Role of Oxidative Stress in Pathophysiology of Nonalcoholic Fatty Liver Disease

Impact of dietary compositions and patterns on the prevalence of nonalcoholic fatty liver disease in Japanese men: a cross-sectional study

BACKGROUND

This study aimed to examine the impact of dietary compositions and patterns on nonalcoholic fatty liver disease (NAFLD) morbidity in Japanese men.

METHODS

We conducted a cross-sectional study of 281 individuals who underwent comprehensive medical examinations during health screening. Dietary intake was assessed using a semi-quantitative food frequency questionnaire, and factor analysis was performed to detect dietary patterns. NAFLD was diagnosed by the presence of fatty liver on abdominal ultrasonography in nondrinkers (< 30 g/day), and patients were categorized into control (n = 192) and NAFLD groups (n = 89).

RESULTS

Compared with the control group, the NAFLD group consumed fewer mushrooms. Three dietary patterns were identified, namely, a healthy pattern, a western pattern, and a snack pattern. The score of healthy pattern was negatively correlated with the risk of NAFLD. Compared with the lowest tertile of the healthy pattern, the middle tertile was associated with a lower risk of NAFLD after adjusting for age, physical activity, and smoking (odds ratio: 0.47, 95% confidence interval: 0.25-0.91). After further adjustments for body mass index, the middle tertile was associated with a lower risk of NAFLD (odds ratio: 0.46, 95% confidence interval: 0.23-0.92).

CONCLUSIONS

A healthy dietary pattern comprising frequent intake of seaweeds, vegetables, mushrooms, pulses, and potatoes and starches was associated with a lower risk of NAFLD in Japanese men. In our opinion, this healthy pattern closely resembles the Japanese Washoku diet, indicating that adherence to Washoku may help prevent NAFLD.

3,4-dihydroxytoluene, a metabolite of rutin, suppresses the progression of nonalcoholic fatty liver disease in mice by inhibiting p300 histone acetyltransferase activity

3,3',4',5,7-Pentahydroxyflavone-3-rhamnoglucoside (rutin) is a flavonoid with a wide range of pharmacological activities. Dietary rutin is hardly absorbed because the microflora in the large intestine metabolize rutin into a variety of compounds including quercetin and phenol derivatives such as 3,4-dihydroxyphenolacetic acid (DHPAA), 3,4-dihydroxytoluene (DHT), 3,4-hydroxyphenylacetic acid (HPAA) and homovanillic acid (HVA). We examined the potential of rutin and its metabolites as novel histone acetyltransferase (HAT) inhibitors. DHPAA, HPAA and DHT at the concentration of 25 μM significantly inhibited in vitro HAT activity with DHT having the strongest inhibitory activity. Furthermore, DHT was shown to be a highly efficient inhibitor of p300 HAT activity, which corresponded with its high degree of inhibition on intracellular lipid accumulation in HepG2 cells. Docking simulation revealed that DHT was bound to the p300 catalytic pocket, bromodomain. Drug affinity responsive target stability (DARTS) analysis further supported the possibility of direct binding between DHT and p300. In HepG2 cells, DHT concentration-dependently abrogated p300-histone binding and induced hypoacetylation of histone subunits H3K9, H3K36, H4K8 and H4K16, eventually leading to the downregulation of lipogenesis-related genes and attenuating lipid accumulation. In ob/ob mice, administration of DHT (10, 20 mg/kg, iv, every other day for 6 weeks) dose-dependently improved the NAFLD pathogenic features including body weight, liver mass, fat mass, lipid accumulation in the liver, and biochemical blood parameters, accompanied by the decreased mRNA expression of lipogenic genes in the liver. Our results demonstrate that DHT, a novel p300 histone acetyltransferase inhibitor, may be a potential preventive or therapeutic agent for NAFLD.

Ferulic acid attenuates non-alcoholic steatohepatitis by reducing oxidative stress and inflammation through inhibition of the ROCK/NF-κB signaling pathways

Ferulic acid (FA) is a natural polyphenol compound existing in many plants. The purpose of this study was to investigate the effect of FA on non-alcoholic steatohepatitis (NASH) induced by high-cholesterol and high-fat diet (HCHF) and its possible mechanism. Rats were fed HCHF for 12 weeks to establish NASH model. FA improved liver coefficients and had no effect on body weight changes. FA could reduce serum alanine transferase (ALT) and aspartate transferase (AST) activities. FA attenuated the increase of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL) levels caused by NASH, improved the liver pathological damage induced by NASH, and inhibited the progression of liver fibrosis. FA prevented the production of reactive oxygen species (ROS) and the increase of malondialdehyde (MDA) levels, and attenuated the decrease in superoxide dismutase (SOD) activity. Meanwhile, FA significantly restored the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α). In addition, we also found that FA inhibited the activity of ROCK and the activation of NF-κB signaling pathway in the liver of NASH rats. Overall, FA has a hepatoprotective anti-oxidative stress and anti-inflammatory effects in NASH rats, and its mechanism may be related to the inhibition of ROCK/NF-κB signaling pathway.

Rho-Kinase as a Therapeutic Target for Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is a major public health problem and the most common form of chronic liver disease, affecting 25% of the global population. Although NAFLD is closely linked with obesity, insulin resistance, and type 2 diabetes mellitus, knowledge on its pathogenesis remains incomplete. Emerging data have underscored the importance of Rho-kinase (Rho-associated coiled-coil-containing kinase [ROCK]) action in the maintenance of normal hepatic lipid homeostasis. In particular, pharmacological blockade of ROCK in hepatocytes or hepatic stellate cells prevents the progression of liver diseases such as NAFLD and fibrosis. Moreover, mice lacking hepatic ROCK1 are protected against obesity-induced fatty liver diseases by suppressing hepatic de novo lipogenesis. Here we review the roles of ROCK as an indispensable regulator of obesity-induced fatty liver disease and highlight the key cellular pathway governing hepatic lipid accumulation, with focus on de novo lipogenesis and its impact on therapeutic potential. Consequently, a comprehensive understanding of the metabolic milieu linking to liver dysfunction triggered by ROCK activation may help identify new targets for treating fatty liver diseases such as NAFLD.

Antioxidant activity of Hydroxytyrosol and Vitamin E reduces systemic inflammation in children with paediatric NAFLD

BACKGROUND

The rise in paediatric non-alcoholic fatty liver disease (NAFLD) is particularly alarming. We recently reported that Hydroxytyrosol (HXT) and Vitamin E (VitE) may improve oxidative stress, insulin resistance, and steatosis in children with biopsy-proven NAFLD.

AIM

Here, we investigated if HXT+VitE may reduce systemic inflammation in the above-mentioned patients.

METHODS

This study analysed the plasma levels of IL (interleukin)-6, IL-1β, IL-10, tumour necrosis factor (TNF)-α, 4‑hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2'deoxyguanosine (8-OHdG) in children enrolled in the HXT+VitE trial (ClinicalTrials.gov, NCT02842567).

RESULTS

Changes in markers of systemic inflammation were found in both placebo (Pla) and HXT+VitE. In particular, after four months, the levels of IL-1β and TNF-α were reduced in both groups, while IL-6 decreased, and IL-10 increased significantly only in the group treated with HXT+VitE. Children treated with HXT+VitE showed a significant decrease of 4-HNE and 8-OHdG that correlated with the improvement of triglyceride levels. Noticeably, only the 8-OHdG decrease correlated with steatosis amelioration and with the increase of IL-10 levels.

CONCLUSION

The treatment with HXT and VitE reduced the NAFLD-related systemic inflammation in children, mainly by an increase of IL-10 circulating levels that occurred in response to DNA damage recovery, ultimately improving steatosis and hypertriglyceridemia.

Analytical and Omics-Based Advances in the Study of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a significant clinical issue, affecting 1-1.5 million patients annually, and remains a major challenge during drug development-toxicity and safety concerns are the second-highest reason for drug candidate failure. The future prevalence of DILI can be minimized by developing a greater understanding of the biological mechanisms behind DILI. Both qualitative and quantitative analytical techniques are vital to characterizing and investigating DILI. In vitro assays are capable of characterizing specific aspects of a drug's hepatotoxic nature and multiplexed assays are capable of characterizing and scoring a drug's association with DILI. However, an even deeper insight into the perturbations to biological pathways involved in the mechanisms of DILI can be gained through the use of omics-based analytical techniques: genomics, transcriptomics, proteomics, and metabolomics. These omics analytical techniques can offer qualitative and quantitative insight into genetic susceptibilities to DILI, the impact of drug treatment on gene expression, and the effect on protein and metabolite abundance. This review will discuss the analytical techniques that can be applied to characterize and investigate the biological mechanisms of DILI and potential predictive biomarkers.

Cadmium chloride induces non-alcoholic fatty liver disease in rats by stimulating miR-34a/SIRT1/FXR/p53 axis

Cadmium (Cd) is associated with non-alcoholic fatty liver disease (NAFLD). The hepatic activation of p53/miR-43a-induced suppression of SIRT1/FXR axis plays a significant role in the development of NAFLD. In this study, we have investigated CdCl₂-induced NAFLD in rats involves activation of miR34a/SIRT1/FXR axis. Adult male rats were divided into 4 groups (n-8/each) as a control, CdCl₂ (10 mg/l), CdCl₂ + miR-34a antagomir (inhibitor), and CdCl₂ + SRT1720 (a SIRT1 activator) for 8 weeks, daily. With no effect on fasting glucose and insulin levels, CdCl₂ significantly reduced rats' final body, fat pads, and liver weights, and food intake. Concomitantly, it increased the circulatory levels of liver markers (ALT, AST, and γ-GTT), increased the serum and hepatic levels of total cholesterol and triglycerides coincided with increased hepatic lipid accumulation. Besides, it increased the mRNA and protein levels of SREBP1, SREBP2, FAS, and HMGCOA reductase but reduced mRNA levels of PPARα, CPT1, and CPT2. Interestingly, CdCl₂ also increased mRNA levels of miR34 without altering mRNA levels of SIRT1 but with a significant reduction in protein levels of SIRT1. These effects were associated with increased total protein levels of p53 and acetylated protein of p53, and FXR. Of note, suppressing miR-34a with a specific anatomic or activating SIRT1 by SRT1720 completely prevented all these effects and reduced hepatic fat accumulations in the livers of rats. In conclusion, CdCl₂ induced NAFLD by increasing the transcription of miR-34a which in turn downregulates SIRT1 at the translational level.

Peroxisomal footprint in the pathogenesis of nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a form of fatty liver disease where benign hepatic steatosis leads to chronic inflammation in the steatotic liver of a patient without any history of alcohol abuse. Mechanisms underlying the progression of hepatic steatosis to NASH have long been investigated. This review outlines the potential role of peroxisomal dysfunctions in exacerbating the disease in NASH. Loss of peroxisomes as well as impaired peroxisomal functions have been demonstrated to occur in inflammatory conditions including NASH. Because peroxisomes and mitochondria co-operatively perform many metabolic functions including O₂ and lipid metabolisms, a compromised peroxisomal biogenesis and function can potentially contribute to defective lipid and reactive oxygen species metabolism which in turn can lead the progression of disease in NASH. Impaired peroxisomal biogenesis and function may be due to the decreased expression of peroxisomal proliferator-activated receptor-α (PPAR-α), the major transcription factor of peroxisomal biogenesis. Recent studies indicate that the reduced expression of PPAR-α in NASH is correlated with the activation of the toll-like receptor-4 pathway (TLR-4). Further investigations are required to establish the mechanistic connection between the TLR-4 pathway and PPAR-α-dependent impaired biogenesis/function of peroxisomes in NASH.

microRNA profiles of serum exosomes derived from children with nonalcoholic fatty liver

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a chronic disease caused by excessive fat accumulation in the liver in addition to alcohol consumption and other pathological factors. The incidence of NAFLD is rapidly growing, currently affecting 25% of the world population. Exosomes are extracellular vesicles containing a variety of biological molecules, including microRNAs (miRNAs).

OBJECTIVE

To monitor the expression of exosomal microRNAs in the NAFLD.

METHODS

In this study, five nonalcoholic fatty liver patients were included in the disease group, and five simple obesity patients were included in the control group. Exosomes from NAFLD patient serum were collected, and exosomal miRNAs were extracted. Exosomes were isolated and then confirmed by electron microscopy, nanoparticle tracking analysis (NTA) and western blotting. High-throughput sequencing methods were used to determine the expression profile of exosome-derived miRNAs.

RESULTS

The sequencing results revealed that a total of 2588 miRNAs were identified. The expression of 80 miRNAs significantly differed between the NAFLD and control groups, including 30 upregulated and 50 downregulated miRNAs. miR-122-5p, miR-27a, and miR-335-5p may play an important role in NAFLD. Finally, GO and KEGG analyses were applied to explore the function of miRNA targets.

CONCLUSIONS

Collectively, this study identified some key exosomal miRNAs and pathways in NAFLD that might be used as molecular targets or diagnostic biomarkers for NAFLD.

Commentary: Novel strategies and new tools to curtail the health effects of pesticides

BACKGROUND

Flaws in the science supporting pesticide risk assessment and regulation stand in the way of progress in mitigating the human health impacts of pesticides. Critical problems include the scope of regulatory testing protocols, the near-total focus on pure active ingredients rather than formulated products, lack of publicly accessible information on co-formulants, excessive reliance on industry-supported studies coupled with reticence to incorporate published results in the risk assessment process, and failure to take advantage of new scientific opportunities and advances, e.g. biomonitoring and "omics" technologies.

RECOMMENDED ACTIONS

Problems in pesticide risk assessment are identified and linked to study design, data, and methodological shortcomings. Steps and strategies are presented that have potential to deepen scientific knowledge of pesticide toxicity, exposures, and risks. We propose four solutions: (1) End near-sole reliance in regulatory decision-making on industry-supported studies by supporting and relying more heavily on independent science, especially for core toxicology studies. The cost of conducting core toxicology studies at labs not affiliated with or funded directly by pesticide registrants should be covered via fees paid by manufacturers to public agencies. (2) Regulators should place more weight on mechanistic data and low-dose studies within the range of contemporary exposures. (3) Regulators, public health agencies, and funders should increase the share of exposure-assessment resources that produce direct measures of concentrations in bodily fluids and tissues. Human biomonitoring is vital in order to quickly identify rising exposures among vulnerable populations including applicators, pregnant women, and children. (4) Scientific tools across disciplines can accelerate progress in risk assessments if integrated more effectively. New genetic and metabolomic markers of adverse health impacts and heritable epigenetic impacts are emerging and should be included more routinely in risk assessment to effectively prevent disease.

CONCLUSIONS

Preventing adverse public health outcomes triggered or made worse by exposure to pesticides will require changes in policy and risk assessment procedures, more science free of industry influence, and innovative strategies that blend traditional methods with new tools and mechanistic insights.

Intervention by picroside II on FFAs induced lipid accumulation and lipotoxicity in HepG2 cells

Background

Accumulation of free fatty acids (FFAs) in hepatocytes is a hallmark of liver dysfunction and non-alcoholic fatty liver disease (NAFLD). Excessive deposition of FFAs alters lipid metabolism pathways increasing the oxidative stress and mitochondrial dysfunction. Attenuating hepatic lipid accumulation, oxidative stress, and improving mitochondrial function could provide potential targets in preventing progression of non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH). Earlier studies with Picrorhiza kurroa extract have shown reduction in hepatic damage and fatty acid infiltration in several experimental models and also clinically in viral hepatitis. Thus, the effect of P. kurroa's phytoactive, picroside II, needed mechanistic investigation in appropriate in vitro liver cell model.

Objective(s)

To study the effect of picroside II on FFAs accumulation, oxidative stress and mitochondrial function with silibinin as a positive control in in vitro NAFLD model.

Materials and methods

HepG2 cells were incubated with FFAs-1000μM in presence and absence of Picroside II-10 μM for 20 hours.

Results

HepG2 cells incubated with FFAs-1000μM lead to increased lipid accumulation. Picroside II-10μM attenuated FFAs-induced lipid accumulation (33%), loss of mitochondrial membrane potential (ΔΨm), ATP depletion, and production of reactive oxygen species (ROS). A concomitant increase in cytochrome C at transcription and protein levels was observed. An increase in expression of MnSOD, catalase, and higher levels of tGSH and GSH:GSSG ratios underlie the ROS salvaging activity of picroside II.

Conclusion

Picroside II significantly attenuated FFAs-induced-lipotoxicity. The reduction in ROS, increased antioxidant enzymes, and improvement in mitochondrial function underlie the mechanisms of action of picroside II. These findings suggest a need to develop an investigational drug profile of picroside II for NAFLD as a therapeutic strategy. This could be evaluated through the fast-track path of reverse pharmacology.

PPARs as Metabolic Sensors and Therapeutic Targets in Liver Diseases

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs’ critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.

Regulation of hepatic fibrosis by carcinoembryonic antigen-related cell adhesion molecule 1

OBJECTIVE

NAFLD is a complex disease marked by cellular abnormalities leading to NASH. NAFLD patients manifest low hepatic levels of CEACAM1, a promoter of insulin clearance. Consistently, Cc1^-/- null mice displayed spontaneous hyperinsulinemia/insulin resistance and steatohepatitis. Liver-specific reconstitution of Ceacam1 reversed these metabolic anomalies in 8-month-old Cc1^-/-xliver+ mice fed a regular chow diet. The current study examined whether it would also reverse progressive hepatic fibrosis in mice fed a high-fat (HF) diet.

METHODS

3-Month-old mice were fed a high-fat diet for 3-5 months, and metabolic and histopathological analysis were conducted to evaluate their NASH phenotype.

RESULTS

Reconstituting CEACAM1 to Cc1^-/- livers curbed diet-induced liver dysfunction and NASH, including macrovesicular steatosis, lobular inflammation, apoptosis, oxidative stress, and chicken-wire bridging fibrosis. Persistence of hepatic fibrosis in HF-fed Cc1^-/- treated with nicotinic acid demonstrated a limited role for lipolysis and adipokine release in hepatic fibrosis caused by Ceacam1 deletion.

CONCLUSIONS

Restored metabolic and histopathological phenotype of HF-fed Cc1^{-/-xliver+xliver+} assigned a critical role for hepatic CEACAM1 in preventing NAFLD/NASH including progressive hepatic fibrosis.

Neutral sphingomyelinase-2 and cardiometabolic diseases

Sphingolipids, in particular ceramides, play vital role in pathophysiological processes linked to metabolic syndrome, with implications in the development of insulin resistance, pancreatic ß-cell dysfunction, type 2 diabetes, atherosclerosis, inflammation, nonalcoholic steatohepatitis, and cancer. Ceramides are produced by the hydrolysis of sphingomyelin, catalyzed by different sphingomyelinases, including neutral sphingomyelinase 2 (nSMase2), whose dysregulation appears to underlie many of the inflammation-related pathologies. In this review, we discuss the current knowledge on the biochemistry of nSMase2 and ceramide production and its regulation by inflammatory cytokines, with particular reference to cardiometabolic diseases. nSMase2 contribution to pathogenic processes appears to involve cyclical feed-forward interaction with proinflammatory cytokines, such as TNF-α and IL-1ß, which activate nSMase2 and the production of ceramides, that in turn triggers the synthesis and release of inflammatory cytokines. We elaborate these pathogenic interactions at the molecular level and discuss the potential therapeutic benefits of inhibiting nSMase2 against inflammation-driven cardiometabolic diseases.

Diagnostic Accuracy of FIB-4 and FIB-5 Scores as Compared to Fibroscan for Assessment of Liver Fibrosis in Patients With Non-Alcoholic Fatty Liver Disease

Introduction Limited access/exorbitant cost of fibroscan and the associated risks with biopsy to assess fibrosis in non-alcoholic fatty liver disease (NAFLD) patients has made exigent demand of serum-based fibrosis scores to be validated for their accuracy and efficacy. The objective of the study was to compare the accuracy of FIB-4 (fibrosis-4) and FIB-5 (fibrofast) scores to rule out advanced fibrosis in NAFLD patients. Methods A total of 145 patients were categorized as group I with mild/moderate fibrosis (MF) comprising of F0 to F2 and group II with advanced fibrosis (AF) comprising of F3 and F4 based on fibroscan kPa (kilopascal) score. Results Group II had significantly higher alanine transaminase (ALT), aspartate transaminase (AST), haemoglobin % (Hb %), bilirubin and alkaline phosphatase (ALP) values and significantly lower platelet count and albumin as compared to group I. The FIB-4 score was significantly higher in group II [1.8 (1.1 - 4.7)], as compared with group I [0.98 (0.63 - 1.67)], p-value = 0.0001. FIB-5 score of group II [-6.4 (-8.8 - 3.4)] was significantly lower as compared with group I [-4.8 (-6.8 - 2.0)], p-value = 0.003. FIB-4 and FIB-5 had area under receiver operator characteristic (AUROC) curve of 0.712 and 0.655, respectively. FIB-4 at cut-off of <2.02 had a negative predictive value (NPV) of 90.7%. FIB-5 at a cut-off of <-7.11 has an NPV of 94.1% and at a cut-off of <-3.24 had an NPV of 88.9%. Conclusion We concluded that both FIB-4 and FIB-5 can be used to rule out advanced fibrosis in NAFLD patients in a resource-limited and indigent setting as both the scores have NPV greater than 90%.

Oxidative stress in obesity-associated hepatocellular carcinoma: sources, signaling and therapeutic challenges

Obesity affects more than 650 million individuals worldwide and is a well-established risk factor for the development of hepatocellular carcinoma (HCC). Oxidative stress can be considered as a bona fide tumor promoter, contributing to the initiation and progression of liver cancer. Indeed, one of the key events involved in HCC progression is excessive levels of reactive oxygen species (ROS) resulting from the fatty acid influx and chronic inflammation. This review provides insights into the different intracellular sources of obesity-induced ROS and molecular mechanisms responsible for hepatic tumorigenesis. In addition, we highlight recent findings pointing to the role of the dysregulated activity of BCL-2 proteins and protein tyrosine phosphatases (PTPs) in the generation of hepatic oxidative stress and ROS-mediated dysfunctional signaling, respectively. Finally, we discuss the potential and challenges of novel nanotechnology strategies to prevent ROS formation in obesity-associated HCC.

Zonisamide Therapy Reduces Metabolic Consequences and Diminishes Nonalcoholic Fatty Liver Disease in Patients with Epilepsy

Antiepileptic drugs that can reduce aberrant metabolism are beneficial for patients. Zonisamide (ZNS) is a chemical with antiepileptic and antioxidant activities. Here, we evaluate the efficacy of ZNS therapy on reducing obesity and decreasing risks of vascular diseases and hepatic steatosis. Clinical and metabolic indicators including body weight, body mass index (BMI), serum lipid profiles, glycated hemoglobin (HbA1c), homocysteine, and an inflammatory marker, high-sensitivity C-reactive protein (hs-CRP), were assessed at baseline and at the end of 12 and 24 weeks of treatment. Nonalcoholic fatty liver disease was evaluated using the hepatic steatosis index (HSI). A body weight reduction of ≥5% was observed in 24.6% and 32.8% of patients after 12 and 24 weeks of ZNS treatment, respectively. After adjusting for age, sex, time, and the corresponding dependent variable at baseline, the generalized estimating equation analysis revealed that the body weight, BMI, serum levels of HbA1c, triglycerides, hs-CRP, and the index for HSI were significantly declined. These results suggest that ZNS provides benefits in patients with obesity and metabolic syndrome at high vascular risk.

CYP2E1 in Alcoholic and Non-Alcoholic Liver Injury. Roles of ROS, Reactive Intermediates and Lipid Overload

CYP2E1 is one of the fifty-seven cytochrome P450 genes in the human genome and is highly conserved. CYP2E1 is a unique P450 enzyme because its heme iron is constitutively in the high spin state, allowing direct reduction of, e.g., dioxygen, causing the formation of a variety of reactive oxygen species and reduction of xenobiotics to toxic products. The CYP2E1 enzyme has been the focus of scientific interest due to (i) its important endogenous function in liver homeostasis, (ii) its ability to activate procarcinogens and to convert certain drugs, e.g., paracetamol and anesthetics, to cytotoxic end products, (iii) its unique ability to effectively reduce dioxygen to radical species causing liver injury, (iv) its capability to reduce compounds, often generating radical intermediates of direct toxic or indirect immunotoxic properties and (v) its contribution to the development of alcoholic liver disease, steatosis and NASH. In this overview, we present the discovery of the enzyme and studies in humans, 3D liver systems and genetically modified mice to disclose its function and clinical relevance. Induction of the CYP2E1 enzyme either by alcohol or high-fat diet leads to increased severity of liver pathology and likelihood to develop ALD and NASH, with subsequent influence on the occurrence of hepatocellular cancer. Thus, fat-dependent induction of the enzyme might provide a link between steatosis and fibrosis in the liver. We conclude that CYP2E1 has many important physiological functions and is a key enzyme for hepatic carcinogenesis, drug toxicity and liver disease.

Dimethyl fumarate reduces oxidative stress, inflammation and fat deposition by modulation of Nrf2, SREBP-1c and NF-κB signaling in HFD fed mice

Nonalcoholic fatty liver disease (NAFLD) occurs due to lipid metabolic disorders, which is associated with hepatic oxidative stress and inflammation. There is no definitive drug treatment for this disease. Accordingly, the present study aimed to evaluate the effects of dimethyl fumarate (DMF) as one of the superior effective drugs that induces a transcription factor of nuclear factor erythroid 2-related factor 2 (Nrf2) on development of NAFLD in mice. The metabolic disturbance in High-fat diet (HFD)-treated animals was associated with hyperlipidemia, increased activity levels of hepatic enzymes in serum, hyperglycemia, hyperinsulinemia, oxidative stress and inflammation. DMF supplementation had anti-inflammatory, antioxidant, anti-lipogenic and molecular compatibility effects induced by HFD in mice. In comparison to the HFD group, the DMF therapy could significantly suppress the sterol regulatory element binding protein-1 c (SREBP-1c) gene and protein levels, as well as upregulate the Nrf2 gene and protein levels. Additionally, the anti-inflammatory activity was observed for the DMF by inhibiting the nuclear factor kappa B (NF-κB) level. DMF reduces the development of NAFLD induced by HFD in mice through the modulation of transcription factors Nrf2, SREBP-1c and NF-κB. Thus, DMF can be considered as an effective candidate in the treatment of human NAFLD.

Corrigendum to "Role of Oxidative Stress in Pathophysiology of Nonalcoholic Fatty Liver Disease"

[This corrects the article DOI: 10.1155/2018/9547613.].

Antioxidant and Antisteatotic Activities of Fucoidan Fractions from Marine and Terrestrial Sources

Fucoidan is a fucose-rich sulfated polysaccharide typically found in the cell wall of marine algae but also recently isolated from terrestrial sources. Due to a variety of biological activities, including antioxidant properties, fucoidan exhibits an attractive therapeutic potential against a wide array of metabolic diseases associated with oxidative stress. We used FTIR, 1H NMR and 13C NMR spectroscopy to investigate the structural features of a fucoidan fraction extracted from the brown alga Cystoseira compressa (CYS). The antioxidant potential of CYS was measured by DPPH, ABTS and FRAP assays, which revealed a radical scavenging capacity that was confirmed in in vitro cellular models of hepatic and endothelial cells. The same antioxidant effects were observed for another fucoidan fraction previously identified in the terrestrial tree Eucalyptus globulus (EUC). Moreover, in hepatic cells, CYS and EUC exhibited a significant antisteatotic action, being able to reduce intracellular triglyceride content through the regulation of key genes of hepatic lipid metabolism. EUC exerted stronger antioxidant and antisteatotic effects as compared to CYS, suggesting that both marine and terrestrial sources should be considered for fucoidan extraction and therapeutic applications.

Mitochondria Matter: Systemic Aspects of Nonalcoholic Fatty Liver Disease (NAFLD) and Diagnostic Assessment of Liver Function by Stable Isotope Dynamic Breath Tests

The liver plays a key role in systemic metabolic processes, which include detoxification, synthesis, storage, and export of carbohydrates, lipids, and proteins. The raising trends of obesity and metabolic disorders worldwide is often associated with the nonalcoholic fatty liver disease (NAFLD), which has become the most frequent type of chronic liver disorder with risk of progression to cirrhosis and hepatocellular carcinoma. Liver mitochondria play a key role in degrading the pathways of carbohydrates, proteins, lipids, and xenobiotics, and to provide energy for the body cells. The morphological and functional integrity of mitochondria guarantee the proper functioning of β-oxidation of free fatty acids and of the tricarboxylic acid cycle. Evaluation of the liver in clinical medicine needs to be accurate in NAFLD patients and includes history, physical exam, imaging, and laboratory assays. Evaluation of mitochondrial function in chronic liver disease and NAFLD is now possible by novel diagnostic tools. "Dynamic" liver function tests include the breath test (BT) based on the use of substrates marked with the non-radioactive, naturally occurring stable isotope 13C. Hepatocellular metabolization of the substrate will generate 13CO2, which is excreted in breath and measured by mass spectrometry or infrared spectroscopy. Breath levels of 13CO2 are biomarkers of specific metabolic processes occurring in the hepatocyte cytosol, microsomes, and mitochondria. 13C-BTs explore distinct chronic liver diseases including simple liver steatosis, non-alcoholic steatohepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug, and alcohol effects. In NAFLD, 13C-BT use substrates such as α-ketoisocaproic acid, methionine, and octanoic acid to assess mitochondrial oxidation capacity which can be impaired at an early stage of disease. 13C-BTs represent an indirect, cost-effective, and easy method to evaluate dynamic liver function. Further applications are expected in clinical medicine. In this review, we discuss the involvement of liver mitochondria in the progression of NAFLD, together with the role of 13C-BT in assessing mitochondrial function and its potential use in the prevention and management of NAFLD.

Supplementation of cumin seed powder prevents oxidative stress, hyperlipidemia and non-alcoholic fatty liver in high fat diet fed rats

The present investigation was an attempt to evaluate the hypoglycemic, lipid-lowering, antioxidant and hepatoprotective effects of cumin (Cuminum cyminum family: Apiaceae) supplementation in high fat (HF) diet fed rats. Male Wistar rats were divided into four groups, such as control, control+ cumin, HF and HF+ cumin. Oral glucose tolerance test, plasma lipids, oxidative stress parameters, antioxidant enzymes activities, and liver dysfunction marker enzyme activities were evaluated. Additionally, histological staining of liver tissue was performed to evaluate the inflammatory cells infiltration, iron deposition and fibrosis. The current investigation demonstrated that 1% (w/w) supplementation of cumin powder significantly reduced HF diet-induced glucose intolerance, epididymal and mesenteric fat wet weights and lipid parameters like triglycerides, total cholesterol and low-density lipoproteins. Oxidative stress-related biomarkers including thiobarbituric acid reactive substances (TBARS), nitric oxide (NO) and advanced oxidation protein product (APOP) were also reduced by cumin supplementation. Moreover, HF-diet increased the activity of hepatic biomarker enzymes such as alanine transaminase (ALT) and alkaline phosphatase (ALP) activities which were significantly reduced by cumin powder supplementation. On the other hand, cumin powder supplementation was able to restore the reduced glutathione level with parallel augmentation of the antioxidant enzymes activities such as superoxide dismutase (SOD) and catalase in liver of HF diet-fed rats. Additionally, histological assessments confirmed that cumin powder supplementation also normalized the fat droplet deposition and inflammatory cells infiltration in the liver of HF diet-fed rats. This study suggests that cumin powder supplementation ameliorates dyslipidemia, oxidative stress and hepatic damage in HF diet-fed rats.

Caveolin-1 Alleviates Acetaminophen-Induced Fat Accumulation in Non-Alcoholic Fatty Liver Disease by Enhancing Hepatic Antioxidant Ability via Activating AMPK Pathway

Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for acute liver injury caused by overuse of acetaminophen (APAP). Caveolin-1 (CAV1), a regulator of hepatic energy metabolism and oxidative stress, was found to have a protective effect against NAFLD in our previous study. However, it remains unclear whether CAV1 has a protective effect against APAP-induced hepatotoxicity in NAFLD. The aim of this study was to determine whether CAV1 inhibits oxidative stress through the AMPK/Nrf2/HO-1 pathway to protect the liver from fat accumulation exacerbated by APAP in NAFLD. In this study, seven-week-old C57BL/6 male mice (18–20 g) were raised under similar conditions for in vivo experiment. In vitro, L02 cells were treated with A/O (alcohol and oleic acid mixture) for 48 h, and APAP was added at 24 h for further incubation. The results showed that the protein expression of the AMPK/Nrf2 pathway was enhanced after CAV1 upregulation. The effects of CAV1 on fat accumulation, ROS, and the AMPK/Nrf2 anti-oxidative pathway were reduced after the application of CAV1-siRNA. Finally, treatment with compound C (an AMPK inhibitor) prevented CAV1 plasmid-mediated alleviation of oxidative stress and fat accumulation and reduced the protein level of Nrf2 in the nucleus, demonstrating that the AMPK/Nrf2/HO-1 pathway was involved in the protective effect of CAV1. These results indicate that CAV1 exerted a protective effect against APAP-aggravated lipid deposition and hepatic injury in NAFLD by inhibiting oxidative stress. Therefore, the upregulation of CAV1 might have clinical benefits in reducing APAP-aggravated hepatotoxicity in NAFLD.

Green Tea and Epigallocatechin Gallate (EGCG) for the Management of Nonalcoholic Fatty Liver Diseases (NAFLD): Insights into the Role of Oxidative Stress and Antioxidant Mechanism

Nonalcoholic fatty liver diseases (NAFLD) represent a set of liver disorders progressing from steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma, which induce huge burden to human health. Many pathophysiological factors are considered to influence NAFLD in a parallel pattern, involving insulin resistance, oxidative stress, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory cascades, fibrogenic reaction, etc. However, the underlying mechanisms, including those that induce NAFLD development, have not been fully understood. Specifically, oxidative stress, mainly mediated by excessive accumulation of reactive oxygen species, has participated in the multiple NAFLD-related signaling by serving as an accelerator. Ameliorating oxidative stress and maintaining redox homeostasis may be a promising approach for the management of NAFLD. Green tea is one of the most important dietary resources of natural antioxidants, above which epigallocatechin gallate (EGCG) notably contributes to its antioxidative action. Accumulative evidence from randomized clinical trials, systematic reviews, and meta-analysis has revealed the beneficial functions of green tea and EGCG in preventing and managing NAFLD, with acceptable safety in the patients. Abundant animal and cellular studies have demonstrated that green tea and EGCG may protect against NAFLD initiation and development by alleviating oxidative stress and the related metabolism dysfunction, inflammation, fibrosis, and tumorigenesis. The targeted signaling pathways may include, but are not limited to, NRF2, AMPK, SIRT1, NF-κB, TLR4/MYD88, TGF-β/SMAD, and PI3K/Akt/FoxO1, etc. In this review, we thoroughly discuss the oxidative stress-related mechanisms involved in NAFLD development, as well as summarize the protective effects and underlying mechanisms of green tea and EGCG against NAFLD.

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.

Links between metabolic syndrome and metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a chronic condition characterized by hepatic fat accumulation combined with underlying metabolic dysregulation. Having evolved from the previous term of nonalcoholic fatty liver disease (NAFLD), the term MAFLD more closely implicates the presence of overweight/obesity, type 2 diabetes, or metabolic dysregulation as essential pathogenic factors, leading to better identification of individuals with this metabolic liver disease. Low-grade inflammation, increased oxidative stress, mitochondrial dysfunction, and intestinal dysbiosis are also involved in its pathogenesis. MAFLD is not only associated with liver-related complications, but also with adverse cardiometabolic outcomes. Further studies are needed to assess whether the newly proposed definition of MAFLD is more accurate than the NAFLD in predicting the adverse liver-related and extrahepatic outcomes.

Alleviative effects of total flavones of Glycyrrhiza uralensis Fisch on oxidative stress and lipid metabolism disorder induced by high-fat diet in intestines of Tilapia (Oreochromis niloticus)

Total flavones of Glycyrrhiza uralensis Fisch (GTF) are main components of Glycyrrhiza uralensis Fisch, which have anti-oxidation and lipid-lowering effects. However, its protective effects on the intestinal tissue of tilapia (Oreochromis niloticus) are unknown. The aims of the study were to evaluate the protective effects of GTF on the intestinal tissue of tilapia after high-fat diet (HFD) feeding. Tilapia (initial weight 30 ± 1 g) received diets containing four doses of GTF (0.05, 0.1, 0.5, and 1.0 g/kg diet) for 90 days. The intestinal tissues were collected to determine biochemical parameter, gene expression and protein level. The results showed that the HFD reduced antioxidant indexes and increased the fat level, lipid oxidation products in the intestinal tissue relative to the control. Adding GTF to the HFD resulted in an increase of antioxidant indexes, fat level and lipid oxidation products decreased after 60, 90 days. In the HFD group, mRNA level of fatty acid transport protein 1 (FATP1) was increased at 60 day and then decreased at 90 day. The mRNA levels of fatty acid binding protein 1 (FABP1) and sterol regulatory element binding protein 1c (SREBP 1c) were significantly increased at 60 or 90 day after HFD feeding. The mRNA levels of acetate coenzyme A carboxylase (ACCA) peroxisome proliferator-activated receptor γ (PPAR-γ) and PPAR-α were decreased significantly at 30, 60 and/or 90 days after HFD feeding. Western blotting results also showed that nuclear factor (NF)-κβ C-Rel (NF-κβ C-Rel) and mitogen-activated protein kinase 8 (MAPK8) protein expression in intestinal tissue increased after consumption of the HFD. However, adding GTF to the HFD reversed the changes of genes related to fatty acid synthesis and metabolism, and the level of NF-κβ c-Rel and MAPK8 at different degrees. Overall, these results indicated that GTF promoted decomposition and metabolism of fatty acids in intestinal tissue, alleviated oxidative stress damage caused by the HFD, and had certain protective effects on the intestinal tissue of tilapia.

Exploring the Changes of Peroxisomal Polarity in the Liver of Mice with Nonalcoholic Fatty Liver Disease

Peroxisome proliferator-activated receptor alpha (PPAR-a) is a crucial nuclear transcription regulator of lipid metabolism, which is closely associated with the initiation and development of nonalcoholic fatty liver disease (NAFLD). Because PPAR-a can directly decide the level of peroxisomal metabolic enzymes, its changes might directly cause variations in peroxisomal polarity. Therefore, we developed a new two-photon fluorescence imaging probe, PX-P, in which the triphenylamine and cyanide moieties can real-time sense peroxisomal polarity changes. Using PX-P, we observed a prominent decrease in the peroxisomal polarity in the liver of mice with NAFLD for the first time. More importantly, we discovered that intracellular excessive peroxynitrite (ONOO^-) and hydrogen peroxide (H₂O₂) underwent nitrification and oxidation, respectively, with various sites of PPAR-a. Interestingly, the key site of PPAR-a was nitrated by a low concentration of ONOO^- rather than being oxidized by the high level of H₂O₂. These drastically reduced the activity of PPAR-a, accelerating the occurrence of NAFLD. Moreover, through activating PPARs with pioglitazone, peroxisomal polarity markedly increased compared with that of NAFLD. Altogether, our work presents a new approach for the early diagnosis of NAFLD and identifies potential therapeutic targets.

β-patchoulene protects against non-alcoholic steatohepatitis via interrupting the vicious circle among oxidative stress, histanoxia and lipid accumulation in rats

Non-alcoholic steatohepatitis (NASH), an extreme progressive subtype of metabolic associated fatty liver disease, is well characterized by hepatic steatosis, injury and inflammation. It causes irreversible hepatic damage and there are no approved interventions for it. β-PAE, a representatively pharmacological active substance isolated from Pogostemon cablin, has been indicated to alleviate hepatic steatosis and injury through modulating lipid metabolism in rats with simple steatosis. However, its protection against NASH remains unclear. Here, this study explored the potential effect of β-PAE against high-fat diet-induced NASH in rats. The results displayed that β-PAE significantly reduced the gains of body weight and epididymal adipose tissue, liver index and attenuated liver histological damages in NASH rats. It also markedly alleviated hepatic inflammation by inhibiting NLRP3 inflammasome activation. In NASH, the active NLRP3 inflammasome is caused by hepatic lipid abnormal accumulation-induced oxidative stress. Excessive oxidative stress results in hepatic histanoxia, which exacerbates lipid metabolism disorders by elevating CD36 to suppress AMPK signalling pathways. Moreover, the lipid accumulation led by lipid metabolism dysfunction intensifies oxidative stress. A vicious circle is formed among oxidative stress, histanoxia and lipid accumulation, eventually, but β-PAE effectively interrupted it. Interestingly, soluble CD36 (sCD36) was tightly associated not only with hepatic steatosis and injury but also with inflammation. Collectively, β-PAE exerted a positive effect against NASH by interrupting the vicious circle among oxidative stress, histanoxia and lipid accumulation, and sCD36 may be a promising non-invasive tool for NASH diagnosis.

Buchholzia coriacea seed (wonderful kolanut) alleviates insulin resistance, steatosis, inflammation and oxidative stress in high fat diet model of fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a hepatic condition with multiple pathological features and it currently has no specific treatment or approved drug. Wonderful kolanut widely consumed fresh or cooked has been applied in the treatment of numerous diseases in folk medicine. In this study, we evaluate the therapeutic potentials of hydroethanolic extract of defatted Buccholzia coriacea seeds (HEBCS) in NAFLD model. HEBCS was subjected to liquid chromatography - mass spectrometry, and 30 male BALB/c mice (28 ± 2 g) were allocated to three (3) experimental groups (n = 10/group). Mice in group I were fed chow diet (CD); those in group II, high fat diet (HFD) and group III, HFD and 250 mg/kg HEBCS p.o. daily for six weeks. HEBCS alleviates HFD-induced insulin resistance and high plasma insulin and glucose levels. It further alleviates hepatic steatosis, and alters plasma lipid profile. HEBCS also protected against HFD-induced inflammation, oxidative stress and hepatocellular damage. In conclusion, HEBCS alleviated NAFLD in mice via suppression of insulin resistance, hyperlipidemia, inflammation and oxidative stress. PRACTICAL APPLICATIONS: Bioactive polyphenols and alkaloids were identified in hydroethanolic extract of defatted Buccholzia coriacea seeds (HEBCS). This study projects HEBCS as a potential therapeutic agent in the treatment of NAFLD. NAFLD is a multi-factorial condition and therefore, HEBCS is promising considering its multiple-target actions in the current model of NAFLD. HEBCS alleviates insulin resistance, metabolic dysfunction, steatosis, and inflammation in this model. There is a need to further investigate HEBCS in other models of NAFLD as a lead to future use in clinical studies.

Association of hepatic steatosis derived from ultrasound and quantitative MRI with prediabetes in the general population

The aim of our study was to investigate the association of hepatic steatosis derived from quantitative ultrasound and magnetic resonance imaging (MRI) with prediabetes in a large population-based study conducted in Northeast Germany. Hepatic steatosis was assessed through transabdominal ultrasound and quantitative MRI. For analysis we included 1622 subjects with MRI who participated in an oral glucose tolerance test and reported no known type 2 diabetes mellitus (T2DM). We classified participants as proposed by the American Diabetes Association: isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), combined IFG and IGT (IFG + IGT), and undiagnosed T2DM. Regression models were adjusted for age, sex body mass index and alcohol consumption. We observed positive associations of hepatic steatosis with glycated hemoglobin, fasting glucose and insulin, 2-h glucose and insulin, as well as homeostasis model assessment-insulin resistance index. Similarly, individuals having hepatic steatosis as defined by MRI had a higher relative risk ratio (RR) to be in the prediabetes groups i-IFG (RR = 1.6; 95% confidence interval (CI) 1.2; 2.2), i-IGT (RR = 3.3, 95% CI 2.0; 5.6) and IFG + IGT (RR = 2.5, 95% CI 1.6; 3.9) or to have undiagnosed T2DM (RR = 4.8, 95% CI 2.6; 9.0). All associations were attenuated when defining hepatic steatosis by ultrasound. Hepatic steatosis is associated with prediabetes and undiagnosed T2DM in the general population. Quantitative liver MRI revealed stronger associations with prediabetes and undiagnosed T2DM compared to ultrasound, which indicates the higher sensitivity and specificity of MRI to determine hepatic steatosis.

Ethyl Acetate Fraction of Amomum villosum var. xanthioides Attenuates Hepatic Endoplasmic Reticulum Stress-Induced Non-Alcoholic Steatohepatitis via Improvement of Antioxidant Capacities

Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH), affects 25% of the global population. Despite the prevalence of NAFLD worldwide, effective therapeutics are currently lacking. Amomum villosum var. xanthioides (Wall. ex Baker) T.L.Wu & S.J.Chen (AX) is a medicinal herb traditionally used for treating digestive tract disorders in countries across Asia. We aimed to examine the pharmacological effects of the ethyl acetate fraction of AX (AXEF) against tunicamycin (TM)-induced ER stress in a NASH mouse model using C57/BL6J male mice. Following TM injections (2 mg/kg), the mice were orally administrated AXEF (12.5, 25, or 50 mg/kg), silymarin (50 mg/kg), or distilled water daily for 5 days, and the outcomes for fatty liver, inflammation, and oxidative stress were measured in serum or liver tissue levels. AXEF drastically attenuated hepatic ER stress-induced NASH as indicated by decreases in lipid droplet accumulations, serum liver enzymes, hepatic inflammations, and cell death signals in the hepatic tissue and/or serum levels. Interestingly, AXEF showed potent antioxidant effects by quenching reactive oxidative stress and its final product lipid peroxide in the hepatic tissue, specifically an increase in metallothionein (MT). To confirm the underlying actions of AXEF, we observed that AXEF increases MT1 gene promoter activities in the physiological levels. Collectively, AXEF showed antioxidant properties on TM-induced ER stress in a NASH mice model through the improvement of MTs.

Enzyme-Treated Zizania latifolia Extract Protects against Alcohol-Induced Liver Injury by Regulating the NRF2 Pathway

Binge drinking patterns easily produce a state of oxidative stress that disturbs liver function. Eventually, this leads to alcoholic liver disease. A safe and effective therapy for alcoholic liver disease remains elusive. Enzyme-treated Z. latifolia extract (ETZL) was studied as a potential agent for treating alcohol-induced liver disease. In addition, its underlying mechanisms were elucidated. In the binge model, ETZL was pretreated with alcohol (5 g/kg) three times at 12-h intervals. Our results showed that ETZL pretreatment decreased the serum levels of ALT, AST, ALP, and TG. ETZL treatment appeared to prevent an increase in hepatic TG and MDA levels, and there was a decrease in total GSH following alcohol treatment. Histopathological examination showed that lipid droplets were significantly reduced in the ETZL group compared to the control group. ETZL also exhibited radical scavenging activity. It significantly reduced t-BHP-induced cytotoxicity and the production of reactive oxygen species (ROS) in HepG2 cells. ETZL also enhanced NRF2 nuclear translocation and increased expression of the downstream target genes HO-1, NQO1, and GCLC as an antioxidant defense. Finally, ETZL treatment significantly reduced cell death. Our study suggests that ETZL ameliorates binge ethanol-induced liver injury by upregulating the antioxidant defense mechanism.

Diet-Regulating Microbiota and Host Immune System in Liver Disease

The gut microbiota has been known to modulate the immune responses in chronic liver diseases. Recent evidence suggests that effects of dietary foods on health care and human diseases are related to both the immune reaction and the microbiome. The gut-microbiome and intestinal immune system play a central role in the control of bacterial translocation-induced liver disease. Dysbiosis, small intestinal bacterial overgrowth, translocation, endotoxemia, and the direct effects of metabolites are the main events in the gut-liver axis, and immune responses act on every pathways of chronic liver disease. Microbiome-derived metabolites or bacteria themselves regulate immune cell functions such as recognition or activation of receptors, the control of gene expression by epigenetic change, activation of immune cells, and the integration of cellular metabolism. Here, we reviewed recent reports about the immunologic role of gut microbiotas in liver disease, highlighting the role of diet in chronic liver disease.

Lipoic Acid Exacerbates Oxidative Stress and Lipid Accumulation in the Liver of Wistar Rats Fed a Hypercaloric Choline-Deficient Diet

Non-alcoholic fatty liver disease (NAFLD) is currently estimated as the most prevalent chronic liver disease in all age groups. An increasing body of evidence obtained in experimental and clinical data indicates that oxidative stress is the most important pathogenic factor in the development of NAFLD. The study aimed to investigate the impact of α-lipoic acid (LA), widely used as an antioxidant, on the effects of a hypercaloric choline-deficient diet. Male Wistar rats were divided into three groups: control diet (C); hypercaloric choline-deficient diet (HCCD), and hypercaloric choline-deficient diet with α-lipoic acid (HCCD+LA). Supplementation of HCCD with LA for eight weeks led to a decrease in visceral adipose tissue/body weight ratio, the activity of liver glutathione peroxidase and paraoxonase-1, plasma, and liver total antioxidant activity, as well as an increase in liver/body weight ratio, liver total lipid and triglyceride content, and liver transaminase activities compared to the HCCD group without LA. In conclusion, our study shows that α-lipoic acid detains obesity development but exacerbates the severity of diet-induced oxidative stress and lipid accumulation in the liver of male Wistar rats fed a hypercaloric choline-deficient diet.

Effects of C60 Fullerene on Thioacetamide-Induced Rat Liver Toxicity and Gut Microbiome Changes

Thioacetamide (TAA) is widely used to study liver toxicity accompanied by oxidative stress, inflammation, cell necrosis, fibrosis, cholestasis, and hepatocellular carcinoma. As an efficient free radical's scavenger, C60 fullerene is considered a potential liver-protective agent in chemically-induced liver injury. In the present work, we examined the hepatoprotective effects of two C60 doses dissolved in virgin olive oil against TAA-induced hepatotoxicity in rats. We showed that TAA-induced increase in liver oxidative stress, judged by the changes in the activities of SOD, CAT, GPx, GR, GST, the content of GSH and 4-HNE, and expression of HO-1, MnSOD, and CuZnSOD, was more effectively ameliorated with a lower C60 dose. Improvement in liver antioxidative status caused by C60 was accompanied by a decrease in liver HMGB1 expression and an increase in nuclear Nrf2/NF-κB p65 ratio, suggesting a reduction in inflammation, necrosis and fibrosis. These results were in accordance with liver histology analysis, liver comet assay, and changes in serum levels of ALT, AST, and AP. The changes observed in gut microbiome support detrimental effects of TAA and hepatoprotective effects of low C60 dose. Less protective effects of a higher C60 dose could be a consequence of its enhanced aggregation and related pro-oxidant role.

Pirfenidone modifies hepatic miRNAs expression in a model of MAFLD/NASH

miRNAs are involved in the development of metabolic associated fatty liver disease (MAFLD) and nonalcoholic steatohepatitis (NASH). We aimed to evaluate modifications by prolonged-release pirfenidone (PR-PFD) on key hepatic miRNAs expression in a MAFLD/NASH model. First, male C57BL/6J mice were randomly assigned into groups and fed with conventional diet (CVD) or high fat and carbohydrate diet (HFD) for 16 weeks. At the end of the eighth week, HFD mice were divided in two and only one half was treated with 300 mg/kg/day of PR-PFD mixed with food. Hepatic expression of miRNAs and target genes that participate in inflammation and lipid metabolism was determined by qRT-PCR and transcriptome by microarrays. Increased hepatic expression of miR-21a-5p, miR-34a-5p, miR-122-5p and miR-103-3p in MAFLD/NASH animals was reduced with PR-PFD. Transcriptome analysis showed that 52 genes involved in lipid and collagen biosynthesis and inflammatory response were downregulated in PR-PFD group. The expression of Il1b, Tnfa, Il6, Tgfb1, Col1a1, and Srebf1 were decreased in PR-PFD treated animals. MAFLD/NASH animals compared to CVD group showed modifications in gene metabolic pathways implicated in lipid metabolic process, inflammatory response and insulin resistance; PR-PFD reversed these modifications.

Comprehensive analysis of the translatome reveals the relationship between the translational and transcriptional control in high fat diet-induced liver steatosis

Translational regulation plays a critical role in gene expression. However, there are few genome-wide studies on translational regulation in non-alcoholic fatty liver disease (NAFLD), which is a severe non-communicable epidemic worldwide. In this study, we performed RNC-mRNA (mRNAs bound to ribosome-nascent chain complex) sequencing and mRNA sequencing to probe the translation status of high-fat-diet (HFD) induced mouse fatty liver. Generally, in the HFD group compared to the control group, changes of translation ratios and changes in mRNA abundance had a negative correlation. The relative abundance of RNC-mRNAs and mRNAs were positively correlated, yet the former changed more slowly than the latter. However, the rate of change became more balanced when it came to the livers of mice that were fed the HFD plus lycopene, an antioxidant. This indicated relatively independent roles of translational modulation and transcriptional regulation. Furthermore, many genes were differentially regulated at the transcriptional or translational levels, suggesting a new screening strategy for functional genes. In conclusion, our analysis revealed the different and correlated role of translational control with transcriptional regulation in the HFD-induced mouse fatty liver relative to the control, which indicates critical roles of translational control for liver steatosis; thus, adding a new dimension towards a better understanding and improvement of treatment for NAFLD.

Moringa peregrina leaf extracts produce anti-obesity, hypoglycemic, anti-hyperlipidemic, and hepatoprotective effects on high-fat diet fed rats

This present research investigated the anti-obesity and hepatoprotective effects of ethanolic Moringa peregrina leaf (MPLE) and bark extracts (MPBE), in the rats fed with a high-fat diet (HFD). Healthy male rats (n = 48) were randomly distributed to six groups (n = 8): control AIN-93 diet; HFD; HFD + MPBE bark extracts ((300 mg/kg); HFD + MPBE (600 mg/kg); HFD + MPLE (300 mg/kg); HFD + MPLE (600 mg/kg). HFD-fed rats in the Moringa peregrina (MP) treatment groups received orally administered MP leaf or bark extract daily for eight weeks. The results revealed that both doses of MP leaf extract significantly reduced HFD-induced increases in their food intake and the gained body weight, fat pad weights (visceral, subcutaneous, and epididymal), glucose and insulin plasma levels, and leptin and resistin serum levels in HFD-fed rats. Concomitantly, MP leaf extract improved glucose levels after oral or intraperitoneal glucose tolerance tests, reduced serum cholesterol, triglycerides, and the low-density lipoprotein LDL concentration, reduced hepatic triglycerides and cholesterol levels, and increased serum high-density lipoproteins HDL levels and triglycerides and cholesterol levels in fecal. Moreover, the administration of MPLE to HFD-fed rats improved liver architecture, reduced fat accumulation, reduced hepatic malondialdehyde, tumor necrosis factor-α, and interleukin-6 levels. Hepatic glutathione peroxidase, superoxide dismutase, and catalase activities were significantly increased. All observed effects were more pronounced in HFD-fed rats treated with a 600 mg/kg MP dose. However, neither dose of MPBE altered the measured markers in the HFD-fed rats. In conclusion, MPLE showed potential anti-obesity and hepatoprotective activity in HFD-induced obese rats, mediated by reduced lipid absorption, anti-hyperlipidemic effects, and hepatic antioxidant effects.

Urinary biomarkers of polycyclic aromatic hydrocarbons and their associations with liver function in adolescents

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Hyoscyamus albus nortropane alkaloids reduce hyperglycemia and hyperinsulinemia induced in HepG2 cells through the regulation of SIRT1/NF-kB/JNK pathway

BACKGROUND

Chronic superphysiological glucose and insulin concentrations are known to trigger several tissue and organ failures, including insulin resistance, oxidative stress and chronic low-grade inflammation. Hence, the screening for molecules that may counteract such conditions is essential in current existing therapeutic strategies, thereby the use of medicinal plant derivatives represents a promising axis in this regard.

METHODS

In this study, the effect of a selected traditional medicinal plant, Hyoscyamus albus from which, calystegines have been isolated, was investigated in an experimental model of hyperinsulinemia and hyperglycemia induced on HepG2 cells. The mRNA and protein expression levels of different insulin signaling, gluconeogenic and inflammatory pathway- related molecules were examined. Additionally, cell viability and apoptosis, oxidative stress extent and mitochondrial dysfunctions were assayed using flow cytometric and qRT-PCR techniques.

RESULTS

Treatment of IR HepG2 cells with calystegines strongly protected the injured cells from apoptosis, oxidative stress and mitochondrial integrity loss. Interestingly, nortropane alkaloids efficiently regulated the impaired glucose metabolism in IR HepG2 cells, through the stimulation of glucose uptake and the modulation of SIRT1/Foxo1/G6PC/mTOR pathway, which is governing the hepatic gluconeogenesis. Furthermore, the alkaloidal extract restored the defective insulin signaling pathway, mainly by promoting the expression of Insr at the mRNA and protein levels. What is more, treated cells exhibited significant mitigated inflammatory response, as evidenced by the modulation and the regulation of the NF- κB/JNK/TLR4 axis and the downstream proinflammatory cytokines recruitment.

CONCLUSION

Overall, the present investigation demonstrates that calystegines from Hyoscyamus albus provide cytoprotection to the HepG2 cells against insulin/glucose induced insulin resistance and apoptosis due to the regulation of SIRT1/Foxo1/G6PC/mTOR and NF-κB/JNK/TLR4 signaling pathways. Video Abstract.

Lasting Effects of Low to Non-Lethal Radiation Exposure during Late Gestation on Offspring's Cardiac Metabolism and Oxidative Stress

Ionizing radiation (IR) is known to cause fetal programming, but the physiological effects of low-dose IR are not fully understood. This study examined the effect of low (50 mGy) to non-lethal (300 and 1000 mGy) radiation exposure during late gestation on cardiac metabolism and oxidative stress in adult offspring. Pregnant C57BL/6J mice were exposed to 50, 300, or 1000 mGy of gamma radiation or Sham irradiation on gestational day 15. Sixteen weeks after birth, ¹⁸F-Fluorodeoxyglucose (FDG) uptake was examined in the offspring using Positron Emission Tomography imaging. Western blot was used to determine changes in oxidative stress, antioxidants, and insulin signaling related proteins. Male and female offspring from irradiated dams had lower body weights when compared to the Sham. 1000 mGy female offspring demonstrated a significant increase in ¹⁸F-FDG uptake, glycogen content, and oxidative stress. 300 and 1000 mGy female mice exhibited increased superoxide dismutase activity, decreased glutathione peroxidase activity, and decreased reduced/oxidized glutathione ratio. We conclude that non-lethal radiation during late gestation can alter glucose uptake and increase oxidative stress in female offspring. These data provide evidence that low doses of IR during the third trimester are not harmful but higher, non-lethal doses can alter cardiac metabolism later in life and sex may have a role in fetal programming.

Hypertension and Aging Affect Liver Sulfur Metabolism in Rats

Hypertension and age are key risk factors for cardiovascular morbidity and mortality. Hydrogen sulfide (H2S), a gaseous transmitter, contributes significantly to regulating arterial blood pressure and aging processes. This study evaluated the effects of hypertension and aging on the hepatic metabolism of sulfur-containing compounds, the activity of the enzymes involved in sulfur homeostasis, and the liver's ability to generate H2S. Livers isolated from 16- and 60-week-old normotensive Wistar Kyoto rats (WKY) and Spontaneously Hypertensive Rats (SHR) were used to evaluate gene expression using RT-PCR, and the activity of enzymes participating in H2S metabolism, including thiosulfate sulfurtransferase (rhodanese; TST), cystathionine gamma-lyase (CTH), and 3-mercaptopyruvate sulfurtransferase (MPST). The levels of cysteine, cystine, reduced and oxidized glutathione were measured using RP-HPLC. SHR livers from both age groups showed a higher capacity to generate H2S than livers from WKY. The gene expression and activity of enzymes involved in sulfur metabolism differed between WKY and SHR, and between the age groups. For example, 16-week-old SHR had significantly higher activity of TST than 16-week-old WKY. Furthermore, differences between younger and older WKY rats in the expression and/or activity of TST and MPST were present. In conclusion, our study shows that arterial hypertension and aging affect hepatic sulfur metabolism and H2S production in rats. These findings pave the way for interventional studies evaluating a potential causal relation between liver sulfur metabolism, hypertension and aging.

Hepatocyte HIF-1 and Intermittent Hypoxia Independently Impact Liver Fibrosis in Murine NAFLD

Obstructive sleep apnea (OSA) is associated with insulin resistance, lipid dysregulation, and hepatic steatosis and fibrosis in nonalcoholic fatty liver disease (NAFLD). We have previously shown that hepatocyte hypoxia inducible factor-1 (HIF-1) mediates the development of liver fibrosis in a mouse model of NAFLD. We hypothesized that intermittent hypoxia (IH) modeling OSA would worsen hepatic steatosis and fibrosis in murine NAFLD, via HIF-1. Mice with hepatocyte-specific deletion of Hif1a (Hif1a^-/-hep) and wild-type (Hif1a^F/F) controls were fed a high trans-fat diet to induce NAFLD with steatohepatitis. Half from each group were exposed to IH, and the other half to intermittent air. Glucose tolerance test was performed prior to sacrifice. Liver collagen and triglycerides were determined. Mitochondrial efficiency was assessed in fresh liver tissue at sacrifice. Hepatic malondialdehyde concentration and pro-inflammatory cytokine levels were assessed, and genes of collagen and fatty acid metabolism were queried. Hif1a^-/-hep mice gained less weight than Hif1a^F/F mice (-2.3 grams, p=0.029). There was also a genotype-independent effect of IH on body weight, with less weight gain in IH (p=0.003). Fasting glucose, HOMA-IR, and glucose tolerance test were all improved in Hif1a^-/-hep mice. Liver collagen was increased in IH (p=0.033), and reduced in Hif1a^-/-hep mice (p<0.001), without any significant exposure/genotype interaction. Liver TNF-α and IL-1β were significantly increased in IH, and decreased in Hif1a^-/-hep. We conclude that HIF-1 signaling worsens the metabolic profile and hastens NAFLD progression, and that IH may worsen liver fibrosis. These effects are plausibly mediated by hepatic inflammatory stress.

Nutrigenomics and Nutrigenetics in Metabolic- (Dysfunction) Associated Fatty Liver Disease: Novel Insights and Future Perspectives

Metabolic- (dysfunction) associated fatty liver disease (MAFLD) represents the predominant hepatopathy and one of the most important systemic, metabolic-related disorders all over the world associated with severe medical and socio-economic repercussions due to its growing prevalence, clinical course (steatohepatitis and/or hepatocellular-carcinoma), and related extra-hepatic comorbidities. To date, no specific medications for the treatment of this condition exist, and the most valid recommendation for patients remains lifestyle change. MAFLD has been associated with metabolic syndrome; its development and progression are widely influenced by the interplay between genetic, environmental, and nutritional factors. Nutrigenetics and nutrigenomics findings suggest nutrition’s capability, by acting on the individual genetic background and modifying the specific epigenetic expression as well, to influence patients’ clinical outcome. Besides, immunity response is emerging as pivotal in this multifactorial scenario, suggesting the interaction between diet, genetics, and immunity as another tangled network that needs to be explored. The present review describes the genetic background contribution to MAFLD onset and worsening, its possibility to be influenced by nutritional habits, and the interplay between nutrients and immunity as one of the most promising research fields of the future in this context.

Mechanisms and disease consequences of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the leading chronic liver disease worldwide. Its more advanced subtype, nonalcoholic steatohepatitis (NASH), connotes progressive liver injury that can lead to cirrhosis and hepatocellular carcinoma. Here we provide an in-depth discussion of the underlying pathogenetic mechanisms that lead to progressive liver injury, including the metabolic origins of NAFLD, the effect of NAFLD on hepatic glucose and lipid metabolism, bile acid toxicity, macrophage dysfunction, and hepatic stellate cell activation, and consider the role of genetic, epigenetic, and environmental factors that promote fibrosis progression and risk of hepatocellular carcinoma in NASH.

Açaí (Euterpe oleracea Martius) supplementation improves oxidative stress biomarkers in liver tissue of dams fed a high-fat diet and increases antioxidant enzymes' gene expression in offspring

Lipids excess from an uterine environment can increase free radicals production of and thus induce oxidative status imbalance, a key factor for progression of non-alcoholic fatty liver disease (NAFLD) in offspring. Food antioxidant components in maternal diet may play an important role in preventing offspring metabolic disorders. The objective of the study was to evaluate the effects of açaí pulp supplementation on maternal high-fat diet, by assessing activity and expression of antioxidant enzymes and biomarkers of oxidative stress in the liver. Female Fisher rats were divided into four groups and fed a control diet (C), a high-fat diet (HF), a control diet supplemented with açaí (CA) and a high-fat diet supplemented with açaí (HFA) before mating, during gestation and lactation. The effects of açaí supplementation on oxidative stress biomarkers and antioxidant enzymes expression were evaluated in dams and male offspring after weaning. HFA diet increased body weight in dams, however reduced absolute and relative liver weight. There was a reduction in liver biomarkers of oxidative stress, malondialdehyde and carbonyl protein, as well as in catalase, glutathione peroxidase and superoxide dismutase activity. In offspring, HFA diet reduced liver weight and increased Gpx1, Gpx4 and Sod1 mRNA expression. These results suggest that açaí is able to restore redox status, preventing oxidative damage in dams by a direct mechanism and to promote beneficial effects on expression of antioxidant defences related genes in offspring.

Hepatic Accumulation of Hypoxanthine: A Link Between Hyperuricemia and Nonalcoholic Fatty Liver Disease

BACKGROUND

An elevated level of plasma uric acid has been widely recognized as a risk factor for non-alcoholic fatty liver disease (NAFLD), where oxidative stress and inflammation play an important role in the pathophysiology of the disease. Although the complete molecular mechanisms involved remain unknown, while under physiological conditions uric acid presents antioxidant properties, hyperuricemia has been linked to oxidative stress, chronic low-grade inflammation, and insulin resistance, basic signs of NAFLD.

AIM OF STUDY

Employing in vivo experimentation, we aim to investigate whether a high-fat diet rich in cholesterol (HFD), modifies the metabolism of purines in close relationship to molecular events associated with the development of NAFLD. In vitro experiments employing HepG2 cells are also carried out to study the phenomenon of oxidative stress.

METHODS

Adult male rabbits were fed for 8 weeks an HFD to induce NAFLD. At the beginning of the experiment and every 15 d until the completion of the study, plasma levels of lipids, lipoproteins, and uric acid were measured. Liver tissue was isolated, and histology performed followed by the biochemical determination of hypoxanthine, protein expression of xanthine oxidoreductase (XOR) by western blot analysis, and xanthine oxidase (XO) activity using an enzymatic kinetic assay. Furthermore, we employed in vitro experimentation studying HepG2 cells to measure the effect of hypoxanthine and H₂O₂ upon the production of radical oxygen species (ROS), XO activity, and cell viability.

RESULTS AND CONCLUSION

Hepatic tissue from rabbits fed the HFD diet showed signs of NAFLD associated with an increased ROS concentration and an altered purine metabolism characterized by the increase in hypoxanthine, together with an apparent equilibrium displacement of XOR towards the xanthine dehydrogenase (XDH) isoform of the enzyme. This protein shift visualized by a western blot analysis, associated with an increase in plasma uric acid and hepatocyte hypoxanthine could be understood as a compensatory series of events secondary to the establishment of oxidative stress associated with the chronic establishment of fatty liver disease.

Quercetin prevents cadmium chloride-induced hepatic steatosis and fibrosis by downregulating the transcription of miR-21

This study investigated if cadmium chloride (CdCl₂ )-induced hepatic steatosis and fibrosis and the protective effect of quercetin (QUR) are mediated modulating the activity of miR-21, a known hepatic lipogenic and fibrotic miRNA. Male rats (n = 8/group) were divided as control, control + QUR (50 mg/kg; orally), CdCl₂ (10 moml/L; drinking water), CdCl₂  + miR-21 antagomir (inhibitor) (16 mg/kg/first 3 days), and CdCl₂  + QUR (50 mg/kg). Treatments were conducted for 20 weeks, daily. All treatments showed no effect on fasting glucose and insulin levels. Administration of either miR-21 or QUR prevented CdCl₂ -induced hepatic damage, as well as lipid droplets and collagen deposition. They also reduced serum levels of ALT and AST and decreased serum and hepatic levels of total cholesterol, triglycerides, and low-density lipoproteins in CdCl₂ -treated rats. Concomitantly, they reduced hepatic levels of reactive oxygen species, malondialdehyde, interleukin-6, and tumor necrosis factor-α, suppressed the activation of NF-kb P65, and increased hepatic levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione (GSH), and superoxide dismutase (SOD). These effects were associated with reduced expression of SREBP1, TGF-β1, Smad3, and collagen1 A and increased expression of PPARα, CPT1, and smad7. Interestingly, QUR significantly lowered levels of miR-21 and increased the protein levels and activity of Nrf2, as well as levels of GSH and SOD in the livers of both the control and CdCl₂ -treated rats. Of note, levels of Nrf2 were negatively correlated with the transcription of miR-21. In conclusion: QUR prevents CdCl₂ -induced hepatic steatosis and fibrosis mainly through attenuating its ability to upregulate miR-21, at least, by upregulation of Nrf2.