Glutathione defense mechanism in liver injury: insights from animal models. Food Chem Toxicol. 2013;60:38-44. [PMID: 23856494 DOI: 10.1016/j.fct.2013.07.008]

Liver epigenomic signature associated with chronic oxidative stress in a mouse model of glutathione deficiency

Oxidative stress is intimately involved in the pathogenesis of fatty liver disease (FLD). A major factor contributing to oxidative stress is the depletion of the ubiquitous antioxidant glutathione (GSH). Unexpectedly, chronic GSH deficiency renders glutamate-cysteine ligase modifier subunit (Gclm)-null mice protected from fatty liver injuries. Epigenetic regulation serves as an important cellular mechanism in modulating gene expression and disease outcome in FLD, although it is not well understood how systemic redox imbalance modifies the liver epigenome. In the current study, utilizing the Gclm-null mouse model, we aimed to elucidate redox-associated epigenomic changes and their implications in liver stress response. We performed high-throughput array-based DNA methylation profiling (MeDIP array) in 22,327 gene promoter regions (from -1300 bp to +500 bp of the Transcription Start Sites) in the liver and peripheral blood cells. Results from the MeDIP array demonstrate that, although global methylation enrichment in gene promoters did not change, low GSH resulted in prevalent demethylation at the individual promoter level. Such an effect likely attributed to a declined availability of the methyl donor S-adenosyl methionine (SAM) in Gclm-null liver. Functional enrichment analysis of liver target genes is suggestive of a potential role of epigenetic mechanisms in promoting cellular survival and lipid homeostasis in Gclm-null liver. In comparison with the liver tissue, MeDIP array in peripheral blood cells revealed a panel of 19 gene promoters that are candidate circulating biomarkers for hepatic epigenomic changes associated with chronic GSH deficiency. Collectively, our results provided new insights into the in vivo interplay between liver redox state and DNA methylation status. The current study laid the groundwork for future epigenetic/epigenomic investigations in experimental settings or human populations under conditions of liver oxidative stress induced by environmental or dietary challenges.

L-Cysteine: A promising nutritional supplement for alleviating anxiety disorders

Anxiety disorders are prevalent chronic psychological disease with complex pathogenic mechanisms. Current anxiolytics have limited efficacy and numerous side effects in many anxiety patients, highlighting the urgent need for new therapies. Recent research has been focusing on nutritional supplements, particularly amino acids, as potential therapies for anxiety disorders. Among these, L-Cysteine plays a crucial role in various biological processes. L-Cysteine exhibits antioxidant properties that can enhance the antioxidant functions of the central nervous system (CNS). Furthermore, metabolites of L-cysteine, such as glutathione and hydrogen sulfide have been shown to alleviate anxiety through distinct molecular mechanisms. Long-term administration of L-Cysteine has anxiolytic, antidepressant, and memory-improving effects. L-Cysteine depletion can lead to increased oxidative stress in the brain. This review delves into the potential mechanisms of L-Cysteine and its main products, glutathione (GSH) and hydrogen sulfide (H2S) in the management of anxiety and related diseases.

Molecular mechanism of geniposide against ANIT-induced intrahepatic cholestasis by integrative analysis of transcriptomics and metabolomics

Geniposide (GE), a bioactive compound extracted from the fruit of Gardenia jasminoides Ellis, has attracted significant attention for its hepatoprotective therapeutic applications. Although GE displays a protective effect on treating intrahepatic cholestasis (IC), the underlying mechanism remains elusive. In this study, we aimed to elucidate the pharmacological mechanisms of GE in treating IC by an integrated analysis of transcriptomics and metabolomics. Firstly, we evaluated the hepatoprotective effect of GE in α-naphthylisothiocyanate (ANIT)-induced IC rats by examining biochemical indices, inflammatory factors, and oxidative stress levels. Secondly, by transcriptomics and serum metabolomics, we identified differentially expressed genes and metabolites, revealing phenotype-related metabolic pathways and gene functions. Lastly, we screened the core targets of GE in the treatment of IC by integrating transcriptomic and metabolomic data and validated these targets using western blotting. The results indicated that GE improved serum indexes and alleviated inflammation reactions and oxidative stress in the liver. The transcriptomics analysis revealed 739 differentially expressed genes after GE treatment, mainly enriched in retinol metabolism, steroid hormone synthesis, PPAR signal transduction, bile secretion metabolism, and other pathways. The metabolomics analysis identified 98 differential metabolites and 10 metabolic pathways. By constructing a "genes-targets-pathways-compounds" network, we identified two pathways: the bile secretion pathway and the glutathione pathway. Within these pathways, we discovered nine crucial targets that were subsequently validated through western blotting. The results revealed that the GE group significantly increased the expression of ABCG5, NCEH1, OAT3, and GST, compared with the ANIT group. We speculate that GE has a therapeutic effect on IC by modulating the bile secretion pathway and the glutathione pathway and regulating the expression of ABCG5, NCEH1, OAT3, and GST.

X chromosome dosage drives statin-induced dysglycemia and mitochondrial dysfunction

Statin drugs lower blood cholesterol levels for cardiovascular disease prevention. Women are more likely than men to experience adverse statin effects, particularly new-onset diabetes (NOD) and muscle weakness. Here we find that impaired glucose homeostasis and muscle weakness in statin-treated female mice are associated with reduced levels of the omega-3 fatty acid, docosahexaenoic acid (DHA), impaired redox tone, and reduced mitochondrial respiration. Statin adverse effects are prevented in females by administering fish oil as a source of DHA, by reducing dosage of the X chromosome or the Kdm5c gene, which escapes X chromosome inactivation and is normally expressed at higher levels in females than males. As seen in female mice, we find that women experience more severe reductions than men in DHA levels after statin administration, and that DHA levels are inversely correlated with glucose levels. Furthermore, induced pluripotent stem cells from women who developed NOD exhibit impaired mitochondrial function when treated with statin, whereas cells from men do not. These studies identify X chromosome dosage as a genetic risk factor for statin adverse effects and suggest DHA supplementation as a preventive co-therapy.

Ultrasensitive upconverting nanoprobes for in situ imaging of drug-induced liver injury using miR-122 as the biomarker

Drug-induced liver injury (DILI) is a frequent adverse drug reaction. The current clinical diagnostic methods are inadequate for accurate and early detection of DILI due to the lack of effective diagnostic biomarkers. Hepatocyte-specific miR-122 is released from injured hepatocytes promptly and its efflux is significantly correlated with the progression of DILI. Therefore, achieving precise in situ detection of miR-122 with high sensitivity is vital for early visualization of DILI. Herein, a new nanoprobe, consisting of miR-122 aptamer, upconversion nanoparticles (UCNPs) and Prussian blue nanoparticles (PBNPs) was introduced for the early and sensitive detection of DILI in situ. As the nanoprobes reached in the liver, miR-122 aptamer-based entropy-driven strand displacement (ESDR) signal amplification reaction was triggered and luminescence resonance energy transfer (LRET) between UCNPs and PBNPs was responded to achieve the high-fidelity detection of DILI. A negative correlation was observed between the intensity of upconversion luminescence (UCL) and the concentration of miR-122. UCL imaging conducted both in vivo and ex vivo indicated that a reduction in miR-122 concentration led to an increase in UCL intensity, revealing a precise state of DILI. The detection technique demonstrated a positive correlation between signal intensity and severity, offering a more straightforward and intuitive method of visualizing DILI.

Development of hepatic steatosis in male and female mule ducks after respective force-feeding programs

Male and female mule ducks were subjected to a force-feeding diet to induce liver steatosis as it is generally done only with male ducks for the production of foie gras. The different biochemical measurements indicated that the course of hepatic steatosis development was present in both sexes and associated with a huge increase in liver weight mainly due to the synthesis and accumulation of lipids in hepatocytes. In livers of male and female ducks, this lipid accumulation was associated with oxidative stress and hypoxia. However, certain specific modifications (kinetics of lipid droplet development and hepatic inflammation) indicate that female ducks may tolerate force-feeding less well, at least at the hepatic level. This is in contradiction with what is generally reported concerning hepatic steatosis induced by dietary disturbances in mammals but could be explained by the very specific conditions imposed by force-feeding. Despite this, force-feeding female ducks seems entirely feasible, provided that the final quality of the product is as good as that of the male ducks, which will remain to be demonstrated in future studies.

Discovery of genomic loci for liver health and steatosis reveals overlap with glutathione redox genetics

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in the United States, encompassing a wide spectrum of liver pathologies including steatosis, steatohepatitis, fibrosis, and cirrhosis. Despite its high prevalence, there are no medications currently approved by the Food and Drug Administration for the treatment of NAFLD. Recent work has suggested that NAFLD has a strong genetic component and identifying causative genes will improve our understanding of the molecular mechanisms contributing to NAFLD and yield targets for future therapeutic investigations. Oxidative stress is known to play an important role in NAFLD pathogenesis, yet the underlying mechanisms accounting for disturbances in redox status are not entirely understood. To better understand the relationship between the glutathione redox system and signs of NAFLD in a genetically-diverse population, we measured liver weight, serum biomarkers aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and graded liver pathology in a large cohort of Diversity Outbred mice. We compared hepatic endpoints to those of the glutathione redox system previously measured in the livers and kidneys of the same mice, and we screened for statistical and genetic associations using the R/qtl2 software. We discovered several novel genetic loci associated with markers of liver health, including loci that were associated with both liver steatosis and glutathione redox status. Candidate genes within each locus point to possible new mechanisms underlying the complex relationship between NAFLD and the glutathione redox system, which could have translational implications for future studies targeting NAFLD pathology.

The role of anoctamin 1 in liver disease

Liver diseases include all types of viral hepatitis, alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), cirrhosis, liver failure (LF) and hepatocellular carcinoma (HCC). Liver disease is now one of the leading causes of disease and death worldwide, which compels us to better understand the mechanisms involved in the development of liver diseases. Anoctamin 1 (ANO1), a calcium-activated chloride channel (CaCC), plays an important role in epithelial cell secretion, proliferation and migration. ANO1 plays a key role in transcriptional regulation as well as in many signalling pathways. It is involved in the genesis, development, progression and/or metastasis of several tumours and other diseases including liver diseases. This paper reviews the role and molecular mechanisms of ANO1 in the development of various liver diseases, aiming to provide a reference for further research on the role of ANO1 in liver diseases and to contribute to the improvement of therapeutic strategies for liver diseases by regulating ANO1.

Quillaja saponin mitigates methotrexate-provoked renal injury; insight into Nrf-2/Keap-1 pathway modulation with suppression of oxidative stress and inflammation

BACKGROUND

Methotrexate (MTX) is an antineoplastic/immunosuppressive drug, whose clinical use is impeded owing to its serious adverse effects; one of which is acute kidney injury (AKI). Most of MTX complications emerged from the provoked pro-oxidant-, pro-inflammatory- and pro-apoptotic effects. Quillaja saponaria bark saponin (QBS) is a bioactive triterpene that has been traditionally used as an antitussive, anti-inflammatory supplement, and to boost the immune system due to its potent antioxidant- and anti-inflammatory activities. However, the protective/therapeutic potential of QBS against AKI has not been previously evaluated. This study aimed to assess the modulatory effect of QBS on MTX-induced reno-toxicity.

METHODS

Thirty-two male rats were divided into 4-groups. Control rats received oral saline (group-I). In group-II, rats administered QBS orally for 10-days. In group-III, rats were injected with single i.p. MTX (20 mg/kg) on day-5. Rats in group-IV received QBS and MTX. Serum BUN/creatinine levels were measured, as kidney-damage-indicating biomarkers. Renal malondialdehyde (MDA), reduced-glutathione (GSH) and nitric-oxide (NOx) were determined, as oxidative-stress indices. Renal expression of TNF-α protein and Nrf-2/Keap-1 mRNAs were evaluated as regulators of inflammation. Renal Bcl-2/cleaved caspase-3 immunoreactivities were evaluated as apoptosis indicators.

RESULTS

Exaggerated kidney injury upon MTX treatment was evidenced histologically and biochemically. QBS attenuated MTX-mediated renal degeneration, oxidant-burden enhancement, excessive inflammation, and proapoptotic induction. Histopathological analysis further confirmed the reno-protective microenvironment rendered by QBS.

CONCLUSIONS

In conclusion, our results suggest the prophylactic and/or therapeutic effects of QBS in treating MTX-induced AKI. Such reno-protection is most-likely mediated via Nrf-2 induction that interferes with oxidant load, inflammatory pathways, and proapoptotic signaling.

LINC00942 Alleviates NaAsO2-induced Apoptosis by Promoting GSH Synthesis Through Targeting miR-214-5p

The mechanism of arsenic-induced liver toxicity is not fully understood. This study aimed to investigate the role of LINC00942 in arsenic-induced hepatotoxicity by regulating miR-214-5p. As the exposure dose of NaAsO2 gradually increases, cell viability, intracellular GSH content, ΔΨm, and the protein levels of GCLC and GCLM were reduced significantly. Apoptosis rate, ROS, and expression of apoptosis-related and NF-κB pathway proteins increased. The expression of LINC00942 was increased, while the expression of miR-214-5p was decreased. After suppressing LINC00942 levels, NaAsO2 exposure further decreased cell viability, intracellular GSH content, ΔΨm, GCLC protein, and miR-214-5p expression. The apoptosis rate, ROS, and apoptosis-related and NF-κB pathway proteins further increased. miR-214-5p is targeted and negatively regulated by LINC00942. After miR-214-5p was overexpressed, NaAsO2 further decreased cell viability, intracellular GSH content, ΔΨm, and GCLC protein expression compared to NaAsO2 exposure. The apoptosis rate, ROS, apoptosis-related and NF-κB pathway proteins p65, and IKKβ were higher than those exposed to NaAsO2. LINC00942 inhibitor along with miR-214-5p inhibitor combined with NaAsO2 treatment resulted in increased cell viability, GSH, Bcl-2, and GCLC protein expression and decreased apoptosis rate, apoptosis related, p65, IKKβ protein, and ΔΨm, as compared to the combined NaAsO2 and si LINC00942 group. NaAsO2 exposure induces oxidative damage and apoptosis in LX-2 cells by activating NF-κB and inhibiting GSH synthesis. During this process, the expression level of LINC00942 increases, targeting to reduce the level of miR-214-5p, then weakening the effect of NaAsO2 on NF-κB, thereby alleviating cellular oxidative damage and playing a protective role.

Engineered exosomes with enhanced stability and delivery efficiency for glioblastoma therapy

Due to the blood-brain barrier (BBB), the application of chemical drugs for glioblastoma treatment is severely limited. Recently, exosomes have been widely applied for drug delivery to the brain. However, the differences in brain targeting efficiency among exosomes derived from different cell sources, as well as the premature drug leakage during circulation, still limit the therapeutic efficacy. Here, we designed a functional oligopeptide-modified exosome loaded with doxorubicin (Pep2-Exos-DOX) for glioblastoma treatment. BV2 mouse microglial cell line was selected as the exosome source due to the favorable BBB penetration. To avoid drug release in the circulation, a redox-response oligopeptide was designed for incorporation into the membranes of exosomes to lock the drug during circulation. The enrichment of the drug in glioblastoma was confirmed. Pharmacodynamic evaluation showed Pep2-Exos-DOX possessed significant anti-cancer activity against glioblastoma as well as relative biosafety. This exosome-based drug delivery system modified with redox-response oligopeptides provides us a novel strategy for brain diseases treatment.

Repurposing N-acetylcysteine for management of non-acetaminophen induced acute liver failure: an evidence scan from a global health perspective

Background

The World Health Organization (WHO)'s Essential Medicines List (EML) plays an important role in advocating for access to key treatments for conditions affecting people in all geographic settings. We applied our established drug repurposing methods to one EML agent, N-acetylcysteine (NAC), to identify additional uses of relevance to the global health community beyond its existing EML indication (acetaminophen toxicity).

Methods

We undertook a phenome-wide association study (PheWAS) of a variant in the glutathione synthetase (GSS) gene in approximately 35,000 patients to explore novel indications for use of NAC, which targets glutathione. We then evaluated the evidence regarding biologic plausibility, efficacy, and safety of NAC use in the new phenotype candidates.

Results

PheWAS of GSS variant R418Q revealed increased risk of several phenotypes related to non-acetaminophen induced acute liver failure (ALF), indicating that NAC may represent a therapeutic option for treating this condition. Evidence review identified practice guidelines, systematic reviews, clinical trials, retrospective cohorts and case series, and case reports. This evidence suggesting benefit of NAC use in this subset of ALF patients. The safety profile of NAC in this literature was also concordant with existing evidence on safety of this agent in acetaminophen-induced ALF.

Conclusions

This body of literature indicates efficacy and safety of NAC in non-acetaminophen induced ALF. Given the presence of NAC on the EML, this medication is likely to be available across a range of resource settings; promulgating its use in this novel subset of ALF can provide healthcare professionals and patients with a valuable and safe complement to supportive care for this disease.

L-cysteine improves boar semen motility at 5 ºC but does not affect the oxidative status

Hypothermic storage has been proposed as a method to reduce bacterial loads and promoting prudent use of antibiotics. Reducing temperature, however, can lead to cold shock damage and oxidative stress in boar semen. This study verified the effect of L-cysteine on the quality of semen stored at 5 °C for 120 h. Twenty-one normospermic ejaculates were diluted in Beltsville Thawing Solution into five treatments: Positive control (Pos_Cont, storage at 17 °C without L-cysteine) and groups with 0, 0.5, 1, and 2 mmol/L of L-cysteine supplementation stored at 5 °C. Variables were analyzed as repeated measures, considering treatment, storage time, and interaction as main factors. The effects of different L-cysteine concentrations were also evaluated using polynomial orthogonal contrasts. Sperm motility and pH were higher in the Pos_Cont compared to the groups stored at 5 °C (P < 0.05). In polynomial orthogonal contrast models, total motility was affected by the interaction between L-cysteine and storage time (P = 0.04), with a linear increase in motility when increasing the amount of L-cysteine at 72 and 120 h. Progressive motility increased quadratically as the L-cysteine reached 1 mmol/L (P < 0.01). In the thermoresistance test at 120 h, sperm motility increased quadratically up to an L-cysteine dose of 1 mmol/L (P < 0.05). Sulfhydryl content linearly increased with L-cysteine supplementation (P = 0.01), with no effect on intracellular ROS and sperm lipid peroxidation (P ≥ 0.06) in 5ºC-stored doses. In conclusion, L-cysteine supplementation has a positive effect on sperm motility up to 120 h of storage at 5 °C.

Mitochondrial Dysfunction in Metabolic Dysfunction Fatty Liver Disease (MAFLD)

Nonalcoholic fatty liver disease (NAFLD) has become an increasingly common disease in Western countries and has become the major cause of liver cirrhosis or hepatocellular carcinoma (HCC) in addition to viral hepatitis in recent decades. Furthermore, studies have shown that NAFLD is inextricably linked to the development of extrahepatic diseases. However, there is currently no effective treatment to cure NAFLD. In addition, in 2020, NAFLD was renamed metabolic dysfunction fatty liver disease (MAFLD) to show that its pathogenesis is closely related to metabolic disorders. Recent studies have reported that the development of MAFLD is inextricably associated with mitochondrial dysfunction in hepatocytes and hepatic stellate cells (HSCs). Simultaneously, mitochondrial stress caused by structural and functional disorders stimulates the occurrence and accumulation of fat and lipo-toxicity in hepatocytes and HSCs. In addition, the interaction between mitochondrial dysfunction and the liver-gut axis has also become a new point during the development of MAFLD. In this review, we summarize the effects of several potential treatment strategies for MAFLD, including antioxidants, reagents, and intestinal microorganisms and metabolites.

Spatially Resolved Co-Imaging of Polyhalogenated Xenobiotics and Endogenous Metabolites Reveals Xenobiotic-Induced Metabolic Alterations

A large group of polyhalogenated compounds has been added to the list of persistent organic pollutants in a global convention endorsed by over 100 nations. Once entering the biotas, these pollutants are transported to focal sites of toxicological action and affected endogenous metabolites, which exhibited distinct tissue or organ distribution patterns. However, no study is available to achieve simultaneous mapping of the spatial distributions of xenobiotics and endogenous metabolites for clarifying the molecular mechanism of toxicities. Herein, we present a sensitive mass spectrometry imaging method─tetraphenyl phosphonium chloride-enhanced ionization coupled with air flow-assisted ionization-Orbitrap mass spectrometry─which simultaneously determined the spatial distributions of polyhalogenated xenobiotics and endogenous metabolites. The spatially resolved toxicokinetics and toxicodynamics of typical polyhalogenated compounds (chlorinated paraffins (CPs) and hexabromocyclododecane (HBCD)) were assessed in zebrafish. Co-imaging of polyhalogenated compounds and metabolites visualized the major accumulation organs and maternal transfer of HBCD and CPs, and it clarified the reproductive toxicity of HBCD. CPs were accumulated in the liver, heart, and brain and decreased the concentrations of polyamine/inosine-related metabolites and lipid molecules in these organs. HBCD accumulated in the ovary and was effectively transferred to eggs, and it also disrupted normal follicular development and impaired the production of mature eggs from the ovary by inhibiting expressions of the luteinizing hormone/choriogonadotropin receptor gene. The toxic effects of metabolic disruptions were validated by organ-specific histopathological examinations. These results highlight the necessity to assess the distributions and bioeffects of pollutants in a spatial perspective.

Slc7a11 stimulates glutathione synthesis to preserve fatty acid metabolism in primary hepatocytes

Primary hepatocytes are widely used as a tool for studying metabolic function and regulation in the liver. However, the metabolic properties of primary hepatocytes are gradually lost after isolation. Here, we illustrated that fatty acid metabolism is the major compromised metabolic process in isolated primary hepatocytes, along with drastically decreased GSH and ROS content, while lipid peroxidation is increased. Gain- and loss-of-function studies revealed that Slc7a11 expression is critical in maintaining fatty acid metabolism and facilitating hormone-induced fatty acid metabolic events, which is synergistic with dexamethasone treatment. Intriguingly, Slc7a11 expression and dexamethasone treatment cooperatively upregulated AKT and AMPK signaling and mitochondrial complex expression in primary hepatocytes. Furthermore, direct treatment with reduced GSH or inhibition of ferroptosis is sufficient to drive protective effects on fatty acid metabolism in primary hepatocytes. Our results demonstrate that Slc7a11 expression in isolated primary hepatocytes induces GSH production, which protects against ferroptosis, to increase fatty acid metabolic gene expression, AKT and AMPK signaling and mitochondrial function in synergy with dexamethasone treatment, thereby efficiently preserving primary hepatocyte metabolic signatures, thus providing a promising approach to better reserve primary hepatocyte metabolic activities after isolation to potentially improve the understanding of liver biological functions from studies using primary hepatocytes.

Glutathione Might Attenuate Arsenic-Induced Liver Injury by Modulating the Foxa2-XIAP Axis to Reduce Oxidative Stress and Mitochondrial Apoptosis

Arsenic (AS) is a metalloid element that widely exists and can cause different degrees of liver damage. The molecular mechanism of arsenic-induced liver injury has yet to be fully elucidated. Clinically, glutathione (GSH) is often used as an antidote for heavy metal poisoning and hepatoprotective drugs. However, the hepatoprotective effect of glutathione remains unknown in arsenic-induced liver injury. The regulatory relationship between Foxa2 and XIAP may play an important role in mitochondrial survival and death. Therefore, we took Foxa2-XIAP as the axis to explore the protective mechanism of GSH. In this study, we first established a mouse model of chronic arsenic exposure and examined liver function as reflected by quantitative parameters such as aspartate aminotransferase and alanine aminotransferase. Also, redox parameters in the liver were measured, including malondialdehyde, superoxide dismutase, 8-hydroxy-2'-deoxyguanosin, and glutathione peroxidase. RT-qPCR and western-blotting were used to detect the levels of related genes and proteins, such as Foxa2, XIAP, Smac, Bax, Bcl2, Caspase9, and Caspase3. Subsequently, GSH was administered at the same time as high arsenic exposure, and changes in the above parameters were observed. After a comprehensive analysis of the above results, we demonstrate that GSH treatment alleviates arsenic-induced oxidative stress and inhibits the mitochondrial pathway of apoptosis, which can be regulated through the Foxa2 and XIAP axis. The present study would be helpful in elucidating the molecular mechanism of arsenic-induced liver injury and identifying a new potential therapeutic target. And we also provided new theoretical support for glutathione in the treatment of liver damage caused by arsenic.

Theaflavine inhibits hepatic stellate cell activation by modulating the PKA/LKB1/AMPK/GSK3β cascade and subsequently enhancing Nrf2 signaling

Activation of hepatic stellate cells (HSCs) constitutes a crucial etiological factor leading to liver fibrosis. Theaflavine (TF) is a characteristic bioactive compound in fermented tea. Here, we found that TF attenuated the activation of LX-2 HSCs induced by transforming growth factor-β1 (TGF-β1). TF potentiated nuclear factor erythroid 2-related Factor 2 (Nrf2) signaling. Knockdown of Nrf2 abrogated TF-mediated resistance to TGF-β1. Liver kinase B1 (LKB1), AMP-activated kinase (AMPK), and glycogen synthase kinase-3β (GSK3β) are upstream regulators of Nrf2. TF modulated the LKB1/AMPK/GSK3β axis. Inhibition of AMPK or knockdown of LKB1 crippled TF-mediated potentiation of Nrf2. Protein kinase A (PKA) catalyzes LKB1 phosphorylation. In LX-2 cells, TF increased the LKB1/PKA interaction without affecting their contents. Inhibition of PKA abolished TF-mediated potentiation of LKB1/Nrf2 and abrogated the inhibitory effects of TF on their activation. TF also enhanced direct binding between purified catalytic subunit α of PKA (PKA-Cα) and LKB1 proteins in vitro. Molecular docking indicated that TF showed binding activity with both LKB1 and PKA-Cα proteins. In mouse primary HSCs, TF elevated LKB1/PKA-Cα binding, boosted LKB1 phosphorylation, potentiated Nrf2 and suppressed their spontaneous activation. PKA inhibition or LKB1 knockdown eliminated TF-mediated induction of Nrf2 and suppression of HSC activation. Furthermore, TF considerably alleviated CCl4-induced mouse liver fibrosis. In mouse livers, TF increased the LKB1/PKA-Cα interaction, upregulated LKB1 phosphorylation and modulated its downstream AMPK/GSK3β/Nrf2 cascade. Our findings collectively indicated that TF suppresses HSC activation. Mechanistically, TF elevated the LKB1/PKA interaction in HSCs, which increased LKB1 phosphorylation and subsequently modulated the downstream AMPK/GSK3β/Nrf2 axis.

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.

Mitochondrial heterogeneity in diseases

As key organelles involved in cellular metabolism, mitochondria frequently undergo adaptive changes in morphology, components and functions in response to various environmental stresses and cellular demands. Previous studies of mitochondria research have gradually evolved, from focusing on morphological change analysis to systematic multiomics, thereby revealing the mitochondrial variation between cells or within the mitochondrial population within a single cell. The phenomenon of mitochondrial variation features is defined as mitochondrial heterogeneity. Moreover, mitochondrial heterogeneity has been reported to influence a variety of physiological processes, including tissue homeostasis, tissue repair, immunoregulation, and tumor progression. Here, we comprehensively review the mitochondrial heterogeneity in different tissues under pathological states, involving variant features of mitochondrial DNA, RNA, protein and lipid components. Then, the mechanisms that contribute to mitochondrial heterogeneity are also summarized, such as the mutation of the mitochondrial genome and the import of mitochondrial proteins that result in the heterogeneity of mitochondrial DNA and protein components. Additionally, multiple perspectives are investigated to better comprehend the mysteries of mitochondrial heterogeneity between cells. Finally, we summarize the prospective mitochondrial heterogeneity-targeting therapies in terms of alleviating mitochondrial oxidative damage, reducing mitochondrial carbon stress and enhancing mitochondrial biogenesis to relieve various pathological conditions. The possibility of recent technological advances in targeted mitochondrial gene editing is also discussed.

Phytochemical Properties of Croton gratissimus Burch (Lavender Croton) Herbal Tea and Its Protective Effect against Iron-Induced Oxidative Hepatic Injury

Oxidative stress plays a vital role in the pathogenesis and progression of various liver diseases. Traditional medicinal herbs have been used worldwide for the treatment of chronic liver diseases due to their high phytochemical constituents. The present study investigated the phytochemical properties of Croton gratissimus (lavender croton) leaf herbal tea and its hepatoprotective effect on oxidative injury in Chang liver cells, using an in vitro and in silico approach. C. gratissimus herbal infusion was screened for total phenolic and total flavonoid contents as well as in vitro antioxidant capacity using ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) methods. Oxidative hepatic injury was induced by incubating 0.007 M FeSO4 with Chang liver cells which has been initially incubated with or without different concentrations (15-240 μg/mL) of C. gratissimus infusion or the standard antioxidants (Gallic acid and ascorbic acid). C. gratissimus displayed significantly high scavenging activity and ferric reducing capacity following DPPH and FRAP assays, respectively. It had no cytotoxic effect on Chang liver cells. C. gratissimus also significantly elevated the level of hepatic reduced glutathione (GSH), superoxide dismutase (SOD), and catalase activities as well as suppressed the malondialdehyde (MDA) level in oxidative hepatic injury. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis of the herbal tea revealed the presence of 8-prenylnaringenin, flavonol 3-O-D-galactoside, caffeine, spirasine I, hypericin, pheophorbide-a, and 4-methylumbelliferone glucuronide. In silico oral toxicity prediction of the identified phytochemicals revealed no potential hepatotoxicity. Molecular docking revealed potent molecular interactions of the phytochemicals with SOD and catalase. The results suggest the hepatoprotective and antioxidative potentials of C. gratissimus herbal tea against oxidative hepatic injury.

Evaluation of Acute and Sub-Acute Toxicity, Oxidative Stress and Molecular Docking of Two Nitrofuranyl Amides as Promising Anti-Tuberculosis Agents

Tuberculosis (TB) remains a widespread infectious disease and one of the top 10 causes of death worldwide. Nevertheless, despite significant advances in the development of new drugs against tuberculosis, many therapies and preventive measures do not lead to the expected favorable health results for various reasons. The aim of this study was to evaluate the acute and sub-acute toxicity and oxidative stress of two selected nitrofuranyl amides with high in vitro antimycobacterial activity. In addition, molecular docking studies were performed on both compounds to elucidate the possibilities for further development of new anti-tuberculosis candidates with improved efficacy, selectivity, and pharmacological parameters. Acute toxicity tests showed that no changes were observed in the skin, coat, eyes, mucous membranes, secretions, and vegetative activity in mice. The histological findings include features consistent with normal histological architecture without being associated with concomitant pathological conditions. The observed oxidative stress markers indicated that the studied compounds disturbed the oxidative balance in the mouse liver. Based on the molecular docking, compound DO-190 showed preferable binding energies compared to DO-209 in three out of four targets, while both compounds showed promising protein-ligand interactions. Thus, both studied compounds displayed promising activity with low toxicity and can be considered for further evaluation and/or lead optimization.

Evaluation of the cytotoxicity and genotoxicity potential of synthetic diacetyl food flavoring in silico, in vivo, and in vitro

Diacetyl is a common ingredient that creates a buttery flavor in baked goods and other food products. The cytotoxic impact of diacetyl on a normal human liver cell line (THLE2) indicated an IC₅₀ value of 41.29 mg/ml through MTT assay and a cell cycle arrest in the G₀/G₁ phase relative to the control. Administration of diacetyl at two-time points (acute-chronic) led to a significant increase in DNA damage indicated by the increase in tail length, tail DNA%, and tail moment. The mRNA and protein expression levels of genes in the rats' livers were then measured using real-time PCR and western blotting. The results showed an activation of the apoptotic and necrosis mechanism, with an upregulation of p53, Caspase 3, and RIP1 and a downregulation of Bcl-2 at the mRNA level. The ingestion of diacetyl disrupted the liver's oxidant/antioxidant balance, as evidenced by alterations in levels of GSH, SOD, CAT, GPx, GR, MDA, NO, and peroxynitrite. Additionally, heightened levels of inflammatory cytokines were shown. Histopathological examinations revealed necrotic foci and congested portal areas in the rats' liver cells after treatment with diacetyl. Diacetyl may interact moderately with Caspase, RIP1, and p53 core domain through In-silico, possibly resulting in upregulated gene expression.

Anti-obesity mechanism of Ganpu tea revealed by microbiome, metabolome and transcriptome analyses

In this study, the anti-obesity mechanism of Ganpu tea (GPT) from the perspectives of microbiome, metabolome and transcriptome was investigated. GPT significantly reduced the high-fat-diet (HFD)-induced levels of inflammatory cytokines and the expansion of lipid droplets and white adipose tissue. GPT also improved HFD-induced gut microbiome imbalance by significantly reducing the proportion of Firmicutes to Bacteroidota. Metabolomic data showed that HFD-induced metabolic disorder was regulated by GPT and probably characterised by being related to 4-aminobutyraldehyde and 5-acetylamino-6-amino-3-methyluracil. Transcriptome showed that the improvement of obesity was mainly related to the IL-17 signaling pathway and the metabolism of xenobiotics by cytochrome P450. Spearman's correlation analysis indicated that gut microbiota were significantly correlated with inflammatory factors, genes and metabolites. Metabolome-transcriptome analysis showed that GPT reversed obesity mainly through the carbohydrate metabolism, amino acid metabolism and lipid metabolism.Collectively, GPT may be used as a health drink to prevent or treat obesity.

Exploring the Mechanism of Hepatotoxicity Induced by Dictamnus dasycarpus Based on Network Pharmacology, Molecular Docking and Experimental Pharmacology

The root bark of Dictamnus dasycarpus Turcz is a traditional Chinese medicine, Dictamni Cortex (DC), which is mainly used in the clinical treatment of skin inflammation, eczema, rubella, rheumatism, and gynecological inflammation. Unexpectedly, there are some cases of liver injury after the administration of DC. However, the mechanism of hepatotoxicity remains ambiguous. The aim of this study was to explore the mechanism and substance bases of DC hepatotoxicity based on network pharmacology and molecular docking, verified through pharmacological experiments. Partial prototype components and metabolites in vivo of quinoline alkaloids from DC were selected as candidate compounds, whose targets were collected from databases. Network pharmacology was applied to study the potential hepatotoxic mechanism after correlating the targets of candidate compounds with the targets of hepatotoxicity. Molecular docking was simulated to uncover the molecular mechanism. Furthermore, the hepatotoxicity of the extract and its constituents from DC was evaluated in vivo and in vitro. We constructed the "potential toxic components-toxic target-toxic pathway" network. Our results showed that the targets of DC included CYP1A2 and GSR, participating in heterologous steroid metabolism, REDOX metabolism, drug metabolism, heterocyclic metabolic processes, the synthesis of steroid hormone, cytochrome P450 metabolism, chemical carcinogens and bile secretion pathways. In vitro and in vivo experiments displayed that DC could result in a decrease in GSH-Px and oxidative stress, simultaneously inhibiting the expression of CYP1A2 and inducing hepatotoxicity. These results further indicated the mechanism of hepatotoxicity induced by Dictamnus dasycarpus, providing a basic theory to explore and prevent hepatotoxicity in the clinical usage of Dictamnus dasycarpus.

Impacts of microgravity on amino acid metabolism during spaceflight

Spaceflight exerts an extreme and unique influence on human physiology as astronauts are subjected to long-term or short-term exposure to microgravity. During spaceflight, a multitude of physiological changes, including the loss of skeletal muscle mass, bone resorption, oxidative stress, and impaired blood flow, occur, which can affect astronaut health and the likelihood of mission success. In vivo and in vitro metabolite studies suggest that amino acids are among the most affected nutrients and metabolites by microgravity (a weightless condition due to very weak gravitational forces). Moreover, exposure to microgravity alters gut microbial composition, immune function, musculoskeletal health, and consequently amino acid metabolism. Appropriate knowledge of daily protein consumption, with a focus on specific functional amino acids, may offer insight into potential combative and/or therapeutic effects of amino acid consumption in astronauts and space travelers. This will further aid in the successful development of long-term manned space mission and permanent space habitats.

Cellular Compartmentalization, Glutathione Transport and Its Relevance in Some Pathologies

Reduced glutathione (GSH) is the most abundant non-protein endogenous thiol. It is a ubiquitous molecule produced in most organs, but its synthesis is predominantly in the liver, the tissue in charge of storing and distributing it. GSH is involved in the detoxification of free radicals, peroxides and xenobiotics (drugs, pollutants, carcinogens, etc.), protects biological membranes from lipid peroxidation, and is an important regulator of cell homeostasis, since it participates in signaling redox, regulation of the synthesis and degradation of proteins (S-glutathionylation), signal transduction, various apoptotic processes, gene expression, cell proliferation, DNA and RNA synthesis, etc. GSH transport is a vital step in cellular homeostasis supported by the liver through providing extrahepatic organs (such as the kidney, lung, intestine, and brain, among others) with the said antioxidant. The wide range of functions within the cell in which glutathione is involved shows that glutathione’s role in cellular homeostasis goes beyond being a simple antioxidant agent; therefore, the importance of this tripeptide needs to be reassessed from a broader metabolic perspective.

Revealing the In Situ Behavior of Aggregation-Induced Emission Nanoparticles and Their Biometabolic Effects via Mass Spectrometry Imaging

Simultaneous imaging of exogenous nanomaterials and endogenous metabolites in situ remains challenging and is beneficial for a systemic understanding of the biological behavior of nanomaterials at the molecular level. Here, combined with label-free mass spectrometry imaging, visualization and quantification of the aggregation-induced emission nanoparticles (NPs) in tissue were realized as well as related endogenous spatial metabolic changes simultaneously. Our approach enables us to identify the heterogeneous deposition and clearance behavior of nanoparticles in organs. The accumulation of nanoparticles in normal tissues results in distinct endogenous metabolic changes such as oxidative stress as indicated by glutathione depletion. The low passive delivery efficiency of nanoparticles to tumor foci suggested that the enrichment of NPs in tumors did not benefit from the abundant tumor vessels. Moreover, spatial-selective metabolic changes upon NPs mediated photodynamic therapy was identified, which enables understanding of the NPs induced apoptosis in the process of cancer therapy. This strategy allows us to simultaneously detect exogenous nanomaterials and endogenous metabolites in situ, hence to decipher spatial selective metabolic changes in drug delivery and cancer therapy processes.

Identification of alternative splicing events related to fatty liver formation in duck using full-length transcripts

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is one of most common diseases in the world. Recently, alternative splicing (AS) has been reported to play a key role in NAFLD processes in mammals. Ducks can quickly form fatty liver similar to human NAFLD after overfeeding and restore to normal liver in a short time, suggesting that ducks are an excellent model to unravel molecular mechanisms of lipid metabolism for NAFLD. However, how alternative splicing events (ASEs) affect the fatty liver process in ducks is still unclear.

RESULTS

Here we identify 126,277 unique transcripts in liver tissue from an overfed duck (77,237 total transcripts) and its sibling control (69,618 total transcripts). We combined these full-length transcripts with Illumina RNA-seq data from five pairs of overfed ducks and control individuals. Full-length transcript sequencing provided us with structural information of transcripts and Illumina RNA-seq data reveals the expressional profile of each transcript. We found, among these unique transcripts, 30,618 were lncRNAs and 1,744 transcripts including 155 lncRNAs and 1,589 coding transcripts showed significantly differential expression in liver tissues between overfed ducks and control individuals. We also detected 27,317 ASEs and 142 of them showed significant relative abundance changes in ducks under different feeding conditions. Full-length transcript profiles together with Illumina RNA-seq data demonstrated that 10 genes involving in lipid metabolism had ASEs with significantly differential abundance in normally fed (control) and overfed ducks. Among these genes, protein products of five genes (CYP4F22, BTN, GSTA2, ADH5, and DHRS2 genes) were changed by ASEs.

CONCLUSIONS

This study presents an example of how to identify ASEs related to important biological processes, such as fatty liver formation, using full-length transcripts alongside Illumina RNA-seq data. Based on these data, we screened out ASEs of lipid-metabolism related genes which might respond to overfeeding. Our future ability to explore the function of genes showing AS differences between overfed ducks and their sibling controls, using genetic manipulations and co-evolutionary studies, will certainly extend our knowledge of genes related to the non-pathogenic fatty liver process.

Fatal Epileptic Seizures in Mice Having Compromised Glutathione and Ascorbic Acid Biosynthesis

Reduced glutathione (GSH) and ascorbic acid (AA) are the two most abundant low-molecular-weight antioxidants in mammalian tissues. Gclm^KO knockout mice lack the gene encoding the modifier subunit of the rate-limiting enzyme in GSH biosynthesis; Gclm^KO mice exhibit 10-40% of normal tissue GSH levels and show no overt phenotype. Gulo^KO knockout mice, lacking a functional Gulo gene encoding L-gulono-γ-lactone oxidase, cannot synthesize AA and depend on dietary ascorbic acid for survival. To elucidate functional crosstalk between GSH and AA in vivo, we generated the Gclm^KO/Gulo^KO double-knockout (DKO) mouse. DKO mice exhibited spontaneous epileptic seizures, proceeding to death between postnatal day (PND)14 and PND23. Histologically, DKO mice displayed neuronal loss and glial proliferation in the neocortex and hippocampus. Epileptic seizures and brain pathology in young DKO mice could be prevented with AA supplementation in drinking water (1 g/L). Remarkably, in AA-rescued adult DKO mice, the removal of AA supplementation for 2-3 weeks resulted in similar, but more severe, neocortex and hippocampal pathology and seizures, with death occurring between 12 and 21 days later. These results provide direct evidence for an indispensable, yet underappreciated, role for the interplay between GSH and AA in normal brain function and neuronal health. We speculate that the functional crosstalk between GSH and AA plays an important role in regulating glutamatergic neurotransmission and in protecting against excitotoxicity-induced brain damage.

Evolution of oxidative stress markers in livers of ducks during force-feeding

Mule ducks have been force-fed to develop a hepatic steatosis, also called "foie gras", which is similar to the non-alcoholic fatty liver disease (NAFLD) described in humans and mammals. However, in hepatic steatosis resulting from force-feeding of ducks, very little is known about the fine biochemical events that occur due to the enormous and very rapid increase in total lipids that mainly accumulate in hepatocytes. To begin to reduce this lack of knowledge associated with the development of this specific hepatic steatosis, liver samples were taken at different times to follow the overall biochemical transformation of the liver as well as different markers of oxidative stress, hypoxia and apoptosis. The results indicate that the lipid content increases rapidly in the liver throughout the force-feeding period while the protein content decreases. The amount of hydroxyproline remains constant indicating that no liver fibrosis develops during the force-feeding period. On the contrary, all the tested biomarkers of cellular oxidative stress increase rapidly but without any visible disorder in the coordination of paired activities. At the same time, hypoxia-inducible factors also increase indicating that a hypoxia situation is gradually occurring in hepatocytes. This leads, in addition to the lipotoxicity induced by the accumulation of lipids, to an increased number of liver cells to enter into apoptosis. A relative variability in the level of these cellular responses was also observed indicating that, probably, certain animals support the development of this steatosis differently. This leads us to imagine that the physiological status of these birds may differ widely for reasons that remain to be clarified.

Impacts of Oral Florfenicol Medication and Residues on the Kidney and Liver of Nile Tilapia Oreochromis niloticus (L.)

Florfenicol (FFC), an approved aquaculture antibiotic, is administered in feed at doses of 10-15 mg kg biomass^-1 day^-1 for 10 successive days. In this study, healthy Oreochromis niloticus were fed with 0-10 times the therapeutic dose of 15 mg kg biomass^-1 day^-1 for 10 days and tracked for 43 days post dosing. Assessments of residue accrual and depletion, oxidative stress, serum biochemistry, histopathology and extent of kidney and liver damages were made. FFC dosing reduced the feed intake significantly. The therapeutic dose produced no mortalities on day 10. Dose-dependent alterations in serum biochemistry were noted upon dosing. Several histopathological alterations were observed in the kidney and liver, which vindicated the toxic potentials of FFC. The residual FFC and florfenicol amine (FFA) accrual, depletion and oxidative stress responses, such as increased malondialdehyde, total nitric oxide, ferric reducing antioxidant power and reduced glutathione S-transferase activity, were documented. The dietary FFC persuaded the physiological state of O. niloticus, the effects of which normalized sparsely with time upon cessation of dosing at the higher doses. The study provided a brief outlook on the physiological responses upon oral FFC administration, which should be kept in mind during its application for fish health safety purposes.

Gomphrena globosa L. extract alleviates carbon tetrachoride-induced liver injury in mice by activating antioxidant signaling pathways and promoting autophagy

BACKGROUND

Carbon tetrachloride (CCl₄) is highly toxic to animal liver and is a major contributor to liver injury. Gomphrena globosa L. (GgL) is an edible plant with anti-inflammation and antioxidation properties. The aim of this study was to investigate the potential therapeutic effects of GgL on liver injury.

METHODS AND RESULTS

A model of chronic liver injury in mice was established by intraperitoneal injection of CCl₄ (0.4 mL/kg) for 3 weeks, and the mice were treated intraperitoneally with different concentrations of GgL crude extract (GgCE; 100, 200, 300 mg/kg) or Bifendatatum (Bif; 20 mg/kg) in the last 2 weeks. The results showed that GgCE treatment alleviated the liver injury, improved the pathological changes caused by CCl₄ on the mice liver, and enhance the antioxidant capacity. We also found that GgCE increased the expression of antioxidant stress related proteins, decreased the phosphorylation levels of autophagy related proteins PI3K and mTOR, and decreased the expression of LC3 II and P62 proteins.

CONCLUSION

These results suggest that GgCE alleviated CCl₄-induced chronic liver injury in mice by activating antioxidant signaling pathways and promoting autophagy, indicating a potential therapeutic effect of GgCE on liver injury.

Gene expression analysis of antioxidant and DNA methylation on the rat liver after 4-week wood preservative chromated copper arsenate exposure

Our previous 4-week repeated dose toxicity study showed that wood preservative chromated copper arsenate (CCA) induced hepatocellular hypertrophy accompanied by biochemical hepatic dysfunction and an increase in oxidative stress marker, 8-hydroxydeoxyguanosine, in female rats. To further explore the molecular mechanisms of CCA hepatotoxicity, we analyzed 10%-buffered formalin-fixed liver samples from female rats for cell proliferation, apoptosis, and protein glutathionylation and conducted microarray analysis on frozen liver samples from female rats treated with 0 or 80 mg/kg/day of CCA. Chemical analysis revealed that dimethylated arsenical was the major metabolite in liver tissues of male and female rats. CCA increase labeling indices of proliferating cell nuclear antigen and decrease terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling accompanied with increased expression of protein glutathionylation, indicating a decrease in glutathione (GSH) in hepatocytes of female rats. Microarray analysis revealed that CCA altered gene expression of antioxidants, glutathione-S-transferase (GST), heat shock proteins and ubiquitin-proteasome pathway, cell proliferation, apoptosis, DNA methylation, cytochrome P450, and glucose and lipid metabolism in female rats. Increased expression of GSTs, including Gsta2, Gsta3, Mgst1, and Cdkn1b (p27), and decreased expression of the antioxidant Mt1, and DNA methylation Dnmt1, Dnmt3a, and Ctcf were confirmed in the liver of female rats in a dose-dependent manner. Methylation status of the promoter region of the Mt1 was not evidently changed between control and treatment groups. The results suggested that CCA decreased GSH and altered the expression of several genes, including antioxidants, GST, and DNA methylation, followed by impaired cell proliferation in the liver of female rats.

6-Gingerdione Reduces Apoptotic Conditions in HepG2 Cells and Inhibits Inflammatory Cytokine Gene Expression in Alcoholic Liver Injured Zebrafish Larvae

Antioxidant natural products and their analogs especially phenolic compounds, exhibit diverse biological properties, including anti-inflammatory, antioxidant, and anticancer activities. Ginger which is widely used worldwide for various beneficial effects also contains several phenolic antioxidants, and 6-gingerol is one of the natural products studied extensively. However, the molecular mechanism of synthetically synthesized 6-gingerdione (compound 1) from 6-gingerol was not known. In this study, compound 1 and methylated 6-gingerdione (compound 2) were obtained semi synthetically from 6-gingerol. Compound 1 and 2 are subjected to SwissADME prediction. Then the protective effect of compound 1 was analyzed in 2 % EtOH induced HepG2 cells and zebrafish larvae. Hydroxyl and nitric oxide scavenging assays reveal that compound 1 showed more antioxidant activity than compound 2 at 50 μM. Moreover, compound 1 exhibited good anti-inflammatory activity via lipoxygenase inhibition and proteinase inhibition. Apoptosis and oxidative stress in HepG2 cells were induced by 2 % EtOH and treated with compound 1. Compound 1 significantly inhibited the EtOH induced nitric oxide production, apoptosis, and ROS generation in HepG2 cells. Encouraged by the in-vitro antioxidant and anti-inflammatory activities, compound 1 was then investigated for its protective effect in 2 % EtOH induced ALD zebrafish larva. Compound 1 protected the zebrafish larvae from liver injury by suppressing inflammatory (COX-2, TNF-α, and IL-1β) and lipogenic genes (C/EBP-α, SREBP1, and IL-1β) while upregulating the antioxidant gene. Our findings indicate that compound 1 synthesized from 6-gingerol ameliorated liver injury that likely, contributes to its potential antioxidant and anti-inflammatory properties.

THE ROLE OF OXIDATIVE STRESS IN PATIENTS WITH CHRONIC KIDNEY DISEASE

OBJECTIVE

The aim: To study the role of oxidative stress in patients with chronic kidney disease.

PATIENTS AND METHODS

Materials and methods: By evaluating MDA and GSH in the serum, we tried to find out how oxidative stress affects CKD patients with end-stage renal dysfunction (ESRD). The study included 90 patients with ESRD disease whom were under hemodialysis treatment, and 30 healthy control people.

RESULTS

Results: Urea, creatinine, and MDA levels were noticeably greater in ESRD patients compared to controls, but GSH levels were noticeably lower. In conclusion, oxidative stress can cause more problems to these patients by its involvement in the appearance of metabolic and cardiovascular diseases.

CONCLUSION

Conclusions: Furthermore, GSH was reduced significantly in ESRD patients and associated negatively with the level of MDA. This indicates the strong involve¬ment of antioxidants, especially GSH, in the development of oxidative stress in ESRD patients.

Vitamin E Prevented Hepatic and Renal Tissue Damage in Hypothyroid Rats

Background

Considering antioxidant effects of vitamin E (Vit E), in the present study, the effect of Vit E on liver and kidney functions and oxidative stress parameters in tissues of these organs of hypothyroid (Hypo) rats were reported.

Materials and Methods

The animals were included in three groups:(1) control, (2) hypo, and (3) hypo-hypo-Vit E. Hypothyroidism was induced in rats by giving 0.05% propylthiouracil (PTU) in drinking water. Besides PTU, the rats in group 3 were daily injected with Vit E (20 mg/kg) for 42 days. The animals were deeply anesthetized and sacrificed, and the serum of the rats was immediately removed to measure thyroxin level and subsequent analysis. The liver and kidney tissues were also immediately removed for biochemical oxidative stress criteria.

Results

PTU administration reduced serum thyroxin level and also thiol content, superoxide dismutase (SOD), and catalase (CAT) activities in the liver and kidney tissues while increasing malondialdehyde (MDA). Hypothyroidism also increased alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine while decreasing albumin. Vit E increased thiol, SOD, and CAT in the liver and kidney tissues while diminished MDA. Vit E also decreased ALT, BUN, and creatinine while increased albumin.

Conclusion

The results of this study showed that Vit E prevented liver and renal tissue damage in hypothyroid rats.

Effects of broccoli sprout supplements enriched in glucoraphanin on liver functions in healthy middle-aged adults with high-normal serum hepatic biomarkers: A randomized controlled trial

Sulforaphane (SFN), an isothiocyanate derived from glucoraphanin, has antioxidant, and anti-inflammatory effects that may be beneficial for improving liver function. However, few studies regarding the effects of glucoraphanin on the biological markers related to liver function, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (γ-GTP) in healthy individuals have been reported. This randomized, double-blind, placebo-controlled parallel- group trial was conducted from April 22 to December 25, 2021 and compared the effects of broccoli sprout supplements enriched in glucoraphanin (glucoraphanin supplements) (n = 35) with those of placebo supplements (n = 35). This trial was registered with the University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR; ID number UMIN000044005) https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view. cgi?recptno=R000050252. Glucoraphanin significantly improved serum ALT levels at 24 weeks compared to placebo supplements. However, no significant difference in serum glutathione levels, one of the major antioxidants synthesized in the liver, was observed between the two groups. In conclusion, daily intake of the glucoraphanin supplements is beneficial for maintaining liver health in healthy, middle-aged adults with high-normal serum hepatic biomarkers, although further studies focusing on other antioxidant markers are needed to understand how glucoraphanin improves liver function.

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

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

Metabolomic exploration of the effects of habituation to livestock trailer and extended transportation in goats

Goats raised for meat production are often transported long distances. Twelve-month-old male Spanish goats were used to determine the effects of habituation to trailers on plasma metabolomic profiles when transported for extended periods. In a split-plot design, 168 goats were separated into two treatment (TRT; whole plot) groups and maintained on two different paddocks. Concentrate supplement was fed to one group inside two livestock trailers (habituated group, H), while the other group received the same quantity of concentrate, but not inside the trailers (non-habituated, NH). Goats were subjected to a 10-h transportation stress in 4 replicates (n = 21 goats/replicate/TRT) after 4 weeks of habituation period. Blood samples were collected prior to loading, 20 min after loading (0 h), and at 2, 4, 6, 8, and 10 h of transportation (Time; subplot). A targeted quantitative metabolomics approach was employed to analyze the samples. The data were analyzed using R software and MIXED procedures in SAS. Several amino acids (alanine, serine, glycine, histidine, glutamate, trans-hydroxyproline, asparagine, threonine, methylhistidine, ornithine, proline, leucine, tryptophan) were higher (p < 0.05) in the H group compared to the NH group. Six long-chain acylcarnitines were higher (p < 0.05), while free (C0) and short-chain (C3, C5) carnitines were lower (p < 0.05) in the NH goats compared to the H goats. In general, amino acid concentrations decreased and long-chain acylcarnitine (>C10) levels increased with transportation time (p < 0.05). Butyric acid, α-ketoglutaric acid, and α-aminoadipic acid concentrations were lower (p < 0.05) and β-hydroxybutyric acid concentrations were higher in the NH goats compared to the H goats. Plasma glucose, non-esterified fatty acid (NEFA) and urea nitrogen concentrations were significantly influenced by Time (p < 0.01). Plasma NEFA concentrations were significantly lower (p < 0.01) in the H group than the NH group. Habituation to trailers can be beneficial in enhancing stress coping abilities in goats due to higher concentrations of metabolites such as butyrate and certain amino acids that support antioxidant activities and immune function. Plasma long-chain acylcarnitines may be good indicators of stress during long-distance transportation in goats.

Transcriptome Analysis of Protection by Dendrobium Nobile Alkaloids (DNLA) against Chronic Alcoholic Liver Injury in Mice

Objective: To investigate the protective effects of Dendrobium nobile Lindl. alkaloids (DNLA) against chronic alcoholic liver injury. C57BL/6J mice were fed with the Lieber−DeCarli alcohol diet to induce chronic alcoholic liver injury. DNLA (20 mg/kg/day) was gavaged along with the alcohol diet for 28 days. Liver injury was evaluated by serum enzymes. Triglyceride levels, histopathology, and transcriptome changes were examined by RNA-Seq and qPCR. DNLA decreased serum triglyceride levels in mice receiving alcohol. Hepatocyte degeneration and steatosis were ameliorated by DNLA, as evidenced by H&E and Oil-red O staining. DNLA brought the alcohol-induced aberrant gene expression pattern towards normal. Alcohol induced 787 differentially expressed genes (padj < 0.01). DNLA induced 280 differentially expressed genes to a much less extent. Ingenuity pathway analysis showed that DNLA ameliorated alcohol-induced oxidative stress and xenobiotic metabolism disruption. qPCR verified that DNLA alleviated over-activation of Cyp2a4, Cyp2b10, and Abcc4; attenuated oxidative stress (Hmox1, Gstm3, Nupr1), reduced the expression of Nrf2 genes (Nqo1, Gclc, Vldlr); and rescued some metabolic genes (Insig1, Xbp1, Socs3, Slc10a2). In conclusion, DNLA was effective against alcohol-induced fatty liver disease, and the protection may be attributed to alleviated oxidative stress and restored metabolism homeostasis, probably through modulating nuclear receptor CAR-, PXR-, and Nrf2-mediated gene expression pathways.

Oxidative stress, glutathione, and CYP2E1 in 1,4-dioxane liver cytotoxicity and genotoxicity: insights from animal models

1,4-Dioxane (DX) is an emerging drinking water contaminant worldwide, which poses a threat to public health due to its demonstrated liver carcinogenicity and potential for human exposure. The lack of drinking water standards for DX is attributed to undetermined mechanisms of DX carcinogenicity. This mini-review provides a brief discussion of a series of mechanistic studies, wherein unique mouse models were exposed to DX in drinking water to elucidate redox changes associated with DX cytotoxicity and genotoxicity. The overall conclusions from these studies support a direct genotoxic effect by high dose DX and imply that oxidative stress involving CYP2E1 activation may play a causal role in DX liver genotoxicity and potentially carcinogenicity. The mechanistic data derived from these studies can serve as important references to refine the assessment of carcinogenic pathways that may be triggered at environmentally relevant low doses of DX in future animal and human studies.

Dose- and time-dependent manners of moxifloxacin induced liver injury by targeted metabolomics study

Moxifloxacin is the most widely prescribed antibiotics due to its excellent oral bioavailability and broad-spectrum antibacterial effect. Despite of its popularity, the rare and severe liver injury induced by moxifloxacin is a big concern that cannot be ignored in clinical practice. However, the early warning and related metabolic disturbances of moxifloxacin induced hepatoxicity were rarely reported. In this study, the dose- and time-dependent manners of moxifloxacin induced liver injury were investigated by a targeted metabolomics method. In dose-dependent experiment, three different dosages of moxifloxacin were administered to the rats, including 36 mg kg⁻¹ d⁻¹, 72 mg kg⁻¹ d⁻¹, and 108 mg kg⁻¹ d⁻¹. In time-dependent experiment, moxifloxacin was orally administered to the rats for 3, 7 or 14 consecutive days. Pathological analysis showed that moxifloxacin caused obvious transient hepatotoxicity, with the most serious liver injury occurred in the 7 days continuous administration group. The transient liver injury can be automatically restored over time. Serum levels of liver function related biochemical indicators, including ALT, AST, TBIL, alkaline phosphatase, superoxide dismutase, and malondialdehyde, were also measured for the evaluation of liver injury. However, these indicators can hardly be used for the early warning of hepatotoxicity caused by moxifloxacin due to their limited sensitivity and significant hysteresis. Targeted metabolomics study demonstrated that serum concentrations of fatty acyl carnitines, fatty acids and dehydroepiandrosterone can change dynamically with the severity of moxifloxacin related liver injury. The elevated serum levels of fatty acyl carnitine, fatty acid and dehydroepiandrosterone were promising in predicting the hepatotoxicity induced by moxifloxacin.

Therapeutic Management of Idiosyncratic Drug-Induced Liver Injury and Acetaminophen Hepatotoxicity in the Paediatric Population: A Systematic Review

Introduction

Drug-induced liver injury (DILI) is a rare but serious adverse event that can progress to acute liver failure (ALF). The evidence for treatment of DILI in children is scarce.

Objective

We aimed to comprehensively review the available literature on the therapies for both acetaminophen overdose (APAP) and idiosyncratic DILI in the paediatric population.

Methods

We included original articles conducted in a paediatric population (< 18 years) in which a therapeutic intervention was described to manage APAP or idiosyncratic DILI. Findings were summarized based on age groups (preterm newborn neonates, term and post-term neonates, infants, children and adolescents).

Results

Overall, 25 publications (fifteen case reports, six case series and four retrospective cohort studies) were included, including a total of 140 paediatric DILI cases, from preterm newborn neonates to adolescents. N-acetylcysteine was used to treat 19 APAP cases. N-acetylcysteine (n = 14), ursodeoxycholic acid (n = 3), corticosteroids (n = 31), carnitine (n = 16) and the combination of glycyrrhizin, reduced glutathione, polyene phosphatidylcholine and S-adenosylmethionine (n = 31) were the therapeutic options for treating idiosyncratic DILI. The molecular adsorbent recirculating system was used in the management of either APAP (n = 4) or idiosyncratic DILI (n = 2), while 20 paediatric ALF cases received continuous renal replacement therapy.

Conclusions

This systematic review identified DILI in the paediatric population who have received specific treatment. These interventions appear to be mainly extrapolated from low-quality evidence from the adult population. Thus, there is a need for high-quality studies to test the efficacy of known and novel therapies to treat DILI specifically addressed to the paediatric population.

PROSPERO registration number CRD42021214702.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-022-01224-w.

The potential role of febrile condition in reversing the hepatoprotective effects of quercetin in the livers of LPS-presensitized mice

AIMS

Consumption of nutraceuticals without enough data regarding their interactions has raised safety concerns. Importantly, consumption of some natural-products in health-compromised conditions has caused liver injury due to the evolved pro-oxidant load. This study evaluates the safety of quercetin (QUR), as an extensively-used flavonoid owing to its antioxidant and hepatoprotective activities, in normal- and lipopolysaccharides (LPS)-primed livers, and to investigate the influence of the LPS-induced mild inflammatory/febrile condition on QUR effects.

MAIN METHODS

For liver priming, a non-injurious LPS dose that mediates limited inflammation/mild fever was chosen. Selection of QUR dose/duration of treatment, for a coherent combination-regimen, was also adopted. Single LPS i.p injection (1.5 mg/kg)/oral QUR (20 mg/kg/day, IG) for 5-days was the optimal regimen for the combination group. On day-6, serum ALT/AST/ALP levels were measured, as liver-damage biomarkers. Hepatic; MDA/GSH were determined, as oxidative-stress measures, Bcl-2/cleaved-caspase-3 were assessed as apoptosis biomarkers, IL-6 expression/NF-κB/Nrf-2 immunoreactivities were evaluated as regulators for inflammation.

KEY FINDINGS

Exaggerated hepatic injury was seen upon QUR treatment in LPS-presensitized mice; as evidenced by liver histopathological degeneration, which was confirmed by biochemical elevations of serum AST/ALT/ALP, along with oxidant-burden increase (↑MDA/↓GSH) and molecular augmentation of inflammation (NF-κB/IL-6 activation) that led to enhancement of proapoptotic signaling (caspase-3 activation/Bcl-2 inhibition). Such events were accompanied by potentiation of endogenous anti-inflammatory/antioxidant response (↑ hepatic Nrf-2).

SIGNIFICANCE

The study highlights caution when QUR is consumed in health-compromised conditions, by revealing the role of fever/mild inflammation in enhancing liver toxicity upon QUR utilization, which was not apparent with moderate consumption of QUR-alone.

Effect of Methionine Supplementation on Serum Metabolism and the Rumen Bacterial Community of Sika Deer (Cervus nippon)

Methionine is the first or second limiting amino acid for ruminants, such as sika deer, and has a variety of biological functions such as antioxidant activity, immune response, and protein synthesis. This study aimed to investigate the effects of methionine supplementation on antler growth, serum biochemistry, rumen fermentation, and the bacterial community of sika deer during the antler-growing period. Twelve 4-year-old male sika deer were randomly assigned to three dietary groups supplemented with 0 g/day (n = 4, CON), 4.0 g/day (n = 4, LMet), and 6.0 g/day (n = 4, HMet) methionine. No significant difference (p > 0.05) was found in the production performance between the three groups, but antler weight was higher in both the LMet and HMet groups than in the CON group. Methionine supplementation significantly increased the serum glutathione peroxidase activity (p < 0.05). The serum immunoglobulin G level was significantly higher in the HMet group than in the other two groups (p < 0.05). No significant effect was found on the apparent amino acid digestibility of the three groups, but cysteine and methionine digestibility were higher in the LMet group. The serum hydroxylysine level was significantly lower in the LMet and HMet groups, whereas the serum lysine level was significantly lower in the HMet group compared with the CON group (p < 0.05). The LMet group had the highest but a nonsignificant total volatile fatty acid content and significantly higher microbial protein content in the rumen than the CON group (p < 0.05). The phyla Bacteroidetes, Firmicutes, and Proteobacteria were dominant in the rumen of the sika deer. The principal coordinate analysis (PCoA) and analysis of similarities (ANOSIM) results showed a significant change in the bacterial composition of the three groups (p < 0.05). The relative abundance of Prevotella and Rikenellaceae-RC9 was significantly higher in the LMet group compared with the CON group and CON and HMet groups, respectively. These results revealed that methionine supplementation improved the antioxidant activity and immune status, affecting amino acid metabolism and rumen microbial composition of the sika deer.

Liposomal Drug Delivery of Blumea lacera Leaf Extract: In-Vivo Hepatoprotective Effects

Background: Blumea lacera (B. lacera) is a herbaceous plant commonly found in south-east Asia. It shows significant therapeutic activities against various diseases. The objectives of this study were to evaluate hepatoprotective effects of Blumea lacera leaf extract and also to investigate the comparative effectiveness between a liposomal preparation and a suspension of B. lacera leaf extract against carbon tetrachloride (CCl₄)-induced liver damage. Methods: B. lacera leaf extract was characterized using a GC-MS method. A liposomal preparation of B. lacera leaf extract was developed using an ethanol injection method and characterized using dynamic light scattering (DLS) and electronic microscopic systems. The hepatoprotective effects of B. lacera leaf extracts and its liposomal preparation were investigated using CCl₄-induced liver damage in Long Evan rats. Results: GC-MS data showed the presence of different components (e.g., phytol) in the B. lacera leaf extract. DLS and microscopic data showed that a liposomal preparation of B. lacera leaf extracts was in the nano size range. In vivo study results showed that liposomal preparation and a suspension of B. lacera leaf extract normalized liver biochemical parameters, enzymes and oxidative stress markers which were elevated due to CCl₄ administration. However, a liposomal formulation of B. lacera leaf extract showed significantly better hepatoprotective effects compared to a suspension of leaf extract. In addition, histopathological evaluation showed that B. lacera leaf extract and its liposomal preparation treatments decreased the extent of CCl₄-induced liver inflammations. Conclusion: Results demonstrated that B. lacera leaf extract was effective against CCl₄-induced liver injury possibly due to the presence of components such as phytol. A liposomal preparation exhibited significantly better activity compared to a B. lacera suspension, probably due to improved bioavailability and stability of the leaf extract.

Slightly different metabolomic profiles are associated with high or low weight duck foie gras

Understanding the evolution of fatty liver metabolism of ducks is a recurrent issue for researchers and industry. Indeed, the increase in weight during the overfeeding period leads to an important change in the liver metabolism. However, liver weight is highly variable at the end of overfeeding within a batch of animals reared, force-fed and slaughtered in the same way. For this study, we performed a proton nuclear magnetic resonance (¹H-NMR) analysis on two classes of fatty liver samples, called low-weight liver (weights between 550 and 599 g) and high-weight liver (weights above 700 g). The aim of this study was to identify the differences in metabolism between two classes of liver weight (low and high). Firstly, the results suggested that increased liver weight is associated with higher glucose uptake leading to greater lipid synthesis. Secondly, this increase is probably also due to a decline in the level of export of triglycerides from the liver by maintaining them at high hepatic concentration levels, but also of hepatic cholesterol. Finally, the increase in liver weight could lead to a significant decrease in the efficiency of aerobic energy metabolism associated with a significant increase in the level of oxidative stress. However, all these hypotheses will have to be confirmed in the future, by studies on plasma levels and specific assays to validate these results.

Astragalus mongholicus polysaccharides ameliorate hepatic lipid accumulation and inflammation as well as modulate gut microbiota in NAFLD rats

Hepatic lipid accumulation, inflammation and gut microbiota dysbiosis are hallmarks of non-alcoholic fatty liver disease (NAFLD), which is the leading cause of chronic liver disease with no therapeutic consensus. The aim of the present study was to elucidate the mechanism of the effects of Astragalus mongholicus polysaccharides (mAPS) on lipid metabolism, inflammation and gut microbiota in a rat model of NAFLD induced by a high-fat diet (HFD). Our results showed that mAPS and Berberine supplementation reduced HFD-induced increases in body weight, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and homeostasis model assessment of insulin resistance (HOMA-IR), and these changes were accompanied by improved histological changes in the liver. Moreover, administration of mAPS and Berberine resulted in lower levels of serum triglycerides, total cholesterol and low-density lipoprotein cholesterol (LDL-c) but higher levels of high-density lipoprotein cholesterol (HDL-c) in HFD-fed rats. mAPS and Berberine treatment markedly reduced HFD-induced hepatic lipid accumulation, which was associated with increased expression of phosphorylated- adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-α (PPAR-α) but decreased expression of sterol-regulatory element binding proteins (SREBP-1). Pretreatment with mAPS or Berberine reduced HFD-induced expression of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α). In addition, mAPS downregulated the expression of colonic and hepatic Toll-like receptor 4 (TLR4) as well as phosphorylated- nuclear factor-κB (NF-κB) and nucleotide-binding domain, leucine-rich repeat-containing receptor, pyrin domain-containing-3 (NLRP3) but upregulated the expression of zonula occludens-1 (ZO-1) and occludin in HFD-fed rats. Notably, mAPS treatment reshaped the intestinal microbiome by lowering the Firmicutes to Bacteroidetes (F/B) ratio and increasing the abundance of Proteobacteria and Epsilonbacteria. mAPS supplementation had little effect on the profile of fecal short-chain fatty acids (SCFAs), but it significantly decreased the expression of colonic and hepatic G-protein coupled receptor (GPR) 41 and 43. Therefore, mAPS supplementation ameliorates hepatic inflammation and lipid accumulation in NAFLD by modulating the gut microbiota and SCFA-GPR signaling pathways. The present study provides new evidence for mAPS as a natural active substance in the treatment of NAFLD.