Astragaloside-IV promotes autophagy via the Akt/mTOR pathway to improve cellular lipid deposition.

The current study aimed to investigate the potential role of astragaloside IV (AS-IV) in improving cellular lipid deposition and its underlying mechanism. A fatty liver cell model was established by treating hepatoma cells with palmitic acid. AS-IV and SC79 were used for treatment. Oil Red O staining was applied to detect intracellular lipid deposition, and transmission electron microscopy was utilized to assess autophagosome formation. Immunofluorescence double staining was applied to determine microtubule-associated proteins 1A/1B light chain 3 (LC3) expression. Western blot analysis was performed to detect the expression of LC3, prostacyclin, Beclin-1, V-akt murine thymoma viral oncogene homolog (Akt), phosphorylated Akt, mTOR, and phosphorylated mTOR. Oil Red O staining revealed that AS-IV reduced intracellular lipid accumulation. Further, it increased autophagosome synthesis and the expression of autophagy proteins LC3 and Beclin-1 in the cells. It also reduced the phosphorylation levels of Akt and mTOR and the levels of prostacyclin. However, the effects of AS-IV decreased with SC79 treatment. In addition, LC3B + BODIPY493/503 fluorescence double staining showed that AS-IV reduced intracellular lipid deposition levels by enhancing autophagy. AS-IV can reduce lipid aggregation in fatty liver cells, which can be related to enhanced hepatocyte autophagy by inhibiting the Akt/mTOR signaling pathway.

Potential utility of l-carnitine for preventing liver tumors derived from metabolic dysfunction-associated steatohepatitis.

BACKGROUND: Recent reports have unveiled the potential utility of l-carnitine to alleviate metabolic dysfunction-associated steatohepatitis (MASH) by enhancing mitochondrial metabolic function. However, its efficacy at preventing the development of HCC has not been assessed fully. METHODS: l-carnitine (2 g/d) was administered to 11 patients with MASH for 10 weeks, and blood liver function tests were performed. Five patients received a serial liver biopsy, and liver histology and hepatic gene expression were evaluated using this tissue. An atherogenic plus high-fat diet MASH mouse model received long-term l-carnitine administration, and liver histology and liver tumor development were evaluated. RESULTS: Ten-week l-carnitine administration significantly improved serum alanine transaminase and aspartate transaminase levels along with a histological improvement in the NAFLD activity score, while steatosis and fibrosis were not improved. Gene expression profiling revealed a significant improvement in the inflammation and profibrotic gene signature as well as the recovery of lipid metabolism. Long-term l-carnitine administration to atherogenic plus high-fat diet MASH mice substantially improved liver histology (inflammation, steatosis, and fibrosis) and significantly reduced the incidence of liver tumors. l-carnitine directly reduced the expression of the MASH-associated and stress-induced transcriptional factor early growth response 1. Early growth response 1 activated the promoter activity of neural precursor cell expressed, developmentally downregulated protein 9 (NEDD9), an oncogenic protein. Thus, l-carnitine reduced the activation of the NEDD9, focal adhesion kinase 1, and AKT oncogenic signaling pathway. CONCLUSIONS: Short-term l-carnitine administration ameliorated MASH through its anti-inflammatory effects. Long-term l-carnitine administration potentially improved the steatosis and fibrosis of MASH and may eventually reduce the risk of HCC.

Molecular Mechanisms of Fucoxanthin in Alleviating Lipid Deposition in Metabolic Associated Fatty Liver Disease.

Metabolic-associated fatty liver disease (MAFLD) is witnessing a global surge; however, it still lacks effective pharmacological interventions. Fucoxanthin, a natural bioactive metabolite derived from marine brown algae, exhibits promising pharmacological functions, particularly in ameliorating metabolic disorders. However, the mechanisms underlying its therapeutic efficacy in addressing MAFLD remain elusive. Our present findings indicated that fucoxanthin significantly alleviated palmitic acid (PA)-induced hepatic lipid deposition in vitro and obesity-induced hepatic steatosis in ob/ob mice. Moreover, at both the protein and transcriptional levels, fucoxanthin effectively increased the expression of PPARα and CPT1 (involved in fatty acid oxidation) and suppressed FASN and SREBP1c (associated with lipogenesis) in both PA-induced HepG2 cells and hepatic tissues in ob/ob mice. This modulation was accompanied by the activation of AMPK. The capacity of fucoxanthin to improve hepatic lipid deposition was significantly attenuated when utilizing the AMPK inhibitor or siRNA-mediated AMPK silencing. Mechanistically, fucoxanthin activates AMPK, subsequently regulating the KEAP1/Nrf2/ARE signaling pathway to exert antioxidative effects and stimulating the PGC1α/NRF1 axis to enhance mitochondrial biogenesis. These collective actions contribute to fucoxanthin's amelioration of hepatic steatosis induced by metabolic perturbations. These findings offer valuable insights into the prospective utilization of fucoxanthin as a therapeutic strategy for managing MAFLD.

Aspirin for Metabolic Dysfunction-Associated Steatotic Liver Disease Without Cirrhosis: A Randomized Clinical Trial.

Importance: Aspirin may reduce severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and lower the incidence of end-stage liver disease and hepatocellular carcinoma, in patients with MASLD. However, the effect of aspirin on MASLD is unknown. Objective: To test whether low-dose aspirin reduces liver fat content, compared with placebo, in adults with MASLD. Design, Setting, and Participants: This 6-month, phase 2, randomized, double-blind, placebo-controlled clinical trial was conducted at a single hospital in Boston, Massachusetts. Participants were aged 18 to 70 years with established MASLD without cirrhosis. Enrollment occurred between August 20, 2019, and July 19, 2022, with final follow-up on February 23, 2023. Interventions: Participants were randomized (1:1) to receive either once-daily aspirin, 81 mg (n = 40) or identical placebo pills (n = 40) for 6 months. Main Outcomes and Measures: The primary end point was mean absolute change in hepatic fat content, measured by proton magnetic resonance spectroscopy (MRS) at 6-month follow-up. The 4 key secondary outcomes included mean percentage change in hepatic fat content by MRS, the proportion achieving at least 30% reduction in hepatic fat, and the mean absolute and relative reductions in hepatic fat content, measured by magnetic resonance imaging proton density fat fraction (MRI-PDFF). Analyses adjusted for the baseline value of the corresponding outcome. Minimal clinically important differences for study outcomes were not prespecified. Results: Among 80 randomized participants (mean age, 48 years; 44 [55%] women; mean hepatic fat content, 35% [indicating moderate steatosis]), 71 (89%) completed 6-month follow-up. The mean absolute change in hepatic fat content by MRS was -6.6% with aspirin vs 3.6% with placebo (difference, -10.2% [95% CI, -27.7% to -2.6%]; P = .009). Compared with placebo, aspirin treatment significantly reduced relative hepatic fat content (-8.8 vs 30.0 percentage points; mean difference, -38.8 percentage points [95% CI, -66.7 to -10.8]; P = .007), increased the proportion of patients with 30% or greater relative reduction in hepatic fat (42.5% vs 12.5%; mean difference, 30.0% [95% CI, 11.6% to 48.4%]; P = .006), reduced absolute hepatic fat content by MRI-PDFF (-2.7% vs 0.9%; mean difference, -3.7% [95% CI, -6.1% to -1.2%]; P = .004]), and reduced relative hepatic fat content by MRI-PDFF (-11.7 vs 15.7 percentage points; mean difference, -27.3 percentage points [95% CI, -45.2 to -9.4]; P = .003). Thirteen participants (32.5%) in each group experienced an adverse event, most commonly upper respiratory tract infections (10.0% in each group) or arthralgias (5.0% for aspirin vs 7.5% for placebo). One participant randomized to aspirin (2.5%) experienced drug-related heartburn. Conclusions and Relevance: In this preliminary randomized clinical trial of patients with MASLD, 6 months of daily low-dose aspirin significantly reduced hepatic fat quantity compared with placebo. Further study in a larger sample size is necessary to confirm these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT04031729.

Effects of NPY-2 Receptor Antagonists, Semaglutide, PYY3-36, and Empagliflozin on Early MASLD in Diet-Induced Obese Rats.

(1) Background: Modulators of the Neuropeptide Y (NPY) system are involved in energy metabolism, but the effect of NPY receptor antagonists on metabolic-dysfunction-associated steatotic liver disease (MASLD), a common obesity-related comorbidity, are largely unknown. In this study, we report on the effects of antagonists of the NPY-2 receptor (Y2R) in comparison with empagliflozin and semaglutide, substances that are known to be beneficial in MASLD. (2) Methods: Diet-induced obese (DIO) male Wistar rats were randomized into the following treatment groups: empagliflozin, semaglutide ± PYY3-36, the Y2R antagonists JNJ 31020028 and a food-restricted group, as well as a control group. After a treatment period of 8 weeks, livers were weighed and histologically evaluated. QrtPCR was performed to investigate liver inflammation and de novo lipogenesis (in liver and adipose tissue). Serum samples were analysed for metabolic parameters. (3) Results: Semaglutide + PYY3-36 led to significant weight loss, reduced liver steatosis (p = 0.05), and decreased inflammation, insulin resistance, and leptin levels. JNJ-31020028 prevented steatosis (p = 0.03) without significant weight loss. Hepatic downregulation of de novo lipogenesis-regulating genes (SREBP1 and MLXIPL) was observed in JNJ-31020028-treated rats (p ≤ 0.0001). Food restriction also resulted in significantly reduced weight, steatosis, and hepatic de novo lipogenesis. (4) Conclusions: Body weight reduction (e.g., by food restriction or drugs like semaglutide ± PYY3-36) is effective in improving liver steatosis in DIO rats. Remarkably, the body-weight-neutral Y2R antagonists may be effective in preventing liver steatosis through a reduction in de novo lipogenesis, making this drug class a candidate for the treatment of (early) MASLD.

Effectiveness of 1-year pemafibrate treatment on steatotic liver disease: the influence of alcohol consumption.

BACKGROUND/AIMS: Pemafibrate is a selective peroxisome proliferator-activated receptor α modulator that improves serum alanine aminotransferase (ALT) in dyslipidemia patients. We previously reported that pemafibrate significantly improves liver function, serum triglyceride (TG) levels and liver stiffness in non-alcoholic fatty liver disease patients, however the influence of alcohol consumption was not considered. Therefore, we explored pemafibrate efficacy in patients with steatotic liver disease (SLD) and alcohol-associated liver disease (ALD). METHODS: We retrospectively evaluated pemafibrate efficacy on liver enzymes and lipids in metabolic dysfunction-associated SLD (MASLD) (n = 93), MASLD plus increased alcohol intake (MetALD; n = 23) and ALD (n = 22) patients who had taken pemafibrate for at least 48 weeks. Liver shear wave velocity (SWV, n = 75) was also evaluated. RESULTS: In MASLD group, ALT, aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP) and TG values were significantly decreased from baseline to week 24 and week 48 ( P  < 0.0001). ALT and TG values in MetALD group and ALT and AST values in ALD group were also significantly decreased from baseline to week 24 and week 48. Study participant SWV values decreased from baseline to week 48. We observed no significant difference in changes to ALT, AST, γ-GTP and TG (value at week 24 or week 48 minus value at baseline) among the three groups. CONCLUSION: Pemafibrate improves liver function and liver stiffness thus making it a promising therapeutic agent for SLD, even in patients with excess alcohol consumption (MetALD and ALD groups).

Effectiveness of metformin for the reversal of cold-ischemia-induced damage in hepatosteatosis.

BACKGROUND: Primary dysfunction and rejection are more common in donor liver tissues with steatosis. AMP-activated protein kinase (AMPK) assumes organ-protective functions during ischemia. Metformin was used for the activation of AMPK in hepatocytes. The aim of this study is to investigate the effectiveness of metformin administration for the reversal of cold-ischemia-induced damage in hepatosteatosis. MATERIAL AND METHODS: Seven-week-old C7BL56 male-mice (n = 109) were separated into four groups depending on diet type and metformin use. A specific diet model was followed for 10 weeks to induce hepatosteatosis. A group of the animals was administered with metformin for the last four weeks via oral gavage. After resection, the liver tissues were perfused and kept for 0-6-12-24 h in the UW solution. Histopathological examinations were performed, and Western blot was utilized to analyze p-AMPK and AMPK expression levels. RESULTS: Hepatosteatosis decreased significantly with metformin. The steatotic liver group had more prominent pericentral inflammation, necrosis as well as showing a decreased and more delayed AMPK response than the non-fat group. All these alterations could be corrected using metformin. CONCLUSION: Metformin can increase the resistance of livers with hepatosteatosis to cold-ischemia-induced damage, which in turn may pave the way for successful transplantation of fatty living-donor livers.

The role of glucagon-like peptide-1 receptor agonists in metabolic dysfunction-associated steatohepatitis.

Despite its considerable and growing burden, there are currently no Food and Drug Administration-approved treatments for metabolic dysfunction-associated steatotic liver disease or its progressive form, metabolic dysfunction-associated steatohepatitis (MASH). Several glucagon-like peptide-1 receptor agonists (GLP-1RAs) and other agents are in various phases of clinical development for use in MASH; an ideal therapy should reduce liver fat content, improve chronic liver disease, help mitigate metabolic comorbidities and decrease all-cause mortality. Because of interconnected disease mechanisms, metabolic dysfunction-associated steatotic liver disease/MASH often coexists with type 2 diabetes (T2D), obesity and cardiovascular disease. Various GLP-1RAs are Food and Drug Administration-approved for use in T2D, and two, liraglutide and semaglutide, are approved for overweight and obesity. GLP-1RAs decrease glucose levels and body weight and improve cardiovascular outcomes in people with T2D who are at high risk of cardiovascular disease. In addition, GLP-1RAs have been reported to reduce liver fat content and liver enzymes, reduce oxidative stress and improve hepatic de novo lipogenesis and the histopathology of MASH. Weight loss may contribute to these effects; however, the exact mechanisms are unknown. Adverse events that are commonly associated with GLP-1RAs include vomiting, nausea and diarrhoea. There is a lack of evidence from meta-analyses regarding the increased risk of acute pancreatitis and various forms of cancer with GLP-1RAs. Large-scale, phase 3 trials, which will provide definitive data on GLP-1RAs and other potential therapies in MASH, are ongoing. Given the spectrum of modalities under investigation, it is hoped that these trials will support the identification of pharmacotherapies that provide clinical benefit for patients with MASH.

Activation of hepatic adenosine A1 receptor ameliorates MASH via inhibiting SREBPs maturation.

Metabolic (dysfunction)-associated steatohepatitis (MASH) is the advanced stage of metabolic (dysfunction)-associated fatty liver disease (MAFLD) lacking approved clinical drugs. Adenosine A1 receptor (A1R), belonging to the G-protein-coupled receptors (GPCRs) superfamily, is mainly distributed in the central nervous system and major peripheral organs with wide-ranging physiological functions; however, the exact role of hepatic A1R in MAFLD remains unclear. Here, we report that liver-specific depletion of A1R aggravates while overexpression attenuates diet-induced metabolic-associated fatty liver (MAFL)/MASH in mice. Mechanistically, activation of hepatic A1R promotes the competitive binding of sterol-regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) to sequestosome 1 (SQSTM1), rather than protein kinase A (PKA) leading to SCAP degradation in lysosomes. Reduced SCAP hinders SREBP1c/2 maturation and thus suppresses de novo lipogenesis and inflammation. Higher hepatic A1R expression is observed in patients with MAFL/MASH and high-fat diet (HFD)-fed mice, which is supposed to be a physiologically adaptive response because A1R agonists attenuate MAFL/MASH in an A1R-dependent manner. These results highlight that hepatic A1R is a potential target for MAFL/MASH therapy.

Ferrostatin-1 improves prognosis and regulates gut microbiota of steatotic liver transplantation recipients in rats.

Aims: To investigate the effects of Ferrostatin-1 (Fer-1) on improving the prognosis of liver transplant recipients with steatotic liver grafts and regulating gut microbiota in rats. Methods: We obtained steatotic liver grafts and established a liver transplantation model. Recipients were divided into sham, liver transplantation and Fer-1 treatment groups, which were assessed 1 and 7 days after surgery (n = 6). Results & conclusion: Fer-1 promotes recovery of the histological structure and function of steatotic liver grafts and the intestinal tract, and improves inflammatory responses of recipients following liver transplantation. Fer-1 reduces gut microbiota pathogenicity, and lowers iron absorption and improves fat metabolism of recipients, thereby protecting steatotic liver grafts.

Therapeutic implication of human placental extract to prevent liver cirrhosis in rats with metabolic dysfunction-associated steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is always accompanied with hepatic fibrosis that could potentially progress to liver cirrhosis and hepatocellular carcinoma. Employing a rat model, we evaluated the role of human placental extract (HPE) to arrest the progression of hepatic fibrosis to cirrhosis in patients with MASH. SHRSP5/Dmcr rats were fed with a high-fat and high-cholesterol diet for 4 weeks and evaluated for the development of steatosis. The animals were divided into control and treated groups and received either saline or HPE (3.6 ml/kg body weight) subcutaneously thrice a week. A set of animals were killed at the end of 6th, 8th, and 12th weeks from the beginning of the experiment. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), hepatic malondialdehyde (MDA), and glutathione content were measured. Immunohistochemical staining was performed for α-smooth muscle actin (α-SMA), 4-hydroxy-2-nonenal (4-HNE), collagen type I, and type III. Control rats depicted progression of liver fibrosis at 6 weeks, advanced fibrosis and bridging at 8 weeks, and cirrhosis at 12 weeks, which were significantly decreased in HPE-treated animals. Treatment with HPE maintained normal levels of MDA and glutathione in the liver. There was marked decrease in the staining intensity of α-SMA, 4-HNE, and collagen type I and type III in HPE treated rats compared with control animals. The results of the present study indicated that HPE treatment mediates immunotropic, anti-inflammatory, and antioxidant responses and attenuates hepatic fibrosis and early cirrhosis. HPE depicts therapeutic potential to arrest the progression of MASH towards cirrhosis.

Kimchi attenuates endoplasmic reticulum stress-induced hepatic steatosis in HepG2 cells and C57BL/6N mice.

Kimchi is a traditional fermented food that contains abundant nutrients and functional ingredients with various health benefits. We previously reported that kimchi active components suppress hepatic steatosis caused by endoplasmic reticulum (ER) stress in vitro and in vivo. Therefore, we assessed the effect of kimchi on the inhibition of hepatic steatosis caused by ER stress in HepG2 cells and C57BL/6N mice to verify the hypothesis that kimchi may potentially inhibit nonalcoholic fatty liver disease. We investigated the effect of kimchi on cell viability and triglyceride concentrations in cells and on lipid profile, lipid accumulation, and expression of related genes in cells and mice with hepatic steatosis. A mechanistic study was also performed using the liver X receptor α agonist T0901317 and the AMP-activated protein kinase agonist AICAR. Kimchi was noncytotoxic and effectively reduced triglyceride concentrations and suppressed hepatic steatosis-related gene expression in cells and mice. Additionally, kimchi recovered weight loss, lowered the serum and liver tissue lipid profiles, suppressed lipid accumulation, and reduced the effects of T0901317 and AICAR on lipogenic gene expression in tunicamycin-treated mice. Our results highlight that kimchi could prevent hepatic steatosis caused by ER stress in cells and mice.

Semaglutide Modulates Extracellular Matrix Production of LX-2 Cells via Exosomes and Improves Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely related to some metabolic disorders, such as central obesity and type 2 diabetes (T2D). Glucagon-like peptide 1 receptor agonists (GLP-1RAs), such as semaglutide, may have therapeutic roles in MASLD associated with T2D. This study aims to investigate the molecular mechanisms underlying the effectiveness of semaglutide on MASLD in terms of progression from liver steatosis to fibrosis. We characterized exosomes from ten patients with type 2 diabetes (T2D) before (T0) and after 12 months (T12) of treatment with once-weekly subcutaneous semaglutide. Six of ten patients were considered responders to therapy (R) based on MASLD severity downgrading by at least one class according to a validated ultrasonographic (US) score. Normal hepatocytes (HEPA-RG) and stellate (LX-2) cells were challenged with exosomes from R and NR patients, isolated before and after 12 months of therapy. Exosomes from both R and NR patients isolated at T0 significantly affected LX-2 viability. After 12 months of treatment, only those isolated from R patients restored cell viability, whereas those from NR patients did not. No effects were observed on HEPA-RG cells. Exosomes at T12 from R but not from NR patients significantly decreased the production of α-SMA, a marker of LX-2 activation, a liver stellate cell model, and ph-SMAD2 and CTGF, involved in fibrosis processes. TGF-ß1 was not modulated by the exosomes of R and NR patients. As a downstream effect, Vimentin, Collagen 1A1, and Fibronectin extracellular matrix components were also downregulated, as measured by droplets digital PCR. In conclusion, these results shed light on the potential effectiveness of semaglutide in improving liver fibrosis in MASLD.

Supplementation of papaya leaf juice has beneficial effects on glucose homeostasis in high fat/high sugar-induced obese and prediabetic adult mice.

Prediabetes is characterized by a cluster of glycemic parameters higher than normal but below the threshold of type 2 diabetes mellitus (T2DM). In recent years, phytochemical-rich plant extracts have gained popularity as therapeutic agents for metabolic disorders. This study investigated the effects of papaya leaf (PL) juice supplementation on blood glucose levels in diet-induced obese and prediabetic adult mice. B65JL F1 mice (n = 20) at 12-14 months old were fed a high fat/sugar diet (HFHS) for 120 days. Mice were switched to restricted rodent chow of 3 g feed/30 g body weight/day, supplemented with 3 g/100 mL PL juice for 30 days. HFHS diet remarkably increased fasting plasma glucose levels from 114 ± 6.54 mg/dL to 192.7 ± 10.1 mg/dL and body weight from 32.5 ± 1.6 to 50.3 ± 4.1 g. HFHS diet results in hyperglycemia, insulin resistance, hyperlipidemia, and liver steatosis. The combination of PL juice and restricted diet significantly reduced body weight and fasting blood glucose levels to 43.75 ± 1.4 g and 126.25 ± 3.2 mg/dl, respectively. Moreover, PL juice with a restricted diet significantly improved lipid profile: cholesterol from 204 to 150 mg/dL, LDL-c from 110.4 to 50 mg/dL, and triglyceride from 93.7 to 60 mg/dL. Additionally, PL juice combined with a restricted diet significantly reduced adiposity, reversed fatty liver, and restored skeletal muscle Glut4 and phosphorylated (p-AKT (ser473). This study demonstrated that supplementation of PL juice with a restricted diet was more effective than a restricted diet alone in reversing major symptoms related to prediabetic and obesity conditions.

Discovery of a peripheral 5HT2A antagonist as a clinical candidate for metabolic dysfunction-associated steatohepatitis.

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is currently the leading cause of chronic liver disease worldwide. Metabolic Dysfunction-Associated Steatohepatitis (MASH), an advanced form of MASLD, can progress to liver fibrosis, cirrhosis, and hepatocellular carcinoma. Based on recent findings by our team that liver 5HT2A knockout male mice suppressed steatosis and reduced fibrosis-related gene expression, we developed a peripheral 5HT2A antagonist, compound 11c for MASH. It shows good in vitro activity, stability, and in vivo pharmacokinetics (PK) in rats and dogs. Compound 11c also shows good in vivo efficacy in a diet-induced obesity (DIO) male mice model and in a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) male mice model, effectively improving histologic features of MASH and fibrosis. According to the tissue distribution study using [14C]-labeled 11c, the compound was determined to be a peripheral 5HT2A antagonist. Collectively, first-in-class compound 11c shows promise as a therapeutic agent for the treatment of MASLD and MASH.

Advances in obesity pharmacotherapy; learning from metabolic surgery and beyond.

Currently, metabolic surgery (MS) constitutes the most effective means for durable weight loss of clinically meaningful magnitude, type 2 diabetes remission and resolution of non-alcoholic steatohepatitis, as well as other obesity-related comorbidities. Accumulating evidence on the mechanisms through which MS exerts its actions has highlighted the altered secretion of hormonally active peptides of intestinal origin with biological actions crucial to energy metabolism as key drivers of MS clinical effects. The initial success of glucagon-like peptide-1 (GLP-1) receptor agonists regarding weight loss and metabolic amelioration have been followed by the development of unimolecular dual and triple polyagonists, additionally exploiting the effects of glucagon and/or glucose-dependent insulinotropic polypeptide (GIP) which achieves a magnitude of weight loss approximating that of common MS operations. Through the implementation of such therapies, the feasibility of a "medical bypass", namely the replication of the clinical effects of MS through non-surgical interventions may be foreseeable in the near future. Apart from weight loss, this approach ought to be put to the test also regarding other clinical outcomes, such as liver steatosis and steatohepatitis, cardiovascular disease, and overall prognosis, on which MS has a robustly demonstrated impact. Besides, a medical bypass as an alternative, salvage, or combination strategy to MS may promote precision medicine in obesity therapeutics.

Palmitoleic acid-rich oleaginous yeast Scheffersomyces segobiensis DSM 27193 exerts anti-obesity effects by ameliorating hepatic steatosis and adipose tissue hypertrophy.

BACKGROUND: Yeast biomass, encompassing fatty acids, terpenoids, vitamins, antioxidants, enzymes, and other bioactive compounds have been extensively utilized in food-related fields. The safety and potential bioactivities of Scheffersomyces segobiensis DSM 27193, an oleaginous yeast strain, are unclear. RESULTS: Scheffersomyces segobiensis DSM 27193 accumulated large palmitoleic acid (POA) levels (43.4 g kg-1 biomass) according to the results of whole-cell components. We annotated the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and predicted the categories and host of the pathogen-host interactions (PHI) genes in S. segobiensis DSM 27193. However, S. segobiensis DSM 27193 did not exert toxic effects in mice. Administration of S. segobiensis DSM 27193 led to substantial weight reduction by diminishing food intake in an obesity mouse model. Additionally, it reversed hepatic steatosis and adipose tissue hypertrophy, and improved abnormalities in serum biochemical profiles such as triglyceride, total cholesterol, low-density lipoprotein cholesterol, lipopolysaccharide, tumor necrosis factor-α, interleukin-1ß, and interleukin-6. CONCLUSION: This study is the first to illustrate the safety and effects of S. segobiensis DSM 27193 against obesity and offers a scientific rationale for its application in functional food supplements. © 2023 Society of Chemical Industry.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

Madecassoside ameliorates hepatic steatosis in high-fat diet-fed mice through AMPK/autophagy-mediated suppression of ER stress.

Hepatic endoplasmic reticulum (ER) stress is a contributing factor in the development of hepatic steatosis in obesity. Madecassoside (MA), a pentacyclic triterpene derived from Centella asiatica, is known for its anti-inflammatory properties in the treatment of skin wounds. However, the impact of MA on hepatic ER stress and lipid metabolism in experimental obesity models has not been investigated. In this study, we examined the effects of MA on primary hepatocytes treated with palmitate and the livers of mice fed a high-fat diet (HFD). Our findings demonstrated that MA treatment reduced lipogenic lipid accumulation, apoptosis, and ER stress in hepatocytes. Additionally, MA treatment increased the phosphorylation of AMP-activated protein kinase (AMPK) and markers of autophagy. Importantly, when AMPK was inhibited by small interfering RNA (siRNA) or autophagy was blocked by 3-methyladenine (3MA), the protective effects of MA against ER stress, lipogenic lipid deposition, and apoptosis in palmitate-treated hepatocytes were abolished. These results suggest that MA mitigates hepatic steatosis in obesity through an AMPK/autophagy-dependent pathway. The present study highlights the potential of MA as a promising therapeutic candidate for hepatic steatosis.

Liraglutide ameliorates hepatic steatosis via retinoic acid receptor-related orphan receptor α-mediated autophagy pathway.

Liraglutide, an analog of human glucagon-like peptide-1 (GLP-1), has been found to improve hepatic steatosis in clinical practice. However, the underlying mechanism remains to be fully defined. Increasing evidence suggests that retinoic acid receptor-related orphan receptor α (RORα) is involved in hepatic lipid accumulation. In the current study, we investigated whether the ameliorating impact of liraglutide on lipid-induced hepatic steatosis is dependent on RORα activity and examined the underlying mechanisms. Cre-loxP-mediated, liver-specific Rorα knockout (Rora LKO) mice, and littermate controls with a Roraloxp/loxp genotype were established. The effects of liraglutide on lipid accumulation were evaluated in mice challenged with a high-fat diet (HFD) for 12 weeks. Moreover, mouse AML12 hepatocytes expressing small interfering RNA (siRNA) of Rora were exposed to palmitic acid to explore the pharmacological mechanism of liraglutide. The results showed that liraglutide treatment significantly alleviated HFD-induced liver steatosis, marked by reduced liver weight and triglyceride accumulation, improved glucose tolerance and serum levels of lipid profiles and aminotransferase. Consistently, liraglutide also ameliorated lipid deposits in a steatotic hepatocyte model in vitro. In addition, liraglutide treatment reversed the HFD-induced downregulation of Rora expression and autophagic activity in mouse liver tissues. However, the beneficial effect of liraglutide on hepatic steatosis was not observed in Rora LKO mice. Mechanistically, the ablation of Rorα in hepatocytes diminished liraglutide-induced autophagosome formation and the fusion of autophagosomes and lysosomes, resulting in weakened autophagic flux activation. Thus, our findings suggest that RORα is essential for the beneficial impact of liraglutide on lipid deposition in hepatocytes and regulates autophagic activity in the underlying mechanism.