Gut microbial trimethylamine is elevated in alcohol-associated hepatitis and contributes to ethanol-induced liver injury in mice.

There is mounting evidence that microbes residing in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcohol-associated hepatitis (AH). However, mechanisms by which gut microbes synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, finding elevated levels of the microbial metabolite trimethylamine (TMA) in AH. In subsequent studies, we treated mice with non-lethal bacterial choline TMA lyase (CutC/D) inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. We show the gut microbial choline metabolite TMA is elevated in AH patients and correlates with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial CutC/D activity protects mice from ethanol-induced liver injury. CutC/D inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome and host liver transcriptome. The microbial metabolite TMA is elevated in patients with AH, and inhibition of TMA production from gut microbes can protect mice from ethanol-induced liver injury.

Feeding mice a diet high in oxidized linoleic acid metabolites does not alter liver oxylipin concentrations.

The oxidation of dietary linoleic acid (LA) produces oxidized LA metabolites (OXLAMs) known to regulate multiple signaling pathways in vivo. Recently, we reported that feeding OXLAMs to mice resulted in liver inflammation and apoptosis. However, it is not known whether this is due to a direct effect of OXLAMs accumulating in the liver, or to their degradation into bioactive shorter chain molecules (e.g. aldehydes) that can provoke inflammation and related cascades. To address this question, mice were fed a low or high LA diet low in OXLAMs, or a low LA diet supplemented with OXLAMs from heated corn oil (high OXLAM diet). Unesterified oxidized fatty acids (i.e. oxylipins), including OXLAMs, were measured in liver after 8 weeks of dietary intervention using ultra-high pressure liquid chromatography coupled to tandem mass-spectrometry. The high OXLAM diet did not alter liver oxylipin concentrations compared to the low LA diet low in OXLAMs. Significant increases in several omega-6 derived oxylipins and reductions in omega-3 derived oxylipins were observed in the high LA dietary group compared to the low LA group. Our findings suggest that dietary OXLAMs do not accumulate in liver, and likely exert pro-inflammatory and pro-apoptotic effects via downstream secondary metabolites.

Ileum Gene Expression in Response to Acute Systemic Inflammation in Mice Chronically Fed Ethanol: Beneficial Effects of Elevated Tissue n-3 PUFAs.

Chronic alcohol consumption leads to disturbances in intestinal function which can be exacerbated by inflammation and modulated by different factors, e.g., polyunsaturated fatty acids (PUFAs). The mechanisms underlying these alterations are not well understood. In this study, RNA-seq analysis was performed on ileum tissue from WT and fat-1 transgenic mice (which have elevated endogenous n-3 PUFAs). Mice were chronically fed ethanol (EtOH) and challenged with a single lipopolysaccharide (LPS) dose to induce acute systemic inflammation. Both WT and fat-1 mice exhibited significant ileum transcriptome changes following EtOH + LPS treatment. Compared to WT, fat-1 mice had upregulated expression of genes associated with cell cycle and xenobiotic metabolism, while the expression of pro-inflammatory cytokines and pro-fibrotic genes was decreased. In response to EtOH + LPS, fat-1 mice had an increased expression of genes related to antibacterial B cells (APRIL and IgA), as well as an elevation in markers of pro-restorative macrophages and γδ T cells that was not observed in WT mice. Our study significantly expands the knowledge of regulatory mechanisms underlying intestinal alterations due to EtOH consumption and inflammation and identifies the beneficial transcriptional effects of n-3 PUFAs, which may serve as a viable nutritional intervention for intestinal damage resulting from excessive alcohol consumption.

Beneficial effects of an endogenous enrichment in n3-PUFAs on Wnt signaling are associated with attenuation of alcohol-mediated liver disease in mice.

Alcohol-associated liver disease (ALD) is a major human health issue for which there are limited treatment options. Experimental evidence suggests that nutrition plays an important role in ALD pathogenesis, and specific dietary fatty acids, for example, n6 or n3-PUFAs, may exacerbate or attenuate ALD, respectively. The purpose of the current study was to determine whether the beneficial effects of n3-PUFA enrichment in ALD were mediated, in part, by improvement in Wnt signaling. Wild-type (WT) and fat-1 transgenic mice (that endogenously convert n6-PUFAs to n3) were fed ethanol (EtOH) for 6 weeks followed by a single LPS challenge. fat-1 mice had less severe liver damage than WT littermates as evidenced by reduced plasma alanine aminotransferase, hepatic steatosis, liver tissue neutrophil infiltration, and pro-inflammatory cytokine expression. WT mice had a greater downregulation of Axin2, a key gene in the Wnt pathway, than fat-1 mice in response to EtOH and LPS. Further, there were significant differences between WT and fat-1 EtOH+LPS-challenged mice in the expression of five additional genes linked to the Wnt signaling pathway, including Apc, Fosl1/Fra-1, Mapk8/Jnk-1, Porcn, and Nkd1. Compared to WT, primary hepatocytes isolated from fat-1 mice exhibited more effective Wnt signaling and were more resistant to EtOH-, palmitic acid-, or TNFα-induced cell death. Further, we demonstrated that the n3-PUFA-derived lipid mediators, resolvins D1 and E1, can regulate hepatocyte expression of several Wnt-related genes that were differentially expressed between WT and fat-1 mice. These data demonstrate a novel mechanism by which n3-PUFAs can ameliorate ALD.

Tributyrin Inhibits Ethanol-Induced Epigenetic Repression of CPT-1A and Attenuates Hepatic Steatosis and Injury.

Ethanol-mediated down-regulation of carnitine palmitoyltransferase-1 (CPT-1A) gene expression plays a major role in the development of hepatic steatosis; however, the underlying mechanisms are not completely elucidated. Tributyrin, a butyrate prodrug that can inhibit histone deacetylase (HDAC) activity, attenuates hepatic steatosis and injury. The present study examined the beneficial effect of tributyrin/butyrate in attenuating ethanol-induced pathogenic epigenetic mechanisms affecting CPT-1A promoter-histone modifications and gene expression and hepatic steatosis/injury. METHODS: Mice were fed a liquid Lieber-DeCarli diet (Research Diet Inc, New Brunswick, NJ) with or without ethanol for 4 weeks. In a subset of mice, tributyrin (2 g/kg) was administered orally by gavage. Primary rat hepatocytes were treated with 50 mmol/L ethanol and/or 2 mmol/L butyrate. Gene expression and epigenetic modifications at the CPT-1A promoter were analyzed by chromatin immunoprecipitation analysis. RESULTS: In vivo, ethanol induced hepatic CPT-1A promoter histone H3K9 deacetylation, which is indicative of a repressive chromatin state, and decreased CPT-1A gene expression. Our data identified HDAC1 as the predominant HDAC causing CPT-1A promoter histone H3K9 deacetylation and epigenetic down-regulation of gene expression. Significantly, Specificity Protein 1 (SP1) and Hepatocyte Nuclear Factor 4 Alpha (HNF4α) participated in the recruitment of HDAC1 to the proximal and distal regions of CPT-1A promoter, respectively, and mediated transcriptional repression. Importantly, butyrate, a dietary HDAC inhibitor, attenuated ethanol-induced recruitment of HDAC1 and facilitated p300-HAT binding by enabling SP1/p300 interaction at the proximal region and HNF4α/peroxisomal proliferator-activated receptor-γ coactivator-1α/p300 interactions at the distal region, leading to promoter histone acetylation and enhanced CPT-1A transcription. CONCLUSIONS: This study identifies HDAC1-mediated repressive epigenetic mechanisms that underlie an ethanol-mediated decrease in CPT-1A expression. Importantly, tributyrin/butyrate inhibits HDAC1, rescues CPT-1A expression, and attenuates ethanol-mediated hepatic steatosis and injury, suggesting its potential use in therapeutic strategies for alcoholic liver disease.

Mechanisms, biomarkers and targets for therapy in alcohol-associated liver injury: From Genetics to nutrition: Summary of the ISBRA 2018 symposium.

The symposium "Mechanisms, Biomarkers and Targets for Therapy in Alcohol-associated Liver Injury: From Genetics to Nutrition" was held at the 19th Congress of International Society for Biomedical Research on Alcoholism on September 13th, 2018 in Kyoto, Japan. The goal of the symposium was to discuss the importance of genetics and nutrition in alcoholic liver disease (ALD) development from mechanistic and therapeutic perspectives. The following is a summary of this session addressing the gene polymorphisms in ALD, the role of zinc in gut-liver axis perturbations associated with ALD, highlighting the importance of dietary fat in ALD pathogenesis, the hepatic n6 and n3 PUFA oxylipin pattern associated with ethanol-induced liver injury, and finally deliberating on new biomarkers for alcoholic hepatitis and their implications for diagnosis and therapy. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows.

Microbiome dysbiosis and alcoholic liver disease☆.

Microbiome dysbiosis is strongly associated with alcoholic liver disease (ALD). Recent studies on comprehensive analyses of microbiome compositional and functional changes have begun to uncover the mechanistic relation between microbiome and the pathogenesis of ALD. Importantly, targeting the microbiome has become a potential strategy for the prevention and treatment of ALD. In this review, we summarize the clinical evidence of microbiome dysbiosis in ALD patients, and experimental advances in microbiome and metabolomic functional changes in animals with different species and genetic backgrounds in ALD. We also summarize the studies in humanized intestinal microbiome and fecal microbiota transplantation in mice. We introduce new developments in the studies on the role of the circulating bacterial microbiome, oral bacterial microbiome and fungal microbiome in the development of ALD. We highlight the potential mechanisms by which microbiome dysbiosis contributes to ALD, including short chain fatty acid changes, bile acid metabolism, intestinal barrier function, release of bacterial and fungal products, and inflammation. In addition, we summarize the recent developments targeting the microbiome in prevention and treatment of ALD, including dietary nutrient interference, herbal medicine, antibiotics, anti-fungal agents, probiotics, engineered bacterial therapy, fecal transplantation and oral hygiene. Although recent preclinical studies have advanced our understanding of the microbiome and ALD, clinical studies, especially prospective studies with large samples, are needed to better understand the cause-effect of microbiome dysbiosis in ALD. Identifying new precision-based strategies targeting the microbiome are expected to be developed as more effective therapies in ALD.

Ethanol and unsaturated dietary fat induce unique patterns of hepatic ω-6 and ω-3 PUFA oxylipins in a mouse model of alcoholic liver disease.

Alcoholic liver disease (ALD), a significant health problem, progresses through the course of several pathologies including steatosis, steatohepatitis, fibrosis, and cirrhosis. There are no effective FDA-approved medications to prevent or treat any stages of ALD, and the mechanisms involved in ALD pathogenesis are not well understood. Bioactive lipid metabolites play a crucial role in numerous pathological conditions, as well as in the induction and resolution of inflammation. Herein, a hepatic lipidomic analysis was performed on a mouse model of ALD with the objective of identifying novel metabolic pathways and lipid mediators associated with alcoholic steatohepatitis, which might be potential novel biomarkers and therapeutic targets for the disease. We found that ethanol and dietary unsaturated, but not saturated, fat caused elevated plasma ALT levels, hepatic steatosis and inflammation. These pathologies were associated with increased levels of bioactive lipid metabolites generally involved in pro-inflammatory responses, including 13-hydroxy-octadecadienoic acid, 9,10- and 12,13-dihydroxy-octadecenoic acids, 5-, 8-, 9-, 11-, 15-hydroxy-eicosatetraenoic acids, and 8,9- and 11,12-dihydroxy-eicosatrienoic acids, in parallel with an increase in pro-resolving mediators, such as lipoxin A4, 18-hydroxy-eicosapentaenoic acid, and 10S,17S-dihydroxy-docosahexaenoic acid. Elucidation of alterations in these lipid metabolites may shed new light into the molecular mechanisms underlying ALD development/progression, and be potential novel therapeutic targets.

Dietary copper-fructose interactions alter gut microbial activity in male rats.

Dietary copper-fructose interactions contribute to the development of nonalcoholic fatty liver disease (NAFLD). Gut microbiota play critical roles in the pathogenesis of NAFLD. The aim of this study was to determine the effect of different dietary doses of copper and their interactions with high fructose on gut microbiome. Male weanling Sprague-Dawley rats were fed diets with adequate copper (6 ppm CuA), marginal copper (1.5 ppm CuM) (low copper), or supplemented copper (20 ppm CuS) (high copper) for 4 wk. Deionized water or deionized water containing 30% fructose (wt/vol) was given ad libitum. Copper status, liver enzymes, gut barrier function, and gut microbiome were evaluated. Both low- and high-copper diets led to liver injury in high-fructose-fed rats, and this was associated with gut barrier dysfunction, as shown by the markedly decreased tight junction proteins and increased gut permeability. 16S rDNA sequencing analysis revealed distinct alterations of the gut microbiome associated with dietary low- and high-copper/high-fructose feeding. The common features of the alterations of the gut microbiome were the increased abundance of Firmicutes and the depletion of Akkermansia. However, they differed mainly within the phylum Firmicutes. Our data demonstrated that a complex interplay among host, microbes, and dietary copper-fructose interaction regulates gut microbial metabolic activity, which may contribute to the development of liver injury and hepatic steatosis. The distinct alterations of gut microbial activity, which were associated with the different dietary doses of copper and fructose, imply that separate mechanism(s) may be involved. NEW & NOTEWORTHY First, dietary low- and high-copper/high-fructose-induced liver injury are associated with distinct alterations of gut microbiome. Second, dietary copper level plays a critical role in maintaining the gut barrier integrity, likely by acting on the intestinal tight junction proteins and the protective commensal bacteria Akkermansia. Third, the alterations of gut microbiome induced by dietary low and high copper with or without fructose differ mainly within the phylum Firmicutes.

Medical Management of Severe Alcoholic Hepatitis: Expert Review from the Clinical Practice Updates Committee of the AGA Institute.

The purpose of this clinical practice update is to review diagnostic criteria for severe acute alcoholic hepatitis and to determine the current best practices for this life-threatening condition. The best practices in this review are based on clinical trials, systematic reviews including meta-analysis and expert opinion to develop an approach to diagnosis and management. Best Practice Advice 1: Abstinence from drinking alcohol is the cornerstone of treatment for alcohol hepatitis (AH). Best Practice Advice 2: Patients with jaundice and suspected AH should have cultures of blood, urine, and ascites, if present, to determine the presence of bacterial infections regardless of whether they have fever. Best Practice Advice 3: Patients with AH who have jaundice should be admitted to the hospital to encourage abstinence, restore adequate nutrition, and exclude serious infections. Best Practice Advice 4: Imaging of the liver is warranted as part of the evaluation, but caution should be used in administering iodinated contrast dye, as it increases the risk of acute kidney injury (AKI). Best Practice Advice 5: Patients with AH require a diet with 1-1.5 g protein and 30-40 kcal/kg body weight for adequate recovery. If the patient is unable to eat because of anorexia or altered mental status, a feeding tube should be considered for enteral feeding. Parenteral nutrition alone is inadequate. Best Practice Advice 6: Severity and prognosis of AH should be evaluated using Maddrey Discriminant Function (MDF), Model for End-Stage Liver Disease (MELD), age, bilirubin, international normalized ratio, and creatinine (ABIC), or Glasgow scoring systems. Current treatments are based on this assessment. Best Practice Advice 7: Presence of systemic inflammatory response syndrome (SIRS) on admission is associated with an increased risk of multi-organ failure (MOF) syndrome. Development of MOF, usually due to infections developing after initial diagnosis of AH, is associated with a very high mortality rate. Best Practice Advice 8: Nephrotoxic drugs, including diuretics, should be avoided or used sparingly in patients with AH, since AKI is an early manifestation of MOF. Best Practice Advice 9: Patients with MDF > 32 or MELD score > 20 without a contraindication to glucocorticoid, such as hepatitis B viral infection, tuberculosis, or other serious infectious diseases, may be treated with methylprednisolone 32 mg daily, but the appropriate duration of treatment remains a subject of controversy. Methylprednisolone does not improve survival beyond 28 days, and the benefits for < 28 days are modest. Best Practice Advice 10: Patients with a contraindication to glucocorticoids may be treated with pentoxifylline 400 mg three times daily with meals. Data regarding the efficacy are conflicting. Best Practice Advice 11: Patients with severe AH, particularly those with a MELD score > 26 with good insight into their alcohol use disorder and good social support should be referred for evaluation for liver transplantation, as the 90-day mortality rate is very high. Best Practice Advice 12: Patients with mild to moderate AH defined by a MELD score < 20 and MDF < 32 should be referred for abstinence counseling and prescribed a high protein diet supplemented with B vitamins and folic acid.

Role of dietary fatty acids in liver injury caused by vinyl chloride metabolites in mice.

BACKGROUND: Vinyl chloride (VC) causes toxicant-associated steatohepatitis at high exposure levels. Recent work by this group suggests that underlying liver disease may predispose the liver to VC hepatotoxicity at lower exposure levels. The most common form of underlying liver disease in the developed world is non-alcoholic fatty liver disease (NAFLD). It is well-known that the type of dietary fat can play an important role in the pathogenesis of NAFLD. However, whether the combination of dietary fat and VC/metabolites promotes liver injury has not been studied. METHODS: Mice were administered chloroethanol (CE - a VC metabolite) or vehicle once, 10weeks after being fed diets rich in saturated fatty acids (HSFA), rich in poly-unsaturated fatty acids (HPUFA), or the respective low-fat control diets (LSFA; LPUFA). RESULTS: In control mice, chloroethanol caused no detectable liver injury, as determined by plasma transaminases and histologic indices of damage. In HSFA-fed mice, chloroethanol increased HSFA-induced liver damage, steatosis, infiltrating inflammatory cells, hepatic expression of proinflammatory cytokines, and markers of endoplasmic reticulum (ER) stress. Moreover, markers of inflammasome activation were increased, while markers of inflammasome inhibition were downregulated. In mice fed HPUFA all of these effects were significantly attenuated. CONCLUSIONS: Chloroethanol promotes inflammatory liver injury caused by dietary fatty acids. This effect is far more exacerbated with saturated fat, versus poly-unsaturated fat; and strongly correlates with a robust activation of the NLRP3 inflammasome in the saturated fed animals only. Taken together these data support the hypothesis that environmental toxicant exposure can exacerbate the severity of NAFLD/NASH.

Effects of Sex, Drinking History, and Omega-3 and Omega-6 Fatty Acids Dysregulation on the Onset of Liver Injury in Very Heavy Drinking Alcohol-Dependent Patients.

BACKGROUND: Heavy alcohol consumption frequently causes liver inflammation/injury, and certain fatty acids (FAs) may be involved in this liver pathology. In this study, we evaluated the association of heavy drinking and the changes in the FA levels involved in the ω-6 (pro-inflammatory) and ω-3 (anti-inflammatory) state in alcohol-dependent (AD) patients who had no clinical manifestations of liver injury. We aimed to identify sex-based differences in patients with mild or no biochemical evidence of liver injury induced by heavy drinking. METHODS: A total of 114 heavy drinking AD female and male patients aged 21 to 65 years without clinical manifestations of liver injury, who were admitted to an alcohol dependence treatment program, were grouped by the alanine aminotransferase (ALT) levels: ≤40 IU/l, as no liver injury (GR.1), and >40 IU/l, as mild liver injury (GR.2). Patients were actively drinking until the day of admission. Comprehensive metabolic panel, comprehensive FA panel, and drinking history data were evaluated. RESULTS: Elevated ALT and aspartate aminotransferase (AST) showed close association with markers of heavy alcohol intake. In the patients with mild biochemical liver injury (GR.2), females showed significantly higher AST level than males. Significant association of AST and total drinks in past 90 days (TD90) in females, and AST and heavy drinking days in past 90 days (HDD90) in males was observed. The ω-6:ω-3 ratio showed a significant pro-inflammatory response only in females with mild liver injury (GR.2) when adjusted by drinking history marker, TD90. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were increased in males with liver injury, while females did not show any comparable rise in EPA; and DHA levels were lower. CONCLUSIONS: Measures of heavy drinking, TD90 and HDD90, predicted changes in liver injury. Changes in the ω-3 and ω-6 FA levels and the ω-6:ω-3 ratio showed a pro-inflammatory shift in patients with biochemical liver injury with a significant effect in females. Changes in FAs involved in the inflammatory state may represent one mechanism for liver inflammation/injury in response to heavy alcohol drinking.

Effects of Dietary Different Doses of Copper and High Fructose Feeding on Rat Fecal Metabolome.

The gut microbiota plays a critical role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Increased fructose consumption and inadequate copper intake are two critical risk factors in the development of NAFLD. To gain insight into the role of gut microbiota, fecal metabolites, obtained from rats exposed to different dietary levels of copper with and without high fructose intake for 4 weeks, were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF MS). In parallel, liver tissues were assessed by histology and triglyceride assay. Our data showed that high fructose feeding led to obvious hepatic steatosis in both marginal copper deficient rats and copper supplementation rats. Among the 38 metabolites detected with significant abundance alteration between groups, short chain fatty acids were markedly decreased with excessive fructose intake irrespective of copper levels. C15:0 and C17:0 long chain fatty acids, produced only by bacteria, were increased by either high copper level or high fructose intake. In addition, increased fecal urea and malic acid paralleled the increased hepatic fat accumulation. Collectively, GC × GC-TOF MS analysis of rat fecal samples revealed distinct fecal metabolome profiles associated with the dietary high fructose and copper level, with some metabolites possibly serving as potential noninvasive biomarkers of fructose induced-NAFLD.

The effects of 3,3',4,4'-tetrabromobiphenyl on rats fed diets containing a constant level of copper and varying levels of molybdenum.

Copper (Cu) metabolism is altered in rats fed diets high in molybdenum (Mo) and low in Cu. This 10-week study was carried out to examine the effects of supplemental Mo (7.5-240 µg/g diet) on male Sprague-Dawley rats fed diets adequate in Cu (5 µg/g diet) and to determine the susceptibility of Mo-treated animals to the environmental pollutant 3,3',4,4'-tetrabromobiphenyl (TBB). After 7 weeks of dietary treatment, half of the rats in each group received a single IP injection of TBB (150 µM/kg bw), while the other half received the corn oil vehicle. Rats sacrificed at 10 weeks showed no effects of Mo on growth, feed efficiency, or selected organ or tissue weights. Dose-dependent effects on plasma Mo (0-5.1 µg/mL), plasma Cu (0.95-0.20 µg/mL), and bone Cu (3.4-10 µg/g) in control through the high dose were found. Cu sequestration in the bone of Mo-treated rats is a new finding. TBB treatment resulted in dramatic weight loss and loss of absolute organ mass. Relative organ weights were increased, except for the thymus. TBB altered the concentrations of certain amino acids. Compared to control rats, this polybrominated biphenyl congener significantly decreased plasma Cu and ceruloplasmin at higher concentrations of dietary Mo and promoted the process of plasma Cu decrease by Mo, suggesting a combined effect.

A pilot study to evaluate the safety and efficacy of an oral dose of (-)-epigallocatechin-3-gallate-rich polyphenon E in patients with mild to moderate ulcerative colitis.

BACKGROUND: Green tea and its main polyphenolic component, (-)-epigallocatechin-3-gallate (EGCG), exert powerful anti-inflammatory effects that are protective against both inflammatory diseases and cancer. Research with animal and human cell lines provide plausible support for these claims. Poor absorption results in low systemic bioavailability of EGCG after oral administration but high colonic mucosal exposure. METHODS: Patients with mild to moderate ulcerative colitis (UC) were randomized to daily doses of oral Polyphenon E (400 mg or 800 mg of total EGCG daily, administered in split doses) or placebo in a double-blinded, placebo-controlled pilot study. Response was measured by the UC disease activity index and the inflammatory bowel disease questionnaire on day 56. RESULTS: Twenty patients were randomized to active therapy or placebo in a 4:1 ratio. Nineteen subjects received >1 dose of study medication (15 Polyphenon E, 4 placebo). The mean UC disease activity index score at study entry was 6.5 ± 1.9 in the treatment group and 7.3 ± 1.7 in the placebo group. After 56 days of therapy, the response rate was 66.7% (10 of 15) in the Polyphenon E group and 0% (0 of 4) in the placebo group (P = 0.03). The active treatment remission rate was 53.3% (8 of 15) compared with 0% (0 of 4) for placebo (P = 0.10). Polyphenon E treatment resulted in only minor side effects. CONCLUSIONS: Administration of Polyphenon E resulted in a therapeutic benefit for patients who were refractory to 5-aminosalicylic and/or azathioprine. This agent holds promise as a novel option for the treatment of patients with UC with mild to moderately active disease.

Ethanol and dietary unsaturated fat (corn oil/linoleic acid enriched) cause intestinal inflammation and impaired intestinal barrier defense in mice chronically fed alcohol.

Alcohol and dietary fat both play an important role in alcohol-mediated multi-organ pathology, including gut and liver. In the present study we hypothesized that the combination of alcohol and dietary unsaturated fat (USF) would result in intestinal inflammatory stress and mucus layer alterations, thus contributing to disruption of intestinal barrier integrity. C57BL/6N mice were fed Lieber-DeCarli liquid diets containing EtOH and enriched in USF (corn oil/linoleic acid) or SF (medium chain triglycerides: beef tallow) for 8 weeks. Intestinal histology, morphometry, markers of inflammation, as well as levels of mucus protective factors were evaluated. Alcohol and dietary USF triggered an intestinal pro-inflammatory response, characterized by increase in Tnf-α, MCP1, and MPO activity. Further, alcohol and dietary USF, but not SF, resulted in alterations of the intestinal mucus layer, characterized by decreased expression of Muc2 in the ileum. A strong correlation was observed between down-regulation of the antimicrobial factor Cramp and increased Tnf-α mRNA. Therefore, dietary unsaturated fat (corn oil/LA enriched) is a significant contributing factor to EtOH-mediated intestinal inflammatory response and mucus layer alterations in rodents.

Zinc and liver disease.

Zinc is an essential trace element required for normal cell growth, development, and differentiation. It is involved in DNA synthesis, RNA transcription, and cell division and activation. It is a critical component in many zinc protein/enzymes, including critical zinc transcription factors. Zinc deficiency/altered metabolism is observed in many types of liver disease, including alcoholic liver disease (ALD) and viral liver disease. Some of the mechanisms for zinc deficiency/altered metabolism include decreased dietary intake, increased urinary excretion, activation of certain zinc transporters, and induction of hepatic metallothionein. Zinc deficiency may manifest itself in many ways in liver disease, including skin lesions, poor wound healing/liver regeneration, altered mental status, or altered immune function. Zinc supplementation has been documented to block/attenuate experimental ALD through multiple processes, including stabilization of gut-barrier function, decreasing endotoxemia, decreasing proinflammatory cytokine production, decreasing oxidative stress, and attenuating apoptotic hepatocyte death. Clinical trials in human liver disease are limited in size and quality, but it is clear that zinc supplementation reverses clinical signs of zinc deficiency in patients with liver disease. Some studies suggest improvement in liver function in both ALD and hepatitis C following zinc supplementation, and 1 study suggested improved fibrosis markers in hepatitis C patients. The dose of zinc used for treatment of liver disease is usually 50 mg of elemental zinc taken with a meal to decrease the potential side effect of nausea.

Zinc supplementation reverses alcohol-induced steatosis in mice through reactivating hepatocyte nuclear factor-4alpha and peroxisome proliferator-activated receptor-alpha.

UNLABELLED: Alcoholic steatosis is a fundamental metabolic disorder in the progression of alcoholic liver disease. Zinc deficiency is one of the most consistently observed biochemical/nutritional manifestations of alcoholic liver disease. The purpose of this study is to determine whether dietary zinc supplementation to mice previously exposed to alcohol could reverse alcoholic steatosis. Male 129S mice were pair-fed an alcohol or isocaloric maltose dextrin liquid diet for 16 weeks with or without dietary zinc supplementation for the last 4 weeks. Zinc supplementation significantly attenuated alcohol-mediated increases in hepatic triglyceride, cholesterol, and free fatty acids in association with accelerated hepatic fatty acid oxidation and very low density lipoproteins (VLDL) secretion. Hepatic genes related to fatty acid oxidation and VLDL secretion were up-regulated by zinc supplementation, which was accompanied by restoring activity of hepatocyte nuclear factor-4alpha (HNF-4alpha) and peroxisome proliferators activated receptor-alpha (PPAR-alpha). Zinc supplementation enhanced alcohol metabolism and attenuated oxidative stress and liver injury. Zinc supplementation also normalized alcohol-mediated increases in plasma triglycerides and partially reversed decrease in gonadal adipose depot mass. Studies in HepG2 cells showed that zinc deprivation significantly suppressed the DNA-binding activities of HNF-4alpha and PPAR-alpha, and reduced HNF-4alpha and PPAR-alpha target proteins. Consequently, zinc deprivation caused cellular accumulation of lipid droplets, triglycerides and free fatty acids in the HepG2 cells. CONCLUSION: Zinc supplementation reverses alcoholic steatosis, and reactivation of HNF-4alpha and PPAR-alpha by increasing zinc availability and inhibiting oxidative stress are potential mechanisms underlying these beneficial effects of zinc on hepatic lipid homeostasis.

Drug-induced hepatotoxicity or drug-induced liver injury.

Drug-induced hepatotoxicity is underreported and underestimated in the United States. It is an important cause of acute liver failure. Common classes of drugs causing drug-induced hepatotoxicity include antibiotics, lipid lowering agents, oral hypoglycemics, psychotropics, antiretrovirals, acetaminophen, and complementary and alternative medications. Hepatotoxic drugs often have a signature or pattern of liver injury including patterns of liver test abnormalities, latency of symptom onset, presence or absence of immune hypersensitivity, and the course of the reaction after drug withdrawal.

Probiotics restore bowel flora and improve liver enzymes in human alcohol-induced liver injury: a pilot study.

The effects of chronic alcohol consumption on the bowel flora and the potential therapeutic role of probiotics in alcohol-induced liver injury have not previously been evaluated. In this study, 66 adult Russian males admitted to a psychiatric hospital with a diagnosis of alcoholic psychosis were enrolled in a prospective, randomized, clinical trial to study the effects of alcohol and probiotics on the bowel flora and alcohol-induced liver injury. Patients were randomized to receive 5 days of Bifidobacterium bifidum and Lactobacillus plantarum 8PA3 versus standard therapy alone (abstinence plus vitamins). Stool cultures and liver enzymes were performed at baseline and again after therapy. Results were compared between groups and with 24 healthy, matched controls who did not consume alcohol. Compared to healthy controls, alcoholic patients had significantly reduced numbers of bifidobacteria (6.3 vs. 7.5 log colony-forming unit [CFU]/g), lactobacilli (3.15 vs. 4.59 log CFU/g), and enterococci (4.43 vs. 5.5 log CFU/g). The mean baseline alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT) activities were significantly elevated in the alcoholic group compared to the healthy control group (AST: 104.1 vs. 29.15 U/L; ALT: 50.49 vs. 22.96 U/L; GGT 161.5 vs. 51.88 U/L), indicating that these patients did have mild alcohol-induced liver injury. After 5 days of probiotic therapy, alcoholic patients had significantly increased numbers of both bifidobacteria (7.9 vs. 6.81 log CFU/g) and lactobacilli (4.2 vs. 3.2 log CFU/g) compared to the standard therapy arm. Despite similar values at study initiation, patients treated with probiotics had significantly lower AST and ALT activity at the end of treatment than those treated with standard therapy alone (AST: 54.67 vs. 76.43 U/L; ALT 36.69 vs. 51.26 U/L). In a subgroup of 26 subjects with well-characterized mild alcoholic hepatitis (defined as AST and ALT greater than 30 U/L with AST-to-ALT ratio greater than one), probiotic therapy was associated with a significant end of treatment reduction in ALT, AST, GGT, lactate dehydrogenase, and total bilirubin. In this subgroup, there was a significant end of treatment mean ALT reduction in the probiotic arm versus the standard therapy arm. In conclusion, patients with alcohol-induced liver injury have altered bowel flora compared to healthy controls. Short-term oral supplementation with B. bifidum and L. plantarum 8PA3 was associated with restoration of the bowel flora and greater improvement in alcohol-induced liver injury than standard therapy alone.