. Metabolic dysfunction-associated fatty liver disease is now the preferred English term and is used interchangeably with metabolic dysfunction-associated steatotic liver disease. Additionally, the guideline emphasizes the importance of multidisciplinary collaboration among hepatologists and other specialists to manage cardiometabolic disorders and liver disease effectively.

Drug treatment for MASLD: Progress and direction

ABSTRACT

Metabolic dysfunction-associated steatotic liver disease (MASLD), also called non-alcoholic fatty liver disease, is the most epidemic chronic liver disease worldwide. Metabolic dysfunction-associated steatohepatitis (MASH) is the critical stage of MASLD, and early diagnosis and treatment of MASH are crucial for reducing the incidence of intrahepatic and extrahepatic complications. So far, pharmacotherapeutics for the treatment of MASH are still a major challenge, because of the complexity of the pathogenesis and heterogeneity of MASH. Many agents under investigation have shown impressive therapeutic effects by targeting different key pathways, including the attenuation of steatohepatitis or fibrosis or both. It is notable that thyroid hormone receptor-β agonist, resmetirom has become the first officially approved drug for treating MASH with fibrosis. Other agents such as peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 analogs, and fibroblast growth factor 21 analogs are awaiting approval. This review focuses on the current status of drug therapy for MASH and summarizes the latest results of new medications that have completed phase 2 or 3 clinical trials, and presents the future directions and difficulties of new drug research for MASH.

Metformin: Beyond Type 2 Diabetes Mellitus

Metformin was developed from an offshoot of Guanidine. It is known to be the first-line medication for type 2 diabetes mellitus, polycystic ovarian syndrome, and weight reduction. Metformin has also been shown to have effectiveness in the management of non-alcoholic fatty liver disease (NAFLD), liver cirrhosis, and various carcinomas like hepatocellular, colorectal, prostate, breast, urinary bladder, blood, melanoma, bone, skin, lung and so on. This narrative review focuses on the effect of metformin on non-alcoholic fatty liver disease, liver cirrhosis, and hepatocellular carcinoma. The search platforms for the topic were PubMed, Scopus, and Google search engine. Critical words for searching included 'Metformin,' AND 'Indications of Metformin,' AND 'Non-Alcoholic Fatty Liver Disease,' AND 'Metformin mechanism of action,' AND 'NAFLD management,' AND 'NAFLD and inflammation,' AND 'Metformin and insulin,' AND 'Metformin and inflammation,' AND 'Liver cirrhosis,' AND 'Hepatocellular carcinoma.' Lifestyle modification and the use of hypoglycemic agents can help improve liver conditions. Metformin has several mechanisms that enhance liver health, including reducing reactive oxygen species, nuclear factor kappa beta (NF-κB), liver enzymes, improving insulin sensitivity, and improving hepatic cell lipophagy. Long-term use of metformin may cause some adverse effects like lactic acidosis and gastrointestinal disturbance. Metformin long-term overdose may lead to a rise in hydrogen sulfide in liver cells, which calls for pharmacovigilance. Drug regulating authorities should provide approval for further research, and national and international guidelines need to be developed for liver diseases, perhaps with the inclusion of metformin as part of the management regime.

Retrospective Longitudinal Observational Study on the Long-Term Effects of Sodium-Glucose Cotransporter-2 Inhibitors on the Development of Metabolic Dysfunction-Associated Steatotic Liver Disease in Type 2 Diabetic Japanese Patients

Background/Objectives: The health burden of metabolic dysfunction-associated fatty liver disease (MASLD) has been increasing lately. Cardiovascular disease (CVD) is the main cause of death in MASLD patients; therefore, the treatments for MASLD should improve both CV risk factors such as obesity, diabetes, and dyslipidemia, in addition to an improvement in liver function. The evidence on the long-term effects of sodium-glucose cotransporter 2 inhibitors (SGLT2is) on the progression of MASLD in Asian populations is very limited. Methods: The retrospective longitudinal study was performed by using the medical records at our institute. We picked up patients with type 2 diabetes who had taken SGLT2is for at least 3 years or longer between 1 April 2014 and 31 March 2018. We collected the data on metabolic parameters, including laboratory data and anthropometric parameters, and compared the data before and after the initiation of SGLT2is treatment. Results: During the observation period, 324 patients had taken SGLT2is for 3 years. Three-year SGLT2is treatment significantly reduced body weight, hemoglobin A1c, low-density lipoprotein cholesterol, triglyceride, and non-high-density lipoprotein cholesterol (non-HDL-C). Such favorable changes in serum lipids were remarkable in patients with statins. Furthermore, this treatment significantly improved liver function and the markers for hepatic steatosis and hepatic fibrosis. Conclusions: Considering that the development of CVD determines the prognosis of MASLD patients, long-term SGLT2is treatment may be an ideal therapy for MASLD patients.

Mechanisms of Non-alcoholic Fatty Liver Disease and Beneficial Effects of Semaglutide: A Review

Non-alcoholic fatty liver disease stands as the predominant cause of chronic liver disease, with its prevalence and morbidity expected to escalate significantly, leading to substantial healthcare costs and diminished health-related quality of life. It comprises a range of disease manifestations that commence with basic steatosis, involving the accumulation of lipids in hepatocytes, a distinctive histological feature. If left untreated, it often advances to non-alcoholic steatohepatitis, marked by inflammatory and/or fibrotic hepatic changes, leading to the eventual development of non-alcoholic fatty liver disease-related cirrhosis and hepatocellular carcinoma. Because of the liver's vital role in body metabolism, non-alcoholic fatty liver disease is considered both a consequence and a contributor to the metabolic abnormalities observed in the metabolic syndrome. As of date, there are no authorized pharmacological agents for non-alcoholic fatty liver disease or non-alcoholic steatohepatitis. Semaglutide, with its glycemic and weight loss advantages, could potentially offer benefits for individuals with non-alcoholic fatty liver disease. This review aims to investigate the impact of semaglutide on non-alcoholic fatty liver disease.

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.

Clinical outcomes with metformin use in diabetic patients with compensated cirrhosis: a systematic review and meta-analysis

BACKGROUND

Previous studies have demonstrated a beneficial effect of metformin in patients with cirrhosis, but no improvement in liver histology.

AIM

To investigate the impact of metformin on mortality and hepatic decompensation in people with diabetes with compensated cirrhosis.

METHODS

Medline, Embase and Cochrane databases were searched from inception to February 2023 for studies reporting results regarding the impact of metformin on all-cause mortality and hepatic decompensation in people with diabetes with compensated cirrhosis. The risk of bias was assessed by ROBINS-I Cochrane tool. R software 4.3.1 was used for all analyses.

RESULTS

Six observational studies were included in the final analysis. Metformin use was associated with reduced all-cause mortality or liver transplantation [hazard ratio (HR): 0.55; 95% confidence interval (CI) 0.37-0.82], while no benefit was shown in the prevention of hepatic decompensation (HR: 0.97; 95% CI: 0.77-1.22). In the subgroup analysis, metformin use was associated with reduced all-cause mortality or liver transplantation (HR: 0.50; 95% CI 0.38-0.65) in patients with metabolic-associated steatohepatitis cirrhosis, while two studies reported no survival benefit in patients with cirrhosis due to hepatitis C (HR: 0.39; 95% CI 0.12-1.20).

CONCLUSION

Metformin use is associated with reduced all-cause mortality, but not with the prevention of hepatic decompensation in people with diabetes with compensated cirrhosis. The mortality benefit is most likely driven by better diabetes and cardiovascular health control.

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.

Dihydromyricetin ameliorates hepatic steatosis and insulin resistance via AMPK/PGC-1α and PPARα-mediated autophagy pathway

BACKGROUND

Dihydromyricetin (DHM), a flavonoid compound of natural origin, has been identified in high concentrations in ampelopsis grossedentata and has a broad spectrum of biological and pharmacological functions, particularly in regulating glucose and lipid metabolism. The objective of this research was to examine how DHM affected nonalcoholic fatty liver disease (NAFLD) and its underlying mechanisms involved in the progression of NAFLD in a rat model subjected to a high-fat diet (HFD). Additionally, the study examines the underlying mechanisms in a cellular model of steatohepatitis using palmitic acid (PA)-treated HepG2 cells, with a focus on the potential correlation between autophagy and hepatic insulin resistance (IR) in the progress of NAFLD.

METHODS

SD rats were exposed to a HFD for a period of eight weeks, followed by a treatment with DHM (at doses of 50, 100, and 200 mg·kg-1·d-1) for additional six weeks. The HepG2 cells received a 0.5 mM PA treatment for 24 h, either alone or in conjunction with DHM (10 µM). The histopathological alterations were assessed by the use of Hematoxylin-eosin (H&E) staining. The quantification of glycogen content and lipid buildup in the liver was conducted by the use of PAS and Oil Red O staining techniques. Serum lipid and liver enzyme levels were also measured. Autophagic vesicle and autolysosome morphology was studied using electron microscopy. RT-qPCR and/or western blotting techniques were used to measure IR- and autophagy-related factors levels.

RESULTS

The administration of DHM demonstrated efficacy in ameliorating hepatic steatosis, as seen in both in vivo and in vitro experimental models. Moreover, DHM administration significantly increased GLUT2 expression, decreased G6Pase and PEPCK expression, and improved IR in the hepatic tissue of rats fed a HFD and in cells exhibiting steatosis. DHM treatment elevated Beclin 1, ATG 5, and LC3-II levels in hepatic steatosis models, correlating with autolysosome formation. The expression of AMPK levels and its downstream target PGC-1α, and PPARα were decreased in HFD-fed rats and PA-treated hepatocytes, which were reversed through DHM treatment. AMPK/ PGC-1α and PPARα knockdown reduced the impact of DHM on hepatic autophagy, IR and accumulation of hepatic lipid.

CONCLUSIONS

Our findings revealed that AMPK/ PGC-1α, PPARα-dependent autophagy pathways in the pathophysiology of IR and hepatic steatosis has been shown, suggesting that DHM might potentially serve as a promising treatment option for addressing this disease.

Metformin and the Liver: Unlocking the Full Therapeutic Potential

Metformin is a highly effective medication for managing type 2 diabetes mellitus. Recent studies have shown that it has significant therapeutic benefits in various organ systems, particularly the liver. Although the effects of metformin on metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis are still being debated, it has positive effects on cirrhosis and anti-tumoral properties, which can help prevent the development of hepatocellular carcinoma. Furthermore, it has been proven to improve insulin resistance and dyslipidaemia, commonly associated with liver diseases. While more studies are needed to fully determine the safety and effectiveness of metformin use in liver diseases, the results are highly promising. Indeed, metformin has a terrific potential for extending its full therapeutic properties beyond its traditional use in managing diabetes.

Mitochondrial Quality Control: Its Role in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease, is characterized by hepatic steatosis and metabolic dysfunction and is often associated with obesity and insulin resistance. Recent research indicates a rapid escalation in MASLD cases, with projections suggesting a doubling in the United States by 2030. This review focuses on the central role of mitochondria in the pathogenesis of MASLD and explores potential therapeutic interventions. Mitochondria are dynamic organelles that orchestrate hepatic energy production and metabolism and are critically involved in MASLD. Dysfunctional mitochondria contribute to lipid accumulation, inflammation, and liver fibrosis. Genetic associations further underscore the relationship between mitochondrial dynamics and MASLD susceptibility. Although U.S. Food and Drug Administration-approved treatments for MASLD remain elusive, ongoing clinical trials have highlighted promising strategies that target mitochondrial dysfunction, including vitamin E, metformin, and glucagon-like peptide-1 receptor agonists. In preclinical studies, novel therapeutics, including nicotinamide adenine dinucleotide+ precursors, urolithin A, spermidine, and mitoquinone, have shown beneficial effects, such as improving mitochondrial quality control, reducing oxidative stress, and ameliorating hepatic steatosis and inflammation. In conclusion, mitochondrial dysfunction is central to MASLD pathogenesis. The innovative mitochondria-targeted approaches discussed in this review offer a promising avenue for reducing the burden of MASLD and improving global quality of life.

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.

The emerging significance of mitochondrial targeted strategies in NAFLD treatment

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, ranging from liver steatosis to nonalcoholic steatohepatitis, which ultimately progresses to fibrosis, cirrhosis, and hepatocellular carcinoma. Individuals with NAFLD have a higher risk of developing cardiovascular and extrahepatic cancers. Despite the great progress being made in understanding the pathogenesis and the introduction of new pharmacological targets for NAFLD, no drug or intervention has been accepted for its management. Recent evidence suggests that NAFLD may be a mitochondrial disease, as mitochondrial dysfunction is involved in the pathological processes that lead to NAFLD. In this review, we describe the recent advances in our understanding of the mechanisms associated with mitochondrial dysfunction in NAFLD progression. Moreover, we discuss recent advances in the efficacy of mitochondria-targeted compounds (e.g., Mito-Q, MitoVit-E, MitoTEMPO, SS-31, mitochondrial uncouplers, and mitochondrial pyruvate carrier inhibitors) for treating NAFLD. Furthermore, we present some medications currently being tested in clinical trials for NAFLD treatment, such as exercise, mesenchymal stem cells, bile acids and their analogs, and antidiabetic drugs, with a focus on their efficacy in improving mitochondrial function. Based on this evidence, further investigations into the development of mitochondria-based agents may provide new and promising alternatives for NAFLD management.

The role of hypoxia-inducible factor 1α in hepatic lipid metabolism

Chronic liver disease is a major public health problem with a high and increasing prevalence worldwide. In the progression of chronic liver disease, steatosis drives the progression of the disease to cirrhosis or even liver cancer. Hypoxia-inducible factor 1α (HIF-1α) is central to the regulation of hepatic lipid metabolism. HIF-1α upregulates the expression of genes related to lipid uptake and synthesis in the liver and downregulates the expression of lipid oxidation genes. Thus, it promotes intrahepatic lipid deposition. In addition, HIF-1α is expressed in white adipose tissue, where lipolysis releases free fatty acids (FFAs) into the blood. These circulating FFAs are taken up by the liver and accumulate in the liver. The expression of HIF-1α in the liver condenses bile and makes it easier to form gallstones. Contrary to the role of hepatic HIF-1α, intestinal HIF-1α expression can maintain a healthy microbiota and intestinal barrier. Thus, it plays a protective role against hepatic steatosis. This article aims to provide an overview of the current understanding of the role of HIF-1α in hepatic steatosis and to encourage the development of therapeutic agents associated with HIF-1α pathways. KEY MESSAGES: • Hepatic HIF-1α expression promotes lipid uptake and synthesis and reduces lipid oxidation leading to hepatic steatosis. • The expression of HIF-1α in the liver condenses bile and makes it easier to form gallstones. • Intestinal HIF-1α expression can maintain a healthy microbiota and intestinal barrier.

Clinical Application of Metformin Use in Anhui Province, China: A Cross-Sectional Study

Purpose

Given the importance of metformin, reasonable utilization is essential. We designed a cross-sectional survey on physicians' attitude and clinical application of metformin in Anhui Province, China.

Methods

The survey was distributed via an electronic questionnaire among endocrinologists and general practitioners. Seven representative questions were used to evaluate professional levels.

Results

Among the 477 valid responses, 72.75% of the respondents preferred to prescribe metformin extended-release, while only 34.38% of them would prescribe metformin extended-release at the correct frequency. More than half of the respondents thought that estimated glomerular filtration rate ˂ 45 mL/min/1.73 m² should be the contraindication of metformin prescription. Less than 10% of the physicians selected correct responses for two questions regarding metformin usage and contrast agent. Physicians with higher levels of hospital grades, education background and professional titles as well as working in general hospitals and in the Department of Endocrinology achieved high scores (P˂0.05). Logistic regression showed that department was an independent predictor for high scores.

Conclusion

Physicians, especially non-endocrinologists, are not at a professional level for prescribing metformin. Physicians should be highly vigilant in terms of standardized prescription for metformin. The guidelines or consensuses about diabetes care for physicians should be promoted.