Ethanol-induced Liver Damage Research Articles

In Vivo Hepatoprotective Effects of a Peptide Fraction from Krill Protein Hydrolysates against Alcohol-Induced Oxidative Damage.

Background: Krill (Euphausia superba) represent the largest animal biomass on earth, and are a rich source of high-quality protein with essential amino acids. Krill-derived peptides are renowned for their antioxidant activities. Hence, these peptides may have protective effects against oxidative stress. Alcoholic liver disease is a prevalent cause of death worldwide. The present study explores the hepatoprotective effects of krill peptide hydrolysate fractions against ethanol-induced liver damage in BALB/c mice. Methods: Hydrolysis was carried out by mimicking the gastrointestinal digestion environment and the filtrate was fractionated based on molecular weight (<1 kDa, 1–3 kDa, and >3 kDa). The 1–3 kDa fraction (KPF), which indicated the highest antioxidant effect, was further investigated for its effect on weight and survival rate increase in mice and its influence on serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and liver cholesterol levels. Moreover, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels were measured, followed by Nrf2 and HO-1 expression. Histopathology studies were conducted to assess hepatic tissue damage. Results: KPF enhanced the weight and survival rate of mice while reducing serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and liver cholesterol levels. Moreover, KPF upregulated SOD, CAT, and GPx in liver tissues, while downregulating tumor necrosis factor α and interleukin-6 mRNA expression. KPF further increased Nrf2 and HO-1 expression and suppressed ethanol-induced apoptotic proteins in the liver. Histopathology of KPF-treated mice showed less hepatic tissue damage compared to ethanol-treated mice. Conclusions: Hydrolysates and bioactive peptides prepared from krill can be employed as functional foods to enhance liver function and health. Further investigations of KPF could lead to the development of functional foods.

EFFECT OF BLUMEA LACERA ON TISSUE GSH, LIPID PEROXIDATION AND HEPATIC CELLS IN ETHANOL INDUCED HEPATOTOXICITY IN RATS

Objective: To evaluate hepatoprotective effects of ethanol extract of aerial part of Blumea lacera (BLEE) against ethanol-induced hepatotoxicity in rats.&#x0D; Methods: The in vivo antioxidant activity of BLEE was assessed by determining the tissue glutathione (GSH) and lipid peroxidation (LPO) levels. The BLEE at the doses of 200 and 400 mg/kg and silymarin 100 mg/kg administered to the ethanol challenged rats. The effects of BLEE and silymarin on Physical and Biochemical Parameters were measured. Similarly, histopathological changes of the liver were studied.&#x0D; Results: The BLEE showed in vivo antioxidant activity. A significant (P&lt;0.001) decrease in SGOT, SGPT, ALP, total and direct bilirubin was observed in BLEE treated group at doses i.e. 200 mg/kg and 400 mg/kg as compared to intoxicated group. Liver damage in animal pretreated with BLEE was minimal with distinct preservation of structures and the architectural frame of the hepatic cells.&#x0D; Conclusion: These findings demonstrated the hepatoprotective effects of BLEE against ethanol-induced liver damage.

Rice Bran Phenolic Extract Protects against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Barrier Dysfunction, and Liver Inflammation Mediated by the Endotoxin-TLR4-NF-κB Pathway.

Alcoholic liver injury, known as the most general result of chronic alcohol intake, is induced by inflammatory responses, which is activated by intestine-derived endotoxins formed from intestinal dysbiosis. The hepatoprotective activity of rice bran phenolic extract (RBPE) on ethanol-fed mice was investigated for the first time in this study, and the underlying mechanism was explored from gut microbiota, barrier function, and hepatic inflammation. Mice were fed an alcohol-containing liquid diet alone or in mixture with RBPE for 8 weeks. RBPE treatment mitigated ethanol-induced liver damage, evidenced by the declined lipid profile levels and hepatic function markers. Moreover, ethanol intake induced intestinal microbiota dysbiosis, which was attenuated by RBPE supplementation. RBPE treatment improved the alcohol-induced decrease in the expression of ZO-1, Claudin-1, Claudin-4, and Reg3g, revealing the ameliorative effect of RBPE on intestinal barrier dysfunction. Furthermore, RBPE treatment repressed the alcohol-induced trigger of the hepatic endotoxin-TLR4-NF-κB pathway, followed by the mitigated liver inflammation. The findings indicate that RBPE supplementation ameliorates intestinal microbiota dysbiosis and barrier dysfunction, inactivates the endotoxin-TLR4-NF-κB pathway, and represses inflammatory responses in liver, and therefore, intake of RBPE or brown rice may be an effective way to mitigate alcoholic liver injury.

Intestinal SIRT1 Deficiency Protects Mice from Ethanol-Induced Liver Injury by Mitigating Ferroptosis

Aberrant liver sirtuin 1 (SIRT1), a mammalian NAD+-dependent protein deacetylase, is implicated in the pathogenesis of alcoholic liver disease (ALD). However, the role of intestinal SIRT1 in ALD is presently unknown. This study investigated the involvement of intestine-specific SIRT1 in ethanol-induced liver dysfunction in mice. Ethanol feeding studies were performed on knockout mice with intestinal-specific SIRT1 deletion [SIRT1i knockout (KO)] and flox control [wild-type (WT)] mice with a chronic-plus-binge ethanol feeding protocol. After ethanol administration, hepatic inflammation and liver injury were substantially attenuated in the SIRT1iKO mice compared with the WT mice, suggesting that intestinal SIRT1 played a detrimental role in the ethanol-induced liver injury. Mechanistically, the hepatic protective effect of intestinal SIRT1 deficiency was attributable to ameliorated dysfunctional iron metabolism, increased hepatic glutathione contents, and attenuated lipid peroxidation, along with inhibition of a panel of genes implicated in the ferroptosis process in the livers of ethanol-fed mice. This study demonstrates that ablation of intestinal SIRT1 protected mice from the ethanol-induced inflammation and liver damage. The protective effects of intestinal SIRT1 deficiency are mediated, at least partially, by mitigating hepatic ferroptosis. Targeting intestinal SIRT1 or dampening hepatic ferroptosis signaling may have therapeutic potential for ALD in humans.

Hepatoprotective Effects of Fadogia ancylantha (Makoni Tea) on Ethanol-Induced Liver Damage in Wistar Rats

Medicinal and food plants contain phytoconstiuents that can provide protection against oxidative damage. The aim of this study was to determine the hepatoprotective effects of Fadogia ancylantha on ethanol-induced liver damage. The rationale for doing this study was because of the increased deaths due to liver disorders and so the potential hepatoprotective effects of the F. ancylantha could alleviate the problem. Twenty male Wistar rats were selected into four groups (n=5) and were orally treated with, control (1 ml of distilled water), ethanol only (5 g/kg b.w), ethanol + Fadogia ancylantha (5 g/kg b.w and 5 ml/kg b.w respectively) and Fadogia ancylantha only (5 ml/kg b.w) for 8 weeks. Body weights, fasting glucose, blood cholesterol and organ weights were measured. Oral glucose tolerance test (OGTT; 2 g/kg glucose) and insulin tolerance test (ITT; 0.75 U/kg i.p) were performed. Total plasma protein and liver glycogen were thereafter measured. The weights of rats in all treatment groups showed general increase. Cholesterol levels in the ethanol-treated group were decreased (P < 0.05). OGTT showed normal glucose tolerance in week 4, but in week 8 the ethanol-treated group showed an increase (P < 0.05) area under the curve. Fadogia ancylantha group showed increased plasma protein concentration (P < 0.05). All treatment groups had decreased liver glycogen content (P < 0.001). This study demonstrated that Fadogia ancylantha has potential hepatoprotective effects and may be effective in protecting against ethanol-induced liver damage.

Investigation of the phytochemical composition and antioxidant properties of chinar (Platanus orientalis L.) leaf infusion against ethanol-induced oxidative stress in rats.

Chinar (Platanus orientalis L.) is used in folk medicine against tooth and knee pain, wounds, inflammation, and stomach discomfort; however, the effects of P. orientalis leaf (PO-leaf) infusion on the liver and kidney are unknown. The aim of this study was to investigate the phytochemical composition and antioxidant properties of an infusion obtained from dried P. orientalis leaves against ethanol-induced oxidative stress (OS) in rats. After a toxicity test, thirty male Wistar rats were divided into five groups: Control, Ethanol 20%, Ethanol 20% + Silymarin (10mg/kg), Ethanol 20% + PO-20mg/mL infusion, and Ethanol 20% + PO-60mg/mL infusion. The PO-leaf infusion doses were given ad libitum during 28days to test the biochemical and antioxidant enzyme levels. According to the results, the PO-leaf contained rich compounds such as benzaldehyde, palmitic acid, 2,4-ditert-butylphenol, stearic acid, octadecanoic acid, linoleic acid, linolenic acid, kaempferol, and kaempferol derivatives. In the Ethanol group, AST, ALT, LDH, GGT, UA, and urea in the serum and GST and malondialdehyde (MDA) in the liver and erythrocyte tissues showed a significant increase compared to the Control group. AST, LDH, GGT, UA, and LDL-C levels in the serum and MDA (all tissues) significantly decreased in the Ethanol + PO-60mg/mL group compared to the Ethanol group. SOD, GPx, and CAT activities in the kidney tissue of the Ethanol group showed a significant decrease compared to the Control group, whereas the GPx activity in kidney tissue in all of the treatment groups increased significantly compared to the Ethanol group. These findings suggest that the administration of the determined PO-leaf infusion doses might have a protective role against ethanol-induced liver and kidney damage in rats.

PROTECTIVE EFFECT OF KADUKKAI MAATHIRAI (TERMINALIA CHEBULA-BASED POLYHERBAL SIDDHA FORMULATION) IN ETHANOL-INDUCED LIVER DISEASE IN RATS

Objective: The objective of this study was to evaluate the prophylactic effect of Kadukkai maathirai (KM) against ethanol-induced hepatotoxicity in rats.Methods: Four groups (n=6) of adult female Sprague–Dawley rats were used. Ethanol was administered in the dose of 45% v/v 15 mL/kg/body weight twice a day for 8 weeks in the study. The four groups were treated orally for 8 weeks with 2% gum acacia (control), ethanol (toxic control), ethanol + KM 72 mg/kg, and ethanol + KM 400 mg/kg, respectively. At the end of 8 weeks, blood was collected by a retro-orbital puncture for the estimation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]). The liver was dissected out for histopathology. Using one-way ANOVA and post hoc Tukey’s test, the data were analyzed.Results: There was a significant (p&lt;0.05) decrease in the serum AST and ALT level in rats treated with KM 72 mg/kg as compared to toxic control. Liver parenchyma showed near normal architecture in KM 72 mg/kg-treated group as compared to ethanol-treated group which showed extensive ballooning degeneration of hepatocytes and microvesicular steatosis.Conclusion: KM, in the dose of 72 mg/kg, which is the therapeutic dosage described in Siddha additional literature, exerted hepatoprotective effect against ethanol-induced liver damage in rats.

EGF receptor plays a role in the mechanism of glutamine-mediated prevention of alcohol-induced gut barrier dysfunction and liver injury

Recent study indicated that glutamine prevents alcoholic tissue injury in mouse gut and liver. Here we investigated the potential role of Epidermal Growth Factor Receptor (EGFR) in glutamine-mediated prevention of ethanol-induced colonic barrier dysfunction, endotoxemia and liver damage. Wild-type and EGFR*Tg transgenic (expressing dominant negative EGFR) mice were fed 1–6% ethanol in Lieber-DeCarli diet. Gut permeability was measured by vascular-to-luminal flux of FITC-inulin, and junctional integrity assessed by confocal microscopy. Liver injury was evaluated by plasma transaminases, histopathology and triglyceride analyses. Glutamine effect on acetaldehyde-induced tight junction disruption was investigated in Caco-2 cell monolayers. Doxycycline-induced expression of EGFR* blocked glutamine-mediated prevention of ethanol-induced disruption of colonic epithelial tight junction, mucosal permeability and endotoxemia. Ethanol activated cofilin and disrupted actin cytoskeleton, which was blocked by glutamine in an EGFR-dependent mechanism. Ethanol down-regulated antioxidant gene expression and up-regulated cytokine and chemokine gene expression, which were blocked by glutamine in wild-type mice in the presence or absence of doxycycline, but not in EGFR*Tg mice in the presence of doxycycline. Histopathology, plasma transaminases, triglyceride and expression of chemokine and antioxidant genes indicated ethanol-induced liver damage, which were blocked by glutamine in an EGFR-dependent mechanism. Src kinase activity and extracellular ligand binding domain of EGFR are required for glutamine-mediated protection of barrier function in Caco-2 cell monolayers. Glutamine released metalloproteinases into the medium, and metalloproteinase inhibitors blocked glutamine-mediated protection of barrier function. Results demonstrate that EGFR plays an important role in glutamine-mediated prevention of alcoholic gut permeability, endotoxemia and liver damage.

How do methanol and higher alcohols found in alcoholic beverages affect membrane fluidity and migration of granulocytes?

Ethanol-induced changes in membrane fluidity and migration of granulocytes has been suggested to contribute to development of alcoholic hepatitis. Besides ethanol other aliphatic alcohols (OAAs) have been detected in alcoholic beverages. We examined the effects of OAAs alone and in combination with ethanol on these processes. Granulocytes isolated from human blood were treated separately with methanol, ethanol, and a mixture of OAAs including methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, and isoamyl alcohol at biologically relevant concentrations. The membrane fluidity and migration activity of granulocytes was examined by fluorescence anisotropy method and migration chambers, respectively. Our findings showed that OAAs increased membrane fluidity and migration activity of granulocytes in a concentration-dependent manner and when combined with ethanol they caused a further increase in the migration activity of granulocytes. It is possible that OAAs consumed with alcoholic beverages may further enhance migration of granulocytes in heavy drinkers and contribute to ethanol-induced liver damage. Practical applications The consumption of OAAs in alcoholic beverages has been hypothesized as an additional risk factor for the development of alcoholic liver diseases. To confirm this suggestion, the potentially adverse effects of exposure to OAAs should be further examined. Our investigation provides new toxicological data on the effects of OAAs found in alcoholic beverages. The results of this study can be used for more precise toxicological evaluations to clarify whether OAAs may pose an additional risk factor for the development of alcoholic liver diseases. Furthermore, information on the harmful effects of OAAs could enable health policy makers to make evidence-based decisions when implementing new regulations on alcoholic beverages.

Expansion of Granulocytic, Myeloid-Derived Suppressor Cells in Response to Ethanol-Induced Acute Liver Damage.

The dual role of ethanol in regulating both pro-inflammatory and anti-inflammatory response has recently been reported. Myeloid-derived suppressor cells (MDSCs) are one of the major components in the immune suppressive network in both innate and adaptive immune responses. In this study, we aim to define the role of a population expressing CD11b+Ly6GhighLy6Cint with immunosuppressive function in response to ethanol-induced acute liver damage. We find this increased granulocytic-MDSCs (G-MDSCs) population in the blood, spleen, and liver of mice treated with ethanol. Depletion of these cells increases serum alanine aminotransferase and aspartate aminotransferase levels, while G-MDSCs population adoptive transfer can ameliorate liver damage induced by ethanol, indicating the protective role in the early stage of alcoholic liver disease. The significant changes of T-cell profiles after G-MDSCs populations adoptive transfer and anti-Gr1 injection signify that both cytotoxic T and T helper cells might be the targeted cells of G-MDSCs. In the in vitro study, we find that myeloid precursors preferentially generate G-MDSCs and improve their suppressive capacity via chemokine interaction and YAP signaling when exposed to ethanol. Furthermore, IL-6 serves as an important indirect factor in mediating the expansion of G-MDSCs populations after acute ethanol exposure. Collectively, we show that expansion of G-MDSCs in response to ethanol consumption plays a protective role in acute alcoholic liver damage. Our study provides novel evidence of the immune response to acute ethanol consumption.

Endocrine Adiponectin-FGF15/19 Axis in Ethanol-Induced Inflammation and Alcoholic Liver Injury.

Alcoholic liver disease (ALD) is the most prevalent form of liver disease, encompassing a spectrum of progressive pathological changes from steatosis to steatohepatitis to fibrosis/cirrhosis and hepatocellular carcinoma. Alcoholic steatosis/steatohepatitis is the initial stage of ALD and a major risk factor for advanced liver injuries. Adiponectin is a hormone secreted from adipocytes. Fibroblast growth factor (FGF) 15 (human homolog, FGF19) is an ileum-derived hormone. Adipocyte-derived adiponectin and gut-derived FGF15/19 regulate each other, share common signaling cascades, and exert similar beneficial functions. Emerging evidence has revealed that dysregulated adiponectin-FGF15/19 axis and impaired hepatic adiponectin-FGF15/19 signaling are associated with alcoholic liver damage in rodents and humans. More importantly, endocrine adiponectin-FGF15/19 signaling confers protection against ethanol-induced liver damage via fine tuning the adipose-intestine-liver crosstalk, leading to limited hepatic inflammatory responses, and ameliorated alcoholic liver injury. This review is focused on the recently discovered endocrine adiponectin-FGF15/19 axis that is emerging as an essential adipose-gut-liver coordinator involved in the development and progression of alcoholic steatohepatitis.

Identification of Bioactive Compounds and Possible Mechanism of Hepatoprotective Activity of Ficus microcarpa l. Fil. Bark Extracts in Ethanol-Induced Chronic Hepatic Injury in Rats

Abstract: Objective: To evaluate the effect of the successive extracts of the FMB on ethanol induced chronic hepatotoxicity. Furthermore, to understand the mechanisms of its pharmacological actions, the in vivo antioxidant activity and major phytoconstituents of FMB were investigated. Methodology: Ficus microcarpa L. fil., (FM) is commonly known as ‘Indian Laurel’, is used for liver complaints in Indian traditional practice. The hepatoprotective effect of four successive extracts (petroleum ether 60-80o, ethyl acetate, ethanol and aqueous) of FM bark (FMB) were studied in chronic ethanol induced liver damage. The protective potential measured by monitoring biochemical parameters and histopathological alterations. Result: The ethyl acetate extract of FMBE produce significant hepatoprotection by stabilizing the biochemical parameters in a dose dependent manner, comparable to that of standard drug, silymarin; also showed the positive involvement of endogenous antioxidant system. Further, it was confirmed by histology examination of liver. Phytochemical studies confirmed the presence of the phenolic and triterpenoids compounds such as catechin, oleanolic and betulinic acid. Conclusion: Hepatoprotective ability of FMB involves antioxidant mechanism associated with up-regulation of endogenous antioxidant system due to presence of phenolics and triterpenoids. Thus, the present study provides a scientific rationale for the traditional use in the management of chronic liver disorders. Key words: Hepatoprotective, Ficus microcarpa, Ethanol, Antioxidant, Catechin, Oleanolic acid, Betulinic acid.

Triticum aestivum sprout-derived polysaccharide exerts hepatoprotective effects against ethanol-induced liver damage by enhancing the antioxidant system in mice.

Triticum aestivum sprout-derived polysaccharide (TASP) has anti-diabetic properties, but no information is available in regards to its protective effect against ethanol-induced hepatic injury. This study aimed to investigate the mechanism behind the protective role of TASP against ethanol-induced liver injury invivo. Male C57BL/6 mice were administered ethanol with or without TASP for 10consecutive days by oral gavage. Silymarin was administered in the same manner as a positive control. TASP reduced ethanol-induced hepatic lipid accumulation and serum alanine aminotransferase(ALT) and aspartate aminotransferase (AST) levels. TASP also prevented glutathione(GSH) depletion and increased the superoxide dismutase(SOD) in liver tissue. In addition, TASP significantly inhibited ethanol-induced cytochrome P4502E1(CYP2E1) activation, and upregulated the expressions of nuclear factor erythroid 2-related factor2(Nrf2) and hemeoxygenase-1(HO-1), and downregulated NADPH oxidase genes in ethanol fed mice. Furthermore, the upregulation of Nrf2 was found to be regulated by a phosphatidylinositol 3-kinase(PI3K)/Akt pathway. TASP also attenuated hepatic injury by modulation of caspase-3 and apoptosis-associated mitochondrial proteins including B-cell lymphoma-2(Bcl-2) and Bcl-2-associatedX (Bax) in liver tissues of mice. The study demonstrated that TASP treatment protects against ethanol-induced hepatic injury via multiple pathways by inhibiting steatosis and improving antioxidant marker levels during hepatic injury. Such properties provide a basis for therapeutic agents against alcohol-induced liver injury.

Hederagenin Supplementation Alleviates the Pro-Inflammatory and Apoptotic Response to Alcohol in Rats.

In this study, we determined the effects of hederagenin isolated from Akebia quinata fruit on alcohol-induced hepatotoxicity in rats. Specifically, we investigated the hepatoprotective, anti-inflammatory, and anti-apoptotic effects of hederagenin, as well as the role of AKT and mitogen-activated protein kinase (MAPK) signaling pathways in ethanol-induced liver injury. Experimental animals were randomly divided into three groups: normal (sham), 25% ethanol, and 25% ethanol + hederagenin (50 mg/kg/day). Each group was orally administered the respective treatments once per day for 21 days. Acetaldehyde dehydrogenase-2 mRNA expression was higher and alcohol dehydrogenase mRNA expression was lower in the ethanol + hederagenin group than those in the ethanol group. Pro-inflammatory cytokines, including TNF-α, IL-6, and cyclooxygenase-2, significantly increased in the ethanol group, but these increases were attenuated by hederagenin. Moreover, Western blot analysis showed increased expression of the apoptosis-associated protein, Bcl-2, and decreased expression of Bax and p53 after treatment with hederagenin. Hederagenin treatment attenuated ethanol-induced increases in activated p38 MAPK and increased the levels of phosphorylated AKT and ERK. Hederagenin alleviated ethanol-induced liver damage through anti-inflammatory and anti-apoptotic activities. These results suggest that hederagenin is a potential candidate for preventing alcoholic liver injury.

The in vivo hepato-recovery effects of the polyphenol-rich fermented food Xeniji™ on ethanol-induced liver damage

Xeniji that rich in caffeoylquinic acid and sakuranetin promoted recovery of the ethanol induced liver damage.

Polydatin Protects Rat Liver against Ethanol-Induced Injury: Involvement of CYP2E1/ROS/Nrf2 and TLR4/NF-κB p65 Pathway.

Excessive alcohol consumption leads to serious liver injury, associating with oxidative stress and inflammatory response. Previous study has demonstrated that polydatin (PD) exerted antioxidant and anti-inflammatory effects and attenuated ethanol-induced liver damage, but the research remained insufficient. Hence, this experiment aimed to evaluate the hepatoprotective effect and potential mechanisms of PD on ethanol-induced hepatotoxicity. Our results showed that PD pretreatment dramatically decreased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in the serum, suppressed the malonaldehyde (MDA) and triglyceride (TG) content and the production of reactive oxygen species (ROS), and enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), andalcohol dehydrogenase (ADH), and aldehyde dehydrogenase (ALDH), paralleled by an improvement of histopathology alterations. The protective effect of PD against oxidative stress was probably associated with downregulation of cytochrome P450 2E1 (CYP2E1) and upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its target gene haem oxygenase-1 (HO-1). Moreover, PD inhibited the release of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) via downregulating toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-κB) p65. To conclude, PD pretreatment protects against ethanol-induced liver injury via suppressing oxidative stress and inflammation.

Different Dietary Proportions of Fish Oil Regulate Inflammatory Factors but Do Not Change Intestinal Tight Junction ZO-1 Expression in Ethanol-Fed Rats.

Sixty male Wistar rats were fed a control or an ethanol-containing diet in groups C or E. The fat compositions were adjusted with 25% or 57% fish oil substituted for olive oil in groups CF25, CF57, EF25, and EF57. Hepatic thiobarbituric acid-reactive substance (TBARS) levels, cytochrome P450 2E1 protein expression, and tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, IL-6, and IL-10 levels, as well as intracellular adhesion molecule (ICAM)-1 levels were significantly elevated, whereas plasma adiponectin level was significantly reduced in group E (p < 0.05). Hepatic histopathological scores of fatty change and inflammation, in group E were significantly higher than those of group C (p < 0.05). Hepatic TBARS, plasma ICAM-1, and hepatic TNF-α, IL-1β, and IL-10 levels were significantly lower, and plasma adiponectin levels were significantly higher in groups EF25 and EF57 than those in group E (p < 0.05). The immunoreactive area of the intestinal tight junction protein, ZO-1, showed no change between groups C and E. Only group CF57 displayed a significantly higher ZO-1 immunoreactive area compared to group C (p = 0.0415). 25% or 57% fish oil substituted for dietary olive oil could prevent ethanol-induced liver damage in rats, but the mechanism might not be related to intestinal tight junction ZO-1 expression.

Protective Effect of Tyrosol and S-Adenosylmethionine against Ethanol-Induced Oxidative Stress of Hepg2 Cells Involves Sirtuin 1, P53 and Erk1/2 Signaling.

Oxidative stress plays a major role in ethanol-induced liver damage, and agents with antioxidant properties are promising as therapeutic opportunities in alcoholic liver disease. In the present work, we investigated the effect of S-adenosylmethionine (AdoMet), Tyrosol (Tyr), and their combination on HepG2 cells exposed to ethanol exploring the potential molecular mechanisms. We exposed HepG2 cells to 1 M ethanol for 4 and 48 h; thereafter, we recorded a decreased cell viability, increase of intracellular reactive oxygen species (ROS) and lipid accumulation, and the release into culture medium of markers of liver disease such as triacylglycerol, cholesterol, transaminases, albumin, ferritin, and homocysteine. On the other hand, AdoMet and Tyrosol were able to attenuate or antagonize these adverse changes induced by acute exposure to ethanol. The protective effects were paralleled by increased Sirtuin 1 protein expression and nuclear translocation and increased ERK1/2 phosphorylation that were both responsible for the protection of cells from apoptosis. Moreover, AdoMet increased p53 and p21 expression, while Tyrosol reduced p21 expression and enhanced the expression of uncleaved caspase 3 and 9, suggesting that its protective effect may be related to the inhibition of the apoptotic machinery. Altogether, our data show that AdoMet and Tyrosol exert beneficial effects in ethanol-induced oxidative stress in HepG2 cells and provide a rationale for their potential use in combination in the prevention of ethanol-induced liver damage.

Assessment of antioxidant activity of metformin in ethanol induced liver damage in Sprague Dawley rats

Background: Alcoholic liver disease (ALD) is a life style associated and one of the most common causes of chronic liver disease in the world. Chronic and excessive ethanol consumption impairs fatty acid oxidation and thereby stimulates lipogenesis, which leads to steatosis. Manifestation of harmful effects by alcohol occurs by free radical species which react with most of the cell components by changing their structures and functions. The hepatoprotective activity of metformin may be due to its antioxidant effect and enhancing fatty acid oxidation. So the aim of the present study is to evaluate preventive hepatoprotective effect of metformin in terms of hepatic oxidative stress marker enzymes and liver-histopathology scores. Methods: Thirty adult Sprague Dawley rats of either sex, weighing 200-250 g were selected for the study. The study was performed as per CPCSEA guidelines. The rats were randomly divided into 5 groups; n=6. All the treatments were given once a day for 21 days. After day 21, the dissected liver was used to assess oxidative stress marker enzymes malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) spectrophotometrically. The liver damage was assessed by histopathological scoring (HPS). Results: A comparison of The liver tissue MDA, SOD, CAT levels (nmol/g) and HPS value in the various groups on day-22 suggests that a treatment with metformin at low dose displayed a minimal hepatocellular protection when compared to that of the ethanol-treated and vehicle treated groups; however, metformin treatment at moderate and high doses elicited a better hepato protection as compared to low dose metformin treated groups. A dose-dependent hepatoprotection by metformin that high-dose metformin may be a potential therapeutic candidate in attenuating the ALD. Conclusions: Metformin co-administration effectively prevented hepatic damage caused by ethanol in animal model with favourable modification in the oxidative stress marker enzymes in liver tissue and histopathology. It may be effective for preventing liver toxicity in chronic alcoholics. A dose dependent hepatoprotection reveals that metformin may be a potential therapeutic candidate in attenuating the ALD which needs a systematic clinical study.

Occludin deficiency promotes ethanol-induced disruption of colonic epithelial junctions, gut barrier dysfunction and liver damage in mice

BackgroundDisruption of epithelial tight junctions (TJ), gut barrier dysfunction and endotoxemia play crucial role in the pathogenesis of alcoholic tissue injury. Occludin, a transmembrane protein of TJ, is depleted in colon by alcohol. However, it is unknown whether occludin depletion influences alcoholic gut and liver injury. MethodsWild type (WT) and occludin deficient (Ocln−/−) mice were fed 1–6% ethanol in Lieber–DeCarli diet. Gut permeability was measured by vascular-to-luminal flux of FITC-inulin. Junctional integrity was analyzed by confocal microscopy. Liver injury was assessed by plasma transaminase, histopathology and triglyceride analyses. The effect of occludin depletion on acetaldehyde-induced TJ disruption was confirmed in Caco-2 cell monolayers. ResultsEthanol feeding significantly reduced body weight gain in Ocln−/− mice. Ethanol increased inulin permeability in colon of both WT and Ocln−/− mice, but the effect was 4-fold higher in Ocln−/− mice. The gross morphology of colonic mucosa was unaltered, but ethanol disrupted the actin cytoskeleton, induced redistribution of occludin, ZO-1, E-cadherin and β-catenin from the junctions and elevated TLR4, which was more severe in Ocln−/− mice. Occludin knockdown significantly enhanced acetaldehyde-induced TJ disruption and barrier dysfunction in Caco-2 cell monolayers. Ethanol significantly increased liver weight and plasma transaminase activity in Ocln−/− mice, but not in WT mice. Histological analysis indicated more severe lesions and fat deposition in the liver of ethanol-fed Ocln−/− mice. Ethanol-induced elevation of liver triglyceride was also higher in Ocln−/− mice. ConclusionThis study indicates that occludin deficiency increases susceptibility to ethanol-induced colonic mucosal barrier dysfunction and liver damage in mice.