N-Acetyl Cysteine Targets Hepatic Lipid Accumulation to Curb Oxidative Stress and Inflammation in NAFLD: A Comprehensive Analysis of the Literature

A patient-centered approach to dietary supplements for patients with chronic liver disease

The use of dietary supplements by patients with chronic liver disease is prevalent and rising. Despite the known risks of dietary supplements, including hepatotoxicity, adulteration, and contamination, patients with chronic liver disease often turn to dietary supplements to support their liver and/or overall health but are not necessarily empowered with the information or guidance from their liver practitioner to do so. This article provides practitioners with a framework for balancing the risks and benefits of dietary supplements in patients with chronic liver disease, offering examples of independent resources and certifications to use this framework in clinical practice. We offer 3 common clinical scenarios to highlight how the use of this framework can improve communication and decision-making in clinical practice. By adapting principles from Integrative Medicine, this article advocates for a patient-centered approach to dietary supplements in patients with chronic liver disease, encouraging open dialogue between clinicians and their patients to facilitate informed decision-making and personalized care.

GA receptor targeted chitosan oligosaccharide polymer nanoparticles improve non-alcoholic fatty liver disease by inhibiting ferroptosis

Excessive iron in the liver may exacerbate Non-alcoholic fatty liver disease (NAFLD) by increasing the risk of liver cell expansion, inflammation and fibrosis. Ferroptosis in liver cells may lead the progression of simple fatty liver degeneration to steatohepatitis (NASH). More and more studies shew that ferroptosis played a crucial role in the pathological process of NAFLD. Based on the mechanism of ferroptosis, this study first synthesized a liver targeted 18-β-Glycyrrhetinic-acid-chitosan oligosaccharide -N-acetylcysteine polymer (GCNp), and further curcumin (Cur) was used as model drug to prepare Cur loaded nanodelivery system (GCNp-Cur NPs). The particle size of GCNp-Cur NPs was 132.5 ± 9.8 nm, PDI was 0.148 ± 0.026 and the potential was 23.8 mV. GCNp-Cur NPs can regulate the GPX4/GSH pathway, inhibit lipid peroxidation, restore cellular oxidative environment, reduce free Fe2+, improve cellular lipid metabolism and iron metabolism, thereby NPs inhibited liver cell ferroptosis through multiple pathways. Additionally, GCNp-Cur NPs could also alleviate liver tissue lipid accumulation and oxidative damage, delaying disease progression, and providing a new method and theoretical basis for the treatment of NAFLD.

Protective effect of N-acetylcysteine against hepatocellular carcinoma in hepatitis B virus carriers

Hepatitis B virus (HBV) infection is a leading risk factor for hepatocellular carcinoma (HCC), contributing to cancer development through direct genomic integration and chronic inflammation. N-acetylcysteine (NAC), known for its antioxidant properties, is widely utilized in cancer prevention. However, clinical evidence regarding its protective effect against HCC in HBV carriers remains sparse. In this retrospective cohort study spanning 2008 to 2018, we utilized Taiwan's National Health Insurance Research Database (NHIRD) to include 1,061,174 chronic HBV carriers. Participants were stratified into NAC users and non-users using Propensity Score Matching. We assessed the incidence of HCC in both cohorts, examining the relationship between NAC usage duration and HCC incidence, and evaluating the dose-response effect. NAC users exhibited a significantly lower risk of developing HCC (adjusted hazard ratio [aHR]: 0.38; 95% confidence interval [CI]: 0.36-0.40; P < 0.0001). A dose-response relationship was evident, with higher cumulative defined daily doses (cDDDs) of NAC correlating with reduced HCC risk, revealing a significant trend (P < 0.0001). Notably, a daily NAC intensity of > 1.4 DDDs was associated with a decreased risk of HCC in HBV patients. Our results demonstrate that the use of NAC, in a dose-dependent manner, is intricately linked with a diminished incidence of HCC in individuals chronically infected with the HBV.

N-acetyl Cysteine Overdose Induced Acute Toxicity and Hepatic Microvesicular Steatosis by Disrupting GSH and Interfering Lipid Metabolisms in Normal Mice

N-acetyl cysteine (NAC) is a versatile drug used in various conditions, but the limitations and toxicities are not clear. The acute toxicity and toxicological mechanisms of an intraperitoneal injection of NAC in normal mice were deciphered. The LD50 for male and female BALB/cByJNarl mice were 800 mg/kg and 933 mg/kg. The toxicological mechanisms of 800 mg/kg NAC (N800) were investigated. The serum biomarkers of hepatic and renal indices dramatically increased, followed by hepatic microvesicular steatosis, renal tubular injury and necrosis, and splenic red pulp atrophy and loss. Thus, N800 resulted in mouse mortality mainly due to acute liver, kidney, and spleen damages. The safe dose (275 mg/kg) of NAC (N275) increased hepatic antioxidant capacity by increasing glutathione levels and catalase activity. N275 elevated the hepatic gene expressions of lipid transporter, lipid synthesis, β-oxidation, and ketogenesis, suggesting a balance between lipid production and consumption, and finally, increased ATP production. In contrast, N800 increased hepatic oxidative stress by decreasing glutathione levels through suppressing Gclc, and reducing catalase activity. N800 decreased the hepatic gene expressions of lipid transporter, lipid synthesis, and interferred β-oxidation, leading to lipid accumulation and increasing Cyp2E1 expression, and finally, decreased ATP production. Therefore, NAC doses are limited for normal individuals, especially via intraperitoneal injection or similar means.

Anti-inflammatory peptide therapeutics and the role of sulphur containing amino acids (cysteine and methionine) in inflammation suppression: A review

BACKGROUND

Inflammation serves as our body's immune response to combat infections, pathogens, viruses, and external stimuli. Inflammation can be classified into two types: acute inflammation and chronic inflammation. Non-steroidal anti-inflammatory medications (NSAIDs) are used to treat both acute and chronic inflammatory disorders. However, these treatments have various side effects such as reduced healing efficiency, peptic ulcers, gastrointestinal toxicities, etc. METHOD: This review assesses the potential of anti-inflammatory peptides (AIPs) derived from various natural sources, such as algae, fungi, plants, animals, and marine organisms. Focusing on peptides rich in cysteines and methionine, sulphur-containing amino acids known for their role in suppression of inflammation.

RESULT

Due to their varied biological activity, ability to penetrate cells, and low cytotoxicity, bioactive peptides have garnered interest as possible therapeutic agents. The utilisation of AIPs has shown great potential in the treatment of disorders associated with inflammation. AIPs can be obtained from diverse natural sources such as algae, fungi, plants, and animals. Cysteine and methionine are sulphur-containing amino acids that aid in the elimination of free radicals, hence assisting in the treatment of inflammatory diseases.

CONCLUSION

This review specifically examines several sources of AIPs including peptides that contain numerous cysteines and methionine. In addition, the biological characteristics of these amino acids and advancements in peptide delivery are also discussed.

Modulation of Sirtuin 3 by N-Acetylcysteine Preserves Mitochondrial Oxidative Phosphorylation and Restores Bisphenol A-Induced Kidney Damage in High-Fat-Diet-Fed Rats

Bisphenol A (BPA) and high-fat diets (HFD) are known to adversely affect the kidneys. However, the combined effects of both cases on kidney health and the potential benefits of N-acetylcysteine (NAC) in mitigating these effects have not been investigated. To explore these aspects, male Wistar rats were fed with HFD and allocated to receive a vehicle or BPA. At week twelve, the BPA-exposed rats were subdivided to receive a vehicle or NAC along with BPA until week sixteen. Rats fed HFD and exposed to BPA showed renal dysfunction and structural abnormalities, oxidative stress, inflammation, and mitochondrial dysfunction, with alterations in key proteins related to mitochondrial oxidative phosphorylation (OXPHOS), bioenergetics, oxidative balance, dynamics, apoptosis, and inflammation. Treatment with NAC for 4 weeks significantly improved these conditions. The findings suggest that NAC is beneficial in protecting renal deterioration brought on by prolonged exposure to BPA in combination with HFD, and modulation of sirtuin 3 (SIRT3) signaling by NAC appears to play a key role in the preservation of homeostasis and integrity within the mitochondria by enhancing OXPHOS activity, maintaining redox balance, and reducing inflammation. This study provides valuable insights into potential therapeutic strategies for preserving kidney health in the face of environmental and dietary challenges.

Afriplex GRTTM extract attenuates hepatic steatosis in an in vitro model of NAFLD

BACKGROUND

Currently, it is acknowledged that vitamin E, insulin sensitizers and anti-diabetic drugs are used to manage non-alcoholic fatty liver disease (NAFLD), however, these therapeutic interventions harbour adverse side effects. Pioglitazone, an anti-diabetic drug, is currently the most effective therapy to manage NAFLD. The use of natural medicines is widely embraced due to the lack of evidence of their negative side effects. Rooibos has been previously shown to decrease inflammation and oxidative stress in experimental models of diabetes, however, this is yet to be explored in a setting of NAFLD. This study was aimed at investigating the effects of an aspalathin-rich green rooibos extract (Afriplex GRTTM) against markers of hepatic oxidative stress, inflammation and apoptosis in an in vitro model of NAFLD.

METHODS

Oleic acid [1 mM] was used to induce hepatic steatosis in C3A liver cells. Thereafter, the therapeutic effect of Afriplex GRTTM, with or without pioglitazone, was determined by assessing its impact on cell viability, changes in mitochondrial membrane potential, intracellular lipid accumulation and the expression of genes and proteins (ChREBP, SREBF1, FASN, IRS1, SOD2, Caspase-3, GSTZ1, IRS1 and TNF-α) that are associated with the development of NAFLD.

RESULTS

Key findings showed that Afriplex GRTTM added to the medium alone or combined with pioglitazone, could effectively block hepatic lipid accumulation without inducing cytotoxicity in C3A liver cells exposed oleic acid. This positive outcome was consistent with effective regulation of genes involved in insulin signaling, as well as carbohydrate and lipid metabolism (IRS1, SREBF1 and ChREBP). Interestingly, in addition to reducing protein levels of an inflammatory marker (TNF-α), the Afriplex GRTTM could ameliorate oleic acid-induced hepatic steatotic damage by decreasing the protein expression of oxidative stress and apoptosis related markers such as GSTZ1 and caspase-3.

CONCLUSION

Afriplex GRTTM reduced hepatic steatosis in oleic acid induced C3A liver cells by modulating SREBF1, ChREBP and IRS-1 gene expression. The extract may also play a role in alleviating inflammation by reducing TNF-α expression, suggesting that additional experiments are required for its development as a suitable therapeutic option against NAFLD. Importantly, further research is needed to explore its antioxidant role in this model.

Mentha rotundifolia (L.) Huds. and Salvia officinalis L. hydrosols mitigate aging related comorbidities in rats

Introduction

Aging is often linked to oxidative stress, where the body experiences increased damage from free radicals. Plants are rich sources of antioxidants, playing a role in slowing down aging and supporting the proper functioning and longevity of cells. Our study focuses on exploring the impact of Mentha rotundifolia (MR) and Salvia officinalis (SO) hydrosols on aging-related comorbidities.

Methods

The chemical composition of MR and SO hydrosols was analyzed by gas chromatography coupled to mass spectrometry. 2,2-Diphenyl 1-picrylhydrazyl and 2,20-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid radicals scavenging assays were used to assess their in vitro antioxidant activity, and heat induced albumin denaturation test was used to evaluate their anti-inflammatory activity. Subsequently, we administered 5% of each plant hydrosol in the drinking water of 18-month-old rats for six months. We then conducted behavioral tests, including open field, dark/light box, rotarod, and Y-maze assessments, and measured biochemical parameters in plasma, liver and brain tissues.

Results and discussion

At two years old, animals treated with MR and SO hydrosols displayed fewer physical and behavioral impairments, along with well-preserved redox homeostasis in comparison with animals in the control group. These results highlighted the significance of MR and SO hydrosols in addressing various aspects of age-related comorbidities. The study suggests that these plant-derived hydrosols may have potential applications in promoting healthy aging and mitigating associated health challenges.

Melatonin targets ferroptosis through bimodal alteration of redox environment and cellular pathways in NAFLD model

Ferroptosis is a non-conventional cellular death caused by lipid peroxide induced iron deposition. Intracellular lipid accumulation followed by generation of lipid peroxides is an hallmark of non-alcoholic fatty liver disease (NAFLD). Melatonin (MLT) is an important pineal hormone with tremendous antioxidant and anti-inflammatory properties. Various studies targeted ferroptosis in different diseases using melatonin. However, none of them focused the intrinsic mechanism of MLT's action to counteract ferroptosis in NAFLD. Hence, the present study investigated the role of MLT in improvement of NAFLD-induced ferroptosis. HepG2 cells were treated with free fatty acids (FFAs) to induce in vitro NAFLD state and C57BL/6 mice were fed with high-fat diet (HFD) followed by MLT administration. The results indicated that MLT administration caused the recovery from both FFA- and HFD-induced ferroptotic state via increasing GSH and SOD level, decreasing lipid reactive oxygen species (ROS) and malondialdehyde (MDA) level, increasing Nrf2 and HO-1 level to defend cells against an oxidative environment. MLT also altered the expression of two key proteins GPX4 and SLC7A11 back to their normal levels, which would otherwise cause ferroptosis. MLT also protected against histopathological damage of both liver tissue and HepG2 cells as depicted by Oil Red O, HE staining and immunofluorescence microscopy. MLT also had control over pAMPKα as well as PPARγ and PPARα responsible for lipid homeostasis and lipogenesis. In brief, MLT exerted its multifaceted effect in FFA- and HFD-induced NAFLD by retrieving cellular oxidative environment, reducing lipogenesis and lipid peroxidation and modulating Nrf2/HO-1 and GPX4/SLC7A11 axis to combat ferroptosis.

Comprehensive analysis of macrosomia: exploring the association between first-trimester alanine aminotransferase and uric acid measurements in pregnant women

OBJECTIVES

Investigating the relationship between liver enzymes, uric acid (UA), and macrosomia will benefit physicians in the early detection of complications that may emerge during/after pregnancy. The study analyzed liver enzyme activity and UA levels in first-trimester pregnant for the risk of macrosomia.

METHODS

This retrospective cross-sectional research analyzed the data of pregnant women who gave birth between Jan 2021-2023. All data were extracted from medical records, and UA and AST-ALT were examined in all the participants.

RESULTS

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were higher in the macrosomia (p<0.05). Similarly, UA levels were higher in the macrosomia (p<0.001). There was a moderate positive correlation between ALT and birth weight (r=0.168, p<0.01), while we found a strong positive correlation between UA and birth weight (r=0.355, p<0.01). In the ROC (receiver operating characteristic), Area Under the Curve (AUC) for ALT and UA was significant (p<0.0001) but not for AST (p=0.157). UA showed a predictive value for macrosomia with 68.1 % sensitivity and 63.8 % specificity at a 3.15 cut-off (AUC:0.689; p:0.0001; CI:0.644-0.725).

CONCLUSIONS

These results indicate that ALT and UA may be potentially important in determining the risk of macrosomia. The UA had a more potent marker for macrosomia than ALT. The occurrence of macrosomia might be more closely related to the mother's metabolic syndrome rather than NAFLD.

N-Acetylcysteine and Its Immunomodulatory Properties in Humans and Domesticated Animals

N-acetylcysteine (NAC), an acetylated derivative of the amino acid L-cysteine, has been widely used as a mucolytic agent and antidote for acetaminophen overdose since the 1960s and the 1980s, respectively. NAC possesses antioxidant, cytoprotective, anti-inflammatory, antimicrobial, and mucolytic properties, making it a promising therapeutic agent for a wide range of diseases in both humans and domesticated animals. Oxidative stress and inflammation play a major role in the onset and progression of all these diseases. NAC's primary role is to replenish glutathione (GSH) stores, the master antioxidant in all tissues; however, it can also reduce levels of pro-inflammatory tumor necrosis factor-alpha (TNF-∝) and interleukins (IL-6 and IL-1β), inhibit the formation of microbial biofilms and destroy biofilms, and break down disulfide bonds between mucin molecules. Many experimental studies have been conducted on the use of NAC to address a wide range of pathological conditions; however, its effectiveness in clinical trials remains limited and studies often have conflicting results. The purpose of this review is to provide a concise overview of promising NAC usages for the treatment of different human and domestic animal disorders.

Comprehensive transcriptomic analysis and meta-analysis identify therapeutic effects of N-acetylcysteine in nonalcoholic fatty liver disease

Introduction: The continuous rise in the prevalence of nonalcoholic fatty liver disease (NAFLD) is emerging as a global health issue. Although the protective effects of N-acetylcysteine (NAC), an antioxidant, against various diseases have been reported, it is still unclear whether NAC has therapeutic potential in NAFLD. Thus, the present meta-analysis aimed to investigate the efficacy of NAC on NAFLD in preclinical studies. Methods: By searching PubMed, Web of Science, and Cochrane Library, 13 studies were included. The methodological quality was assessed based on the SYstematic Review Centre for Laboratory animal Experimentation guideline, and heterogeneity was evaluated with I ² and p values. Publication bias was assessed by Egger's test and sensitivity analysis was performed. Results: The results showed that NAC treatment significantly improved systemic and hepatic lipid metabolism (p < 0.01), inflammation-related liver injury (p < 0.01), glucose intolerance (p < 0.05), and hepatic steatosis (p < 0.01) by restoring hepatic glutathione (GSH) (p < 0.05) and GSH reductase (p < 0.05) levels compared to controls in NAFLD-induced animals. Consistently, in bulk, single-cell, and spatial transcriptomics data, the abovementioned target pathways of NAC were strongly associated with NAFLD development in mice and patients. Conclusion: Our study suggests that NAC has therapeutic potential for NAFLD and should be considered for future clinical trials.

Flavonoids from Scutellaria amoena C. H. Wright alleviate mitochondrial dysfunction and regulate oxidative stress via Keap1/Nrf2/HO-1 axis in rats with high-fat diet-induced nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is among the most common liver diseases in the world. Flavonoids from Scutellaria amoena (SAF) are used in the treatment of hepatopathy in China. However, the effect and mechanism against NASH remain unclear. We investigated the alleviating effect of SAF on NASH via regulating mitochondrial dysfunction and oxidative stress.

METHODS

The effects of SAF on NASH were evaluated using in vitro and in vivo methods. L02 cells were induced by fat emulsion to establish an adipocytes model, followed by treatment with SAF for 24 h. NASH rat models were established by the administration of a high-fat diet for 12 weeks and were administered SAF for six weeks. Changes in body weight, organ indexes, lipid levels, inflammatory cytokines, mitochondrial indicators, and fatty acid metabolism were investigated.

RESULTS

SAF significantly improved body weight, organ indexes, lipid levels, liver injury, and inflammatory infiltration in NASH rats. SAF notably regulated interleukin-6, tumor necrotic factor-alpha, superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), kelch-like ECH-associated protein 1 (Keap1), nuclear factor-erythroid factor 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). Additionally, SAF improved mitochondrial dysfunction, increased the levels of GSH, SOD, ATP synthase, complex I and II, and decreased the level of MDA in liver mitochondria. SAF regulated the expression of β-oxidation genes, including peroxisome proliferator-activated receptor -gamma coactivator-1alpha (PGC-1α), carnitine palmitoyltransferase-1 (CPT1) A, CPT1B, medium-chain acyl-CoA dehydrogenase, long-chain acyl-CoA dehydrogenase, very long-chain acyl-CoA dehydrogenase, and PPARα.

CONCLUSION

SAF can alleviate NASH by regulating mitochondrial function and oxidative stress via the Keap1/Nrf2/HO-1 axis.

Hepatoprotective effects of gentisic acid through its anti-oxidant properties in nicotinamide-streptozotocin induced diabetic mice

Objectives

Type 2 diabetes mellitus (T2DM) is a common metabolic disorder that causes many complications. Liver failure is one of the complications of T2DM. Oxidative stress plays a major role in the development and progression of T2DM-induced liver injury. Gentisic acid (GA) is a metabolite of aspirin and also a phenolic compound found in natural sources that is a highly effective antioxidant and free radical scavenger. So, in this study, the potential preventive benefits of GA against liver damage induced by T2DM were explored.

Materials and Methods

This study was conducted on 24 adult male mice. T2DM was induced by intraperitoneal injection of a single dose of streptozotocin (at a dose of 65 mg/kg), 15 min after the injection of nicotinamide (at a dose of 120 mg/kg). The grouping was as follows: 1) Normal Control Group; 2) Diabetic Control Group; 3) Positive Control Group: received metformin (150 mg/kg body weight daily) through gavage; 4) Treatment Group: received GA at the dose of 100 mg/kg body weight daily through gavage. Treatments continued for two weeks.

Results

Two weeks of GA treatment in diabetic mice reduced fasting blood glucose, improved plasma levels of hepatic enzymes, and increased liver tissue antioxidant capacity. Histopathological examination revealed that GA administration reduced diabetes-induced liver damage. Furthermore, GA treatment led to the down-regulation of Kelch-like ECH-associated protein 1 (Keap1) and up-regulation of nuclear factor E2-related factor 2 (Nrf2).

Conclusion

The results of this study showed that GA exerts hepatoprotective effects in STZ-induced T2DM mice.

The Synergistic Protective Effect of γ-Oryzanol (OZ) and N-Acetylcysteine (NAC) against Experimentally Induced NAFLD in Rats Entails Hypoglycemic, Antioxidant, and PPARα Stimulatory Effects

This study estimated that the combined effect of γ-Oryzanol and N-acetylcysteine (NAC) against high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) in rats also estimated some of their mechanisms of action. Adult male rats were divided into seven groups (n = 8 each) as control, control + NAC, control + γ-Oryzanol, HFD, HFD + NAC, HFD + γ-Oryzanol, and HFD + NAC + γ-Oryzanol. NAC was administered orally at a final concentration of 200 mg/kg, whereas γ-Oryzanol was added to diets at a concentration of 0.16. All treatments were conducted for 17 weeks and daily. Both NAC and γ-Oryzanol were able to reduce final body weights, fat weights, fasting glucose, fasting insulin, serum, and serum levels of liver function enzymes as well as the inflammatory markers such as tumor necrosis factor-α (TNF-α), interleukine-6 (IL-6), and leptin in HFD-fed rats. They also improved hepatic structure and glucose tolerance, increased adiponectin levels, and reduced serum and hepatic levels of triglycerides (TGs) and cholesterol (CHOL) in these rats. These effects were concomitant with a reduction in the hepatic levels of lipid peroxides (MDA) and serum levels of LDL-C, but also with an increment in the hepatic levels of superoxide dismutase (SOD) and glutathione (GSH). Interestingly, only treatment with γ-Oryzanol stimulated the mRNA levels of proliferator-activated receptor alpha (PPARα) and carnitine palmitoyltransferase 1 (CPT1) in the liver and white adipose tissue (WAT) of rats. Of note, the combination therapy of both drugs resulted in maximum effects and restored almost normal liver structure and basal levels of all the above-mentioned metabolic parameters. In conclusion, a combination therapy of γ-Oryzanol and NAC is an effective therapy to treat NAFLD, which can act via several mechanisms on the liver and adipose tissue.

Hepatic neddylation deficiency triggers fatal liver injury via inducing NF-κB-inducing kinase in mice

The conjugation of neural precursor cell expressed, developmentally downregulated 8 (NEDD8) to target proteins, termed neddylation, participates in many cellular processes and is aberrant in various pathological diseases. Its relevance to liver function and failure remains poorly understood. Herein, we show dysregulated expression of NAE1, a regulatory subunit of the only NEDD8 E1 enzyme, in human acute liver failure. Embryonic- and adult-onset deletion of NAE1 in hepatocytes causes hepatocyte death, inflammation, and fibrosis, culminating in fatal liver injury in mice. Hepatic neddylation deficiency triggers oxidative stress, mitochondrial dysfunction, and hepatocyte reprogramming, potentiating liver injury. Importantly, NF-κB-inducing kinase (NIK), a serine/Thr kinase, is a neddylation substrate. Neddylation of NIK promotes its ubiquitination and degradation. Inhibition of neddylation conversely causes aberrant NIK activation, accentuating hepatocyte damage and inflammation. Administration of N-acetylcysteine, a glutathione surrogate and antioxidant, mitigates liver failure caused by hepatic NAE1 deletion in adult male mice. Therefore, hepatic neddylation is important in maintaining postnatal and adult liver homeostasis, and the identified neddylation targets/pathways provide insights into therapeutically intervening acute liver failure.

Mechanistic insights into the pleiotropic effects of butyrate as a potential therapeutic agent on NAFLD management: A systematic review

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic diseases worldwide. As a multifaceted disease, NAFLD's pathogenesis is not entirely understood, but recent evidence reveals that gut microbiota plays a significant role in its progression. Butyrate, a gut microbiota metabolite, has been reported to have hepato-protective effects in NAFLD animal models. The purpose of this systematic review is to determine how butyrate affects the risk factors for NAFLD. Searches were conducted using relevant keywords in electronic databases up to March 2022. According to the evidence presented in this study, butyrate contributes to a wide variety of biological processes in the gut-liver axis. Its beneficial properties include improving intestinal homeostasis and liver health as well as anti-inflammatory, metabolism regulatory and anti-oxidative effects. These effects may be attributed to butyrate's ability to regulate gene expression as an epigenetic modulator and trigger cellular responses as a signalling molecule. However, the exact underlying mechanisms remain unclear. Human trials have not been performed on the effect of butyrate on NAFLD, so there are concerns about whether the results of animal studies can be translated to humans. This review summarises the current knowledge about the properties of butyrate, particularly its potential effects and mechanisms on liver health and NAFLD management.

Microbiota Dysbiosis and Gut Barrier Dysfunction Associated with Non-Alcoholic Fatty Liver Disease Are Modulated by a Specific Metabolic Cofactors' Combination

The gut is a selective barrier that not only allows the translocation of nutrients from food, but also microbe-derived metabolites to the systemic circulation that flows through the liver. Microbiota dysbiosis occurs when energy imbalances appear due to an unhealthy diet and a sedentary lifestyle. Dysbiosis has a critical impact on increasing intestinal permeability and epithelial barrier deterioration, contributing to bacterial and antigen translocation to the liver, triggering non-alcoholic fatty liver disease (NAFLD) progression. In this study, the potential therapeutic/beneficial effects of a combination of metabolic cofactors (a multi-ingredient; MI) (betaine, N-acetylcysteine, L-carnitine, and nicotinamide riboside) against NAFLD were evaluated. In addition, we investigated the effects of this metabolic cofactors' combination as a modulator of other players of the gut-liver axis during the disease, including gut barrier dysfunction and microbiota dysbiosis. Diet-induced NAFLD mice were distributed into two groups, treated with the vehicle (NAFLD group) or with a combination of metabolic cofactors (NAFLD-MI group), and small intestines were harvested from all animals for histological, molecular, and omics analysis. The MI treatment ameliorated gut morphological changes, decreased gut barrier permeability, and reduced gene expression of some proinflammatory cytokines. Moreover, epithelial cell proliferation and the number of goblet cells were increased after MI supplementation. In addition, supplementation with the MI combination promoted changes in the intestinal microbiota composition and diversity, as well as modulating short-chain fatty acids (SCFAs) concentrations in feces. Taken together, this specific combination of metabolic cofactors can reverse gut barrier disruption and microbiota dysbiosis contributing to the amelioration of NAFLD progression by modulating key players of the gut-liver axis.

Effects of dietary mannan oligosaccharides (MOS) supplementation on metabolism, inflammatory response and gut microbiota of juvenile Nile tilapia (Oreochromis niloticus) fed with high carbohydrate diet

High-carbohydrate diet could achieve cost-sparing effect in aquafeed, but it may cause adverse effects on the growth condition or health status of fish. In order to reduce the adverse effects caused by high carbohydrate diet, mannan oligosaccharides (MOS), a commonly used prebiotics, was used as the feed additive to feed juvenile Nile tilapia (Oreochromis niloticus) (1.19 ± 0.01g) for ten weeks. Three treatments including CON (35% carbohydrate diet), HC (45% carbohydrate diet) and HM (45% carbohydrate supplemented diet with 5 g/kg MOS) were involved. The results showed that MOS supplementation increased the weight gain and body length of juvenile Nile tilapia compared with the HC group. Addition of MOS decreased serum glucose and liver glycogen by increasing enzymes activity related to glycolysis. Furthermore, supplementation of MOS decreased the high carbohydrate diet induced triglycerides accumulation in liver by reducing the expression level of genes related to TG synthesis. Dietary MOS also down-regulated the gene expression level of inflammation factors in liver. Intestinal bacterial composition analyses showed that supplementation of MOS in high carbohydrate diet altered the gut microbial composition and enriched pathways related to the glucose metabolism based on KEGG analyses. In general, our results demonstrated that MOS supplementation in high carbohydrate diet could regulate glucose and lipid homeostasis which may be related to the alteration of gut microbiota. These findings shed light on the application of prebiotics to increase the growth performance, alleviate the metabolic disorders and regulate inflammatory response in aquaculture.

Network pharmacology and molecular docking study on the effect of Kaempferol in treatment of metabolic associated fatty liver disease

OBJECTIVE

To study therapeutic effect of kaempferol on metabolic associated fatty liver disease (MAFLD) by network pharmacology and molecular docking combined with cell experiments.

METHODS

First, use the SwissTargetPrediction database to predict the targets of kaempferol, and collect the targets of MAFLD through the Disgenet database and the GeneCards database. Then, the common target of kaempferol and MAFLD was enriched and analyzed by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes, and the protein-protein interaction (PPI) network was constructed through the string database to obtain the key targets, and carry out molecular docking of key targets with kaempferol; In cell experiment, oleic acid induced steatosis in HepG2 cells, which was intervened by kaempferol, the level of triglyceride (TG) was detected, the lipid deposition was observed by oil red O staining, and the protein expression was detected by Western blot.

RESULTS

The results showed that there are 33 common targets for kaempferol and MAFLD. The biological process of GO is related to the regulation of protein kinase B, cell apoptosis, inflammatory factors, lipoxygenase, etc. Its action pathway is related to the phosphatidylinositol-3-kinase and protein kinase B (PI3K-AKT) signaling pathway, hypoxia-inducible factor 1 signaling pathway, forkhead box protein O signaling pathway, AMP-activated protein kinase signaling pathway, tumor necrosis factor signaling pathway, etc., the key targets are protein kinase B (AKT1), pros-taglandin G/H synthase 2, matrix metalloproteinase-9, epidermal growth factor receptor, and the molecular docking of kaempferol with the four key targets shows good binding properties. Cell experiments show that kaempferol can reduce cell TG levels, reduce lipid deposition, increase the expression of PI3K, AKT, and beclin-1, and reduce the expression of caspase-3 and nuclear factor-kappa B. Kaempferol can treat MAFLD by regulating the PI3K-AKT signaling pathway to regulate cell autophagy, apoptosis, and inflammation.

CONCLUSIONS

This study shows that kaempferol can regulate lipid metabolism, reduce apoptosis, regulate inflammation and autophagy in the fatty liver cell model. It reveals the therapeutic mechanism of kaempferol on MAFLD and provides a natural product candidate for the treatment of MAFLD.

[TSPAN8 is involved in lipid metabolism in non-alcoholic fatty liver disease in mice]

OBJECTIVE

To investigate the changes of tetraspanin 8 (TSPAN8) expression levels and its role in lipid metabolism during the development of non-alcoholic fatty liver disease (NAFLD).

METHODS

Thirty male C57BL/6J mice were randomly divided into normal diet group and high-fat diet (HFD) group (n=15), and after feeding for 1, 3, and 6 months, the expression levels of TSPAN8 in the liver tissues of the mice were detected with Western blotting. In a HepG2 cell model of NAFLD induced by free fatty acids (FFA), the effect of TSPAN8 overexpression on lipid accumulation was examined using Oil Red O staining and an automated biochemical analyzer, and the mRNA expressions of the key genes involved in lipid metabolism were detected using qRT-PCR.

RESULTS

Western blotting showed that compared with that in mice with normal feeding, the expression of TSPAN8 was significantly decreased in the liver tissues of mice with HFD feeding for 3 and 6 months (P < 0.05). In HepG2 cells, treatment with FFA significantly decreased the expression of TSPAN8 at both the mRNA and protein levels (P < 0.01). TSPAN8 overexpression in FFA-treated cells showed significantly lowered intracellular triglyceride levels (P < 0.001) and obviously reduced mRNA expression of fatty acid transport protein 5 (FATP5) (P < 0.01). The expression of FATP5 was significantly increased in FFA-treated cells as compared with the control cells (P < 0.001).

CONCLUSION

TSPAN8 is involved in lipid metabolism in NAFLD, and overexpression of TSPAN8 may inhibit cellular lipid deposition by reducing the expression of FATP5.

Bisphenol A Coupled with a High-Fat Diet Promotes Hepatosteatosis through Reactive-Oxygen-Species-Induced CD36 Overexpression

Bisphenol A (BPA) is an endocrine-disrupting chemical that affects lipid metabolism and contributes to non-alcoholic fatty liver disease (NAFLD). The mechanism of BPA exposure in hepatic lipid accumulation and its potential effect on NAFLD remain unclear. This study investigated the effect of BPA-exposure-induced hepatic lipid deposition on the pathology of NAFLD and its underlying mechanism in vitro and in vivo. BPA increased intracellular reactive oxygen species (ROS) levels, and promoted fatty acid uptake through upregulation of a free fatty acid uptake transporter, cluster of differentiation 36 (CD36), in HUH-7 cells. Additionally, C57BL/6 mice administered a high-fat/high-cholesterol/high-cholic acid diet (HFCCD) and BPA (50 mg/kg body weight) for 8 weeks developed a steatohepatitis-like phenotype, characterized by alpha-smooth muscle actin (α-SMA, an indicator of hepatic fibrosis) and cleaved caspase 3 (an indicator of apoptosis) in hepatic tissue; moreover, they had a higher oxidative stress index of 8-hydroxydeoxyguanosine (8-OHdG) in liver tissue compared to the control group. Treatment with ROS scavenger n-acetylcysteine (NAC) ameliorated BPA-mediated HFCCD-induced lipid accumulation and steatohepatitis in the livers of treated mice. Our study indicates that BPA acts synergistically to increase hepatic lipid uptake and promote NAFLD development by stimulating ROS-induced CD36 overexpression.

Mitochondria, oxidative stress and nonalcoholic fatty liver disease: A complex relationship

According to the 'multiple-hit' hypothesis, several factors can act simultaneously in nonalcoholic fatty liver disease (NAFLD) progression. Increased nitro-oxidative (nitroso-oxidative) stress may be considered one of the main contributors involved in the development and risk of NAFLD progression to nonalcoholic steatohepatitis (NASH) characterized by inflammation and fibrosis. Moreover, it has been repeatedly postulated that mitochondrial abnormalities are closely related to the development and progression of liver steatosis and NAFLD pathogenesis. However, it is difficult to determine with certainty whether mitochondrial dysfunction or oxidative stress are primary events or a simple consequence of NAFLD development. On the one hand, increasing lipid accumulation in hepatocytes could cause a wide range of effects from mild to severe mitochondrial damage with a negative impact on cell fate. This can start the cascade of events, including an increase of cellular reactive nitrogen species (RNS) and reactive oxygen species (ROS) production that promotes disease progression from simple steatosis to more severe NAFLD stages. On the other hand, progressing mitochondrial bioenergetic catastrophe and oxidative stress manifestation could be considered accompanying events in the vast spectrum of abnormalities observed during the transition from NAFL to NASH and cirrhosis. This review updates our current understanding of NAFLD pathogenesis and clarifies whether mitochondrial dysfunction and ROS/RNS are culprits or bystanders of NAFLD progression.

N-Acetylcysteine Inhibits Platelet Function through the Regeneration of the Non-Oxidative Form of Albumin

N-acetylcysteine (NAC) is able to break down protein disulfides, generating free thiols. This mechanism occurs on mixed disulfides of albumin (HSA) to form mercaptoalbumin (HMA), the main antioxidant species in the plasma. Circulating HSA exists in two main forms: the reduced form (HMA), and the oxidized forms, whose predominant modification is cystenylation (HSA-Cys). Increased levels of oxidized HSA have been detected in several diseases associated with oxidative stress. This study showed that NAC inhibits platelet aggregation by restoring HMA. In addition, the regeneration of HMA by NAC inhibits platelet functions such as intracellular calcium mobilization, reactive oxygen species generation, arachidonic acid metabolites synthesis, and adhesion to the collagen matrix. In our conditions, the exposure of platelets to NAC did not increase GSH levels. However, the inhibition of platelet aggregation was also detected following treatment of platelet-rich plasma with GSH, which, similarly to NAC, reduced HSA-Cys levels. Furthermore, this study showed that cysteine, another compound able to restore HMA by reducing the HSA-Cys content, inhibited platelet aggregation to a similar extent as NAC. The results obtained in this study suggest a new mechanism by which NAC can modulate platelet activation and suggest its possible use as an antiplatelet drug in conditions associated with oxidative stress.

Dietary and Lifestyle Inflammation Scores Are Inversely Associated with Metabolic-Associated Fatty Liver Disease among Iranian Adults: A Nested Case-Control Study

BACKGROUND

Diet and lifestyle may affect risk for metabolic-associated fatty liver disease (MAFLD) by chronically elevating systemic inflammation.

OBJECTIVES

In this study we investigated the separate and joint associations of dietary and lifestyle inflammation scores (DIS and LIS, respectively) with MAFLD risk.

METHODS

For this nested case-control study we identified and recruited 968 patients with MAFLD (defined as having a fatty liver index ≥60 plus ≥1 of the following conditions: overweight or obese, type II diabetes mellitus, evidence of metabolic dysregulation) and 964 controls from among 35-70-y-old men and women in the baseline phase of the Sabzevar Persian Cohort Study. We collected demographic, lifestyle, anthropometric, biochemical, and dietary intake information (via a validated FFQ) from which we calculated a circulating inflammation biomarker-weighted, predominantly whole foods and beverages-based, 19-component DIS and a 3-component LIS. We estimated DIS- and LIS-MAFLD associations using multivariable unconditional logistic regression. We also calculated equal-weight DIS and LIS to capture all potential mechanisms (inflammation plus other mechanisms) for associations of diet and lifestyle with MAFLD risk.

RESULTS

Among those in the highest relative to the lowest DIS and LIS tertiles, the multivariable-adjusted ORs and their 95% CIs were OR: 1.84; 95% CI: 1.61, 2.07; Ptrend < 0.001, and OR: 1.96; 95% CI: 1.69, 2.21; Ptrend < 0.001, respectively. For those in the highest relative to the lowest joint DIS and LIS tertile, the values were OR: 2.56; 95% CI: 2.19, 2.93; Pinteraction < 0.001. The findings were similar by sex. The third tertile values for the equal-weight DIS- and LIS-MAFLD associations were OR: 1.87; 95% CI: 1.41, 2.34; and OR: 2.16; 95% CI: 1.85, 2.46, respectively.

CONCLUSIONS

Our results suggest that higher balances of pro- relative to anti-inflammatory dietary and lifestyle exposures, separately and especially jointly, may be associated with higher MAFLD risk among adults. Also, inflammation may be the primary mechanism through which diet affects MAFLD risk.

NEFAs Influence the Inflammatory and Insulin Signaling Pathways Through TLR4 in Primary Calf Hepatocytes in vitro

Transition dairy cows are often in a state of negative energy balance because of decreased dry matter intake and increased energy requirements, initiating lipid mobilization and leading to high serum β-hydroxybutyrate (BHBA) and non-esterified fatty acid (NEFAs) levels, which can induce ketosis and fatty liver in dairy cows. Inflammation and insulin resistance are also common diseases in the perinatal period of dairy cows. What is the relationship between negative energy balance, insulin resistance and inflammation in dairy cows? To study the role of non-esterified fatty acids in the nuclear factor kappa beta (NF-κB) inflammatory and insulin signaling pathways through Toll-like receptor 4 (TLR4), we cultured primary calf hepatocytes and added different concentrations of NEFAs to assess the mRNA and protein levels of inflammatory and insulin signaling pathways. Our experiments indicated that NEFAs could activate the NF-κB inflammatory signaling pathway and influence insulin resistance through TLR4. However, an inhibitor of TLR4 alleviated the inhibitory effects of NEFAs on the insulin pathway. In conclusion, all of these results indicate that high-dose NEFAs (2.4 mM) can activate the TLR4/NF-κB inflammatory signaling pathway and reduce the sensitivity of the insulin pathway through the TLR4/PI3K/AKT metabolic axis.

Drug-Induced Liver Injury: Clinical Evidence of N-Acetyl Cysteine Protective Effects

Oxidative stress is a key pathological feature implicated in both acute and chronic liver diseases, including drug-induced liver injury (DILI). The latter describes hepatic injury arising as a direct toxic effect of administered drugs or their metabolites. Although still underreported, DILI remains a significant cause of liver failure, especially in developed nations. Currently, it is understood that mitochondrial-generated oxidative stress and abnormalities in phase I/II metabolism, leading to glutathione (GSH) suppression, drive the onset of DILI. N-Acetyl cysteine (NAC) has attracted a lot of interest as a therapeutic agent against DILI because of its strong antioxidant properties, especially in relation to enhancing endogenous GSH content to counteract oxidative stress. Thus, in addition to updating information on the pathophysiological mechanisms implicated in oxidative-induced hepatic injury, the current review critically discusses clinical evidence on the protective effects of NAC against DILI, including the reduction of patient mortality. Besides injury caused by paracetamol, NAC can also improve liver function in relation to other forms of liver injury such as those induced by excessive alcohol intake. The implicated therapeutic mechanisms of NAC extend from enhancing hepatic GSH levels to reducing biomarkers of paracetamol toxicity such as keratin-18 and circulating caspase-cleaved cytokeratin-18. However, there is still lack of evidence confirming the benefits of using NAC in combination with other therapies in patients with DILI.

Curcumin supplementation improves biomarkers of oxidative stress and inflammation in conditions of obesity, type 2 diabetes and NAFLD: updating the status of clinical evidence

Oxidative stress and inflammation remain the major complications implicated in the development and progression of metabolic complications, including obesity, type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD). In fact, due to their abundant antioxidant and anti-inflammatory properties, there is a general interest in understanding the therapeutic effects of some major food-derived bioactive compounds like curcumin against diverse metabolic diseases. Hence, a systematic search, through prominent online databases such as MEDLINE, Scopus, and Google Scholar was done focusing on randomized controlled trials (RCTs) reporting on the impact of curcumin supplementation in individuals with diverse metabolic complications, including obesity, T2D and NAFLD. Summarized findings suggest that curcumin supplementation can significantly reduce blood glucose and triglycerides levels, including markers of liver function like alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in patients with T2D and NAFLD. Importantly, this effect was consistent with the reduction of predominant markers of oxidative stress and inflammation, such as the levels of malonaldehyde (MDA), tumor necrosis factor-alpha (TNF-α), high sensitivity C-reactive protein (hs-CRP) and monocyte chemoattractant protein-1 (MCP-1) in these patients. Although RCTs suggest that curcumin is beneficial in ameliorating some metabolic complications, future research is still necessary to enhance its absorption and bioavailability profile, while also optimizing the most effective therapeutic doses.

Progressive Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Non-alcoholic steatohepatitis (NASH) is a chronic and progressive form of non-alcoholic fatty liver disease. Its global incidence is increasing and makes NASH an epidemic and a public health threat. Non-alcoholic fatty liver disease is associated with major morbidity and mortality, with a heavy burden on quality of life and liver transplant requirements. Due to repeated insults to the liver, patients are at risk for developing hepatocellular carcinoma. The progression of NASH was initially defined according to a two-hit model involving an initial development of steatosis, followed by a process of lipid peroxidation and inflammation. In contrast, current evidence proposes a “multi-hit” or “multi-parallel hit” model that includes multiple pathways promoting progressive fibrosis and oncogenesis. This model includes multiple cellular, genetic, immunological, metabolic, and endocrine pathways leading to hepatocellular carcinoma development, underscoring the complexity of this disease.

Contribution of oxidative stress in the mechanisms of postoperative complications and multiple organ dysfunction syndrome

BACKGROUND

The extent of the damage following surgery has been subject of study for several years. Numerous surgical complications can impact postoperative quality of life of patients and even can cause mortality. Although these complications are generally due to multifactorial mechanisms, oxidative stress plays a key pathophysiological role. Moreover, oxidative stress could be an unavoidable effect derived even from the surgical procedure itself.

METHODS

A systematic review was performed following an electronic search of Pubmed and ScienceDirect databases. Keywords such as sepsis, oxidative stress, organ dysfunction, antioxidants, outcomes in postoperative complications, among others, were used. Review articles were preferably used between the years 2015 onwards, not excluding older ones.

RESULTS

The vast majority point to the role of oxidative stress in generating greater damage and worse prognosis in postoperative patients without the necessary care and precautions, taking importance on the use of antioxidants to prevent this problem.

DISCUSSIONS

Oxidative stress represents a common final pathway related to pathological processes such as inflammation or ischemia-reperfusion, among others. The expression of greater severity of these complications can result in multiple organ dysfunction or sepsis. The aim of this study was to present an update of the role of oxidative stress on surgical postoperative complications.

Carnitine Palmitoyltransferase System: A New Target for Anti-Inflammatory and Anticancer Therapy?

Lipid metabolism involves multiple biological processes. As one of the most important lipid metabolic pathways, fatty acid oxidation (FAO) and its key rate-limiting enzyme, the carnitine palmitoyltransferase (CPT) system, regulate host immune responses and thus are of great clinical significance. The effect of the CPT system on different tissues or organs is complex: the deficiency or over-activation of CPT disrupts the immune homeostasis by causing energy metabolism disorder and inflammatory oxidative damage and therefore contributes to the development of various acute and chronic inflammatory disorders and cancer. Accordingly, agonists or antagonists targeting the CPT system may become novel approaches for the treatment of diseases. In this review, we first briefly describe the structure, distribution, and physiological action of the CPT system. We then summarize the pathophysiological role of the CPT system in chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, chronic granulomatous disease, nonalcoholic fatty liver disease, hepatic ischemia–reperfusion injury, kidney fibrosis, acute kidney injury, cardiovascular disorders, and cancer. We are also concerned with the current knowledge in either preclinical or clinical studies of various CPT activators/inhibitors for the management of diseases. These compounds range from traditional Chinese medicines to novel nanodevices. Although great efforts have been made in studying the different kinds of CPT agonists/antagonists, only a few pharmaceuticals have been applied for clinical uses. Nevertheless, research on CPT activation or inhibition highlights the pharmacological modulation of CPT-dependent FAO, especially on different CPT isoforms, as a promising anti-inflammatory/antitumor therapeutic strategy for numerous disorders.

Garcinia cambogia Ameliorates Non-Alcoholic Fatty Liver Disease by Inhibiting Oxidative Stress-Mediated Steatosis and Apoptosis through NRF2-ARE Activation

Excessive free fatty acids (FFAs) causes reactive oxygen species (ROS) generation and non-alcoholic fatty liver disease (NAFLD) development. Garcinia cambogia (G. cambogia) is used as an anti-obesity supplement, and its protective potential against NAFLD has been investigated. This study aims to present the therapeutic effects of G. cambogia on NAFLD and reveal underlying mechanisms. High-fat diet (HFD)-fed mice were administered G. cambogia for eight weeks, and steatosis, apoptosis, and biochemical parameters were examined in vivo. FFA-induced HepG2 cells were treated with G. cambogia, and lipid accumulation, apoptosis, ROS level, and signal alterations were examined. The results showed that G. cambogia inhibited HFD-induced steatosis and apoptosis and abrogated abnormalities in serum chemistry. G. cambogia increased in NRF2 nuclear expression and activated antioxidant responsive element (ARE), causing induction of antioxidant gene expression. NRF2 activation inhibited FFA-induced ROS production, which suppressed lipogenic transcription factors, C/EBPα and PPARγ. Moreover, the ability of G. cambogia to inhibit ROS production suppressed apoptosis by normalizing the Bcl-2/BAX ratio and PARP cleavage. Lastly, these therapeutic effects of G. cambogia were due to hydroxycitric acid (HCA). These findings provide new insight into the mechanism by which G. cambogia regulates NAFLD progression.

Exposure to Plasma From Non-alcoholic Fatty Liver Disease Patients Affects Hepatocyte Viability, Generates Mitochondrial Dysfunction, and Modulates Pathways Involved in Fat Accumulation and Inflammation

Changes of lipidic storage, oxidative stress and mitochondrial dysfunction may be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Although the knowledge of intracellular pathways has vastly expanded in recent years, the role and mechanisms of circulating triggering factor(s) are debated. Thus, we tested the hypothesis that factors circulating in the blood of NAFLD patients may influence processes underlying the disease. Huh7.5 cells/primary human hepatocytes were exposed to plasma from 12 NAFLD patients and 12 healthy subjects and specific assays were performed to examine viability, H₂O₂ and mitochondrial reactive oxygen species (ROS) release, mitochondrial membrane potential and triglycerides content. The involvement of NLRP3 inflammasome and of signaling related to peroxisome-proliferator-activating-ligand-receptor-γ (PPARγ), sterol-regulatory-element-binding-protein-1c (SREBP-1c), nuclear-factor-kappa-light-chain-enhancer of activated B cells (NF-kB), and NADPH oxidase 2 (NOX2) was evaluated by repeating the experiments in the presence of NLRP3 inflammasome blocker, MCC950, and through Western blot. The results obtained shown that plasma of NAFLD patients was able to reduce cell viability and mitochondrial membrane potential by about 48 and 24% (p < 0.05), and to increase H₂O₂, mitochondrial ROS, and triglycerides content by about 42, 19, and 16% (p < 0.05), respectively. An increased expression of SREBP-1c, PPARγ, NF-kB and NOX2 of about 51, 121, 63, and 46%, respectively, was observed (p < 0.05), as well. Those effects were reduced by the use of MCC950. Thus, in hepatocytes, exposure to plasma from NAFLD patients induces a NAFLD-like phenotype by interference with NLRP3-inflammasome pathways and the activation of intracellular signaling related to SREBP-1c, PPARγ, NF-kB and NOX2.

N-Acetylcysteine (NAC): Impacts on Human Health

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC's relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.

N-Acetylcysteine: A Review of Clinical Usefulness (an Old Drug with New Tricks)

OBJECTIVE

To review the clinical usefulness of N-acetylcysteine (NAC) as treatment or adjunctive therapy in a number of medical conditions. Use in Tylenol overdose, cystic fibrosis, and chronic obstructive lung disease has been well documented, but there is emerging evidence many other conditions would benefit from this safe, simple, and inexpensive intervention. Quality of Evidence. PubMed, several books, and conference proceedings were searched for articles on NAC and health conditions listed above reviewing supportive evidence. This study uses a traditional integrated review format, and clinically relevant information is assessed using the American Family Physician Evidence-Based Medicine Toolkit. A table summarizing the potential mechanisms of action for N-acetylcysteine in these conditions is presented. Main Message. N-acetylcysteine may be useful as an adjuvant in treating various medical conditions, especially chronic diseases. These conditions include polycystic ovary disease, male infertility, sleep apnea, acquired immune deficiency syndrome, influenza, parkinsonism, multiple sclerosis, peripheral neuropathy, stroke outcomes, diabetic neuropathy, Crohn's disease, ulcerative colitis, schizophrenia, bipolar illness, and obsessive compulsive disorder; it can also be useful as a chelator for heavy metals and nanoparticles. There are also a number of other conditions that may show benefit; however, the evidence is not as robust.

CONCLUSION

The use of N-acetylcysteine should be considered in a number of conditions as our population ages and levels of glutathione drop. Supplementation may contribute to reducing morbidity and mortality in some chronic conditions as outlined in the article.

Does Short-Term and Low-Dose N-Acetylcysteine Affect Oxidative Stress and Inflammation in The Liver Tissues of Diabetic Rats?

Diabetes mellitus is a serious chronic disease in which the oxidant-antioxidant balance is impaired, causing many complications, including hepatopathy. In this study, the effects of short-term and low-dose N-acetylcysteine (NAC) administration on the biochemical, proinflammatory, and oxidative stress parameters in the liver tissue of diabetic rats were investigated. Twenty-four adult male Wistar albino rats weighing approximately 250-300 g were divided into 4 groups (n = 6): Control, Streptozotosin (STZ)-induced diabetes (DM), NAC treatment (60 mg/kg), and STZ-induced diabetes treated with NAC (DM+NAC; 60 mg/kg). NAC treatment was administered intraperitoneally as a single daily dose for 7 days. At the end of the experiment (3 weeks), blood and liver samples were collected for biochemical parameter analysis. Lipid peroxidation, antioxidant parameters, and nitric oxide (NOx) levels were determined by spectrophotometric method. Tissue inflammation parameters were evaluated by ELISA. Lipid peroxidation, proinflammatory cytokines, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) values increased significantly with diabetes. NAC treatment significantly decreased serum ALT and AST levels and proinflammatory cytokines in the diabetic group. Liver glutathione (GSH) and NOx levels increased significantly in the DM+NAC group (p < 0.05). While NAC treatment reduced lipid peroxidation in the liver, it improved the inflammatory response and antioxidant status. The beneficial effect of NAC treatment may be due to its antioxidant activity and the resulting increased level of GSH. The results show that low-dose and short-term NAC treatment had a positive effect on oxidative damage and inflammation in liver tissue. NAC can be used as a potential antioxidant in diabetes to prevent hepatopathy.

N-Acetyl Cysteine Overdose Inducing Hepatic Steatosis and Systemic Inflammation in Both Propacetamol-Induced Hepatotoxic and Normal Mice

Acetaminophen (APAP) overdose induces acute liver damage and even death. The standard therapeutic dose of N-acetyl cysteine (NAC) cannot be applied to every patient, especially those with high-dose APAP poisoning. There is insufficient evidence to prove that increasing NAC dose can treat patients who failed in standard treatment. This study explores the toxicity of NAC overdose in both APAP poisoning and normal mice. Two inbred mouse strains with different sensitivities to propacetamol-induced hepatotoxicity (PIH) were treated with different NAC doses. NAC therapy decreased PIH by reducing lipid oxidation, protein nitration and inflammation, and increasing glutathione (GSH) levels and antioxidative enzyme activities. However, the therapeutic effects of NAC on PIH were dose-dependent from 125 (N125) to 275 mg/kg (N275). Elevated doses of NAC (400 and 800 mg/kg, N400 and N800) caused additional deaths in both propacetamol-treated and normal mice. N800 treatments significantly decreased hepatic GSH levels and induced inflammatory cytokines and hepatic microvesicular steatosis in both propacetamol-treated and normal mice. Furthermore, both N275 and N400 treatments decreased serum triglyceride (TG) and induced hepatic TG, whereas N800 treatment significantly increased interleukin-6, hepatic TG, and total cholesterol levels. In conclusion, NAC overdose induces hepatic and systemic inflammations and interferes with fatty acid metabolism.

Astragaloside IV Alleviates Liver Inflammation, Oxidative Stress and Apoptosis to Protect Against Experimental Non-Alcoholic Fatty Liver Disease

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is the main form of chronic liver disease in the world. Astragaloside IV (ASIV) has been tested in experimental models of different diseases. The purpose of this study was to evaluate the effect and protective mechanism of ASIV on NAFLD.

METHODS

Lipopolysaccharide (LPS)- and palmitate acid (PA)-induced RAW264.7 cells and LO2 cells were used as a NAFLD model. The mice NAFLD model was evaluated by hematoxylin-eosin staining (HE staining), and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Liver lipid metabolism was evaluated by triglyceride (TG) and total cholesterol (TC) kits and oil red O staining. Oxidative stress indicators were examined through biochemical methods. Inflammatory factors were explored through enzyme-linked immuno sorbent assay (ELISA), real-time quantitative PCR and oxidative stress indicator kits. The expression levels of 5-LO (5-lipoxygenase) and leukotriene A4 hydrolase (LTA4H) were checked by real-time quantitative PCR and Western blotting. Apoptosis was detected by Annexin V-FITC/PI cell apoptosis detection kit.

RESULTS

Our results showed that in vivo ASIV significantly reduced liver tissue damage, and serum AST, ALT and serum TG levels in NAFLD mice. In vitro, ASIV reduced cell supernatant TG and TC content increased by PA treatment, and significantly decreased the accumulation of intracellular lipid droplets induced by PA treatment. Additionally, ASIV reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and restored glutathione peroxidase (GSH-Px) levels in PA-treated LO2 cell supernatant. Furthermore, ASIV inhibited the production of proinflammatory cytokines (IL-6 and TNF-α) in RAW264.7 cells induced by LPS. We also found that ASIV downregulated the expression of 5-LO and LTB4 (leukotriene B4) in NAFLD mice. Moreover, ASIV restored apoptotic protein (Bax and Bcl-2) expression in PA-treated LO2 cells.

CONCLUSION

ASIV may reduce liver steatosis, hepatocyte oxidative stress and apoptosis, and decrease liver inflammation, thereby attenuating the progression of NAFLD and thus might be of therapeutic interest.