Effects of Epeleuton, a Novel Synthetic Second-Generation n-3 Fatty Acid, on Non-Alcoholic Fatty Liver Disease, Triglycerides, Glycemic Control, and Cardiometabolic and Inflammatory Markers

The gut-liver axis: emerging mechanisms and therapeutic approaches for nonalcoholic fatty liver disease and type 2 diabetes mellitus

Nonalcoholic fatty liver disease (NAFLD), more appropriately known as metabolic (dysfunction) associated fatty liver disease (MAFLD), a prevalent condition in type 2 diabetes mellitus (T2DM) patients, is a complex condition involving hepatic lipid accumulation, inflammation, and liver fibrosis. The gut-liver axis is closely linked to metabolic dysfunction, insulin resistance, inflammation, and oxidative stress that are leading to the cooccurrence of MAFLD and T2DM cardiovascular diseases (CVDs). The purpose of this review is to raise awareness about the role of the gut-liver axis in the progression of MAFLD, T2DM and CVDs with a critical analysis of available treatment options for T2DM and MAFLD and their impact on cardiovascular health. This study analysed over 100 articles on this topic, using online searches and predefined keywords, to understand and summarise published research. Numerous studies have shown a strong correlation between gut dysfunction, particularly the gut microbiota and its metabolites, and the occurrence and progression of MAFLD and type 2 diabetes mellitus (T2DM). Herein, this article also examines the impact of the gut-liver axis on MAFLD, T2DM, and related complications, focusing on the role of gut microbiota dysbiosis in insulin resistance, T2DM and obesity-related cardiovascular complications. The study suggests potential treatment targets for MAFLD linked to T2DM, focusing on cardiovascular outcomes and the molecular mechanism of the gut-liver axis, as gut microbiota dysbiosis contributes to obesity-related metabolic abnormalities.

Epeleuton, a novel synthetic ω-3 fatty acid, reduces hypoxia/ reperfusion stress in a mouse model of sickle cell disease

Inflammatory vasculopathy is critical in sickle cell disease (SCD)-associated organ damage. An imbalance between pro-inflammatory and pro-resolving mechanisms in response to different triggers such as hypoxia/reoxygenation or infections has been proposed to contribute to the progression of SCD. Administration of specialized pro-resolving lipid mediators may provide an effective therapeutic strategy to target inflammatory vasculopathy and to modulate inflammatory response. Epeleuton (15 hydroxy eicosapentaenoic acid ethyl ester) is a novel, orally administered, second-generation ω-3 fatty acid with a favorable clinical safety profile. In this study we show that epeleuton re-programs the lipidomic pattern of target organs for SCD towards a pro-resolving pattern. This protects against systemic and local inflammatory responses and improves red cell features, resulting in reduced hemolysis and sickling compared with that in vehicle-treated SCD mice. In addition, epeleuton prevents hypoxia/reoxygenation-induced activation of nuclear factor-κB with downregulation of the NLRP3 inflammasome in lung, kidney, and liver. This was associated with downregulation of markers of vascular activation in epeleuton-treated SCD mice when compared to vehicle-treated animals. Collectively our data support the potential therapeutic utility of epeleuton and provide the rationale for the design of clinical trials to evaluate the efficacy of epeleuton in patients with SCD.

Exploring the Multifaceted Landscape of MASLD: A Comprehensive Synthesis of Recent Studies, from Pathophysiology to Organoids and Beyond

Non-alcoholic fatty liver disease (NAFLD) is a widespread contributor to chronic liver disease globally. A recent consensus on renaming liver disease was established, and metabolic dysfunction-associated steatotic liver disease, MASLD, was chosen as the replacement for NAFLD. The disease's range extends from the less severe MASLD, previously known as non-alcoholic fatty liver (NAFL), to the more intense metabolic dysfunction-associated steatohepatitis (MASH), previously known as non-alcoholic steatohepatitis (NASH), characterized by inflammation and apoptosis. This research project endeavors to comprehensively synthesize the most recent studies on MASLD, encompassing a wide spectrum of topics such as pathophysiology, risk factors, dietary influences, lifestyle management, genetics, epigenetics, therapeutic approaches, and the prospective trajectory of MASLD, particularly exploring its connection with organoids.

Type 2 Diabetes Mellitus, Non-Alcoholic Fatty Liver Disease, and Metabolic Repercussions: The Vicious Cycle and Its Interplay with Inflammation

The prevalence of metabolic-related disorders, such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (DM2), has been increasing. Therefore, developing improved methods for the prevention, treatment, and detection of these two conditions is also necessary. In this study, our primary focus was on examining the role of chronic inflammation as a potential link in the pathogenesis of these diseases and their interconnections. A comprehensive search of the PubMed database using keywords such as "non-alcoholic fatty liver disease", "type 2 diabetes mellitus", "chronic inflammation", "pathogenesis", and "progression" yielded 177 relevant papers for our analysis. The findings of our study revealed intricate relationships between the pathogenesis of NAFLD and DM2, emphasizing the crucial role of inflammatory processes. These connections involve various molecular functions, including altered signaling pathways, patterns of gene methylation, the expression of related peptides, and up- and downregulation of several genes. Our study is a foundational platform for future research into the intricate relationship between NAFLD and DM2, allowing for a better understanding of the underlying mechanisms and the potential for introducing new treatment standards.

What's New in the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem due to its high incidence and consequences. In view of the existing controversies, new therapeutic options for NAFLD are still being sought. Therefore, the aim of our review was to evaluate the recently published studies on the treatment of NAFLD patients. We searched for articles in the PubMed database using appropriate terms, including "non-alcoholic fatty liver disease", "nonalcoholic fatty liver disease", "NAFLD", "diet", "treatment", "physical activity", "supplementation", "surgery", "overture" and "guidelines". One hundred forty-eight randomized clinical trials published from January 2020 to November 2022 were used for the final analysis. The results show significant benefits of NAFLD therapy associated with the use of not only the Mediterranean but also other types of diet (including low-calorie ketogenic, high-protein, anti-inflammatory and whole-grain diets), as well as enrichment with selected food products or supplements. Significant benefits in this group of patients are also associated with moderate aerobic physical training. The available therapeutic options indicate, above all, the usefulness of drugs related to weight reduction, as well as the reduction in insulin resistance or lipids level and drugs with anti-inflammatory or antioxidant properties. The usefulness of therapy with dulaglutide and the combination of tofogliflozin with pioglitazone should be emphasized. Based on the results of the latest research, the authors of this article suggest a revision of the therapeutic recommendations for NAFLD patients.

Potential Mechanisms by Which Hydroxyeicosapentaenoic Acids Regulate Glucose Homeostasis in Obesity

Dysregulation of glucose metabolism in response to diet-induced obesity contributes toward numerous complications, such as insulin resistance and hepatic steatosis. Therefore, there is a need to develop effective strategies to improve glucose homeostasis. In this review, we first discuss emerging evidence from epidemiological studies and rodent experiments that increased consumption of EPA (either as oily fish, or dietary/pharmacological supplements) may have a role in preventing impairments in insulin and glucose homeostasis. We then review the current evidence on how EPA-derived metabolites known as hydroxyeicosapentaenoic acids (HEPEs) may be a major mode of action by which EPA exerts its beneficial effects on glucose and lipid metabolism. Notably, cell culture and rodent studies show that HEPEs prevent fat accumulation in metabolic tissues through peroxisome proliferator activated receptor (PPAR)-mediated mechanisms. In addition, activation of the resolvin E1 pathway, either by administration of EPA in the diet or via intraperitoneal administration of resolvin E1, improves hyperglycemia, hyperinsulinemia, and liver steatosis through multiple mechanisms. These mechanisms include shifting immune cell phenotypes toward resolution of inflammation and preventing dysbiosis of the gut microbiome. Finally, we present the next steps for this line of research that will drive future precision randomized clinical trials with EPA and its downstream metabolites. These include dissecting the variables that drive heterogeneity in the response to EPA, such as the baseline microbiome profile and fatty acid status, circadian rhythm, genetic variation, sex, and age. In addition, there is a critical need to further investigate mechanisms of action for HEPEs and to establish the concentration of HEPEs in differing tissues, particularly in response to consumption of oily fish and EPA-enriched supplements.

Diagnostic and therapeutic strategies for non-alcoholic fatty liver disease

The global incidence rate of non-alcoholic fatty liver disease (NAFLD) is approximately 25%. With the global increase in obesity and its associated metabolic syndromes, NAFLD has become an important cause of chronic liver disease in many countries. Despite recent advances in pathogenesis, diagnosis, and therapeutics, there are still challenges in its treatment. In this review, we briefly describe diagnostic methods, therapeutic targets, and drugs related to NAFLD. In particular, we focus on evaluating carbohydrate and lipid metabolism, lipotoxicity, cell death, inflammation, and fibrosis as potential therapeutic targets for NAFLD. We also summarized the clinical research progress in terms of drug development and combination therapy, thereby providing references for NAFLD drug development.

Pharmacotherapy for Non-Alcoholic Fatty Liver Disease: Emerging Targets and Drug Candidates

Non-alcoholic fatty liver disease (NAFLD), or metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by high global incidence and prevalence, a tight association with common metabolic comorbidities, and a substantial risk of progression and associated mortality. Despite the increasingly high medical and socioeconomic burden of NAFLD, the lack of approved pharmacotherapy regimens remains an unsolved issue. In this paper, we aimed to provide an update on the rapidly changing therapeutic landscape and highlight the major novel approaches to the treatment of this disease. In addition to describing the biomolecules and pathways identified as upcoming pharmacological targets for NAFLD, we reviewed the current status of drug discovery and development pipeline with a special focus on recent evidence from clinical trials.

Beneficial effects of eicosapentaenoic acid on the metabolic profile of obese female mice entails upregulation of HEPEs and increased abundance of enteric Akkermansia muciniphila

Eicosapentaenoic acid (EPA) ethyl esters are of interest given their clinical approval for lowering circulating triglycerides and cardiometabolic disease risk. EPA ethyl esters prevent metabolic complications driven by a high fat diet in male mice; however, their impact on female mice is less studied. Herein, we first investigated how EPA influences the metabolic profile of female C57BL/6J mice consuming a high fat diet. EPA lowered murine fat mass accumulation, potentially through increased biosynthesis of 8-hydroxyeicosapentaenoic acid (HEPE), as revealed by mass spectrometry and cell culture studies. EPA also reversed the effects of a high fat diet on circulating levels of insulin, glucose, and select inflammatory/metabolic markers. Next, we studied if the improved metabolic profile of obese mice consuming EPA was associated with a reduction in the abundance of key gut Gram-negative bacteria that contribute toward impaired glucose metabolism. Using fecal 16S-ribosomal RNA gene sequencing, we found EPA restructured the gut microbiota in a time-dependent manner but did not lower the levels of key Gram-negative bacteria. Interestingly, EPA robustly increased the abundance of the Gram-negative Akkermansia muciniphila, which controls glucose homeostasis. Finally, predictive functional profiling of microbial communities revealed EPA-mediated reversal of high fat diet-associated changes in a wide range of genes related to pathways such as Th-17 cell differentiation and PI3K-Akt signaling. Collectively, these results show that EPA ethyl esters prevent some of the deleterious effects of a high fat diet in female mice, which may be mediated mechanistically through 8-HEPE and the upregulation of intestinal Akkermansia muciniphila.

Specialized Proresolving Mediators in Symptomatic Women With Coronary Microvascular Dysfunction (from the Women's Ischemia Trial to Reduce Events in Nonobstructive CAD [WARRIOR] Trial)

Resolvins and maresins, members of the specialized proresolving mediator (SPM) family, are omega-3 fatty acid-derived lipid mediators that attenuate inflammation. We hypothesized that they play a role in the pathophysiology of coronary microvascular dysfunction (CMD) in women with ischemia and no obstructive coronary disease. In a pilot study, we measured the D-series resolvins (D1, D2, D3, and D5), resolvin E1, maresin 1, docosahexaenoic acid, eicosapentaenoic acid (precursor of resolvin E1), and 18-hydroxyeicosapentaenoic acid by mass spectrometry in the peripheral blood of 31 women enrolled in the Women's Ischemia Trial to Reduce Events in Nonobstructive CAD (WARRIOR) trial who had confirmed CMD assessed by coronary flow reserve. We compared SPM levels with 12 gender and age-matched reference subjects. Compared with the reference subject group, those with CMD had significantly lower plasma concentrations of resolvin D1 and maresin 1 and significantly higher levels of docosahexaenoic acid and 18-hydroxyeicosapentaenoic acid. In conclusion, insufficient or ineffective SPM production may play a role in the pathophysiology of CMD. If our results are validated in a larger cohort, omega-3 fatty acid supplementation could be tested as a novel treatment for these patients.

Treatment of Hypertriglyceridemia: A Review of Therapies in the Pipeline

BackgroundThe 2018 American College of Cardiology/American Heart Association (ACC/AHA) guidelines and 2021 ACC Expert Consensus Decision Pathway recommend nonpharmacological interventions and initiation of statin therapy for patients with moderate hypertriglyceridemia and addition of fibrates or omega-3 fatty acids in severe hypertriglyceridemia. Although the association between triglyceride (TG) lowering and atherosclerotic cardiovascular disease (ASCVD) risk reduction remains controversial, patients with hypertriglyceridemia may represent a subgroup that require additional therapy to further reduce residual ASCVD risk. Moreover, medications that target novel pathways could provide alternative options for patients who are intolerant of existing therapies or doses needed to provide adequate triglyceride lowering. Objective: Assess recent evidence for TG-lowering agents including omega-3 fatty acid-based therapies, PPARα modulators, apoC-III mRNA antisense inhibitors, angiopoietin-like 3 (ANGPTL3) antibodies, and herbal supplements. Methods: A literature search was performed using PubMed with hypertriglyceridemia specified as a MeSH term or included in the title or abstract of the article along with each individual agent. For inclusion, trials needed to have a primary or secondary outcome of TG levels or TG lowering. Conclusion: Currently, the only US Food and Drug Administration approved medication for CV risk reduction in patients with hypertriglyceridemia is icosapent ethyl. Results from phase 3 trials for CaPre, pemafibrate, and volanesorsen as well as additional evidence for pipeline pharmacotherapies with novel mechanisms of action (e.g., ApoC-III mRNA antisense inhibitors and ANGPTL3 antibodies) will help to guide future pharmacotherapy considerations for patients with hypertriglyceridemia.

Nutritional supplementation for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of non-alcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases risks of liver cirrhosis, hepatocellular carcinoma, and the requirement for liver transplantation. Uncertainty surrounds relative benefits and harms of various nutritional supplements in NAFLD. Currently no nutritional supplement is recommended for people with NAFLD.

OBJECTIVES

• To assess the benefits and harms of different nutritional supplements for treatment of NAFLD through a network meta-analysis • To generate rankings of different nutritional supplements according to their safety and efficacy SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, the World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) for people with NAFLD, irrespective of method of diagnosis, age and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods whenever possible and calculated differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios with 95% credible intervals (CrIs) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included in the review a total of 202 randomised clinical trials (14,200 participants). Nineteen trials were at low risk of bias. A total of 32 different interventions were compared in these trials. A total of 115 trials (7732 participants) were included in one or more comparisons. The remaining trials did not report any of the outcomes of interest for this review. Follow-up ranged from 1 month to 28 months. The follow-up period in trials that reported clinical outcomes was 2 months to 28 months. During this follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. We did not calculate effect estimates for mortality because of sparse data (zero events for at least one of the groups in the trial). None of the trials reported that they measured overall health-related quality of life using a validated scale. The evidence is very uncertain about effects of interventions on serious adverse events (number of people or number of events). We are very uncertain about effects on adverse events of most of the supplements that we investigated, as the evidence is of very low certainty. However, people taking PUFA (polyunsaturated fatty acid) may be more likely to experience an adverse event than those not receiving an active intervention (network meta-analysis results: OR 4.44, 95% CrI 2.40 to 8.48; low-certainty evidence; 4 trials, 203 participants; direct evidence: OR 4.43, 95% CrI 2.43 to 8.42). People who take other supplements (a category that includes nutritional supplements other than vitamins, fatty acids, phospholipids, and antioxidants) had higher numbers of adverse events than those not receiving an active intervention (network meta-analysis: rate ratio 1.73, 95% CrI 1.26 to 2.41; 6 trials, 291 participants; direct evidence: rate ratio 1.72, 95% CrI 1.25 to 2.40; low-certainty evidence). Data were sparse (zero events in all groups in the trial) for liver transplantation, liver decompensation, and hepatocellular carcinoma. So, we did not perform formal analysis for these outcomes. The evidence is very uncertain about effects of other antioxidants (antioxidants other than vitamins) compared to no active intervention on liver cirrhosis (HR 1.68, 95% CrI 0.23 to 15.10; 1 trial, 99 participants; very low-certainty evidence). The evidence is very uncertain about effects of interventions in any of the remaining comparisons, or data were sparse (with zero events in at least one of the groups), precluding formal calculations of effect estimates. Data were probably because of the very short follow-up period (2 months to 28 months). It takes follow-up of 8 to 28 years to detect differences in mortality between people with NAFLD and the general population. Therefore, it is unlikely that differences in clinical outcomes are noted in trials providing less than 5 to 10 years of follow-up.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about effects of nutritional supplementation compared to no additional intervention on all clinical outcomes for people with non-alcohol-related fatty liver disease. Accordingly, high-quality randomised comparative clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (study design in which multiple interventions are trialed within large longitudinal cohorts of patients to gain efficiencies and align trials more closely to standard clinical practice) comparing interventions such as vitamin E, prebiotics/probiotics/synbiotics, PUFAs, and no nutritional supplementation. The reason for the choice of interventions is the impact of these interventions on indirect outcomes, which may translate to clinical benefit. Outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource utilisation measures including costs of intervention and decreased healthcare utilisation after minimum follow-up of 8 years (to find meaningful differences in clinically important outcomes).

Liver-targeting drugs and their effect on blood glucose and hepatic lipids

The global epidemic of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) and the high prevalence among individuals with type 2 diabetes has attracted the attention of clinicians specialising in liver disorders. Many drugs are in the pipeline for the treatment of NAFLD/NASH, and several glucose-lowering drugs are now being tested specifically for the treatment of liver disease. Among these are nuclear hormone receptor agonists (e.g. peroxisome proliferator-activated receptor agonists, farnesoid X receptor agonists and liver X receptor agonists), fibroblast growth factor-19 and -21, single, dual or triple incretins, sodium-glucose cotransporter inhibitors, drugs that modulate lipid or other metabolic pathways (e.g. inhibitors of fatty acid synthase, diacylglycerol acyltransferase-1, acetyl-CoA carboxylase and 11β-hydroxysteroid dehydrogenase type-1) or drugs that target the mitochondrial pyruvate carrier. We have reviewed the metabolic effects of these drugs in relation to improvement of diabetic hyperglycaemia and fatty liver disease, as well as peripheral metabolism and insulin resistance.

Pro-resolving lipid mediators: regulators of inflammation, metabolism and kidney function

Obesity, diabetes mellitus, hypertension and cardiovascular disease are risk factors for chronic kidney disease (CKD) and kidney failure. Chronic, low-grade inflammation is recognized as a major pathogenic mechanism that underlies the association between CKD and obesity, impaired glucose tolerance, insulin resistance and diabetes, through interaction between resident and/or circulating immune cells with parenchymal cells. Thus, considerable interest exists in approaches that target inflammation as a strategy to manage CKD. The initial phase of the inflammatory response to injury or metabolic dysfunction reflects the release of pro-inflammatory mediators including peptides, lipids and cytokines, and the recruitment of leukocytes. In self-limiting inflammation, the evolving inflammatory response is coupled to distinct processes that promote the resolution of inflammation and restore homeostasis. The discovery of endogenously generated lipid mediators - specialized pro-resolving lipid mediators and branched fatty acid esters of hydroxy fatty acids - which promote the resolution of inflammation and attenuate the microvascular and macrovascular complications of obesity and diabetes mellitus highlights novel opportunities for potential therapeutic intervention through the targeting of pro-resolution, rather than anti-inflammatory pathways.

Effects of Epeleuton, a Novel Synthetic Second-Generation n-3 Fatty Acid, on Non-Alcoholic Fatty Liver Disease, Triglycerides, Glycemic Control, and Cardiometabolic and Inflammatory Markers

Background

Epeleuton is 15‐hydroxy eicosapentaenoic acid ethyl ester, a second‐generation synthetic n‐3 fatty acid derivative of eicosapentaenoic acid. The primary objective was to assess the effect of epeleuton on markers of nonalcoholic fatty liver disease (NAFLD) with post hoc analyses of cardiometabolic markers.

Methods and Results

In a multicenter, randomized, double‐blind, placebo‐controlled trial, 96 adults with nonalcoholic fatty liver disease and body mass index 25 to 40 were randomized in a 1:1:1 ratio to receive epeleuton 2 g/day, epeleuton 1 g/day, or placebo for 16 weeks. A total of 27% of patients had diabetes mellitus. Primary end points of changes in alanine aminotransferase and liver stiffness did not improve at week 16. Secondary and post hoc analyses investigated changes in cardiometabolic markers. Epeleuton 2 g/day significantly decreased triglycerides, very‐low‐density lipoprotein cholesterol, and total cholesterol without increasing low‐density lipoprotein cholesterol. Despite a low mean baseline hemoglobin A1C (HbA_1C; 6.3±1.3%), epeleuton 2 g/day significantly decreased HbA_1c (−0.4%; P=0.026). Among patients with baseline HbA_1c >6.5%, epeleuton 2 g/day decreased HbA_1c by 1.1% (P=0.047; n=26). Consistent dose‐dependent reductions were observed for fasting plasma glucose, insulin, and insulin resistance indices. Epeleuton 2 g/day decreased circulating markers of cardiovascular risk and endothelial dysfunction. Epeleuton was well tolerated, with a safety profile not different from placebo.

Conclusions

While epeleuton did not meet its primary end points on alanine aminotransferase or liver stiffness, it significantly decreased triglycerides, HbA_1C, plasma glucose, and inflammatory markers. These data suggest epeleuton may have potential for cardiovascular risk reduction and nonalcoholic fatty liver disease by simultaneously targeting hypertriglyceridemia, hyperglycemia, and systemic inflammation. Further trials are planned.

Registration

URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT02941549.