Dysregulation of glutathione synthesis in liver disease

Electrochemical sensor for glutathione reductase based on screen-printed electrodes coated with 3,5-dinitrobenzoic acid-modified carbon nanotubes

The preparation of a hybrid nanomaterial is reported by covalently attaching 3,5-dinitrobenzoic acid groups to the surface of oxidized multi-walled carbon nanotubes using 1,6-diaminohexane as cross-linking agent. This nanomaterial, modified with the redox mediator, was used as transduction element to construct an amperometric sensor for the efficient indirect determination of glutathione reductase at a low working potential of - 0.05 V, through the oxidation of unconsumed nicotinamide adenine dinucleotide phosphate (NADPH) in the enzymatic reaction. The sensor exhibited an excellent linear response in the range 1.6 to 174 µU/µL, with high reproducibility and selectivity. The developed device was successfully validated in real samples, accurately determining the active enzyme in diluted human serum, making it a promising alternative for the determination of glutathione reductase and other related NADPH-dependent enzymes with relevance in clinical analysis.

A novel pharmacological strategy using nanoparticles with glutathione and virgin coconut oil to treat gentamicin-induced acute renal failure in rats

In acute renal failure (ARF), the glomerular filtration rate is reduced, and nitrogenous waste products accumulate persistently, which can last anywhere from a few hours to several days. There is hope for a reversal of the rapid loss of renal function caused by this condition. This study, with gentamicin-induced acute ARF as a prospective setting, sets out to examine the reno-protective benefits of virgin coconut oil (VCO) and GSH. Furthermore, the study evaluated the effect of medication nanoparticle compositions on several kidney function markers. The induction of ARF is achieved with the intraperitoneal injection of gentamicin. To assess renal function, rats underwent 24 h of dehydration and hunger before their deaths. The study examined various aspects, including kidney function tests, markers of oxidative stress, histology of kidney tissue, inflammatory cytokines, immunohistochemistry expression of nuclear factor-kappa B (NF-κB), and specific biomarkers for kidney tissue damage, such as kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). The results of our study indicated that the combination of VCO and GSH, using both regular and nanoparticle formulations, had a better protective impact on the kidneys compared to using either drug alone. The recovery of renal tissue and serum markers, which are symptomatic of organ damage, indicates improvement. This was also demonstrated by the reduction in tubular expression of TNF-α, IL-1β, KIM-1, and NGAL. The immunohistochemical studies showed that the combination therapy, especially with the nanoforms, greatly improved the damaged cellular changes in the kidneys, as shown by higher levels of NF-κB. The study shows that VCO and GSH, when administered individually or combined, significantly improve ARF in a gentamicin-induced rat model, highlighting potential therapeutic implications. Notably, the combined nanoparticulate formulations exhibit substantial effectiveness.

Vascular endothelial growth factor is associated with hepatocellular carcinoma recurrence, independent of folate and glutathione-related antioxidant enzymes: A follow-up study

The associations of tumor angiogenesis with folate and antioxidant capacities in patients with hepatocellular carcinoma (HCC) and their effects on HCC recurrence have not yet been investigated. We investigated the changes and relationships of VEGF, folate, GSH, and GSH-related antioxidant enzymes in patients with HCC before tumor resection, as well as 1 month, 1 year, and 3 years after tumor resection, and their effects on HCC recurrence. 95 HCC patients who underwent tumor resection were recruited. Patients were followed up before tumor resection (pre-resection), 1 month after tumor resection (post-resection), 1 year, and 3 years of follow-up. The recurrence and survival status of patients were evaluated. Plasma VEGF concentrations decreased slightly during follow-up. Serum folate and GSH concentrations and plasma GPx and GR activities increased significantly from pre-resection to post-resection and remained stable at follow-up. Pre-resection plasma VEGF was positively correlated with GSH, GPx, and GR, but negatively correlated with folate and GST. The high pre-resection plasma VEGF was a significant predictor of a high HCC rate (hazard ratio = 1.05, p = 0.035), remaining significant after adjustments for folate, GSH, GPx, GR, and GST to diminish their interference with VEGF. Pre-tumor-resection plasma VEGF constitutes a potential independent marker for predicting HCC recurrence. However, the associations of plasma VEGF with folate and GSH-related antioxidant capacities in HCC patients cannot be ignored.

Characterisation of an outbreak of acute liver injury after ingestion of plant-based food supplement

BACKGROUND

In April 2022, French Lentil and Leek Crumble (FLLC), a new frozen food preparation manufactured by Daily Harvest™ (containing Tara flour) was offered as a natural high-protein meal product. Soon thereafter, widespread anecdotal reports of acute gastrointestinal symptoms with liver injury were reported, leading to its voluntary withdrawal in June 2022, after shipment of 28,000 preparations.

AIMS

To summarise the clinical and laboratory features of 17 patients with FLLC associated liver injury from the Drug Induced Liver Injury Network (DILIN).

METHODS

Patients with FLLC-associated liver injury were enrolled into a prospective protocol and followed for 6 months. Cases were adjudicated by expert opinion causality assessment with summary statistics for data analysis.

RESULTS

Enrolled subjects had a mean age of 41 years, 82% were female with mean BMI of 24 kg/m2. All were Caucasian without underlying liver disease. In most cases, abdominal pain and nausea arose within hours of FLLC ingestion. Mean days from ingestion to identification of liver injury was 3.1 days (±2.8). On enrolment, 53% had jaundice, 47% nausea, 24% fever, 59% abdominal pain, 41% itching and 12% rash. The mean initial serum ALT was 475 U/L (±302), AST 315 U/L (±315), alkaline phosphatase 190 U/L (±76), with a total bilirubin of 2.6 mg/dL (±2). In this study, 63% presented with a hepatocellular pattern of liver injury, 6% cholestatic and 31% mixed as determined by the R value. In addition, 24% of patients were hospitalised, and there were no fatalities or liver transplants. Liver biopsy in one subject revealed acute hepatitis with mild ductular reaction, mild lymphocytic and eosinophilic portal inflammation, mild lobular inflammation, preserved bile ducts and absence of interface hepatitis, steatosis, granulomatous reaction or cholestasis. Phylogenetic analysis confirmed the presence of Tara spinosa, the source of Tara flour.

CONCLUSIONS

Natural food products are increasingly ubiquitous and may unexpectedly cause significant illness. All clinicians should inquire whether patients are consuming natural food products or herbal supplements and consider them as a potential cause of liver injury.

Alleviating effect of methionine on intestinal mucosal injury induced by heat stress

Climate change is an increasing concern of stakeholders worldwide. The intestine is severely impacted by the heat stress. This study aimed to investigate the alleviating effects of methionine on the intestinal damage induced by heat stress in mice. The mice were divided into four groups: control group (C), methionine deficiency group (MD), methionine + heat stress group (MH), and methionine deficiency + heat stress group (MDH). Histopathological techniques, PAS-Alcian blue staining, immunohistochemistry method, biochemical quantification method, ELISA, and micro method were used to study the changes in the intestinal mucosal morphology, the number of goblet cells, the expression of tight junction proteins, the peroxide product contents and antioxidant enzyme activities, the intestinal mucosal damage, the content of immunoglobulins and HSP70, the activity of Na+/K+-ATPase. The results showed that methionine can improve intestinal mucosal morphology (increase the villi height, V/C value, and muscle layer thickness, decrease crypt depth), increase the expression of tight junction proteins (Claudin-1, Occludin, ZO-1) and the content of DAO, decrease the content of intestinal mucosa damage markers (ET, FABP2) and peroxidation products (MDA), increase the activity of antioxidant enzymes (GR, GSH-Px, SOD), the number of goblet cells, the contents of immunoglobulins (sIgA, IgA, IgG, IgM) and stress protein (HSP70), and the activity of Na+/K+-ATPase. It is suggested that methionine can alleviate intestinal damage in heat-stressed mice.

Busulfan induces steatosis in HepaRG cells but not in primary human hepatocytes: Possible explanations and implication for the prediction of drug-induced liver injury

BACKGROUND

The antineoplastic drug busulfan can induce different hepatic lesions including cholestasis and sinusoidal obstruction syndrome. However, hepatic steatosis has never been reported in patients.

OBJECTIVES

This study aimed to determine whether busulfan could induce steatosis in primary human hepatocytes (PHH) and differentiated HepaRG cells.

METHODS

Neutral lipids were determined in PHH and HepaRG cells. Mechanistic investigations were performed in HepaRG cells by measuring metabolic fluxes linked to lipid homeostasis, reduced glutathione (GSH) levels, and expression of genes involved in lipid metabolism and endoplasmic reticulum (ER) stress. Analysis of two previous transcriptomic datasets was carried out.

RESULTS

Busulfan induced lipid accumulation in HepaRG cells but not in six different batches of PHH. In HepaRG cells, busulfan impaired VLDL secretion, increased fatty acid uptake, and induced ER stress. Transcriptomic data analysis and decreased GSH levels suggested that busulfan-induced steatosis might be linked to the high expression of glutathione S-transferase (GST) isoenzyme A1, which is responsible for the formation of the hepatotoxic sulfonium cation conjugate. In keeping with this, the GST inhibitor ethacrynic acid and the chemical chaperone tauroursodeoxycholic acid alleviated busulfan-induced lipid accumulation in HepaRG cells supporting the role of the sulfonium cation conjugate and ER stress in steatosis.

CONCLUSION

While the HepaRG cell line is an invaluable tool for pharmacotoxicological studies, it might not be always an appropriate model to predict and mechanistically investigate drug-induced liver injury. Hence, we recommend carrying out toxicological investigations in both HepaRG cells and PHH to avoid drawing wrong conclusions on the potential hepatotoxicity of drugs and other xenobiotics.

Glutathione Therapy in Diseases: Challenges and Potential Solutions for Therapeutic Advancement

An endogenous antioxidant, reduced glutathione (GSH), is found at high concentrations in nearly all typical cells. GSH synthesis is a controlled process, and any disruption in the process of GSH synthesis could result in GSH depletion. Cellular oxidative damage results from GSH depletion. Various pathological conditions such as aging, cardiovascular disease (CVD), psychiatric disorders, neurological disorders, liver disorders, and diabetes mellitus are more affected by this stress. There are various reasons for GSH reduction, but replenishing it can help to improve this condition. However, there are challenges in this field. Low bioavailability and poor stability of GSH limit its delivery to tissues, mainly brain tissue. Today, new approaches are used for the optimal amount and efficiency of drugs and alternative substances such as GSH. The use of nano-materials and liposomes are effective methods for improving the treatment effects of GSH. The difficulties of GSH decrease and its connection to the most important associated disorders are reviewed for the first time in this essay. The other major concerns are the molecular mechanisms involved in them; the impact of treatment with replacement GSH; the signaling pathways impacted; and the issues with alternative therapies. The utilization of nano-materials and liposomes as potential new approaches to solving these issues is being considered.

Yerba Maté (Ilex paraguariensis) Supplement Exerts Beneficial, Tissue-Specific Effects on Mitochondrial Efficiency and Redox Status in Healthy Adult Mice

Yerba maté, a herbal tea derived from Ilex paraguariensis, has previously been reported to be protective against obesity-related and other cardiometabolic disorders. Using high-resolution respirometry and reverse-phase high-performance liquid chromatography, the effects of four weeks of yerba maté consumption on mitochondrial efficiency and cellular redox status in skeletal muscle, adipose, and liver, tissues highly relevant to whole-body metabolism, were explored in healthy adult mice. Yerba maté treatment increased the mitochondrial oxygen consumption in adipose but not in the other examined tissues. Yerba maté increased the ATP concentration in skeletal muscle and decreased the ATP concentration in adipose. Combined with the observed changes in oxygen consumption, these data yielded a significantly higher ATP:O2, a measure of mitochondrial efficiency, in muscle and a significantly lower ATP:O2 in adipose, which was consistent with yerba maté-induced weight loss. Yerba maté treatment also altered the hepatic glutathione (GSH)/glutathione disulfide (GSSG) redox potential to a more reduced redox state, suggesting the treatment's potential protective effects against oxidative stress and for the preservation of cellular function. Together, these data indicate the beneficial, tissue-specific effects of yerba maté supplementation on mitochondrial bioenergetics and redox states in healthy mice that are protective against obesity.

Inhibition of glutathione generation in hepatic steatotic rats augments oxidative stress

Fatty liver disease has been strongly associated with a low glutathione (GSH) level in hepatocytes with increased oxidative stress, which is critically involved in the initiation and progression of the disease. The study investigated whether the GSH deficiency induced by buthionine sulfoximine (BSO), an inhibitor of γ-glutamyl cysteine synthetase, can be restored by the administration of GSH ester. We showed that mice fed a diet with cholesterol plus sodium cholate developed steatosis followed by hepatic GSH reduction. Moreover, the GSH level in the cytosol and mitochondria of steatosis plus BSO decreased than that of steatosis alone. Subsequent studies with the liver tissues and plasma of BSO plus steatosis revealed the accumulation of cholesterol in the hepatocytes, downregulating the concentration of GSH, antioxidant enzymes, and GSH metabolizing enzymes with a significant rise in reactive oxygen species (ROS), blood glucose level and plasma lipid profile. The administration of GSH ester in BSO-administered mice, prevented the depletion of GSH by upregulating the GSH concentration, antioxidant enzymes, and GSH metabolizing enzymes, followed by a reduction in ROS and plasma lipid concentration. The histopathological analysis showed a marked increase in inflammation followed by hepatocytes ballooning in BSO-induced group and steatosis control group, which was ameliorated by GSH ester administration. In conclusion, our data suggest that the restoration of GSH in the cytosol and mitochondria through the injection with GSH ester plays a principal role in maintaining the GSH level in the liver, thereby delaying the progression of fatty liver disease.

Recent Progress in the Rational Design of Biothiol-Responsive Fluorescent Probes

Biothiols such as cysteine, homocysteine, and glutathione play significant roles in important biological activities, and their abnormal concentrations have been found to be closely associated with certain diseases, making their detection a critical task. To this end, fluorescent probes have become increasingly popular due to their numerous advantages, including easy handling, desirable spatiotemporal resolution, high sensitivity, fast response, and favorable biocompatibility. As a result, intensive research has been conducted to create fluorescent probes for the detection and imaging of biothiols. This brief review summarizes recent advances in the field of biothiol-responsive fluorescent probes, with an emphasis on rational probe design, including the reaction mechanism, discriminating detection, reversible detection, and specific detection. Furthermore, the challenges and prospects of fluorescence probes for biothiols are also outlined.

From liver fibrosis to hepatocarcinogenesis: Role of excessive liver H2O2 and targeting nanotherapeutics

Liver fibrosis and hepatocellular carcinoma (HCC) have been worldwide threats nowadays. Liver fibrosis is reversible in early stages but will develop precancerosis of HCC in cirrhotic stage. In pathological liver, excessive H₂O₂ is generated and accumulated, which impacts the functionality of hepatocytes, Kupffer cells (KCs) and hepatic stellate cells (HSCs), leading to genesis of fibrosis and HCC. H₂O₂ accumulation is associated with overproduction of superoxide anion (O₂^•−) and abolished antioxidant enzyme systems. Plenty of therapeutics focused on H₂O₂ have shown satisfactory effects against liver fibrosis or HCC in different ways. This review summarized the reasons of liver H₂O₂ accumulation, and the role of H₂O₂ in genesis of liver fibrosis and HCC. Additionally, nanotherapeutics targeting H₂O₂ were summarized for further consideration of antifibrotic or antitumor therapy.

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Liver fibrosis and HCC are closely related because ROS induced liver damage and inflammation, especially over-cumulated H₂O₂.

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Excess H₂O₂ diffusion in pathological liver was due to increased metabolic rate and diminished cellular antioxidant systems.

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Freely diffused H₂O₂ damaged liver-specific cells, thereby leading to fibrogenesis and hepatocarcinogenesis.

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Nanotherapeutics targeting H₂O₂ are summarized for treatment of liver fibrosis and HCC, and also challenges are proposed.

Molecular Genetics of Abnormal Redox Homeostasis in Type 2 Diabetes Mellitus

Numerous studies have shown that oxidative stress resulting from an imbalance between the production of free radicals and their neutralization by antioxidant enzymes is one of the major pathological disorders underlying the development and progression of type 2 diabetes (T2D). The present review summarizes the current state of the art advances in understanding the role of abnormal redox homeostasis in the molecular mechanisms of T2D and provides comprehensive information on the characteristics and biological functions of antioxidant and oxidative enzymes, as well as discusses genetic studies conducted so far in order to investigate the contribution of polymorphisms in genes encoding redox state-regulating enzymes to the disease pathogenesis.

Hibiscus sabdariffa L. polyphenolic-rich extract promotes muscle glucose uptake and inhibits intestinal glucose absorption with concomitant amelioration of Fe2+ -induced hepatic oxidative injury

In this current study, the antidiabetic effectiveness of Hibiscus sabdariffa and its protective function against Fe²⁺ -induced oxidative hepatic injury were elucidated using in vitro, in silico, and ex vivo studies. The oxidative damage was induced in hepatic tissue by incubation with 0.1 mMolar ferrous sulfate (FeSO4) and then treated with different concentrations of crude extracts (ethyl acetate, ethanol, and aqueous) of H. sabdariffa flowers for 30 min at 37°C. When compared to ethyl acetate and aqueous extracts, the ethanolic extract displayed the most potent scavenging activity in ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and nitric oxide (NO) assays, with IC₅₀ values of 2.8 μl/ml, 3.3 μl/ml, and 9.2 μl/ml, respectively. The extracts significantly suppressed α-glucosidase and α-amylase activities (p < .05), with the ethanolic extract demonstrating the highest activity. H. sabdariffa significantly (p < .05) raised reduced glutathione (GSH) levels while simultaneously decreasing malondihaldehyde (MDA) and NO levels and increasing superoxide dismutase (SOD) and catalase activity in Fe²⁺ induced oxidative hepatic injury. The extract of the plant inhibited intestinal glucose absorption and increased muscular glucose uptake. The extract revealed the presence of several phenolic compounds when submitted to gas chromatography-mass Spectroscopy (GC-MS) screening, which was docked with α-glucosidase and α- amylase. The molecular docking displayed the compound 4-(3,5-Di-tert-butyl-4-hydroxyphenyl)butyl acrylate strongly interacted with α-glucosidase and α-amylase and had the lowest free binding energy compared to other compounds and acarbose. These results suggest that H. sabdariffa has promising antioxidant and antidiabetic activity. PRACTICAL APPLICATIONS: In recent years, there has been increased concern about the side effects of synthetic anti-diabetic drugs, as well as their expensive cost, especially in impoverished nations. This has instigated a radical shift towards the use of traditional plants, which are rich in phytochemicals many years ago. Among these plants, H. sabdariffa has been used to treat diabetes in traditional medicine. In this present study, H. sabdariffa extracts demonstrated the ability to inhibit carbohydrate digesting enzymes, facilitate muscle glucose uptake and attenuate oxidative stress in oxidative hepatic injury. Hence, demonstrating H. sabdariffa's potential to protect against oxidative damage and the complications associated with diabetes. Consumption of Hibiscus tea or juice may be a potential source for developing an anti-diabetic drug.

Recent Advances in Stimuli-Responsive Doxorubicin Delivery Systems for Liver Cancer Therapy

Doxorubicin (DOX) is one of the most commonly used drugs in liver cancer. Unfortunately, the traditional chemotherapy with DOX presents many limitations, such as a systematic release of DOX, affecting both tumor tissue and healthy tissue, leading to the apparition of many side effects, multidrug resistance (MDR), and poor water solubility. Furthermore, drug delivery systems' responsiveness has been intensively studied according to the influence of different internal and external stimuli on the efficiency of therapeutic drugs. In this review, we discuss both internal stimuli-responsive drug-delivery systems, such as redox, pH and temperature variation, and external stimuli-responsive drug-delivery systems, such as the application of magnetic, photo-thermal, and electrical stimuli, for the controlled release of Doxorubicin in liver cancer therapy, along with the future perspectives of these smart delivery systems in liver cancer therapy.

Genome-Scale Metabolic Modeling Reveals Sequential Dysregulation of Glutathione Metabolism in Livers from Patients with Alcoholic Hepatitis

Alcoholic hepatitis (AH) is the most severe form of alcoholic liver disease for which there is no efficacious treatment aiding most patients. AH manifests differently in individuals, with some patients showing debilitating symptoms more so than others. Previous studies showed significant metabolic dysregulation associated with AH. Therefore, we sought to analyze how the activity of metabolic pathways differed in the liver of patients with varying degrees of AH severity. We utilized a genome-scale metabolic modeling approach that allowed for integration of a generic human cellular metabolic model with specific RNA-seq data corresponding to healthy and multiple liver disease states to predict the metabolic fluxes within each disease state. Additionally, we performed a systems-level analysis of the transcriptomic data and predicted metabolic flux data to identify the regulatory and functional differences in liver metabolism with increasing severity of AH. Our results provide unique insights into the sequential dysregulation of the solute transport mechanisms underlying the glutathione metabolic pathway with increasing AH disease severity. We propose targeting of the solute transporters in the glutathione pathway to mimic the flux activity of the healthy liver state as a potential therapeutic intervention for AH.

Phosphatidylethanolamine N-Methyltransferase Knockout Modulates Metabolic Changes in Aging Mice

Phospholipid metabolism, including phosphatidylcholine (PC) biosynthesis, is crucial for various biological functions and is associated with longevity. Phosphatidylethanolamine N-methyltransferase (PEMT) is a protein that catalyzes the biosynthesis of PC, the levels of which change in various organs such as the brain and kidneys during aging. However, the role of PEMT for systemic PC supply is not fully understood. To address how PEMT affects aging-associated energy metabolism in tissues responsible for nutrient absorption, lipid storage, and energy consumption, we employed NMR-based metabolomics to study the liver, plasma, intestine (duodenum, jejunum, and ileum), brown/white adipose tissues (BAT and WAT), and skeletal muscle of young (9-10 weeks) and old (91-132 weeks) wild-type (WT) and PEMT knockout (KO) mice. We found that the effect of PEMT-knockout was tissue-specific and age-dependent. A deficiency of PEMT affected the metabolome of all tissues examined, among which the metabolome of BAT from both young and aged KO mice was dramatically changed in comparison to the WT mice, whereas the metabolome of the jejunum was only slightly affected. As for aging, the absence of PEMT increased the divergence of the metabolome during the aging of the liver, WAT, duodenum, and ileum and decreased the impact on skeletal muscle. Overall, our results suggest that PEMT plays a previously underexplored, critical role in both aging and energy metabolism.

A new nutraceutical (Livogen Plus®) improves liver steatosis in adults with non-alcoholic fatty liver disease

Background

Currently, there is no approved medication for non-alcoholic fatty liver disease management. Pre-clinical and clinical studies showed that several bioactive molecules in plants or foods (i.e., curcumin complex, bergamot polyphenol fraction, artichoke leaf extract, black seed oil, concentrate fish oil, picroliv root, glutathione, S-adenosyl-l-methionine and other natural ingredients) have been associated with improved fatty liver disease. Starting from these evidences, our purpose was to evaluate the effects of a novel combination of abovementioned nutraceuticals as a treatment for adults with fatty liver disease.

Methods

A total of 140 participants with liver steatosis were enrolled in a randomized, double-blind, placebo controlled clinical trial. The intervention group received six softgel capsules daily of a nutraceutical (namely Livogen Plus®) containing a combination of natural bioactive components for 12 weeks. The control group received six softgel capsules daily of a placebo containing maltodextrin for 12 weeks. The primary outcome measure was the change in liver fat content (CAP score). CAP score, by transient elastography, serum glucose, lipids, transaminases, and cytokines were measured at baseline and after intervention.

Results

After adjustment for confounding variables (i.e., CAP score and triglyceride at baseline, and changes of serum γGT, and vegetable and animal proteins, cholesterol intake at the follow-up), we found a greater CAP score reduction in the nutraceutical group rather than placebo (− 34 ± 5 dB/m vs. − 20 ± 5 dB/m, respectively; p = 0.045). The CAP score reduction (%) was even greater in those with aged 60 or less, low baseline HDL-C, AST reduction as well as in men.

Conclusion

Our results showed that a new combination of bioactive molecules as nutraceutical was safe and effective in reducing liver fat content over 12 weeks in individuals with hepatic steatosis.

Trial registration ISRCTN, ISRCTN70887063. Registered 03 August 2021—retrospectively registered, https://doi.org/10.1186/ISRCTN70887063

Rapid Detection of Direct Compound Toxicity and Trailing Detection of Indirect Cell Metabolite Toxicity in a 96-Well Fluidic Culture Device for Cell-Based Screening Environments: Tactics in Six Sigma Quality Control Charts

Microfluidic screening tools, in vitro, evolve amid varied scientific disciplines. One emergent technique, simultaneously assessing cell toxicity from a primary compound and ensuing cell-generated metabolites (dual-toxicity screening), entails in-line systems having sequentially aligned culture chambers. To explore dual-tox screens, we probe the dissemination of nutrients involving 1-way transport with upstream compound dosing, midstream cascading flows, and downstream cessation. Distribution of flow gives rise to broad concentration ranges of dosing compound (0→ICcompound100) and wide-ranging concentration ranges of generated cell metabolites (0→ICmetabolites100). Innately, single-pass unidirectional flow retains 1st pass informative traits across the network, composed of nine interconnected culture wells, preserving both compound and cell-secreted byproducts as data indicators in each adjacent culture chamber. Thereafter, to assess effective compound hepatotoxicity (0→ECcompound100) and simultaneously classify for cell-metabolite toxicity (0→ECmetabolite100), we reveal utility by analyzing culture viability against ramping exposures of acetaminophen (APAP) and nefazodone (NEF), compounds of hepatic significance. We then discern metabolite generation with an emphasis on amplification across µchannel multiwell sites. Lastly, using conventional cell functions as indicator tools to assess dual toxicity, we investigate a non-drug induced liver injury (non-DILI) compound and DILI compound. The technology is for predictive evaluations of new compound formulations, new chemical entities (NCE), or drugs that have previously failed testing for unresolved reasons.

Construction of Glycogen-Based Nanoparticles Loaded with Resveratrol for the Alleviation of High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease

The purpose of this study was to construct a glycogen (Gly)-based nanoparticle (NP) with liver-targeted and redox response to effectively deliver resveratrol (Res) for improving nonalcoholic fatty liver disease (NAFLD). Herein, Gly was modified using α-lipoic acid (α-LA) and lactobionic acid (Lac) to obtain an amphiphilic polymer (Gly-LA-Lac), which was self-assembled in water and then encapsulated in Res to form Res NPs with excellent stability. As expected, the Res NPs exhibited liver-targeted and redox response release behavior. In vitro cell studies demonstrated that the nanocarrier treatment enhanced the cellular uptake of Res and reduced oxidative stress and inflammatory factor levels. Meanwhile, the in vivo tests proved that the nanocarriers effectively reduced hepatic lipid accumulation and oxidative stress levels via regulating the TLR4/NF-κB signal pathway to improve liver damage in NAFLD mice. In conclusion, this study provides a promising strategy through the construction of Gly-based nanocarriers for the encapsulation of Res to effectively alleviate the process of NAFLD.

Precision-cut liver slices as a model for assess hepatic cellular response of chitosan-glutathione nanoparticles on cultures treated with zilpaterol and clenbuterol

Zilpaterol and clenbuterol are two β-adrenergic agonist drugs used in animal production. Both drugs have anabolic effects with advantages on carcass yield. Meanwhile, zilpaterol is approved for animal feed in authorized countries. Clenbuterol is a banned substance due to the risk of toxicity; however, it is still being used in unknown dose levels in many farm species. Therefore, the use and abuse of these substances should be closely monitored, considering the clenbuterol ability and the not proved yet of zilpaterol to produce reactive oxygen and nitrogen species. Regarding glutathione which is the main intracellular antioxidant plays detoxification functions on liver metabolism; in this work, it is our interest to know the capacity of chitosan-glutathione nanoparticles (CS/GSH-NP) as a complementary source of exogenous GSH to modify the oxide-reduction status on bovine precision-cut liver slice cultures (PCLS) exposed to clenbuterol and zilpaterol. A single drug assay was performed in first instance by adding clenbuterol, zilpaterol, chitosan nanoparticles (CS-NP), and CS/GSH-NP. Then combinate drug assay was carried out by testing clenbuterol and zilpaterol combined with CS-NP or CS/GSH-NP. The results showed that both β-adrenergic agonists modify in a dose-dependent manner in oxide-reduction response through ROS generation. The activity or content of glutathione peroxidase activity, intracellular GSH, gamma glutamyl-transpeptidase, aspartate aminotrasnferase and alanine aminotrasnferase were modified. The exogenous GSH delivered by nanoparticles could be used to modulate these markers.

Redox-Activated Contrast-Enhanced T1-Weighted Imaging Visualizes Glutathione-Mediated Biotransformation Dynamics in the Liver

GSH-mediated liver biotransformation is a crucial physiological process demanding efficient research tools. Here, we report a type of amorphous Fe_xMn_yO nanoparticles (AFMO-ZDS NPs) as redox-activated probes for in vivo visualization of the dynamics of GSH-mediated biotransformation in liver with T₁-weighted magnetic resonance imaging (MRI). This imaging technique reveals the periodic variations in GSH concentration during the degradation of AFMO-ZDS NPs due to the limited transportation capacity of GSH carriers in the course of GSH efflux from hepatocytes to perisinusoidal space, providing direct imaging evidence for this important carrier-mediated process during GSH-mediated biotransformation. Therefore, this technique offers an effective method for in-depth investigations of GSH-related biological processes in liver under various conditions as well as a feasible means for the real-time assessment of liver functions, which is highly desirable for early diagnosis of liver diseases and prompt a toxicity evaluation of pharmaceuticals.

The Prognostic Role of Glutathione and Its Related Antioxidant Enzymes in the Recurrence of Hepatocellular Carcinoma

The imbalance of high oxidative stress and low antioxidant capacities is thought to be a significant cause of the development and progression of hepatocellular carcinoma (HCC). However, the impact of oxidative stress, glutathione (GSH), and its related antioxidant enzymes on the recurrence of HCC has not been investigated. The purpose of this study was to compare the changes to oxidative stress and GSH-related antioxidant capacities before and after tumor resection in patients with HCC recurrence and non-recurrence. We also evaluated the prognostic significance of GSH and its related enzymes in HCC recurrence. This was a cross-sectional and follow-up study. Ninety-two HCC patients who were going to receive tumor resection were recruited. We followed patients' recurrence and survival status until the end of the study, and then assigned patients into the recurrent or the non-recurrent group. The tumor recurrence rate was 52.2% during the median follow-up period of 3.0 years. Patients had significantly lower plasma malondialdehyde level, but significantly or slightly higher levels of GSH, glutathione disulfide, trolox equivalent antioxidant capacity, glutathione peroxidase (GPx), and glutathione reductase (GR) activities after tumor resection compared to the respective levels before tumor resection in both recurrent and non-recurrent groups. GSH level in HCC tissue was significantly higher than that in adjacent normal tissue in both recurrent and non-recurrent patients. Decreased plasma GPx (HR = 0.995, p = 0.01) and GR (HR = 0.98, p = 0.04) activities before tumor resection, and the increased change of GPx (post-pre-resection) (HR = 1.004, p = 0.03) activity were significantly associated with the recurrence of HCC. These findings suggest there might be a possible application of GPx or GR as therapeutic targets for reducing HCC recurrence.

Activity-based photoacoustic probe for biopsy-free assessment of copper in murine models of Wilson's disease and liver metastasis

The development of high-performance photoacoustic (PA) probes that can monitor disease biomarkers in deep tissue has the potential to replace invasive medical procedures such as a biopsy. However, such probes must be optimized for in vivo performance and exhibit an exceptional safety profile. In this study, we have developed PACu-1, a PA probe designed for biopsy-free assessment (BFA) of hepatic Cu via photoacoustic imaging. PACu-1 features a Cu(I)-responsive trigger appended to an aza-BODIPY dye platform that has been optimized for ratiometric sensing. Owing to its excellent performance, we were able to detect basal levels of Cu in healthy wild-type mice as well as elevated Cu in a Wilson's disease model and in a liver metastasis model. To showcase the potential impact of PACu-1 for BFA, we conducted two blind studies in which we were able to successfully identify Wilson's disease animals from healthy control mice in each instance.

Quantitative trait mapping in Diversity Outbred mice identifies novel genomic regions associated with the hepatic glutathione redox system

The tripeptide glutathione (GSH) is instrumental to antioxidant protection and xenobiotic metabolism, and the ratio of its reduced and oxidized forms (GSH/GSSG) indicates the cellular redox environment and maintains key aspects of cellular signaling. Disruptions in GSH levels and GSH/GSSG have long been tied to various chronic diseases, and many studies have examined whether variant alleles in genes responsible for GSH synthesis and metabolism are associated with increased disease risk. However, past studies have been limited to established, canonical GSH genes, though emerging evidence suggests that novel loci and genes influence the GSH redox system in specific tissues. The present study marks the most comprehensive effort to date to directly identify genetic loci associated with the GSH redox system. We employed the Diversity Outbred (DO) mouse population, a model of human genetics, and measured GSH and the essential redox cofactor NADPH in liver, the organ with the highest levels of GSH in the body. Under normal physiological conditions, we observed substantial variation in hepatic GSH and NADPH levels and their redox balances, and discovered a novel, significant quantitative trait locus (QTL) on murine chromosome 16 underlying GSH/GSSG; bioinformatics analyses revealed Socs1 to be the most likely candidate gene. We also discovered novel QTL associated with hepatic NADP⁺ levels and NADP⁺/NADPH, as well as unique candidate genes behind each trait. Overall, these findings transform our understanding of the GSH redox system, revealing genetic loci that govern it and proposing new candidate genes to investigate in future mechanistic endeavors.

Clinical Outcomes after Oat Beta-Glucans Dietary Treatment in Gastritis Patients

The prevalence of gastritis in humans is constantly growing and a prediction of an increase in this health problem is observed in many countries. For this reason, effective dietary therapies are sought that can alleviate the course of this disease. The objective of this study was to determine the effect of chemically pure oat beta-glucan preparations with different molar masses, low or high, used for 30 days in patients with histologically diagnosed chronic gastritis. The study enrolled 48 people of both genders of different ages recruited from 129 patients with a gastritis diagnosis. Before and after the therapy, hematological, biochemical, immunological and redox balance parameters were determined in the blood and the number of lactic acid bacteria and SCFA concentrations in the feces. Our results demonstrated a beneficial effect of oat beta-glucans with high molar mass in chronic gastritis in humans, resulting in reduced mucosal damage and healthy changes in SCFA fecal concentration and peripheral blood serum glutathione metabolism and antioxidant defense parameters. This fraction of a highly purified oat beta-glucan is safe for humans. Its action is effective after 30 days of use, which sheds new light on the nutritional treatment of chronic gastritis.

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.

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.

Effects of losartan and l-serine in a mouse liver fibrosis model

Hepatic fibrosis is a common liver disease caused by excessive collagen deposition in the liver. Since liver transplantation is the only current treatment for cirrhosis with worsened fibrosis, a new strategy to develop anti-fibrosis drugs with no adverse effects is necessary. In recent studies, amino acids have been applied as a type of therapy in various fields. l-serine plays a major role in antioxidant production via the maintenance of nicotinamide adenine dinucleotide phosphate hydride production in the mitochondria. l-serine may reduce fibrotic lesions in a mouse model of chronic liver injury. This study used 27 six-week-old C57BL/6 mice and injected them three times a week for eight weeks with carbon tetrachloride (CCl₄) (1.5 mg/kg, 10% v/v CCl₄ in olive oil) to create a hepatic fibrosis mouse model. The mice, which weighed approximately 20-30 g, were randomly classified into four groups: 1) the olive oil group, which received intraperitoneal injection of olive oil (1.5 mg/kg, 3 times per week for 8 weeks); 2) the CCl4-only group; 3) the CCl4 + losartan (10 mg/kg, PO, 5 days on, weekend off for 8 weeks) group; and 4) the CCl4 + l-serine (100 g/L, free access for 8 weeks) group. Hematoxylin and eosin staining and Masson's trichrome staining showed reduced inflammatory cell deposition and collagen deposition in the liver tissue in the l-serine supplemented group. l-serine was found to reduce the spread of hepatic fibrosis and has potential use in clinical settings. Based on these histopathological observations, l-serine is a potential anti-fibrosis drug.

Patients with cirrhosis during the COVID-19 pandemic: Current evidence and future perspectives

The outbreak of coronavirus disease-2019 (COVID-19) has resulted in a global public health emergency. Patients with cirrhosis were deemed more susceptible to viral infection because of their dysregulated immune response. Similar to the general population, cirrhotic patients exhibit various degrees of COVID-19-related liver injury, which could be attributed to direct virus cytotoxicity, systemic immune system activation, drug-related liver injury, reactivation of pre-existing liver disease, and hypoxic hepatitis. The clinical symptoms in patients with cirrhosis and COVID-19 were similar to those in the general population with COVID-19, with a lower proportion of patients with gastrointestinal symptoms. Although respiratory failure is the predominant cause of mortality in cirrhotic patients with COVID-19, a significant proportion of them lack initial respiratory symptoms. Most evidence has shown that cirrhotic patients have relatively higher rates of morbidity and mortality associated with COVID-19. Advanced cirrhosis was also proposed as an independent factor affecting a poor prognosis and the need to consider COVID-19 palliative care. General measures implemented to prevent the transmission of the virus are also essential for cirrhotic patients, and they should also receive standard cirrhosis care with minimal interruptions. The efficacy of the available COVID-19 vaccines in cirrhotic patients still needs investigation.