Treatment Of Alcoholic Liver Disease Research Articles

γ-Glutamylcysteine alleviates ethanol-induced hepatotoxicity via suppressing oxidative stress, apoptosis, and inflammation.

Alcohol abuse is a major cause of alcoholic liver disease (ALD) and can result in fibrosis and cirrhosis. γ-glutamylcysteine (γ-GC) is a precursor of glutathione (GSH) with antioxidant and anti-inflammatory properties. Our research aimed to explore the protective impact of γ-GC on ALD and its potential mechanisms of efficiency in vitro and in vivo. L02 cells were pretreated with γ-GC (20, 40, and 80 μM) for 2h and exposed to ethanol for 24 h. Cell viability, apoptosis, oxidative stress, and inflammatory levels were measured. The expression of protein cleaved caspase-3 and cleaved PARP and flow cytometry results indicated that γ-GC decreases apoptosis on L02 cells after ethanol treatment. Moreover, γ-GC also attenuated oxidative stress and mitochondrial damage in hepatocytes caused by ethanol via increasing cellular GSH, SOD activity, and mitochondrial membrane potential. In vivo experiments, γ-GC effectively reduced the AST, ALT, and TG levels in mice. The inflammation of ALD was alleviated by γ-GC both in vivo and in vitro. Additionally, histopathological examination demonstrated that γ-GC treatment lessened lipid droplet formation and inflammatory damage. In conclusion, these results showed that γ-GC has anti-inflammatory and anti-apoptotic effects on ALD because it could help hepatocytes maintain sufficient GSH levels to combat the excess reactive oxygen species (ROS) generated during ethanol metabolism. PRACTICAL APPLICATIONS: Alcohol intake is the fifth highest risk factor for premature death and disability among all risk variables. However, few medicines are both safe and effective for the treatment of ALD. As a direct precursor of GSH, γ-GC has a broad variety of potential antioxidant and anti-inflammatory applications for the treatment of numerous medical conditions. In conclusion, these results showed that γ-GC could protect cells from ALD via suppressing oxidative stress, alleviating inflammation, and preventing apoptosis.

Resveratrol protects against chronic alcohol-induced liver disease in a rat model

Hepatic ethanol metabolism participates in the pathogenesis of alcoholic liver disease (ALD). We aimed to evaluate the protecting effects and underlying mechanisms of Resveratrol against ALD. Adult male rats were fed with liquid ethanol diet, in the presence or absence of Resveratrol for 23 weeks. It was demonstrated that Resveratrol attenuated ethanol-induced release of serum alanine and aspartate aminotransferase. Ethanol insult caused malondialdehyde elevation and the impairment of antioxidant defense system, leading to reactive oxygen species generation, which could be greatly reversed by Resveratrol treatment. Moreover, Resveratrol protected against chronic ethanol-induced upregulation in hepatic cytochrome P-4502E1 expression, whereas hepatic alcohol dehydrogenase expression was unaffected by Resveratrol. Unexpectedly, hepatic aldehyde dehydrogenase2 expression was markedly diminished in ethanol-fed rats, which was gradually improved by Resveratrol treatment. Our data demonstrate that the protecting effects of Resveratrol on ALD might be associated with changes in the regulation of alcohol-metabolizing enzymes. Our findings could provide new perspective into the pharmacological targets of Resveratrol in the treatment of ALD.

Rumex hanus by. Extract Protects Against Chronic Alcohol-Induced Liver Injury in Mice.

Alcoholic liver disease (ALD) has become a global health problem. The hepatoprotective effects of bioactive ingredients extracted from Rumex hanus by. on chronic alcoholic liver injury was investigated for the first time. The extract from R. hanus by. (ERHB) was obtained by 70% ethanol extraction, and the endotoxin antagonism rate of ERHB was 88.94 ± 1.24% in vitro. The animal experiments demonstrated that ERHB promoted hepatic function by significantly enhancing the activities of alcohol dehydrogenase and acetaldehyde dehydrogenase, and by reducing the activities of cytochrome P450 proteins, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase. Furthermore, ERHB improved alcohol-induced dyslipidemia by regulating lipid metabolism. In addition, ERHB ameliorated the alcohol-induced liver injury by inhibiting endotoxin-caused inflammation. Seven compounds with antagonistic activity on endotoxin were identified in ERHB. These results demonstrated that ERHB had protective effects on ALD and if the results can be confirmed in humans, it might be useful as a functional food supplement for ALD treatment.

The Beneficial Effects of Natural Extracts and Bioactive Compounds on the Gut-Liver Axis: A Promising Intervention for Alcoholic Liver Disease.

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. It can cause fatty liver (steatosis), steatohepatitis, fibrosis, cirrhosis, and liver cancer. Alcohol consumption can also disturb the composition of gut microbiota, increasing the composition of harmful microbes and decreasing beneficial ones. Restoring eubiosis or preventing dysbiosis after alcohol consumption is an important strategy in treating ALD. Plant natural products and polyphenolic compounds exert beneficial effects on several metabolic disorders associated with ALD. Natural products and related phytochemicals act through multiple pathways, such as modulating gut microbiota, improving redox stress, and anti-inflammation. In the present review article, we gather information on natural extract and bioactive compounds on the gut-liver axis for the possible treatment of ALD. Supplementation with natural extracts and bioactive compounds promoted the intestinal tight junction, protected against the alcohol-induced gut leakiness and inflammation, and reduced endotoxemia in alcohol-exposed animals. Taken together, natural extracts and bioactive compounds have strong potential against ALD; however, further clinical studies are still needed.

Ameliorative effects of chlorogenic acid on alcoholic liver injury in mice via gut microbiota informatics

Chlorogenic acid (CGA) is a functional phenolic acid widely used in food and medicine-related fields. It has been proved to be effective in the treatment of alcoholic liver disease (ALD). However, the exact mechanism by which CGA prevents ALD, especially from the crosstalk between gut and liver, has not been previously reported. This work was aimed to explore the protective effects of CGA against ALD and its relationships to gut-liver axis abnormalities. Experimental results showed the increased (p < 0.05) serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), low density lipoprotein (LDL), total cholesterol (TC) and triglyceride (TG) levels of mice fed with ethanol were ameliorated by supplementing with CGA. Moreover, CGA promoted the production of n-butyric acid by nearly 3 times (1.78 vs 0.62 nM, p < 0.01), a short-chain fatty acid that helps maintain the integrity of the intestinal barrier. Furthermore, CGA alleviated microbial dysbiosis, evidenced by the increased relative abundances of beneficial bacteria Muribaculaceae, Bacteroides, Alloprevotella, and Parabacteroides, and decreased that of opportunistic pathogens Eubacterium_nodatum, Eubacterium_ruminantium, and Anaerotruncus. Correlation analysis further elucidated the microbiota altered after CGA intervention was positively correlated with short-chain fatty acids and antioxidant indexes, while negatively correlated with inflammatory cytokines. In summary, these findings suggested the hepatoprotective effect of CGA was ascribed to the modulation of gut-liver axis homeostasis.

Rhoifolin Alleviates Alcoholic Liver Disease In Vivo and In Vitro via Inhibition of the TLR4/NF-κB Signaling Pathway.

Background: Alcoholic liver disease (ALD) is a common chronic liver disorder worldwide, which is detrimental to human health. A preliminary study showed that the total flavonoids within Citrus grandis “Tomentosa” exerted a remarkable effect on the treatment of experimental ALD. However, the active substances of Citrus grandis “Tomentosa” were not elucidated. Rhoifolin (ROF) is a flavonoid component present in high levels. Therefore, this research aimed to evaluate the hepatoprotective effects of ROF and its possible mechanisms. Methods: Molecular docking was performed to analyze the binding energy of ROF to the main target proteins related to ALD. Subsequently, mice were fed ethanol (ETH) for 49 days to establish the chronic alcoholic liver injury models. The liver pathological injury, serum aminotransferase levels, and oxidative stress levels in the liver tissue were measured. Human normal hepatocytes (LO2 cells) were incubated with ETH to construct the alcoholic liver cell model. The inflammatory markers and apoptosis factors were evaluated using real-time PCR and flow cytometry. Finally, the effects of ROF on the CYP2E1 and NF-κB signaling pathways were tested in vitro and in vivo. Results: Molecular docking results demonstrated that ROF was able to successfully dock with the target proteins associated with ALD. In animal studies, ROF attenuated ETH-induced liver damage in mice by decreasing the serum concentrations of AST and ALT, reducing the expression of inflammatory cytokines, and maintaining antioxidant balance in the liver tissue. The in vitro experiments demonstrated that ROF suppressed ETH-induced apoptosis in LO2 cells by promoting Bcl-2 mRNA and inhibiting Bax mRNA and caspase 3 protein expression. ROF decreased the level of LDH, ALT, AST, ROS, and MDA in the supernatant; induced the activity of GSH and SOD; and inhibited TNF-α, IL-6, and IL-1β expression levels. Mechanistically, ROF could significantly downregulate the expression levels of CYP2E1, TLR4, and NF-κB phosphorylation. Conclusion: This study indicates that ROF is the active component within the total flavonoids, which may alleviate ETH-induced liver injury by inhibiting NF-κB phosphorylation. Therefore, ROF may serve as a promising compound for treating ALD.

P2X7 Receptor in Alcoholic Steatohepatitis and Alcoholic Liver Fibrosis.

Alcoholic liver disease is one of the most common chronic liver diseases in the world. It is a liver disease caused by prolonged heavy drinking and its main clinical features are nausea, vomiting, enlargement of the liver, and jaundice. Recent studies suggest that Kupffer cell-mediated inflammatory response is a core driver in the development of alcoholic steatohepatitis and alcoholic liver fibrosis. As a danger signal, extracellular ATP activates the assembly of NLPR3 inflammasome by acting on purine P2X7 receptor, the activated NLRP3 inflammasome prompts ASC to cleave pro-cCaspase-1 into active caspase-1in KCs. Active caspase-1 promotes the conversion of pro-IL-1β to IL-1β, which further enhances the inflammatory response. Here, we briefly review the role of the P2X7R-NLRP3 inflammasome axis in the pathogenesis of alcoholic liver disease and the evolution of alcoholic steatohepatitis and alcoholic liver fibrosis. Regulation of the inflammasome axis of P2X7R-NLRP3 may be a new approach for the treatment of alcoholic liver disease.

Roxadustat, a Hypoxia-Inducible Factor 1α Activator, Attenuates Both Long- and Short-Term Alcohol-Induced Alcoholic Liver Disease.

Alcoholic liver disease (ALD) is a worldwide healthcare problem featured by inflammation, reactive oxygen species (ROS), and lipid dysregulation. Roxadustat is used for chronic kidney disease anemia treatment. As a specific inhibitor of prolyl hydroxylase, it can maintain high levels of hypoxia-inducible factor 1α (HIF-1α), through which it can further influence many important pathways, including the three featured in ALD. However, its effects on ALD remain to be elucidated. In this study, we used chronic and acute ALD mouse models to investigate the protective effects of roxadustat in vivo. Our results showed that long- and short-term alcohol exposure caused rising activities of serum transaminases, liver lipid accumulation, and morphology changes, which were reversed by roxadustat. Roxadustat-reduced fatty liver was mainly contributed by the reducing sterol-responsive element-binding protein 1c (SREBP1c) pathway, and enhancing β-oxidation through inducing peroxisome proliferator-activated receptor α (PPARα) and carnitine palmitoyltransferase 1A (CPT1A) expression. Long-term alcohol treatment induced the infiltration of monocytes/macrophages to hepatocytes, as well as inflammatory cytokine expression, which were also blocked by roxadustat. Moreover, roxadustat attenuated alcohol caused ROS generation in the liver of those two mouse models mainly by reducing cytochrome P450 2E1 (CYP2E1) and enhancing superoxidase dismutase 1 (SOD1) expression. In vitro, we found roxadustat reduced inflammation and lipid accumulation mainly via HIF-1α regulation. Taken together, our study demonstrates that activation of HIF-1α can ameliorate ALD, which is contributed by reduced hepatic lipid synthesis, inflammation, and oxidative stress. This study suggested that roxadustat could be a potential drug for ALD treatment.

The amelioration of alcohol-induced liver and intestinal barrier injury by Lactobacillus rhamnosus Gorbach-Goldin (LGG) is dependent on Interleukin 22 (IL-22) expression

ABSTRACT Alcoholic liver disease (ALD) is a common clinical liver injury disease. Lactobacillus rhamnosus Gorbach-Goldin (LGG) has been revealed to alleviate alcohol-induced intestinal barrier and liver injury. However, the underlying mechanism of LGG treatment for ALD remains unclear. To clarify this aspect, a chronic plus binge ALD model was constructed using C57BL/6 mice in line with a chronic alcohol binge feeding protocol. Interleukin 22 (IL-22) level was determined by quantitative real-time polymerase-chain reaction and enzyme-linked immunosorbent assays. Effects of LGG in model or IL-22 knockdown in LGG-treated model on the liver injury and steatosis status, as well as intestinal barrier function were assessed by hematoxylin eosin (HE) staining. Levels of alanine aminotransferase (ALT), triglyceride (TG), and aspartate aminotransferase (AST) in serum were measured by the corresponding kit. Western blot analysis was conducted to detect protein expressions of intestinal tight junction protein 1 (ZO-1) and Claudin-1. Concretely, LGG elevated IL-22 level in liver tissues and serum, while inhibiting ALT, TG, and AST levels in alcohol-exposed mice. Moreover, LGG alleviated liver injury, steatosis, and intestinal barrier injury caused by alcohol, and enhanced ZO-1 and Claudin-1 expressions. Furthermore, IL-22 knockdown increased ALT, TG, and AST levels in serum, and aggravated liver injury, steatosis, and intestinal barrier injury. ZO-1 and Claudin-1 levels were downregulated by IL-22 silencing. Importantly, downregulation of IL-22 reversed the effect of LGG on the liver and intestinal barrier injury. To conclude, LGG protects against chronic alcohol-induced intestinal and liver injury via regulating the intestinal IL-22 signaling pathway.

Identification of a protective Bacteroides strain of alcoholic liver disease and its synergistic effect with pectin.

The depletion of Bacteroides in the gut is closely correlated with the progression of alcoholic liver disease (ALD). This study aimed to identify Bacteroides strains with protective effects against ALD and evaluate the synergistic effects of Bacteroides and pectin in this disease. Mice were fed Lieber-DeCarli alcohol diet to establish an experimental ALD model and pre-treated with 4 Bacteroides strains. The severity of the liver injury, hepatic steatosis, and inflammation was evaluated through histological and biochemical assays. We found that Bacteroides fragilis ATCC25285 had the best protective effects against ALD strains by alleviating both ethanol-induced liver injury and steatosis. B. fragilis ATCC25285 could counteract inflammatory reactions in ALD by producing short-chain fat acids (SCFAs) and enhancing the intestinal barrier. In the subsequent experiment, the synbiotic combination of B. fragilis ATCC25285 and pectin was evaluated and the underlying mechanisms were investigated by metabolomic and microbiome analyses. The combination elicited superior anti-ALD effects than the individual agents used alone. The synergistic effects of B. fragilis ATCC25285 and pectin were driven by modulating gut microbiota, improving tryptophan metabolism, and regulating intestinal immune function. Based on our findings, the combination of B. fragilis ATCC25285 and pectin can be considered a potential treatment for ALD. KEY POINTS: • B. fragilis ATCC25285 was identified as a protective Bacteroides strain against ALD. • The synbiotic combination of B. fragilis and pectin has better anti-ALD effects. • The synbiotic combination modulates gut microbiota and tryptophan metabolism.

Magnesium isoglycyrrhizinate attenuates acute alcohol-induced hepatic steatosis in a zebrafish model by regulating lipid metabolism and ER stress

BackgroundAlcoholism is a well-known risk factor for liver injury and is one of the major causes of hepatic steatosis worldwide. Although many drugs have been reported to have protective effects against acute alcohol-induced hepatotoxicity, there is limited available treatment for alcoholic liver disease (ALD), indicating an urgent need for effective therapeutic options. Herein, we first reported the protective effects of magnesium isoglycyrrhizinate (MgIG) on acute alcohol-induced hepatic steatosis and its related mechanisms in a zebrafish model.MethodsAlcohol was administered directly to embryo medium at 5 days post-fertilization (dpf) for up to 32 h. MgIG was given to the larvae 2 h before the administration of alcohol and then cotreated with alcohol starting at 5 dpf. Oil red O staining was used to determine the incidence of steatosis, and pathological features of the liver were assessed by hematoxylin–eosin staining. Biological indexes, total cholesterol (TC) and triacylglycerol (TG) were detected in the livers of zebrafish larvae. Morphological changes in the livers of zebrafish larvae were observed using liver-specific EGFP transgenic zebrafish (Tg(lfabp10a:eGFP)). The expression levels of critical molecules related to endoplasmic reticulum (ER) stress and lipid metabolism were detected by qRT–PCR, whole-mount in situ hybridization and western blotting.ResultsAlcohol-treated larvae developed hepatomegaly and steatosis after 32 h of exposure. We found that MgIG improved hepatomegaly and reduced the incidence of steatosis in a dose-dependent manner by oil red O staining and diminished deposits of alcohol-induced fat droplets by histologic analysis. Moreover, MgIG significantly decreased the levels of TC and TG in the livers of zebrafish larvae. Furthermore, the expression levels of critical genes involved in ER stress (atf6, irela, bip, chop) and the key enzymes regulating lipid metabolism (acc1, fasn, hmgcs1 and hmgcra) were significantly higher in the alcohol-treated group than in the control group. However, in the MgIG plus alcohol-treated group, the expression of these genes was markedly decreased compared with that in the alcohol-treated group. Whole-mount in situ hybridization and western blotting also showed that MgIG had an effect on the expression levels of critical genes and proteins involved in lipid metabolism and ER stress. Our results revealed that MgIG could markedly regulate these genes and protect the liver from ER stress and lipid metabolism disorders.ConclusionsOur study is the first to demonstrate that MgIG could protect the liver from acute alcohol stimulation by ameliorating the disorder of lipid metabolism and regulating ER stress in zebrafish larvae.

Clinical characteristics and survival analysis of liver transplantation in patients with alcoholic liver disease: A single-center retrospective study

ObjectiveBy reviewing the clinical data of liver transplantation in the treatment of alcoholic liver disease in a single center and analyzing the clinical characteristics, the long-term prognosis and main risk factors for early postoperative death were investigated. MethodsThe clinical data of 98 cases of orthotopic liver transplantation performed due to alcoholic liver disease were collected to explore the effect on survival following liver transplants. The patients had been treated in the Organ Transplantation Center of the Tianjin First Central Hospital from November 2011 to November 2020. ResultsThe follow-up duration was 1–108 months. Nine cases died; among these cases, three died during the perioperative period. Univariate analysis revealed that daily ethanol intake, Model for End-Stage Liver Disease (MELD) scores, and preoperative liver failure were associated with perioperative death, and multivariate analysis revealed that daily ethanol intake was an independent risk factor for perioperative death (P = 0.048 < 0.05); the daily intake of ethanol in the death group was significantly higher than that in the survival group (293 ± 11.5 g vs. 178.3 ± 66.8 g, P = 0.004 < 0.05). Six patients died during long-term follow-up. The one-, five-, and nine-year cumulative survival rates were 96.8%, 92.0%, and 92.0%, respectively. Preoperative liver cancer was the main risk factor for long-term survival (ORR = 2884.3, P = 0.041 < 0.05). The primary cause of death was recurrence of malignant liver tumors, followed by new lung malignancies, intracerebral hemorrhage, and hepatic allograft dysfunction. ConclusionAlcoholic liver disease is a good indication for liver transplantation. Heavy daily drinking before an operation increases the risk of perioperative death. Recurrence of malignant liver tumors is the main risk factor affecting long-term survival.

Inhibition of HMGB1/TLR4 Signaling Pathway by Digitoflavone: A Potential Therapeutic Role in Alcohol-Associated Liver Disease.

Digitoflavone (DG) is a natural flavonoid abundant in many fruits, vegetables, and medicinal plants. We investigated whether DG inhibits lipid accumulation and inflammatory responses in alcoholic liver disease (ALD) in vivo and in vitro. The mouse ALD model was established by chronically feeding male C57BL/6 mice an ethanol-containing Lieber-DeCarli liquid diet. In vitro, mouse peritoneal macrophages (MPMs) and mouse bone marrow-derived macrophages (BMDMs) were stimulated with LPS/ATP, whereas HepG2 cells and mouse primary hepatocytes were treated with ethanol. DG reduced the serum levels of transaminase and serum and hepatic levels of triglycerides and malondialdehyde in ALD mice. DG downregulated SREBP1 and its target genes and upregulated PPARα and its target genes in the liver of mice with ALD. DG inhibited TLR4-mediated NLRP3 inflammasome activation, consequently reversing the inflammatory response, including the production of HMGB1, IL-1β, and IL-36γ, as well as the infiltration of macrophages and neutrophils. DG blocked NLRP3/ASC/caspase-1 inflammasome activation and HMGB1 release in LPS/ATP-stimulated MPMs. When Tlr4 was knocked in LPS/ATP-stimulated BMDMs, HMGB1 production and release were blocked, and NLRP3-mediated cleavage and release of IL-1β was suppressed in Hmgb1-silenced BMDMs. DG amplified these inhibitory effects in Tlr4 or Hmgb1 knockdown BMDMs. In ethanol-exposed hepatocytes, DG reduced lipogenesis and promoted lipid oxidation by inhibiting the HMGB1-TLR4 signaling pathway while suppressing the inflammatory response induced by ethanol exposure. Our data demonstrated that DG inhibited the occurrence of lipid accumulation and the inflammatory response via the HMGB1-TLR4 axis, underscoring a promising approach and utility of DG for the treatment of ALD.

Roles of necroptosis in alcoholic liver disease and hepatic pathogenesis.

Chronic alcohol consumption can cause alcoholic liver disease (ALD), leading to morbidity and mortality worldwide. Complex disease progression of ALD varies from alcoholic fatty liver to alcoholic steatohepatitis, eventually contributing to fibrosis and cirrhosis. Accumulating evidence revealed that necroptosis, a way of programmed cell death different from apoptosis and traditional necrosis, is involved in the underlying pathogenic molecular mechanism of ALD. Receptor‐interacting protein kinase 1 (RIPK1), RIPK3 and mixed‐lineage kinase domain‐like pseudokinase have been implicated as key mediators to execute necroptosis. Also, necroptosis has gained increasing attention due to its potential association with primary pathological hallmarks of ALD, including oxidative stress, hepatic steatosis and inflammation. This review summarizes the recent progress on the roles and mechanisms of necroptosis and focuses on the crosstalk between necroptosis and the other pathogenesis of ALD, providing a theoretical basis for targeting necroptosis as a novel treatment for ALD.

O-alkyl and o-benzyl hesperetin derivative-1L attenuates inflammation and protects against alcoholic liver injury via inhibition of BRD2-NF-κB signaling pathway

Alcoholic liver injury (ALI) is a major risk factor for alcoholic liver disease, characterized by excessive inflammatory response and abnormal liver dysfunction. Previous studies have indicated that O-alkyl and o-benzyl hesperetin derivative-1 L (HD-1 L) has anti-inflammatory and hepato-protective effects in CCl4-induced liver injury. However, its effect on ALI and underlying mechanism has not been elucidated. This study was designed to evaluate the protective effects of HD-1 L on alcoholic liver injury and reveal the underlying mechanisms. ALI model was established in male C57BL/6 J mice (aged 6–8 weeks) by Gao-Binge protocol. The mice were received different doses of HD-1 L (25 mg/kg, 50 mg/kg, 100 mg/kg) by daily intragastric administration, respectively. Liver function and inflammation were measured. Mechanism underlying the anti-inflammatory and hepato-protective effect of HD-1 L were studied in RAW264.7 cells. In alcoholic liver injury mice, HD-1 L effectively improved the liver pathology, and remarkably reduced the levels of alanine transaminase (ALT), aspartate transaminase (AST), triglyceride (TG) and total cholesterol (T-CHO) in serum. Moreover, HD-1 L markedly suppressed inflammation in vivo and inhibited the secretion of inflammatory factors in vitro. Our results showed that HD-1 L decreased the activity of Bromodomain-containing Protein 2 (BRD2) and inhibited expression of BRD2 in vivo and in vitro. Furthermore, HD-1 L further alleviated alcohol-induced inflammation after blocking BRD2 with inhibitor (JQ1) or BRD2 small interfering (si)-RNA in RAW264.7 cells. Besides, HD-1 L failed to effectively exert its anti-inflammatory effects after over expression of BRD2. In addition, HD-1 L significantly inhibited the phosphorylation and activation of NF-κB-P65 mediated by BRD2. In conclusion, HD-1 L alleviated liver injury and inflammation mainly by inhibiting BRD2-NF-κB signaling pathway, and HD-1 L may be a potential anti-inflammatory compound in treatment of alcoholic liver disease.

Dual therapy with zinc acetate and rifaximin prevents from ethanol-induced liver fibrosis by maintaining intestinal barrier integrity.

BACKGROUNDHepatic overload of gut-derived lipopolysaccharide dictates the progression of alcoholic liver disease (ALD) by inducing oxidative stress and activating Kupffer cells and hepatic stellate cells through toll-like receptor 4 signaling. Therefore, targeting the maintenance of intestinal barrier integrity has attracted attention for the treatment of ALD. Zinc acetate and rifaximin, which is a nonabsorbable antibiotic, had been clinically used for patients with cirrhosis, particularly those with hepatic encephalopathy, and had been known to improve intestinal barrier dysfunction. However, only few studies focused on their efficacies in preventing the ALD-related fibrosis development. AIMTo investigate the effects of a combined zinc acetate with rifaximin on liver fibrosis in a mouse ALD model.METHODSTo induce ALD-related liver fibrosis, female C57BL/6J mice were fed a 2.5% (v/v) ethanol-containing Lieber-DeCarli liquid diet and received intraperitoneal carbon tetrachloride (CCl4) injection twice weekly (1 mL/kg) for 8 wk. Zinc acetate (100 mg/L) and/or rifaximin (100 mg/L) were orally administered during experimental period. Hepatic steatosis, inflammation and fibrosis as well as intestinal barrier function were evaluated by histological and molecular analyses. Moreover, the direct effects of both agents on Caco-2 barrier function were assessed by in vitro assays.RESULTSIn the ethanol plus CCl4-treated mice, combination of zinc acetate and rifaximin attenuated oxidative lipid peroxidation with downregulation of Nox2 and Nox4. This combination significantly inhibited the Kupffer cells expansion and the proinflammatory response with blunted hepatic exposure of lipopolysaccharide and the toll-like receptor 4/nuclear factor kB pathway. Consequently, liver fibrosis and hepatic stellate cells activation were efficiently suppressed with downregulation of Mmp-2, -9, -13, and Timp1. Both agents improved the atrophic changes and permeability in the ileum, with restoration of tight junction proteins (TJPs) by decreasing the expressions of tumor necrosis factor α and myosin light chain kinase. In the in vitro assay, both agents directly reinforced ethanol or lipopolysaccharide-stimulated paracellular permeability and upregulated TJPs in Caco-2 cells.CONCLUSIONDual therapy with zinc acetate and rifaximin may serve as a strategy to prevent ALD-related fibrosis by maintaining intestinal barrier integrity.

Identification of a novel peptide that activates alcohol dehydrogenase from crucian carp swim bladder and how it protects against acute alcohol-induced liver injury in mice

Alcoholism is a severe threat to public health, and there are no adequate treatments for alcoholic liver disease. The aim of this study was to identify bioactive peptides derived from natural proteins that prevent acute alcohol-induced liver injury. We identified a peptide with the sequence Gly-Leu-hydroxyproline-Gly-Glu-Arg (GLpGER) from the hydrolysate of crucian carp swim bladder using size-exclusion chromatography and reversed-phase chromatography. The in vitro EC50 value of GLpGER to activate alcohol dehydrogenase (ADH) was 137.9 ± 9 µM. Molecular docking experiments indicated that the mechanism by which GLpGER activates ADH may be related to the formation of stable complexes with ADH active pockets through hydrogen bonding, and electrostatic and hydrophobic interactions. Oral administration of GLpGER one hour before acute alcohol ingestion significantly increased alcohol metabolism, manifesting as reduced incidence of the loss of righting reflex, increased alcohol tolerance time, shortened sobering time, and decreased blood alcohol concentration level. GLpGER restored liver ADH activity, maintained the typical morphology of hepatocytes, and reduced serum levels of alanine aminotransferase and aspartate aminotransferase. These findings suggest that GLpGER might reduce acute alcohol-induced liver injury and may have the potential to be developed as an anti-inebriation ingredient.

Alcohol Abstinence Rescues Hepatic Steatosis and Liver Injury via Improving Metabolic Reprogramming in Chronic Alcohol-Fed Mice.

Background: Alcoholic liver disease (ALD) caused by chronic ethanol overconsumption is a common type of liver disease with a severe mortality burden throughout the world. The pathogenesis of ALD is complex, and no effective clinical treatment for the disease has advanced so far. Prolonged alcohol abstinence is the most effective therapy to attenuate the clinical course of ALD and even reverse liver damage. However, the molecular mechanisms involved in alcohol abstinence-improved recovery from alcoholic fatty liver remain unclear. This study aims to systematically evaluate the beneficial effect of alcohol abstinence on pathological changes in ALD.Methods: Using the Lieber-DeCarli mouse model of ALD, we analysed whether 1-week alcohol withdrawal reversed alcohol-induced detrimental alterations, including oxidative stress, liver injury, lipids metabolism, and hepatic inflammation, by detecting biomarkers and potential targets.Results: Alcohol withdrawal ameliorated alcohol-induced hepatic steatosis by improving liver lipid metabolism reprogramming via upregulating phosphorylated 5′-AMP -activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor-α (PPAR-α), and carnitine palmitoyltransferase-1 (CPT-1), and downregulating fatty acid synthase (FAS) and diacylglycerol acyltransferase-2 (DGAT-2). The activities of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px), were significantly enhanced by alcohol withdrawal. Importantly, the abstinence recovered alcohol-fed induced liver injury, as evidenced by the improvements in haematoxylin and eosin (H&E) staining, plasma alanine aminotransferase (ALT) levels, and liver weight/body weight ratio. Alcohol-stimulated toll-like receptor 4/mitogen-activated protein kinases (TLR4/MAPKs) were significantly reversed by alcohol withdrawal, which might mechanistically contribute to the amelioration of liver injury. Accordingly, the hepatic inflammatory factor represented by tumour necrosis factor-alpha (TNF-α) was improved by alcohol abstinence.Conclusion: In summary, we reported that alcohol withdrawal effectively restored hepatic lipid metabolism and reversed liver injury and inflammation by improving metabolism reprogramming. These findings enhanced our understanding of the biological mechanisms involved in the beneficial role of alcohol abstinence as an effective treatment for ALD.

Black Carrot (Daucus carota ssp. sativus var. Atrorubens Alef.) Extract Protects against Ethanol-induced Liver Injury via the Suppression of Phosphodiesterase 4 mRNA Expression

We examined the protective effects of Black Carrot Extract (BCE) on Alcoholic Liver Disease (ALD) using in vivo and in vitro models. In an in vivo ethanol-Carbon Tetrachloride (CCl4)-treated rat model, BCE treatment suppressed serum alanine aminotransferase and aspartate aminotransferase activity. BCE also suppressed ethanol- and CCl4-induced alcoholic liver disease. Furthermore, we observed that the BCE or butanol-extracted fraction of BCE (BCE-BuOH) recovered the cell viability of in vitro ethanol-treated hepatocytes. BCE-BuOH also suppressed the production of reactive oxygen species induced by ethanol to the control level. Moreover, BCE-BuOH regulated the activities of three alcoholic metabolism-related enzymes: cytochrome P450 2E1 activity was suppressed at the posttranslational level, alcohol dehydrogenase activity was increased at the posttranslational level, and aldehyde dehydrogenase 2 activity was increased at the transcriptional level. Novel findings in this study include an increase in intracellular Cyclic Adenosine 3’,5’-Monophosphate (cAMP) levels in hepatocytes with the simultaneous addition of ethanol and BCE-BuOH and the suppression of changes in the activities of three enzymes upon treatment with an inhibitor of cAMP-dependent protein kinase. Our study also found that BCE-BuOH suppressed the expression of phosphodiesterase 4b mRNA, which increased intracellular cAMP levels. These results suggest that BCE is useful for the treatment of ALD.

Black Carrot (Daucus carota ssp. sativus var. Atrorubens Alef.) Extract Protects against Ethanol-induced Liver Injury via the Suppression of Phosphodiesterase 4 mRNA Expression

We examined the protective effects of Black Carrot Extract (BCE) on Alcoholic Liver Disease (ALD) using in vivo and in vitro models. In an in vivo ethanol-Carbon Tetrachloride (CCl4)-treated rat model, BCE treatment suppressed serum alanine aminotransferase and aspartate aminotransferase activity. BCE also suppressed ethanol- and CCl4-induced alcoholic liver disease. Furthermore, we observed that the BCE or butanol-extracted fraction of BCE (BCE-BuOH) recovered the cell viability of in vitro ethanol-treated hepatocytes. BCE-BuOH also suppressed the production of reactive oxygen species induced by ethanol to the control level. Moreover, BCE-BuOH regulated the activities of three alcoholic metabolism-related enzymes: cytochrome P450 2E1 activity was suppressed at the posttranslational level, alcohol dehydrogenase activity was increased at the posttranslational level, and aldehyde dehydrogenase 2 activity was increased at the transcriptional level. Novel findings in this study include an increase in intracellular Cyclic Adenosine 3’,5’-Monophosphate (cAMP) levels in hepatocytes with the simultaneous addition of ethanol and BCE-BuOH and the suppression of changes in the activities of three enzymes upon treatment with an inhibitor of cAMP-dependent protein kinase. Our study also found that BCE-BuOH suppressed the expression of phosphodiesterase 4b mRNA, which increased intracellular cAMP levels. These results suggest that BCE is useful for the treatment of ALD.