Oxidative Stress in Non-alcoholic Fatty Liver Disease. An Updated Mini Review

Liver metabolism in human MASLD: A review of recent advancements using human tissue metabolomics

Global incidence of Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is on the rise while treatments remain elusive. MASLD is a disease of dysregulated systemic and hepatic metabolism. Current understanding of disease pathophysiology as it relates to metabolome changes largely comes from studies on animal models and human plasma. However, human tissue data are crucial for transitioning from mechanisms to clinical therapies. The close relationship between MASLD and comorbidities like obesity, type 2 diabetes and dyslipidemia make it difficult to determine the contribution from liver disease itself. Here, we review recent metabolomics studies in liver tissue from human MASLD patients, which have predominately focused on lipid metabolism, but also include bile acid, tricarboxylic acid (TCA) cycle, and branched chain amino acid (BCAA) metabolism. Several clinical trials are underway to target various of these lipid-related pathways in MASLD. Although only the β-selective thyroid hormone receptor agonist resmetirom has so far been approved for use, many metabolism-targeting pharmaceuticals show promising results for halting disease progression, if not promoting outright reversal. Ultimately, the scarcity of human tissue data and the variability of confounding factors, like obesity, within and between cohorts are impediments to the pathophysiological understanding required for efficient development of metabolic treatments.

Serum glutathione peroxidase is associated with nonalcoholic fatty liver disease in children and adolescents

Introduction

Background and aims: oxidative stress is an important factor in the pathophysiology of non-alcoholic fatty liver disease (NAFLD). This study aimed to compare the serum levels of malondialdehyde (MDA), glutathione peroxidase (GPx) and antioxidant micronutrients in children and adolescents with and without NAFLD. Methods: a cross-sectional study with patients between 8-18 years old, of both sexes. Diagnosis of NAFLD: presence of steatosis on ultrasound and absence of history of ethanol consumption and other liver diseases. Anthropometric measures, MDA, GPx, Interleukin-6, serum levels of vitamins A, C and E, selenium, zinc, and copper were evaluated. Results: eighty-nine children with mean age of 12 (3) years, 57.3 % female and 24 % with NAFLD were evaluated. Those with NAFLD had more frequent abdominal obesity (high waist-height ratio: 81.0 % x 48.5 %; p = 0.009). After logistic regression NAFLD was associated with high body mass index/age (p-adjusted = 0.021) and with reduced serum GPx (p-adjusted = 0.034). There was a positive correlation between MDA and copper (r = 0.288; p = 0.006), IL-6 (r = 0.357; p = 0.003) and a negative one with vitamin A (r = -0.270; p = 0.011). Conclusions: oxidative stress is present in children with NAFLD and non-invasive markers such as GPx and BMI can be used in clinical practice and help in the early screening of NAFLD.

Mechanistic Study of Purple Sweet Potato Anthocyanins: Multifaceted Anti-Fibrotic Effects and Targeting of PDGFRβ in Liver Fibrosis

The purple sweet potato anthocyanins (PSPA) are known for their diverse health benefits, yet their hepatoprotective effects and the mechanisms by which they combat liver fibrosis have not been thoroughly investigated. This study aimed to elucidate these effects by employing a carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis. We conducted a comprehensive analysis of the effects of PSPA on liver injury, oxidative stress, inflammation, and fibrosis-related signaling pathways. Our results demonstrate that PSPA can mitigate liver damage in mice, regulate key antioxidant enzymes such as catalase and SOD, and reduce oxidative stress as indicated by lowered MDA levels. PSPA also decrease the expression of inflammatory proteins, including CD3, CD4, CD45, IL-1β, TNF-α, and IL-17A, and reduce the accumulation of fibrotic markers like type I and III collagens and α-SMA. Additionally, PSPA have demonstrated the ability to inhibit key fibrogenic signaling proteins, including TGFβR2, p-Smad2, p-Smad3, p-PDGFRβ, p-AKT, p-ERK1/2, p-JNK1/2, and p-p38. Furthermore, we identified two potent monomers, PSPA-1 and PSPA-2, which directly target the PDGFRβ, a key player in fibrosis. The mechanism of action involves the inhibition of PDGF-B binding to PDGFRβ, thus disrupting the PDGF-B/PDGFRβ signaling pathway. These findings suggest that the hepatoprotective and antifibrotic effects of PSPA are due to their multifunctional bioactivities and the presence of specific active components that can effectively target fibrogenic protein.

Postbiotics for the management of obesity, insulin resistance/type 2 diabetes and NAFLD. Beyond microbial viability

Highly prevalent comorbidities associated with metabolic syndrome, such as abdominal obesity, nonalcoholic fatty liver disease (NAFLD) and insulin-resistance/Type 2 diabetes (IR/T2D) share alterations in gut microbiota composition as a potential triggering factor. Recent studies put the attention in the potential usage of postbiotics (inactivated probiotics) on these metabolic alterations. This review summarizes the current evidence regarding the efficacy of postbiotic administration in both, preclinical and clinical studies, for the management of obesity, NAFLD and IR/T2D. Data from preclinical studies (rodents) suggest that postbiotic administration effectively prevents obesity, whereas clinical studies corroborate these benefits also in overweight/obese subjects receiving inactivated bacteria. As for NAFLD, although preclinical studies indicate that postbiotic administration improves different liver markers, no data obtained in humans have been published so far since all the studies are ongoing clinical trials. Finally, while the administration of inactivated bacteria demonstrated to be a promising approach for the management of IR/T2D in rodents, data from clinical trials indicates that in humans, this approach is more effective on IR than in T2D. In conclusion, the available scientific data indicate that postbiotic administration not only is safer, but also as effective as probiotic administration for the management of obesity associated prevalent metabolic alterations.

Unveiling functionality and conducting two-sample mendelian randomization on WGCNA-identified oxidative stress-related hub genes in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) shows accelerated development under the impact of oxidative stress (OS). There is an imperative to identify OS-related biomarkers in MAFLD and explore their potential mechanistic insights. The objective of this study was to identify OS-related biomarkers in MAFLD and explore their potential mechanisms. DEG analysis was performed using GSE17470 and GSE24807 datasets. An investigative exploration utilizing WGCNA was executed to elucidate hub OS-related genes. The intersection of OS-related hub genes identified by WGCNA and DEGs was systematically employed for thorough analyses. A mendelian randomization (MR) study examined the causal effect of C-reactive protein (CRP) on MAFLD. 59 OS-related DEGs were identified in MAFLD. WGCNA revealed 100 OS-related hub genes in MAFLD. Sixteen OS-related genes have been delineated as critical components in MAFLD. Enrichment analyses, employing GO and KEGG pathways, revealed pathways enriched with these genes. Following PPI analyses, the highest-ranking ten hub genes demonstrating abnormal expression were determined. Ultimately, a two-sample MR analysis demonstrated a causal link between the hub gene CRP and the occurrence of MAFLD. In this study, we harnessed WGCNA to formulate a co-expression network and identified hub OS-related DEGs in MAFLD. Additionally, the hub gene CRP exhibited a significant correlation with the predisposition to MAFLD. These findings offer innovative perspectives on the applications of OS-associated genes in individuals afflicted with MAFLD.

Analyses of mitochondrial metabolism in diseases: a review on 13C magnetic resonance tracers

Metabolic diseases such as obesity, type 2 diabetes, and cardiovascular diseases have become a global health concern due to their widespread prevalence and profound impact on life expectancy, healthcare expenditures, and the overall economy. Devising effective treatment strategies and management plans for these diseases requires an in-depth understanding of the pathophysiology of the metabolic abnormalities associated with each disease. Mitochondrial dysfunction is intricately linked to a wide range of metabolic abnormalities and is considered an important biomarker for diseases. However, assessing mitochondrial functions in viable tissues remains a challenging task, with measurements of oxygen consumption rate (OCR) and ATP production being the most widely accepted approaches for evaluating the health of mitochondria in tissues. Measurements of cellular metabolism using carbon-13 (or 13C) tracers have emerged as a viable method for characterizing mitochondrial metabolism in a variety of organelles ranging from cultured cells to humans. Information on metabolic activities and mitochondrial functions can be obtained from magnetic resonance (MR) analyses of 13C-labeled metabolites in tissues and organs of interest. Combining novel 13C tracer technologies with advanced analytical and imaging tools in nuclear magnetic resonance spectroscopy (NMR) and magnetic resonance imaging (MRI) offers the potential to detect metabolic abnormalities associated with mitochondrial dysfunction. These capabilities would enable accurate diagnosis of various metabolic diseases and facilitate the assessment of responses to therapeutic interventions, hence improving patient health and optimizing clinical outcomes.

Quercetin: A Promising Candidate for the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a chronic liver disease. The development of MASLD is influenced by a multitude of diseases associated with modern lifestyles, including but not limited to diabetes mellitus, hypertension, hyperlipidaemia and obesity. These conditions are often consequences of the adoption of unhealthy habits, namely a sedentary lifestyle, a lack of physical activity, poor dietary choices and excessive alcohol consumption. The treatment of MASLD is primarily based on modifying the patient's lifestyle and pharmacological intervention. Despite the absence of FDA-approved pharmacological agents for the treatment of MASLD, several potential therapeutic modalities have demonstrated efficacy in reversing the histopathological features of the disease. Among the botanical ingredients belonging to the flavonoid group is quercetin (QE). QE has been demonstrated to possess a number of beneficial physiological effects, including anti-inflammatory, anticancer and antifungal properties. Additionally, it functions as a natural antioxidant. Preclinical evidence indicates that QE may play a beneficial role in reducing liver damage and improving metabolic health. Early human studies also suggest that QE may be an effective treatment for MASLD due to its antioxidant, anti-inflammatory, and lipid-regulating properties. This review aims to summarize the available information on the therapeutic effects of QE in MASLD.

The NRF-2/HO-1 Signaling Pathway: A Promising Therapeutic Target for Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a progressive liver disorder with a rising prevalence. It begins with lipid accumulation in hepatocytes and gradually progresses to Metabolic-associated steatohepatitis (MASH), fibrosis, cirrhosis, and potentially hepatocellular carcinoma (HCC). The pathophysiology of MASLD is complex and involves multiple factors, with oxidative stress playing a crucial role. Oxidative stress drives the progression of MASLD by causing cellular damage, inflammatory responses, and fibrosis, making it a key pathogenic mechanism. The Nuclear Factor Erythroid 2-Related Factor 2 / Heme Oxygenase-1 (Nrf2/HO-1) signaling axis provides robust multi-organ protection against a spectrum of endogenous and exogenous insults, particularly oxidative stress. It plays a pivotal role in mediating antioxidant, anti-inflammatory, and anti-apoptotic responses. Many studies indicate that activating the Nrf2/HO-1 signaling pathway can significantly mitigate the progression of MASLD. This article examines the role of the Nrf2/HO-1 signaling pathway in MASLD and highlights natural compounds that protect against MASLD by targeting Nrf2/HO-1 activation. The findings indicate that the Nrf2/HO-1 signaling pathway holds great promise as a therapeutic target for MASLD.

Cocoa shell ingredients improve their lipid-lowering properties under simulated digestion: In vitro and HepG2 cells study

Cocoa (Theobroma cacao) shell, the main by-product of cocoa industry, is associated with the regulation of several biomarkers of metabolic syndrome. However, there is little information about the digestion effect on the physiological properties of cocoa shell. The aim of this study was to assess the impact of a standardized in vitro digestion protocol on the hypolipidemic capacity of two cocoa shell ingredients, a flour (CSF) and an aqueous extract (CSE), through the evaluation of their in vitro hypolipidemic properties and lipid-lowering effects in HepG2 cells. CSF and CSE digested fractions increased their capacity to bind primary bile acids (16-88 %) and inhibit lipase activity (41-100 %), while their ability to bind secondary bile acids (33-42 %) was maintained. Likewise, the digested fractions of cocoa shell ingredients reduced the solubility of the cholesterol micelles (35-97 %) and inhibited the hydroxymethylglutaryl-Co-enzyme A reductase (HMGCR) activity (18-100 %). The hypolipidemic properties of non-digested fractions further enhanced the CSF potential to decrease lipid absorption. Cocoa shell ingredients demonstrated lipid-lowering properties after simulated digestion by effectively reducing the accumulation of intracellular lipids (78-122 %), triacylglycerides (60-90 %), and cholesterol (100 %) induced by palmitic acid in hepatic cells. These results were confirmed by their ability to stimulate lipolysis, reducing the increase in lipase activity (28-78 %) and increasing glycerol release (27-80 %) with respect to palmitic acid treated cells, and inhibiting HMGCR activity. Phenolic compounds and dietary fiber are significantly associated to the observed hypolipidemic effects of cocoa shell ingredients. These findings demonstrated the potential efficacy of CSF and CSE in reducing lipid absorption and reversing its hepatic accumulation. Hence, these cocoa shell ingredients might prevent diseases related to lipid accumulation by improving overall health status.

Western diet promotes the progression of metabolic dysfunction-associated steatotic liver disease in association with ferroptosis in male mice

Non-alcoholic fatty liver disease (NAFLD), now referred to as metabolic dysfunction-associated steatotic liver disease (MASLD), is a silent killer that often progresses to metabolic dysfunction-associated steatohepatitis (MASH). To date, there are no pharmacological treatments for MASLD. While obesity is a major cause of the development and progression of MASLD, the underlying mechanisms remain unclear. We hypothesize that ferroptosis, a recently discovered nonapoptotic iron-dependent form of cell death, is activated during the progression of MASLD and may be a potential target for treating MASLD. Using a murine model of Western diet-induced obesity, C57BL/6J male mice were exposed to a long-term (36 weeks) Western diet. Controls were maintained with a standard chow diet. Western diet-induced obesity was confirmed by increased body mass index (BMI). Histopathological analysis demonstrated the progression of MASLD to MASH in the obese group, which was accompanied by significant hepatic iron deposition, oxidative damage, and lipid peroxidation. Hepatic ferroptosis was further confirmed by decreased protein expression of glutathione peroxidase 4 (GPX4) and increased acyl-CoA synthetase long-chain family member 4 (ACSL4), markers of ferroptosis. These findings suggest that ferroptosis is a potential mechanism involved in the pathogenesis of MASLD in male mice.

Metabolic dysfunction-associated steatotic liver disease-induced changes in the antioxidant system: a review

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a heterogeneous condition characterized by liver steatosis, inflammation, consequent fibrosis, and cirrhosis. Chronic impairment of lipid metabolism is closely related to oxidative stress, leading to cellular lipotoxicity, mitochondrial dysfunction, and endoplasmic reticulum stress. The detrimental effect of oxidative stress is usually accompanied by changes in antioxidant defense mechanisms, with the alterations in antioxidant enzymes expression/activities during MASLD development and progression reported in many clinical and experimental studies. This review will provide a comprehensive overview of the present research on MASLD-induced changes in the catalytic activity and expression of the main antioxidant enzymes (superoxide dismutases, catalase, glutathione peroxidases, glutathione S-transferases, glutathione reductase, NAD(P)H:quinone oxidoreductase) and in the level of non-enzymatic antioxidant glutathione. Furthermore, an overview of the therapeutic effects of vitamin E on antioxidant enzymes during the progression of MASLD will be presented. Generally, at the beginning of MASLD development, the expression/activity of antioxidant enzymes usually increases to protect organisms against the increased production of reactive oxygen species. However, in advanced stage of MASLD, the expression/activity of several antioxidants generally decreases due to damage to hepatic and extrahepatic cells, which further exacerbates the damage. Although the results obtained in patients, in various experimental animal or cell models have been inconsistent, taken together the importance of antioxidant enzymes in MASLD development and progression has been clearly shown.

Unraveling the Dual Anti-Inflammatory and Antioxidant Mechanisms of Acteoside: Computational Insights and Experimental Validation

Acteoside (ACT) is one of the primary bioactive ingredients in Cistanche tubulosa (Schenk). Its remarkable efficacy in treating immune-related and inflammatory disorders has garnered significant interest among scientific circles. However, the anti-inflammatory and antioxidant effects of ACT and its underlying molecular mechanisms require further investigation. In this study, pharmacophore-based reverse docking and molecular dynamics simulations identified potential anti-inflammatory targets in silico. Studies conducted in vitro with lipopolysaccharide (LPS)-induced RAW264.7 cells validated the anti-inflammatory properties of ACT. Methyl thiazolyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays indicated ACT's non-toxic and growth-promoting effects on cells. ACT significantly reduced nitric oxide (NO) and reactive oxygen species (ROS) production and restored levels of antioxidant enzymes. It also decreased pro-inflammatory cytokines. Western blotting assays indicated that ACT inhibited p38, TNF-α, PI3 K/AKT, and NF-κB signaling pathways. These findings underscore ACT's ability to mitigate acute inflammation in RAW264.7 cells by modulating key signaling pathways and provide the scientific basis for enhancing the medicinal value of ACT and future drug development.

Emerging perspectives of copper-mediated transcriptional regulation in mammalian cell development

Copper (Cu) is a vital micronutrient necessary for proper development and function of mammalian cells and tissues. Cu mediates the function of redox active enzymes that facilitate metabolic processes and signaling pathways. Cu levels are tightly regulated by a network of Cu-binding transporters, chaperones, and small molecule ligands. Extensive research has focused on the mammalian Cu homeostasis (cuprostasis) network and pathologies, which result from mutations and perturbations. There are roles for Cu-binding proteins as transcription factors (Cu-TFs) and regulators that mediate metal homeostasis through the activation or repression of genes associated with Cu handling. Emerging evidence suggests that Cu and some Cu-TFs may be involved in the regulation of targets related to development-expanding the biological roles of Cu-binding proteins. Cu and Cu-TFs are implicated in embryonic and tissue-specific development alongside the mediation of the cellular response to oxidative stress and hypoxia. Cu-TFs are also involved in the regulation of targets implicated in neurological disorders, providing new biomarkers and therapeutic targets for diseases such as Parkinson's disease, prion disease, and Friedreich's ataxia. This review provides a critical analysis of the current understanding of the role of Cu and cuproproteins in transcriptional regulation.

Clinopodium gracile Alleviates Metabolic Dysfunction-Associated Steatotic Liver Disease by Upregulating Peroxisome Proliferator-Activated Receptor α and Inhibiting Mitochondrial Oxidative Damage

The most prevalent chronic liver disease, known as metabolic dysfunction-associated steatotic liver disease (MASLD), is characterized by an excessive accumulation of lipids and oxidative damage. Clinopodium gracile, a natural herbal medicine widely used by Chinese folk, has antioxidative, anti-inflammatory, and lipid metabolism-regulating effects. Here, we explored the effect of C. gracile extract (CGE) on MASLD using palmitic acid (PA)-induced hepatocytes and high-fat diet (HFD)-fed mice. In vitro, CGE could promote fatty acid oxidation and inhibit fatty acid synthesis and uptake to reduce lipid accumulation by regulating PPARα activation. Moreover, CGE could inhibit reactive oxygen species production and maintain mitochondrial homeostasis in PA-induced HepG2 cells. In vivo, animal study results indicated that CGE could effectively reduce lipid metabolism disorder, inhibit oxidative stress, and upregulate PPARα protein in the liver of HFD-fed mice. Molecular docking results also showed that active compounds isolated from CGE had low binding energy and highly stable binding with PPARα. In summary, these findings reveal that CGE may be a potential therapeutic candidate for MASLD and act by upregulating PPARα to reduce lipid accumulation and suppress mitochondrial oxidative damage.

Treatment of Acute and Long-COVID, Diabetes, Myocardial Infarction, and Alzheimer's Disease: The Potential Role of a Novel Nano-Compound-The Transdermal Glutathione-Cyclodextrin Complex

Oxidative stress (OS) occurs from excessive reactive oxygen species or a deficiency of antioxidants-primarily endogenous glutathione (GSH). There are many illnesses, from acute and post-COVID-19, diabetes, myocardial infarction to Alzheimer's disease, that are associated with OS. These dissimilar illnesses are, in order, viral infections, metabolic disorders, ischemic events, and neurodegenerative disorders. Evidence is presented that in many illnesses, (1) OS is an early initiator and significant promotor of their progressive pathophysiologic processes, (2) early reduction of OS may prevent later serious and irreversible complications, (3) GSH deficiency is associated with OS, (4) GSH can likely reduce OS and restore adaptive physiology, (5) effective administration of GSH can be accomplished with a novel nano-product, the GSH/cyclodextrin (GC) complex. OS is an overlooked pathological process of many illnesses. Significantly, with the GSH/cyclodextrin (GC) complex, therapeutic administration of GSH is now available to reduce OS. Finally, rigorous prospective studies are needed to confirm the efficacy of this therapeutic approach.

Carthamus tinctorius L. (Safflower) Flower Extract Attenuates Hepatic Injury and Steatosis in a Rat Model of Type 2 Diabetes Mellitus via Nrf2-Dependent Hypoglycemic, Antioxidant, and Hypolipidemic Effects

This study aimed to examine the hepatic and anti-steatotic protective effects of methanolic extract from Carthamus tinctorius (safflower) flowers (SFFE), using a rat model of type 2 diabetes mellitus (T2DM), and to examine the molecular mechanisms underlying these effects. Adult male Wistar rats were used for this study. First, T2DM was induced in some rats by feeding them a high-fat diet (HFD) for 4 weeks, followed by a single dose of streptozotocin (STZ) (35 mg/kg, i.p.). Experimental groups included the following five groups (n = 8 in each): control, control + SFFE, T2DM, T2DM + SFFE, and T2DM + SFFE + brusatol (an Nrf2 inhibitor, 2 mg/kg, i.p.). SFFE was administered at a concentration of 300 mg/kg, and all experiments concluded after 8 weeks. Treatments with SFFE significantly reduced fasting blood glucose levels, free fatty acids (FFAs), cholesterol, triglycerides, and low-density lipoprotein cholesterol in both the control and T2DM rats, but they failed to reduce fasting insulin levels in these groups. SFFE treatments also improved the liver structure and reduced hepatocyte vacuolization and hepatic levels of triglycerides and cholesterol in T2DM rats, in addition to increasing the hepatic mRNA levels of keap1 and the cytoplasmic levels and nuclear activities of Nrf2 in both the control and T2DM rats. SFFE also stimulated the expression levels of PPARα and CPT-1 but reduced the malondialdehyde (MDA), mRNA levels of SREBP1, fatty acid synthase, and acetyl CoA carboxylase in both the control and T2DM rats; meanwhile, it reduced hepatic mRNA and the nuclear activities of NF-κB and increased levels of glutathione, superoxide dismutase, and heme oxygenase-1 in the livers of both groups of treated rats. Furthermore, SFFE suppressed the levels of caspase-3, Bax, tumor necrosis factor-α, and interleukin-6 in the T2DM rats. Treatment with brusatol prevented all of these effects of SFFE. In conclusion, SFFE suppresses liver damage and hepatic steatosis in T2DM through Nrf2-dependent hypoglycemic, antioxidant, anti-inflammatory, and hypolipidemic effects.

Paricalcitol attenuates oxidative stress and inflammatory response in the liver of NAFLD rats by regulating FOXO3a and NFκB acetylation

The lack of therapeutics along with complex pathophysiology made non-alcoholic fatty liver disease (NAFLD) a research hotspot. Studies showed that the deficiency of Vitamin D plays a vital role in NAFLD pathogenesis. While several research studies focused on vitamin D supplementation in NAFLD, there is still a need to understand the regulatory mechanism of direct vitamin D receptor activation in NAFLD. In the present study, we explored the role of direct Vitamin D receptor activation using paricalcitol in choline-deficient high-fat diet-induced NAFLD rat liver and its modulation on protein acetylation. Our results showed that paricalcitol administration significantly reduced the fat accumulation in HepG2 cells and the liver of NAFLD rats. Paricalcitol attenuated the elevated serum level of alanine transaminase, aspartate transaminase, insulin, low-density lipoprotein, triglyceride, and increased high-density lipoprotein in NAFLD rats. Paricalcitol significantly decreased the increased total protein acetylation by enhancing the SIRT1 and SIRT3 expression in NAFLD liver. Further, the study revealed that paricalcitol reduced the acetylation of NFκB and FOXO3a in NAFLD liver along with a decrease in the mRNA expression of IL1β, NFκB, TNFα, and increased catalase and MnSOD. Moreover, total antioxidant activity, glutathione, and catalase were also elevated, whereas lipid peroxidation, myeloperoxidase, and reactive oxygen species levels were significantly decreased in the liver of NAFLD after paricalcitol administration. The study concludes that the downregulation of SIRT1 and SIRT3 in NAFLD liver was associated with an increased acetylated NFκB and FOXO3a. Paricalcitol effectively reversed hepatic inflammation and oxidative stress in NAFLD rats through transcriptional regulation of NFκB and FOXO3a, respectively, by inhibiting their acetylation.

Expression of Vascular Adhesion Protein-1 and Thrombospondin-1 in Gingival Crevicular Fluid of Patients with Periodontitis and Non-Alcoholic Fatty Liver Disease

Purpose

Non-alcoholic fatty liver disease (NAFLD) represents a heterogeneous spectrum of liver diseases that encompass simple steatosis, non-alcoholic steatohepatitis (NASH), and advanced fibrosis or cirrhosis. Periodontitis is a chronic infectious disease with multiple causal factors that presents a complex interaction between the microbial biofilm and the host's immune response. The aim of this study was to investigate the concentrations of Vascular Adhesion Protein-1 (VAP-1) and Thrombospondin-1 (TSP-1) in patients with coexisting periodontitis and NAFLD.

Patients and Methods

This study included 48 patients, who were dental and periodontal assessed. Of these patients, 25 were diagnosed with NAFLD. After performing the periodontal clinical examination, gingival crevicular fluid (GCF) samples were collected. Enzyme-linked immunosorbent assay (ELISA) dedicated kits tests were used for the detection and quantitative determination of VAP-1 and TSP-1 in GCF samples. Statistical methods were applied for the comparison and correlation of data.

Results

VAP-1 and TSP-1 levels showed significant differences between all test and control groups (p<0.0001). Statistically significant correlations (p<0.05) between VAP-1 and periodontal and liver parameters were found in patients with NAFLD and periodontitis.

Conclusion

Periodontal inflammation is more marked in patients with periodontitis-NAFLD association. Vascular adhesion and angiogenesis could be affected in patients with periodontitis and NAFLD. These findings could suggest that addressing periodontal inflammation in individuals with the periodontitis-NAFLD association may have a broader impact on vascular adhesion and angiogenesis, highlighting the interplay between oral health and liver conditions for comprehensive patient care.

Fanlian Huazhuo Formula alleviates high-fat diet-induced non-alcoholic fatty liver disease by modulating autophagy and lipid synthesis signaling pathway

BACKGROUND

Fanlian Huazhuo Formula (FLHZF) has the functions of invigorating spleen and resolving phlegm, clearing heat and purging turbidity. It has been identified to have therapeutic effects on type 2 diabetes mellitus (T2DM) in clinical application. Non-alcoholic fatty liver disease (NAFLD) is frequently diagnosed in patients with T2DM. However, the therapeutic potential of FLHZF on NAFLD and the underlying mechanisms need further investigation.

AIM

To elucidate the effects of FLHZF on NAFLD and explore the underlying hepatoprotective mechanisms in vivo and in vitro.

METHODS

HepG2 cells were treated with free fatty acid for 24 hours to induce lipid accumulation cell model. Subsequently, experiments were conducted with the different concentrations of freeze-dried powder of FLHZF for 24 hours. C57BL/6 mice were fed a high-fat diet for 8-week to establish a mouse model of NAFLD, and then treated with the different concentrations of FLHZF for 10 weeks.

RESULTS

FLHZF had therapeutic potential against lipid accumulation and abnormal changes in biochemical indicators in vivo and in vitro. Further experiments verified that FLHZF alleviated abnormal lipid metabolism might by reducing oxidative stress, regulating the AMPKα/SREBP-1C signaling pathway, activating autophagy, and inhibiting hepatocyte apoptosis.

CONCLUSION

FLHZF alleviates abnormal lipid metabolism in NAFLD models by regulating reactive oxygen species, autophagy, apoptosis, and lipid synthesis signaling pathways, indicating its potential for clinical application in NAFLD.

Silymarin inhibits the lipogenic pathway and reduces worsening of non-alcoholic fatty liver disease (NAFLD) in mice

CONTEXT

The role of silymarin in hepatic lipid dysfunction and its possible mechanisms of action were investigated.

OBJECTIVE

To evaluate the effects of silymarin on hepatic and metabolic profiles in mice fed with 30% fructose for 8 weeks.

METHODS

We evaluated the antioxidant profile of silymarin; mice consumed 30% fructose and were treated with silymarin (120 mg/kg/day or 240 mg/kg/day). We performed biochemical, redox status, and histopathological assays. RT-qPCR was performed to detect ACC-1, ACC-2, FAS, and CS expression, and western blotting to detect PGC-1α levels.

RESULTS

Silymarin contains high levels of phenolic compounds and flavonoids and exhibited significant antioxidant capacity in vitro. In vivo, the fructose-fed groups showed increased levels of AST, ALT, SOD/CAT, TBARS, hepatic TG, and cholesterol, as well as hypertriglyceridaemia, hypercholesterolaemia, and increased ACC-1 and FAS. Silymarin treatment reduced these parameters and increased mRNA levels and activity of hepatic citrate synthase.

CONCLUSIONS

These results suggest that silymarin reduces worsening of NAFLD.

Effects of Portulaca oleracea (purslane) on liver function tests, metabolic profile, oxidative stress and inflammatory biomarkers in patients with non-alcoholic fatty liver disease: a randomized, double-blind clinical trial

Background

Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease. Portulaca oleracea exhibits anti-oxidant, anti-inflammatory, and hepatoprotective effects. This clinical trial aimed to investigate the potential benefits of Portulaca oleracea in improving NAFLD.

Methods

This double-blind, randomized clinical trial enrolled 70 patients with NAFLD assigned to either the intervention group (n = 35) or placebo group (n = 35) using stratified block randomization. The intervention group received 700 mg Portulaca oleracea supplement for eight weeks, while the control group received placebo capsules. In addition, all participants received a calorie-restricted diet. Liver steatosis and fibrosis were assessed using elastography along with liver function and metabolic tests, blood pressure measurements, body composition analysis and dietary records pre-and post-intervention.

Results

The average age of the participants was 44.01 ± 8.6 years, of which 34 (48.6%) were women. The group receiving Portulaca oleracea showed significant weight changes, body mass index, fat mass index, and waist circumference compared to the placebo (p < 0.001). In addition, blood sugar, lipid profile, liver enzymes aspartate and alanine transaminase, gamma-glutamyl transferase, and systolic blood pressure were significantly improved in the intervention group compared to those in the placebo (p < 0.05). During the study, inflammatory and oxidative stress indicators, improved significantly (p < 0.05). Based on the elastography results, the hepatorenal ultrasound index and liver stiffness decreased significantly in the Portulaca oleracea group compared to the placebo (p < 0.001).

Conclusion

The present clinical trial showed that receiving Portulaca oleracea supplement for eight weeks can improve the condition of liver steatosis and fibrosis in patients with NAFLD.

Morin Prevents Non-Alcoholic Hepatic Steatosis in Obese Rats by Targeting the Peroxisome Proliferator-Activated Receptor Alpha (PPARα)

BACKGROUND

Obesity has become a widespread issue globally. Morin, a flavonoid with traditional use in managing hyperglycemia and hyperlipidemia, has demonstrated antioxidant and anti-inflammatory properties in experimental studies. This research aims to explore the anti-obesity potential of morin in rats subjected to a high-fat diet (HFD) and investigate whether its effects are mediated through PPARα regulation.

METHODS

Young adult male Wistar albino rats were divided into four groups (n = 8/group): normal, morin (50 mg/kg/BWT, oral), HFD, and HFD + morin (50 mg/kg/BWT, oral). Treatments were administered daily for 17 consecutive weeks.

RESULTS

Morin mitigated the elevation in glucose levels and decreased fasting glucose and insulin levels, along with the HOMA-IR index, in HFD-fed rats. Furthermore, morin reduced calorie intake, final body weights, and the masses of subcutaneous, epididymal, peritoneal, and mesenteric fat in these rats. It also attenuated the rise in systolic blood pressure in HFD-fed rats and decreased serum levels of triglycerides, cholesterol, free fatty acids, LDL-c, and leptin, while increasing levels of HDL-c and adiponectin in both normal and HFD-fed rats. Moreover, morin restored normal liver structure and reduced fat vacuole accumulation in HFD-fed rats. Notably, it upregulated mRNA levels of PPARα in the livers and white adipose tissue of both normal and HFD-fed rats.

CONCLUSIONS

These findings suggest the potential use of morin to enhance fatty acid oxidation in white adipose tissue and mitigate obesity, warranting further clinical investigation into its therapeutic applications.

Mapping global research trends: Nutrition associations with nonalcoholic fatty liver disease - a Scopus bibliometric analysis

BACKGROUND

Several bibliometric analyses have been carried out to identify research hotspots and trends in nonalcoholic fatty liver disease (NAFLD) research. Nonetheless, there are still significant knowledge gaps that must be filled to advance our understanding of and ability to treat NAFLD.

AIM

To evaluate, through bibliometric and visual analysis, the current status of related research, related research frontiers, and the developmental trends in the field of diet and NAFLD.

METHODS

We retrieved publications about diet and NAFLD published between 1987 and 2022 from Scopus. Next, we used VOSviewer 1.6.20 to perform bibliometric analysis and visualization.

RESULTS

We found a total of 1905 studies, including 1637 (85.93%) original articles and 195 (10.24%) reviews, focused on the examination of NAFLD and its correlation with diet that were published between 1987 and 2022. Among the remaining five types of documents, 38 were letters, notes, editorials, meeting minutes, or brief surveys, representing 1.99% of the total documents. The countries with the most publications on this topic were China (n = 539; 28.29%), followed by the United States (n = 379; 19.90%), Japan (n = 133; 6.98%), and South Korea (n = 127; 6.6%). According to the citation analysis, the retrieved papers were cited an average of 32.3 times and had an h-index of 106, with 61014 total citations. The two main clusters on the map included those related to: (1) Inflammation and oxidative stress; and (2) Dietary interventions for NAFLD.

CONCLUSION

This was the first study to use data taken from Scopus to visualize network mapping in a novel bibliometric analysis of studies focused on diet and NAFLD. After 2017, the two domains that received the most attention were "dietary interventions for NAFL"' and "'inflammation and oxidative stress implicated in NAFLD and its correlation with diet." We believe that this study provides important information for academics, dietitians, and doctors, and that additional research on dietary interventions and NAFLD is warranted.

Oxidative Stress as a Target for Non-Pharmacological Intervention in MAFLD: Could There Be a Role for EVOO?

Oxidative stress plays a central role in most chronic liver diseases and, in particular, in metabolic dysfunction-associated fatty liver disease (MAFLD), the new definition of an old condition known as non-alcoholic fatty liver disease (NAFLD). The mechanisms leading to hepatocellular fat accumulation in genetically predisposed individuals who adopt a sedentary lifestyle and consume an obesogenic diet progress through mitochondrial and endoplasmic reticulum dysfunction, which amplifies reactive oxygen species (ROS) production, lipid peroxidation, malondialdehyde (MDA) formation, and influence the release of chronic inflammation and liver damage biomarkers, such as pro-inflammatory cytokines. This close pathogenetic link has been a key stimulus in the search for therapeutic approaches targeting oxidative stress to treat steatosis, and a number of clinical trials have been conducted to date on subjects with NAFLD using drugs as well as supplements or nutraceutical products. Vitamin E, Vitamin D, and Silybin are the most studied substances, but several non-pharmacological approaches have also been explored, especially lifestyle and diet modifications. Among the dietary approaches, the Mediterranean Diet (MD) seems to be the most reliable for affecting liver steatosis, probably with the added value of the presence of extra virgin olive oil (EVOO), a healthy food with a high content of monounsaturated fatty acids, especially oleic acid, and variable concentrations of phenols (oleocanthal) and phenolic alcohols, such as hydroxytyrosol (HT) and tyrosol (Tyr). In this review, we focus on non-pharmacological interventions in MAFLD treatment that target oxidative stress and, in particular, on the role of EVOO as one of the main antioxidant components of the MD.

Hydroxytyrosol Linoleoyl Ether Ameliorates Metabolic-Associated Fatty Liver Disease Symptoms in Obese Zucker Rats

A main hepatic consequence of obesity is metabolic-associated fatty liver disease (MAFLD), currently treated by improving eating habits and administrating fibrates yet often yielding suboptimal outcomes. Searching for a new therapeutic approach, we aimed to evaluate the efficacy of hydroxytyrosol linoleoyl ether (HTLE), a dual Ppar-α agonist/Cb1 antagonist with inherent antioxidant properties, as an antisteatotic agent. Using lean and obese Zucker rats, they were administrated daily doses of HTLE (3 mg/kg) over a 15-day period, evaluating its safety profile, pharmacokinetics, impact on body weight, hepatic fat content, expression of key enzymes involved in lipogenesis/fatty acid oxidation, and antioxidant capacity. HTLE decreased the body weight and food intake in both rat genotypes. Biochemical analysis demonstrated a favorable safety profile for HTLE along with decreased concentrations of urea, total cholesterol, and aspartate aminotransferase AST transaminases in plasma. Notably, HTLE exhibited potent antisteatotic effects in obese rats, evidenced by a decrease in liver fat content and downregulation of lipogenesis-related enzymes, alongside increased expression of proteins controlling lipid oxidation. Moreover, HTLE successfully counteracted the redox imbalance associated with MAFLD in obese rats, attenuating lipid peroxidation and replenishing both glutathione levels and the overall antioxidant. Our findings highlight the effectiveness of triple-action strategies in managing MAFLD effectively. Based on our results in the Zucker rat model, HTLE emerges as a promising candidate with triple functionality as an anorexigenic, antisteatotic, and antioxidant agent, offering potential relief from MAFLD symptoms associated with obesity while exhibiting minimal side effects. In conclusion, our study positions HTLE as a highly promising compound for therapeutic intervention in MAFLD treatment, warranting further exploration in clinical trials.

Therapeutic potential of Lactobacillus casei and Chlorella vulgaris in high-fat diet-induced non-alcoholic fatty liver disease (NAFLD)-associated kidney damages: a stereological study

BACKGROUND

The non-alcoholic fatty liver disease (NAFLD) is prevalent in as many as 25% of adults who are afflicted with metabolic syndrome. Oxidative stress plays a significant role in the pathophysiology of hepatic and renal injury associated with NAFLD. Therefore, probiotics such as Lactobacillus casei (LBC) and the microalga Chlorella vulgaris (CV) may be beneficial in alleviating kidney injury related to NAFLD.

MATERIALS AND METHODS

This animal study utilized 30 C57BL/6 mice, which were evenly distributed into five groups: the control group, the NAFLD group, the NAFLD + CV group, the NAFLD + LBC group, and the NAFLD + CV + LBC group. A high-fat diet (HFD) was administered to induce NAFLD for six weeks. The treatments with CV and LBC were continued for an additional 35 days. Biochemical parameters, total antioxidant capacity (TAC), and the expression of kidney damage marker genes (KIM 1 and NGAL) in serum and kidney tissue were determined, respectively. A stereological analysis was conducted to observe the structural changes in kidney tissues.

RESULTS

A liver histopathological examination confirmed the successful induction of NAFLD. Biochemical investigations revealed that the NAFLD group exhibited increased ALT and AST levels, significantly reduced in the therapy groups (p < 0.001). The gene expression levels of KIM-1 and NGAL were elevated in NAFLD but were significantly reduced by CV and LBC therapies (p < 0.001). Stereological examinations revealed reduced kidney size, volume, and tissue composition in the NAFLD group, with significant improvements observed in the treated groups (p < 0.001).

CONCLUSION

This study highlights the potential therapeutic efficacy of C. vulgaris and L. casei in mitigating kidney damage caused by NAFLD. These findings provide valuable insights for developing novel treatment approaches for managing NAFLD and its associated complications.

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.

Assessment of melatonin's therapeutic effectiveness against hepatic steatosis induced by a high-carbohydrate high-fat diet in rats

Several studies have demonstrated the protective effects of melatonin against metabolic diseases, such as liver steatosis. However, its therapeutic effects have received less scrutiny. The present study aimed to explore melatonin's therapeutic effectiveness in treating non-alcoholic fatty liver disease (NAFLD) induced by a high-carbohydrate high-fat (HCHF) diet in rats. The NAFLD was developed in male Wistar rats using an HCHF diet for 8 weeks. Afterward, they were given melatonin orally for four weeks at doses of 5 mg/kg, 10 mg/kg, and 30 mg/kg, along with the HCHF diet. In addition, six age-matched healthy rats received the highest dose of melatonin (30 mg/kg) for the same duration. Rats on the HCHF diet exhibited obesity, dyslipidemia, hyperglycemia, glucose intolerance, insulin resistance, inflammation, oxidative stress, and liver injury (steatosis). Melatonin treatment at 10 mg/kg and 30 mg/kg reduced body weight, adiposity index, oxidative damage, and inflammation but did not affect impaired glucose metabolism induced by the HCHF diet. Meanwhile, the highest dose of melatonin (30 mg/kg) reduced the liver steatosis index in HCHF rats but caused mild liver damage in healthy rats. In conclusion, using melatonin demonstrated positive outcomes in treating NAFLD induced by the HCHF diet in rats, with no noteworthy effects observed in healthy rats. A moderate dosage of 10 mg/kg of melatonin proved to be a safer and more efficient method for reducing HCHF diet-induced NAFLD in rats. Higher melatonin doses should be cautiously administered due to potential disruptions in lipid metabolism and the risk of liver complications.

Oral Supplementation of Ozonated Sunflower Oil Augments Plasma Antioxidant and Anti-Inflammatory Abilities with Enhancement of High-Density Lipoproteins Functionality in Rats

Research on ozonated sunflower oil (OSO) is mostly restricted to its topical application, whereas the functional and toxicological assessment of oral OSO consumption is yet to be solved. Herein, OSO was orally supplemented in rats to assess the impact on plasma antioxidant status, low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Also, the functionality of HDL from the OSO-supplemented rats (OSO-HDL) was tested against carboxymethyllysine (CML)- induced hyperinflammation in embryo and adult zebrafish. The results revealed that four weeks of OSO supplementation (3 g/kg BW/day) had no adverse effect on rats' hematological and blood biochemical profiles. Nonetheless, decreased interleukin (IL)-6, and LDL-C levels, along with enhanced ferric ion reduction ability (FRA) and sulfhydryl content, were observed in the plasma of OSO-supplemented rats compared to the control and sunflower oil (SO) supplemented group. In addition, OSO supplementation stabilized apoA-I/HDL and augmented HDL-allied paraoxonase (PON)-1 activity. The microinjection of OSO-HDL (10 nL, 2 mg/mL) efficiently prevented the CML (500 ng)-induced zebrafish embryo mortality and developmental deformities. Similarly, OSO-HDL thwarted CML-posed neurotoxicity and demonstrated a significant hepatoprotective effect against CML-induced fatty liver changes, hepatic inflammation, oxidative stress, and apoptosis, as well as exhibiting a noticeable influence to revert CML-induced dyslipidemia. Conclusively, OSO supplementation demonstrated no toxic effects on rats, ameliorated plasma antioxidant status, and positively influenced HDL stability and functionality, leading to a protective effect against CML-induced toxicity in zebrafish.

Exosomal miR-122, miR-128, miR-200, miR-298, and miR-342 as novel diagnostic biomarkers in NAFL/NASH: Impact of LPS/TLR-4/FoxO3 pathway

Nonalcoholic fatty liver disease (NAFLD) is a common liver disorder affecting a quarter of the global residents. Progression of NAFL into nonalcoholic steatohepatitis (NASH) may cause cirrhosis, liver cancer, and failure. Gut microbiota imbalance causes microbial components translocation into the circulation, triggering liver inflammation and NASH-related fibrosis. MicroRNAs (miRNAs) regulate gene expression via repressing target genes. Exosomal miRNAs are diagnostic and prognostic biomarkers for NAFL and NASH liver damage. Our work investigated the role of the gut microbiota in NAFLD pathogenesis via the lipopolysaccharide/toll-like receptor 4/Forkhead box protein O3 (LPS/TLR-4/FoxO3) pathway and certain miRNAs as noninvasive biomarkers for NAFL or its development to NASH. miRNA expression levels were measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR) in 50 NAFL patients, 50 NASH patients, and 50 normal controls. Plasma LPS, TLR-4, adiponectin, peroxisome proliferator-activated receptor γ (PPAR-γ), and FoxO3 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). In NAFL and NASH patients, miR-122, miR-128, FoxO3, TLR-4, LPS, and PPAR-γ were upregulated while miR-200, miR-298, miR-342, and adiponectin were downregulated compared with the normal control. The examined miRNAs might distinguish NAFL and NASH patients from the normal control using receiver operating characteristic analysis. Our study is the first to examine these miRNAs in NAFLD. Our findings imply that these are potentially promising biomarkers for noninvasive early NAFL diagnosis and NASH progression. Understanding the LPS/TLR-4/FoxO3 pathway involvement in NAFL/NASH pathogenesis may aid disease management.

Targeted platelet with hydrogen peroxide responsive behavior for non-alcoholic steatohepatitis detection

The most common chronic liver illness, non-alcoholic fatty liver disease (NAFLD), refers to a range of abnormalities of the liver with varying degrees of steatosis. When the clinical symptoms including liver damage, inflammation, and fibrosis, are added to the initial steatosis, NAFLD becomes non-alcoholic steatohepatitis (NASH), the problematic and severe stage. The diagnosis of NASH at the right time could therefore effectively prevent deterioration of the disease. Considering that platelets (PLTs) could migrate to the sites of inflamed liver sinusoids with oxidative stress during the development of NASH, we purified the PLTs from fresh blood and engineered their surface with hydrogen peroxide (H2O2) responsive fluorescent probe (5-DP) through lipid fusion. The engineered PLT-DPs were recruited and trapped in the inflammation foci of the liver with NASH through interaction with the extracellular matrix, including hyaluronan and Kupffer cells. Additionally, the fluorescence of 5-DP on the surface of PLT-DP was significantly enhanced upon reacting with the elevated level of H2O2 in the NASH liver. Thus, PLT-DP has great promise for NASH fluorescence imaging with high selectivity and sensitivity.

Boron Facilitates Amelioration of Hepatic Injury by the Osmolyte Glycine and Resolves Injury by Improving the Tissue Redox Homeostasis

Background: Glycine is a conditional non-essential amino acid in human and other mammals. It is abundant in the liver and is known for a wide spectrum of characteristics including the antioxidant, antiinflammatory, immunomodulatory, and cryoprotective effects. The amino acid is a naturally occurring osmolyte compatible with protein surface interactions and has been reported in literature as a potent therapeutic immuno-nutrient for liver diseases such as alcoholic liver disease. Oral glycine administration protects ethanol-induced liver injury, improves serum and tissue lipid profile, and alleviates hepatic injury in various conditions. In recent years, sodium salt of boron (borax) has been reported for its beneficial effects on cellular stress, including the effects on cell survival, immunity, and tissue redox state. Incidentally both glycine and boron prevent apoptosis and promote cell survival under stress. Objective: This study investigates the beneficial effect of borax on liver protection by glycine. Methods: Briefly, liver toxicity was induced in rats by a single intraperitoneal injection of thioacetamide (400 mg/kg b. wt.). Results: Significant changes in oxidative stress and liver function test parameters, the molybdenum Fe-S flavin hydroxylase activity, nitric oxide and tissue histopathology were observed in thioacetamide treated positive control group. The changes were ameliorated both by glycine as well as borax, but the combinatorial treatment yielded a better response indicating the impact of boron supplementation on glycine mediated protection of liver injury in experimental animal model. Conclusions: The study has clinical implications as the hepatotoxicity caused by thioacetamide mimics features of hepatitis C infection in human.

Hepatic Steatosis but Not Fibrosis Is Independently Associated with Poor Outcomes in Patients with Inflammatory Bowel Disease

Background/Aims

Increased prevalence of nonalcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) has been reported. However, the effects of NAFLD on the outcome of IBD remains unclear. We investigated whether the presence of NAFLD could influence the outcomes of patients with IBD.

Methods

We recruited 3,356 eligible patients with IBD into our study between November 2005 and November 2020. Hepatic steatosis and fibrosis were diagnosed using hepatic steatosis index of ≥30 and fibrosis-4 of ≥1.45, respectively. The primary outcome was clinical relapse, defined based on the following: IBD-related admission, surgery, or first use of corticosteroids, immunomodulators, or biologic agents for IBD.

Results

The prevalence of NAFLD in patients with IBD was 16.7%. Patients with hepatic steatosis and advanced fibrosis were older, had a higher body mass index, and were more likely to have diabetes (all p<0.05).

Conclusions

Hepatic steatosis was independently associated with increased risks of clinical relapse in patients with ulcerative colitis and Crohn's disease, whereas fibrotic burden in the liver was not. Future studies should investigate whether assessment and therapeutic intervention for NAFLD will improve the clinical outcomes of patients with IBD.

Comparing rare variants versus common in the pathogenesis of nonalcoholic fatty liver disease: a whole exome sequencing approach

BACKGROUND/PURPOSE

Genome-wide association studies have reported the association of common variants with nonalcoholic fatty liver disease in genes, namely, PNPLA3/TM6SF2/MBOAT7/HSD17B13, across ethnicities. However, the approach does not identify rarer variants with a higher effect size. We therefore sequenced the complete exonic regions of patients with nonalcoholic steatohepatitis and controls to compare rare and common variants with a role in the pathogenesis.

METHODS

This is a prospective study that recruited 54 individuals with/without fatty infiltration. Patients with biopsy-proven nonalcoholic steatohepatitis and persistently elevated liver enzymes were included. Controls were with normal CT/MR fat fraction. DNA was isolated from whole blood, amplified (SureSelectXT Human All Exon V5 + UTR kit) and sequenced (Illumina). Data were filtered for quality, aligned (hg19), and annotated (OpenCRAVAT). Pathogenic (Polyphen-2/SIFT/ClinVar) variants and variants reported to be associated with NAFLD based on published literature were extracted from our data and compared between patients and controls.

RESULTS

The mean age of controls (N = 17) and patients (N = 37) was 46.88 ± 6.94 and 37.46 ± 13.34 years, respectively. A total of 251 missense variants out of 89 286 were classified as pathogenic. Of these, 106 (42.23%) were unique to the patients and remaining (n = 145; 57.77%) were found in both patients and controls. Majority (25/37; 67.57%) patients had a minimum of one or more rare pathogenic variant(s) related to liver pathology that was not seen in the controls.

CONCLUSION

Elucidating the contribution of rare pathogenic variants would enhance our understanding of the pathogenesis. Including the rarer genes in the polygenic risk scores would enhance prediction power.

Comprehensive Transcriptome Profiling of Antioxidant Activities by Glutathione in Human HepG2 Cells

Glutathione (GSH) has long been recognised for its antioxidant and detoxifying effects on the liver. The hepatoprotective effect of GSH involves the activation of antioxidative systems such as NRF2; however, details of the mechanisms remain limited. A comparative analysis of the biological events regulated by GSH under physiological and oxidative stress conditions has also not been reported. In this study, DNA microarray analysis was performed with four experiment arms including Control, GSH, hydrogen peroxide (HP), and GSH + HP treatment groups. The GSH-treated group exhibited a significant upregulation of genes clustered in cell proliferation, growth, and differentiation, particularly those related to MAPK, when compared with the Control group. Additionally, liver functions such as alcohol and cholesterol metabolic processes were significantly upregulated. On the other hand, in the HP-induced oxidative stress condition, GSH (GSH + HP group) demonstrated a significant activation of cell proliferation, cell cycle, and various signalling pathways (including TGFβ, MAPK, PI3K/AKT, and HIF-1) in comparison to the HP group. Furthermore, several disease-related pathways, such as chemical carcinogenesis-reactive oxygen species and fibrosis, were significantly downregulated in the GSH + HP group compared to the HP group. Collectively, our study provides a comprehensive analysis of the effects of GSH under both physiological and oxidative stress conditions. Our study provides essential insights to direct the utilisation of GSH as a supplement in the management of conditions associated with oxidative stress.

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.

Persistent Organic Pollutants released from decomposed adipose tissue affect mitochondrial enzyme function in the brain and eyes other than the liver

Persistent organic pollutants (POPs) are toxic chemicals that can accumulate in the human body, and particularly in adipose tissue. POPs can induce metabolic diseases via mitochondrial dysfunction and can also cause cancer, obesity, and cardiovascular and neurodegenerative diseases. Although the effects of POPs were studied by evaluating mitochondrial function, which is fundamental in investigating the etiologies of various metabolic diseases, the physiological impact of POPs released by the decomposition of fat in adipose tissue is barely understood. Therefore, to investigate the mitochondrial dysfunction caused by POPs released from adipose tissue to other organs, zebrafish were exposed to POPs and placed into four groups: control (C), obesity control (OC), obesity control with POPs (OP), and POP exposure with obesity and caloric restriction (OPR). Next, the activities of the mitochondrial respiratory complexes and the levels of ATP production, reactive oxygen species/reactive nitrogen species (ROS/RNS), and antioxidants, such as glutathione and superoxide dismutase, were measured in the brain, eyes, and liver, as these are the major organs most susceptible to metabolic diseases. POPs released from adipose tissue showed a stronger effect than the direct effects of obesity and POPs on mitochondrial enzyme activity in the brain and eye. Released POPs increased mitochondrial complex I activity and decreased mitochondrial complex II activity compared with normal, obesity, and POP-treated conditions in the brain and eyes. However, the mitochondrial complexes' activities in the liver were affected more by obesity and POPs. In the liver, the mitochondrial enzyme activities of the OPR group seemed to recover to the control level, but it was slightly lowered in the OC and OP groups. Independently, the ROS/RNS and antioxidant levels were not affected by obesity, POPs, or the released POPs in the brain, eye, and liver. The results indicate that POPs stored in adipose tissue and released during fat decomposition did not affect oxidative stress but could affect mitochondrial respiratory enzymes in organ dependent manner. This study is meaningful in that it provides experimental evidence that stored POPs affect specific organs for prolonged periods and can be linked to various diseases in advance.

Prevalence of Non-alcoholic Fatty Liver Disease Detected by Computed Tomography in the General Population Compared with Ultrasonography

Objective To assess the prevalence and clinical correlates of non-alcoholic fatty liver disease (NAFLD) identified by computed tomography (CT) in the general population compared with ultrasonography (US). Methods Four hundred and fifty-eight subjects who received health checkups at Meijo Hospital in 2021 and underwent CT within a year of US in the past decade were analyzed. The mean age was 52.3±10.1 years old, and 304 were men. Results NAFLD was diagnosed in 20.3% by CT and in 40.4% by the US. The NAFLD prevalence in men was considerably greater in subjects 40-59 years old than in those ≤39 years old and in those ≥60 years old by both CT and US. The NAFLD prevalence in women was substantially higher in the subjects 50-59 years old than in those ≤49 years old or those ≥60 years old on US, while no significant differences were observed on CT. The abdominal circumference, hemoglobin value, high-density lipoprotein cholesterol level, albumin level, and diabetes mellitus were independent predictors of NAFLD diagnosed by CT. The body mass index, abdominal circumference, and triglyceride level were independent predictors of NAFLD diagnosed by the US. Conclusion NAFLD was found in 20.3% of CT cases and 40.4% of US cases among recipients of health checkups. An "inverted U curve" in which the NAFLD prevalence rose with age and dropped in late adulthood was reported. NAFLD was associated with obesity, the lipid profile, diabetes mellitus, hemoglobin values, and albumin levels. Our research is the first in the world to compare the NAFLD prevalence in the general population simultaneously by CT and US.

Contributing roles of mitochondrial dysfunction and hepatocyte apoptosis in liver diseases through oxidative stress, post-translational modifications, inflammation, and intestinal barrier dysfunction

This review provides an update on recent findings from basic, translational, and clinical studies on the molecular mechanisms of mitochondrial dysfunction and apoptosis of hepatocytes in multiple liver diseases, including but not limited to alcohol-associated liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), and drug-induced liver injury (DILI). While the ethanol-inducible cytochrome P450-2E1 (CYP2E1) is mainly responsible for oxidizing binge alcohol via the microsomal ethanol oxidizing system, it is also responsible for metabolizing many xenobiotics, including pollutants, chemicals, drugs, and specific diets abundant in n-6 fatty acids, into toxic metabolites in many organs, including the liver, causing pathological insults through organelles such as mitochondria and endoplasmic reticula. Oxidative imbalances (oxidative stress) in mitochondria promote the covalent modifications of lipids, proteins, and nucleic acids through enzymatic and non-enzymatic mechanisms. Excessive changes stimulate various post-translational modifications (PTMs) of mitochondrial proteins, transcription factors, and histones. Increased PTMs of mitochondrial proteins inactivate many enzymes involved in the reduction of oxidative species, fatty acid metabolism, and mitophagy pathways, leading to mitochondrial dysfunction, energy depletion, and apoptosis. Unique from other organelles, mitochondria control many signaling cascades involved in bioenergetics (fat metabolism), inflammation, and apoptosis/necrosis of hepatocytes. When mitochondrial homeostasis is shifted, these pathways become altered or shut down, likely contributing to the death of hepatocytes with activation of inflammation and hepatic stellate cells, causing liver fibrosis and cirrhosis. This review will encapsulate how mitochondrial dysfunction contributes to hepatocyte apoptosis in several types of liver diseases in order to provide recommendations for targeted therapeutics.

Levothyroxine and Non-alcoholic Fatty Liver Disease: A Mini Review

Levothyroxine or l-thyroxine is artificially manufactured thyroxine, which is used as a drug to treat underactive thyroid conditions in humans. The drug, levothyroxine, is consumed daily in a prescribed dose to replace the missing thyroid hormone thyroxine in an individual with an underactive thyroid, and it helps to maintain normal physiological conditions. Though it is a life-maintaining drug, it replaces the missing thyroid hormone and performs the necessary daily metabolic functions in our body. Like all other allopathic drugs, it comes with certain side effects, which include joint pain, cramps in muscle, weight gain/loss, hair loss, etc. The thyroid hormone, thyroxine, is known to mobilize fat in our body, including the ones from the hepatic system. An underactive thyroid may cause an accumulation of fat in the liver, leading to a fatty liver, which is clinically termed Non-Alcoholic Fatty Liver Disease (NAFLD). The correlation between hypothyroidism and NAFLD is now well-studied and recognized. As levothyroxine performs the functions of the missing thyroxine, it is anticipated, based on certain preliminary studies, that the drug helps to mobilize hepatic fat and thus may have a crucial role in mitigating the condition of NAFDL.

Association between Estimated Pulse Wave Velocity and Incident Nonalcoholic Fatty Liver Disease in Korean Adults

Introduction

Nonalcoholic fatty liver disease (NAFLD) is associated with vascular dysfunction, one of the signs of which is arterial stiffness. Carotid-femoral pulse wave velocity (PWV), which is considered the gold standard measure of arterial stiffness, can be estimated using two commonly assessed clinical variables: age and blood pressure. This study aimed to evaluate the association between estimated PWV (ePWV) and the prevalence and incidence of NAFLD among Korean adults.

Methods

This study used data from the Ansan-Ansung cohort study, a subset of the Korean Genome and Epidemiology Study, and included 8,336 adult participants with and without NAFLD at baseline. The participants were subdivided into three tertile groups according to ePWV.

Results

At baseline, the prevalence of NAFLD was 10.5, 27.5, and 35.0% in the first (lowest), second, and third (highest) tertiles of ePWV, respectively. During the 18-year follow-up period, 2,467 (42.9%) incident cases of NAFLD were identified among 5,755 participants who did not have NAFLD at baseline. After adjustment for clinically relevant variables, participants in the second (adjusted hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.12-1.40) and third (adjusted HR, 1.42; 95% CI, 1.24-1.64) tertiles of ePWV had a significantly higher risk of incident NAFLD than those in the first tertile.

Conclusion

Higher ePWV is independently associated with an elevated risk of NAFLD in the general population.

Toxicity mechanisms of biomass burning aerosols in in vitro hepatic steatosis models

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that contributes to the global rise in liver-related morbidity and mortality. Wood tar (WT) aerosols are a significant fraction of carbonaceous aerosol originating from biomass smoldering, contributing to air pollution particles smaller than 2.5 mm (PM2.5). Mechanistic biological associations exist between exposure to PM2.5 and increased NAFLD phenotypes in both cell and animal models. Therefore, this study examines whether an existing NAFLD-like condition can enhance the biological susceptibility of liver cells exposed to air pollution in the form of WT material. Liver cells were incubated with lauric or oleic acid (LA, OA, respectively) for 24 h to accumulate lipids and served as an in vitro hepatic steatosis model. When exposed to 0.02 or 0.2 g/L water-soluble WT aerosols, both steatosis model cells showed increased cell death compared to the control cells (blank-treated cells with or without pre-incubation with LA or OA) or compared to WT-treated cells without pre-incubation with LA or OA. Furthermore, alterations in oxidative status included variations in reactive oxygen species (ROS) levels, elevated levels of lipid peroxidation adducts, and decreased expression of antioxidant genes associated with the NRF2 transcription factor. In addition, steatosis model cells exposed to WT had a higher degree of DNA damage than the control cells (blank-treated cells with or without pre-incubation with LA or OA). These results support a possible systemic effect through the direct inflammatory and oxidative stress response following exposure to water-soluble WT on liver cells, especially those predisposed to fatty liver. Furthermore, the liver steatosis model can be influenced by the type of fatty acid used; increased adverse effects of WT on metabolic dysregulation were observed in the LA model to a higher extent compared to the OA model.

Carbon Monoxide: A Second Biomarker to Couple with Viscosity for the Construction of "Dual-Locked" Near-Infrared Fluorescent Probes for Accurately Diagnosing Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) can progress to cirrhosis and liver cancer if left untreated. Therefore, it is of great importance to develop useful tools for the noninvasive and accurate diagnosis of NAFLD. Increased microenvironmental viscosity was considered as a biomarker of NAFLD, but the occurrence of increased viscosity in other liver diseases highly reduces the diagnosis accuracy of NAFLD by a single detection of viscosity. Hence, it is very necessary to seek a second biomarker of NAFLD. It has been innovatively proposed that the overexpressed heme oxygenase-1 enzyme in NAFLD would produce abnormally high concentrations of CO in hepatocytes and that CO could serve as a potential biomarker. In this work, we screened nine lactam Changsha dyes (HCO-1-HCO-9) with delicate structures to obtain near-infrared (NIR), metal-free, and "dual-locked" fluorescent probes for the simultaneous detection of CO and viscosity. Changsha dyes with a 2-pyridinyl hydrazone substituent could sense CO, and the 5-position substituents on the 2-pyridinyl moiety had a great electron effect on the reaction rate. The double bond in these dyes served as the sensing group for viscosity. Probe HCO-9 was utilized for precise diagnosis of NAFLD by simultaneous detection of CO and viscosity. Upon reacting with CO in a high-viscosity microenvironment, strong fluorescence at 745 nm of probe HCO-9 was turned on with NIR excitation at 700 nm. Probe HCO-9 was proven to be an effective tool for imaging CO and viscosity. Due to the advantages of NIR absorption and low toxicity, probe HCO-9 was successfully applied to image NAFLD in a mouse model.

The potential role of omentin-1 in obesity-related metabolic dysfunction-associated steatotic liver disease: evidence from translational studies

BACKGROUND

Obesity, characterized by visceral adipose tissue (VAT) expansion, is closely associated with metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Recent research has highlighted the crucial role of the adipose tissue-liver axis in the development of MASLD. In this study, we investigated the potential role of omentin-1, a novel adipokine expressed by VAT, in obesity-related MASLD pathogenesis.

METHODS

Through in silico analysis of differentially expressed genes in VAT from obese patients with and without MASH, we identified omentin-1 as a significant candidate. To validate our findings, we measured omentin-1 levels in VAT and plasma of lean controls and obese patients with biopsy-proven MASLD. Additionally, we assessed omentin-1 expression in the VAT of diet-induced mice MASLD model. In vitro and ex vivo studies were conducted to investigate the effects of omentin-1 on MASLD-related mechanisms, including steatosis, inflammation, endoplasmic reticulum (ER) stress, and oxidative stress. We also analyzed the impact of D-glucose and insulin on VAT omentin-1 levels ex vivo.

RESULTS

Compared to the lean group, the obese groups exhibited significantly lower VAT and plasma levels of omentin-1. Interestingly, within the obese groups, omentin-1 is further decreased in MASH groups, independent of fibrosis. Likewise, VAT of mice fed with high-fat diet, showing histological signs of MASH showed decreased omentin-1 levels as compared to their control diet counterpart. In vitro experiments on fat-laden human hepatocytes revealed that omentin-1 did not affect steatosis but significantly reduced TNF-α levels, ER stress, and oxidative stress. Similar results were obtained using ex vivo VAT explants from obese patients upon omentin-1 supplementation. Furthermore, omentin-1 decreased the mRNA expression of NF-κB and mitogen-activated protein kinases (ERK and JNK). Ex vivo VAT explants showed that D-glucose and insulin significantly reduced omentin-1 mRNA expression and protein levels.

CONCLUSIONS

Collectively, our findings suggest that reduced omentin-1 levels contribute to the development of MASLD. Omentin-1 supplementation likely exerts its beneficial effects through the inhibition of the NF-κB and MAPK signaling pathways, and it may additionally play a role in the regulation of glucose and insulin metabolism. Further research is warranted to explore omentin-1 as a potential therapeutic target and/or biomarker for MASLD.

Let-7 suppresses liver fibrosis by inhibiting hepatocyte apoptosis and TGF-β production

OBJECTIVE

FAS-mediated apoptosis of hepatocytes and aberrant TGF-β signaling are major drivers of liver fibrosis. Decreased miRNA let-7 expression in the livers of patients and animals with fibrosis suggests a mechanistic link of let-7 to hepatic fibrogenesis.

METHODS

Using transient transfection we tested the effects of let-7 overexpression and TET3 siRNA knockdown on FAS and TGF-β1 expression and FAS-mediated apoptosis in human and mouse primary hepatocytes. We assessed the therapeutic activity of let-7 miRNA delivered via adeno-associated viral vectors in mouse models of carbon tetrachloride (CCl4)-induced and bile duct ligation (BDL)-induced liver fibrosis.

RESULTS

Let-7 decreased TGF-β1 production from hepatocytes through a negative feedback loop involving TET3. On the other hand, let-7 post-transcriptionally inhibits FAS expression, thereby suppressing hepatocyte apoptosis. Hepatic-specific delivery of let-7 miRNA mitigated liver fibrosis in both CCl4 and BDL mouse models.

CONCLUSIONS

Let-7 is a crucial node in the signaling networks that govern liver fibrosis progression. Let-7 and/or its derivatives may be used as therapeutic agents for liver fibrosis.

Bioactive dipeptides mitigate high-fat and high-fructose corn syrup diet-induced metabolic-associated fatty liver disease via upregulation of Nrf2/HO-1 expressions in C57BL/6J mice

Metabolic-associated fatty liver disease (MAFLD), formerly referred to as non-alcoholic fatty liver disease (NAFLD), is a common liver disease characterized by an abnormal buildup of fat in liver. This study aimed to investigate whether bioactive dipeptides mitigate high-fat and high-fructose corn syrup diet (HFFD)-induced MAFLD in C57BL/6J mice. Sixty male C57BL/6J mice were randomly divided into six groups. The naïve group (untreated) was fed a standard chow diet and other groups were fed with HFFD along with vehicle and bioactive dipeptides treatment throughout experiment period. The control group received vehicle, YF10 and YF50 groups received Tyr-Phe, 10 and 50 mg/kg/day, FY10 and FY50 groups received Phe-Tyr, 10 and 50 mg/kg/day. At the end of experiment, body weight was recorded, and glucose homeostasis was assessed. Mice were sacrificed and blood samples were collected to measure biochemical parameters. Further, liver, visceral fat pads, and other organs were acutely dissected, weighed, and processed. Histopathological and immunohistochemical changes were analyzed. Long-term HFFD feeding resulted in elevated body weight gain, liver weight, visceral adiposity, liver injury, fasting hyperglycemia, hyperinsulinemia, and hyperlipidemia. It also increased severe hepatic steatosis, chronic low-grade inflammation, oxidative stress, mitochondrial dysfunction, and lipid peroxidation. However, bioactive dipeptides dose-dependently alleviated these complications which are associated with MAFLD by modulating adipokines secretion and antioxidant defense system via upregulation of Nrf2/HO-1 expressions. This study highlights potential of bioactive dipeptides as a promising approach for prevention and/or treatment of MAFLD induced by HFFD, providing novel insights into alternative therapeutic strategies.

Unveiling the role of gut dysbiosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial complicated condition, reflected by the accumulation of extra fat in the liver. A detailed study of literature throws light on the fascinating connection between gut dysbiosis and NAFLD. The term 'gut dysbiosis' describes an imbalance in the harmony and operation of the gut microflora, which can upshoot a number of metabolic disorders. To recognize the underlying mechanisms and determine treatment options, it is essential to comprehend the connection between gut dysbiosis and NAFLD. This in-depth review discusses the normal gut microflora composition and its role in health, alterations in the gut microflora composition that leads to disease state focusing on NAFLD. The potential mechanisms influencing the advent and aggravation of NAFLD suggested disturbance of microbial metabolites, changes in gut barrier integrity, and imbalances in the composition of the gut microflora. Furthermore, it was discovered that gut dysbiosis affected immune responses, liver inflammation, and metabolic pathways, aggravating NAFLD.