Hepatic Alcohol Dehydrogenase Research Articles

Dysregulated pancreatic lipid phenotype, inflammation and cellular injury in a chronic ethanol feeding model of hepatic alcohol dehydrogenase-deficient deer mice

AimsDysregulation of pancreatic fat and lipotoxic inflammation are common clinical findings in alcoholic chronic pancreatitis (ACP). In this study, we investigated a relationship between dysregulated pancreatic lipid metabolism and the development of injury in a chronic ethanol (EtOH) feeding model of hepatic alcohol dehydrogenase 1- deficient (ADH−) deer mice. MethodsADH− and hepatic ADH normal (ADH+) deer mice were fed a liquid diet containing 3 % EtOH for three months and received a single gavage of binge EtOH with/without fatty acid ethyl esters (FAEEs) one week before the euthanasia. Plasma and pancreatic tissue were analyzed for lipids including FAEEs, inflammatory markers and adipokines using GC–MS, bioassays/kits, and immunostaining, respectively. Pancreatic morphology and proteins involved in lipogenesis were determined by the H & E staining, electron microscopy and Western blot analysis. Key findingsChronic EtOH feeding in ADH− vs. ADH+ deer mice resulted in a significant increase in the levels of pancreatic lipids including FAEEs, adipokines (leptin and resistin), fat infiltration with inflammatory cells and lipid droplet deposition along with the proteins involved in lipogenesis. The changes exacerbated by an administration of binge EtOH with/without FAEEs in the pancreas of ADH− vs. ADH+ deer mice fed chronic EtOH suggest a metabolic basis for ACP. SignificanceThese findings suggest that the liver-pancreatic axis plays a crucial role in etiopathogenesis of ACP, as the increased body burden of EtOH due to hepatic ADH deficiency exacerbates pancreatic injury.

Musculus senhousei as a promising source of bioactive peptides protecting against alcohol-induced liver injury.

Alcohol-induced liver injury has become a leading risk for human health, however, effective strategies for the prevention or treatment are still lacking. Hence, the present study explored the potential of Musculus senhousei as a source of hepatoprotective peptides against alcoholic liver injury using in vitro, in vivo and in silico methods. Results indicated that Musculus senhousei peptides (MSP, extracted by simulated gastrointestinal digestion of cooked mussel) exhibited notable antioxidant (ABTS and DPPH assays) and alcohol dehydrogenase (ADH) stabilizing activity in vitro. The ingestion of MSP markedly alleviated alcohol-induced liver injury in mice, as indicated by the decrease of serum transaminases (AST and ALT). In line with in vitro assays, significantly increased hepatic ADH activity and activated antioxidative defense system (GSH, SOD, GSH-Px and CAT) were observed, whereas the oxidative stress (MDA) was decreased. Peptidomic analysis revealed over 6000 peptides with favorable amino acid compositions, and a total of 20 potentially novel peptides with bioactivity and bioavailability were excavated among 746 of the most influential peptides using an in silico strategy. Peptides (i.e. WLPMKL, WLWLPA, RLC and RCL) were further synthesized and validated in vitro to be bioactive. These findings suggest that Musculus senhousei can be an ideal source of bioactive peptides for the prevention of alcoholic liver injury.

PBPK modeling to evaluate maximum tolerated doses: A case study with 3-chloroallyl alcohol.

Introduction: A physiologically based pharmacokinetic (PBPK) model for 3-chloroallyl alcohol (3-CAA) was developed and used to evaluate the design of assays for the in vivo genotoxicity of 3-CAA. Methods: Model development was supported by read across from a published PBPK model for ethanol. Read across was motivated by the expectation that 3-CAA, which like ethanol is a primary alcohol, is metabolized largely by hepatic alcohol dehydrogenases. The PBPK model was used to evaluate how two metrics of tissue dosimetry, maximum blood concentration (Cmax; mg/L) and area under the curve (AUC; mg-hr/L) vary with dose of 3-CAA and with dose route (oral gavage, drinking water). Results: The model predicted that oral gavage results in a 6-fold higher Cmax than the same dose administered in drinking water, but in similar AUCs. Predicted Cmax provided the best correlation with severe toxicity (e.g., lethality) from 3-CAA, consistent with the production of a reactive metabolite. Therefore, drinking water administration can achieve higher sustained concentration without severe toxicity in vivo. Discussion: This evaluation is significant because cytotoxicity is a potential confounder of mutagenicity testing. The PBPK model can be used to ensure that studies meet OECD and USEPA test guidelines and that the highest dose used is not associated with severe toxicity. In addition, PBPK modeling provides assurance of target tissue (e.g., bone marrow) exposure even in the absence of laboratory data, by defining the relationship between applied dose and target tissue dose based on accepted principles of pharmacokinetics, relevant physiology and biochemistry of the dosed animals, and chemical-specific information.

Aqueous extract of Laurus nobilis leaf accelerates the alcohol metabolism and prevents liver damage in single-ethanol binge rats.

Excessive alcohol consumption has harmful health effects, including alcohol hangovers and alcohol-related liver disease. Therefore, methods to accelerate the alcohol metabolism are needed. Laurus nobilis is a spice, flavoring agent, and traditional herbal medicine against various diseases. This study examined whether the standardized aqueous extract of L. nobilis leaves (LN) accelerates the alcohol metabolism and protects against liver damage in single-ethanol binge Sprague-Dawley (SD) rats. LN was administered orally to SD rats 1 h before ethanol administration (3 g/kg body weight [BW]) at 100 and 300 mg/kg BW. Blood samples were collected 0.5, 1, 2, and 4 h after ethanol administration. The livers were excised 1 h after ethanol administration to determine the hepatic enzyme activity. The alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities in the liver tissue were measured. LN decreased the serum ethanol and acetaldehyde levels in ethanol-administered rats. LN increased the hepatic ADH and ALDH activities but decreased the alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase activities in the ethanol-administered rats. In addition, LN inhibited lipid peroxidation and increased the activities of SOD and GPx. LN modulates the mediators of various etiological effects of excessive alcohol consumption and enhances the alcohol metabolism and antioxidant activity, making it a potential candidate for hangover treatments.

Purification of Alcohol Dehydrogenase Enzyme from Chicken Liver and Immobilization Onto Florisil

The enzyme alcohol dehydrogenase (ADH) is a dimeric enzyme in which each of its subunits has a Zn2+ metal-containing catalytic domain and a cofactor binding domain. This enzyme converts alcohol into an aldehyde. In this article, the activity of the enzyme was investigated by applying the immobilization process directly to the alcohol dehydrogenase enzyme purified and activated florisil from the chicken liver. For this purpose, homogenization of chicken liver was achieved and its supernatants were separated by applying the ultracentrifugation process to the resulting homogenate. Then, % ammonium precipitation, dialysis, and ion exchange chromatography processes were performed, respectively. As a result of these processes, the hepatic alcohol dehydrogenase was purified 150.3 times compared to the coarse homogenate, and the specific activity of the enzyme was determined to be 0.631 U/mg protein. The activity of the enzyme directly immobilized was found to be 0.034 U/mg protein.

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.

Hepatoprotective effect of clam (Corbicula fluminea) protein hydrolysate on alcohol-induced liver injury in mice and partial identification of a hepatoprotective peptide from the hydrolysate

In the current research, edible meat of freshwater clam Corbicula fluminea was subjected to enzymatic peptide extraction using animal protease. The clam protein hydrolysate (CPH) contained 45.78% essential amino acids and 44.97% hydrophobic amino acids and showed high alcohol dehydrogenase (ADH) activation in vitro. Four fractions were divided from CPH by ultrafiltration and further investigated for their hepatoprotective effects on alcohol-induced injury in mice. The 2.5-5 kDa fraction (CPH-3) showed the best effect for preventing hepatic damage caused by alcohol, as revealed by reduced serum aspartate transaminase (AST) and alanine transaminase (ALT) activities and hepatic malondialdehyde (MDA) level, the marked decrease in the hepatic triglyceride (TG) contents, and the enhanced hepatic ADH, aldehyde dehydrogenase (ALDH), and glutathione (GSH) activities. Furthermore, histopathology of CPH-3-treated mice showed less hepatic tissue damage compared to alcohol- or other CPHs-treated mice. Hence, CPH-3 was further purified by consecutive chromatographic techniques with gel filtration and reverse-phase high-performance liquid chromatography. One hepatoprotective peptide, KKLAGFLRYYS (1330.68 Da), was identified by LC-MS/MS, which exhibited strong ADH activation activity. Results suggested that CPH could be a potential nutraceutical for facilitating alcohol metabolism and preventing or ameliorating early liver injury induced by acute alcohol exposure and that the peptide KKLAGFLRYYS is one of the main bioactive components in CPH.

Role of first aid in the management of acute alcohol intoxication: a narrative review.

Acute alcohol intoxication is actually a common admission cause in the Emergency Department and represents an increasing public health burden, in particular among adolescents. It involves possible and significant illness and injury, which can quickly get worse and may need to be managed in the emergency room. We conducted a narrative review of the literature regarding the effectiveness of first aid role of the Emergency Department setting. This review included eighteen studies about alcohol intoxication management in the Emergency Department; most of all highlights the emerging phenomenon in Europe and around the world of acute alcohol intoxication management in first aid. The treatment of acute alcohol intoxication depends on general clinical conditions of the patient, vital signs, hemodynamic stability, cognitive state, alcohol-related complications, which are closely related to the blood alcohol concentration. At the same time, symptoms could be extremely variable due to individual differences in alcohol metabolism. In case of mild-moderate intoxication (blood alcohol concentration < 1 g/L), no drugs are necessary. In case of severe intoxication (blood alcohol concentration > 1 g/L), it is necessary to support with intravenous fluids, treat hypoglycemia, hypotension, hypothermia and electrolyte imbalance, administer complex B and C vitamins and accelerate alcohol elimination from blood with metadoxine. Unlike adults, adolescents are more exposed to the toxic effect of alcohol (because of their immature hepatic alcohol dehydrogenase activity), and then, acute alcohol-related complications are more frequent and dangerous in young people than in adult population. In many cases, patients affected by acute alcohol intoxication referring to an Emergency Department have mild-moderate transitory symptoms that do not require the use of drugs; they can benefit from a clinical observation, with a clinical course often completed within 24 hours with a favorable outcome. Clinical observation with vital signs control is necessary also to evaluate the possible development of the alcohol withdrawal syndrome (that involves a specific treatment) and to evaluate also possible pathological complications of the organism, above all acute liver damage. Patients affected by acute alcohol intoxication are the best candidates to apply the rules of the Temporary Observation Unit in the Emergency Department, because of a clinical course often completed within 24 hours, a favorable outcome and without the need for hospitalization. In many cases, hospitalization could be not necessary, but the patient affected by Alcohol Use Disorder must be referred to an Alcohol Addiction Unit for the follow-up, to reduce the risk of alcohol relapse and complications related to alcohol abuse, and financial costs of hospitalization.

Linking Dysregulated AMPK Signaling and ER Stress in Ethanol-Induced Liver Injury in Hepatic Alcohol Dehydrogenase Deficient Deer Mice.

Ethanol (EtOH) metabolism itself can be a predisposing factor for initiation of alcoholic liver disease (ALD). Therefore, a dose dependent study to evaluate liver injury was conducted in hepatic alcohol dehydrogenase (ADH) deficient (ADH−) and ADH normal (ADH+) deer mice fed 1%, 2% or 3.5% EtOH in the liquid diet daily for 2 months. Blood alcohol concentration (BAC), liver injury marker (alanine amino transferase (ALT)), hepatic lipids and cytochrome P450 2E1 (CYP2E1) activity were measured. Liver histology, endoplasmic reticulum (ER) stress, AMP-activated protein kinase (AMPK) signaling and cell death proteins were evaluated. Significantly increased BAC, plasma ALT, hepatic lipids and steatosis were found only in ADH− deer mice fed 3.5% EtOH. Further, a significant ER stress and increased un-spliced X-box binding protein 1 were evident only in ADH− deer mice fed 3.5% EtOH. Both strains fed 3.5% EtOH showed deactivation of AMPK, but increased acetyl Co-A carboxylase 1 and decreased carnitine palmitoyltransferase 1A favoring lipogenesis were found only in ADH− deer mice fed 3.5% EtOH. Therefore, irrespective of CYP2E1 overexpression; EtOH dose and hepatic ADH deficiency contribute to EtOH-induced steatosis and liver injury, suggesting a linkage between ER stress, dysregulated hepatic lipid metabolism and AMPK signaling.

Alcohol, its absorption, distribution, metabolism, and excretion in the body and pharmacokinetic calculations

AbstractThe ethanol contained in alcoholic beverages is rapidly absorbed from the gastrointestinal tract and the maximum blood‐alcohol concentration (BAC) is usually reached between 10 and 60 min postdosing. Once in the bloodstream, ethanol is distributed into the total body water (TBW) compartment, which comprises ~55–60% of body weight in nonobese males and ~50–55% in females. The volume of distribution (V d) of ethanol depends on a person's age, gender, and degree of adiposity (ratio of fat to lean tissue). Studies have shown that the average V d for healthy men and women are ~0.70 and ~0.60 L/kg, respectively. Elimination of ethanol from the body occurs primarily through metabolism (92–98% of dose) by hepatic alcohol dehydrogenase (ADH), an enzyme located in the liver cytosol and a microsomal enzyme, denoted CYP2E1. A small fraction (0.1–0.2%) of the dose of ethanol ingested undergoes nonoxidative metabolism by phase II conjugation reactions leading to formation of ethyl glucuronide and ethyl sulfate. Only between 2 and 10% of the dose of ethanol is excreted unchanged in urine, breath, and in sweat/perspiration. Ethanol exhibits dose‐dependent pharmacokinetics, because the hepatic ADH enzyme is saturated with substrate at BAC above 15–20 mg/100 mL (15–20 mg%). Zero‐order kinetics operate for most of the postabsorptive elimination phase and the BAC decreases at a constant rate per unit time ranging from 10 to 35 mg% per hour (average 15 mg% per hour for moderate drinkers). Examples of various pharmacokinetic calculations are presented because these are often necessary in forensic science and legal medicine casework.This article is categorized under: Toxicology &gt; Alcohol Toxicology &gt; Analytical Toxicology Toxicology &gt; Drug‐Impaired Driving

Alcoholic Liver Disease: Alcohol Metabolism, Cascade of Molecular Mechanisms, Cellular Targets, and Clinical Aspects.

Alcoholic liver disease is the result of cascade events, which clinically first lead to alcoholic fatty liver, and then mostly via alcoholic steatohepatitis or alcoholic hepatitis potentially to cirrhosis and hepatocellular carcinoma. Pathogenetic events are linked to the metabolism of ethanol and acetaldehyde as its first oxidation product generated via hepatic alcohol dehydrogenase (ADH) and the microsomal ethanol-oxidizing system (MEOS), which depends on cytochrome P450 2E1 (CYP 2E1), and is inducible by chronic alcohol use. MEOS induction accelerates the metabolism of ethanol to acetaldehyde that facilitates organ injury including the liver, and it produces via CYP 2E1 many reactive oxygen species (ROS) such as ethoxy radical, hydroxyethyl radical, acetyl radical, singlet radical, superoxide radical, hydrogen peroxide, hydroxyl radical, alkoxyl radical, and peroxyl radical. These attack hepatocytes, Kupffer cells, stellate cells, and liver sinusoidal endothelial cells, and their signaling mediators such as interleukins, interferons, and growth factors, help to initiate liver injury including fibrosis and cirrhosis in susceptible individuals with specific risk factors. Through CYP 2E1-dependent ROS, more evidence is emerging that alcohol generates lipid peroxides and modifies the intestinal microbiome, thereby stimulating actions of endotoxins produced by intestinal bacteria; lipid peroxides and endotoxins are potential causes that are involved in alcoholic liver injury. Alcohol modifies SIRT1 (Sirtuin-1; derived from Silent mating type Information Regulation) and SIRT2, and most importantly, the innate and adapted immune systems, which may explain the individual differences of injury susceptibility. Metabolic pathways are also influenced by circadian rhythms, specific conditions known from living organisms including plants. Open for discussion is a 5-hit working hypothesis, attempting to define key elements involved in injury progression. In essence, although abundant biochemical mechanisms are proposed for the initiation and perpetuation of liver injury, patients with an alcohol problem benefit from permanent alcohol abstinence alone.

Hepatic alcohol dehydrogenase deficiency induces pancreatic injury in chronic ethanol feeding model of deer mice

The single most common cause of chronic pancreatitis (CP, a serious inflammatory disease) is chronic alcohol abuse, which impairs hepatic alcohol dehydrogenase (ADH, a major ethanol oxidizing enzyme). Previously, we found ~5 fold greater fatty acid ethyl esters (FAEEs), and injury in the pancreas of hepatic ADH deficient (ADH−) vs. hepatic normal ADH (ADH+) deer mice fed 3.5g% ethanol via liquid diet daily for two months. Therefore, progression of ethanol-induced pancreatic injury was determined in ADH− deer mice fed ethanol for four months to delineate the mechanism and metabolic basis of alcoholic chronic pancreatitis (ACP). In addition to a substantially increased blood alcohol concentration and plasma FAEEs, significant degenerative changes, including atrophy and loss of acinar cells in some areas, ultrastructural changes evident by such features as swelling and disintegration of endoplasmic reticulum (ER) cisternae and ER stress were observed in the pancreas of ethanol-fed ADH− deer mice vs. ADH+ deer mice. These changes are consistent with noted increases in pancreatic injury markers (plasma lipase, pancreatic trypsinogen activation peptide, FAEE synthase and cathepsin B) in ethanol-fed ADH− deer mice. Most importantly, an increased levels of pancreatic glucose regulated protein (GRP) 78 (a prominent ER stress marker) were found to be closely associated with increased phosphorylated eukaryotic initiation factor (eIF) 2α signaling molecule in PKR-like ER kinase branch of unfolded protein response (UPR) as compared to X box binding protein 1S and activating transcription factor (ATF)6 - 50kDa protein of inositol requiring enzyme 1α and ATF6 branches of UPR, respectively, in ethanol-fed ADH− vs. ADH+ deer mice. These results along with findings on plasma FAEEs, and pancreatic histology and injury markers suggest a metabolic basis of ethanol-induced pancreatic injury, and provide new avenues to understand metabolic basis and molecular mechanism of ACP.

Monascus-fermented red mold dioscorea protects mice against alcohol-induced liver injury, whereas its metabolites ankaflavin and monascin regulate ethanol-induced peroxisome proliferator-activated receptor-γ and sterol regulatory element-binding transcription factor-1 expression in HepG2 cells.

Alcoholic hepatitis is a necroinflammatory process that is associated with fibrosis and leads to cirrhosis in 40% of cases. The hepatoprotective effects of red mold dioscorea (RMD) from Monascus purpureus NTU 568 were evaluated in vivo using a mouse model of chronic alcohol-induced liver disease (ALD). ALD mice were orally administered vehicle (ALD group) or vehicle plus 307.5, 615.0 or 1537.5 mg kg-1 (1 ×, 2 × and 5 ×) RMD for 5 weeks. RMD lowered serum leptin, hepatic total cholesterol, free fatty acid and hepatic triglyceride levels and increased serum adiponectin, hepatic alcohol dehydrogenase and antioxidant enzyme levels. Furthermore, ankaflavin (AK) and monascin (MS), metabolites of RMD fermented with M. purpureus 568, induced peroxisome proliferator-activated receptor-γ expression and the concomitant suppression of ethanol-induced elevation of sterol regulatory element-binding transcription factor-1 and TG in HepG2 cells. These results indicate the hepatoprotective effect of Monascus-fermented RMD. Moreover, AK and MS were identified as the active constituents of RMD for the first time and were shown to protect against ethanol-induced liver damage. © 2017 Society of Chemical Industry.

Proteomic Profiling of Liver and Plasma in Chronic Ethanol Feeding Model of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice.

Chronic alcohol abuse, a major risk factor for such diseases as hepatitis and cirrhosis, impairs hepatic alcohol dehydrogenase (ADH; key ethanol [EtOH]-metabolizing enzyme). Therefore, differentially altered hepatic and plasma proteomes were identified in chronic EtOH feeding model of hepatic ADH-deficient (ADH- ) deer mice to understand the metabolic basis of alcoholic liver disease (ALD). ADH- deer mice were fed 3.5g% EtOH via Lieber-DeCarli liquid diet daily for 3months and histology of the liver assessed. Liver and plasma proteins were separated by 2-dimensional gel electrophoresis. The proteins differentially expressed were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Histology of the liver showed panlobular steatosis and infiltration of T lymphocytes. Using the criteria of ≥1.5 for fold change (p-value ≤0.05) with expectation value (E ≤10-3 ) and protein score (≥64), 18 proteins in the livers and 5 in the plasma of EtOH-fed mice were differentially expressed and identified. Prolyl 4-hydroxylase, cytochrome b-5, endo A cytokeratin, ATP synthase, heat-shock 70kD proteins, enoyl CoA hydratase, stress-70 protein, peroxiredoxin 1, and ornithine carbamoyl transferase were up-regulated in the livers. However, carbonic anhydrase 3, mitochondrial ATP synthase, aldolase 2, actin γ, laminin receptor, and carbamoyl phosphate synthase were down-regulated. Contrary to the increased expression of creatine kinase M-type, a decreased expression of serine protease inhibitor A3A precursor, sulfated glycoprotein-2 (clusterin), and apolipoprotein E isoforms were found in the plasma of EtOH group. Chronic EtOH feeding in ADH- deer mice causes steatosis and infiltration of T lymphocytes in the livers along with increased expression of proteins involved in endoplasmic reticulum (ER) stress, fibrosis, fatty acid β oxidation and biogenesis, and decreased expression of proteins involved in ATP synthesis, carbohydrate metabolism, in cell regulation and architecture. Reduced expression of various carrier proteins as found in the plasma of EtOH group has a biomarker potential.

Preparation, characterization and alcoholic liver injury protective effects of algal oligosaccharides from Gracilaria lemaneiformis

Oligosaccharides derived from seaweeds possess diverse biological functions. However, little is known about their effects on liver damage. In this study, algal oligosaccharides (AOS) were prepared from Gracilaria lemaneiformis by biodegradation approaches. HPLC analysis showed AOS were composed of agarooligosaccharides and neoagarooligosaccharides. In vivo animal studies showed AOS significantly attenuated alcohol-induced hepatopathy in mice to some extent, as revealed by the normalization of several serum liver-damage markers. Besides, AOS increased antioxidant levels of hepatic glutathione (GSH) and superoxide dismutase (SOD), and ameliorated the elevated formation of malonaldehyde (MDA), suggesting AOS attenuated hepatopathy mainly through their antioxidant activities. Interestingly, AOS could also enhance the activities of hepatic alcohol dehydrogenase (ADH). Histological examination of liver tissues showed AOS reduced the alcohol-induced liver injury in a dose-dependent manner. Moreover, the comparison of different administration strategies suggested AOS were best taken 2h before alcohol consumption. Therefore, our study provided a novel nutritional strategy for reducing alcohol-induced hepatotoxicity.

Proteins Differentially Expressed in the Pancreas of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice Fed Ethanol For 3 Months.

The aim of this study was to identify differentially expressed proteins in the pancreatic tissue of hepatic alcohol dehydrogenase-deficient deer mice fed ethanol to understand metabolic basis and mechanism of alcoholic chronic pancreatitis. Mice were fed liquid diet containing 3.5 g% ethanol daily for 3 months, and differentially expressed pancreatic proteins were identified by protein separation using 2-dimensional gel electrophoresis and identification by mass spectrometry. Nineteen differentially expressed proteins were identified by applying criteria established for protein identification in proteomics. An increased abundance was found for ribosome-binding protein 1, 60S ribosomal protein L31-like isoform 1, histone 4, calcium, and adenosine triphosphate (ATP) binding proteins and the proteins involved in antiapoptotic processes and endoplasmic reticulum function, stress, and/or homeostasis. Low abundance was found for endoA cytokeratin, 40S ribosomal protein SA, amylase 2b isoform precursor, serum albumin, and ATP synthase subunit β and the proteins involved in cell motility, structure, and conformation. Chronic ethanol feeding in alcohol dehydrogenase-deficient deer mice differentially expresses pancreatic functional and structural proteins, which can be used to develop biomarker(s) of alcoholic chronic pancreatitis, particularly amylase 2b precursor, and 60 kDa heat shock protein and those involved in ATP synthesis and blood osmotic pressure.

Age-dependent Protein Abundance of Cytosolic Alcohol and Aldehyde Dehydrogenases in Human Liver.

Hepatic cytosolic alcohol and aldehyde dehydrogenases (ADHs and ALDHs) catalyze the biotransformation of xenobiotics (e.g., cyclophosphamide and ethanol) and vitamin A. Because age-dependent hepatic abundance of these proteins is unknown, we quantified protein expression of ADHs and ALDH1A1 in a large cohort of pediatric and adult human livers by liquid chromatography coupled with tandem mass spectrometry proteomics. Purified proteins were used as calibrators. Two to three surrogate peptides per protein were quantified in trypsin digests of liver cytosolic samples and calibrator proteins under optimal conditions of reproducibility. Neonatal levels of ADH1A, ADH1B, ADH1C, and ALDH1A1 were 3-, 8-, 146-, and 3-fold lower than the adult levels, respectively. For all proteins, the abundance steeply increased during the first year of life, which mostly reached adult levels during early childhood (age between 1 and 6 years). Only for ADH1A protein abundance in adults (age > 18 year) was ∼40% lower relative to the early childhood group. Abundances of ADHs and ALDH1A1 were not associated with sex in samples with age > 1 year compared with males. Known single nucleotide polymorphisms had no effect on the protein levels of these proteins. Quantification of ADHs and ALDH1A1 protein levels could be useful in predicting disposition and response of substrates of these enzymes in younger children.

흰쥐에서 어성초 열수 추출물을 포함한 혼합물의 숙취해소 효과

This study was performed to investigate the ameliorating effect of a mixture of extracts from Houttuynia cordata Thunb, Nelumbo nucifera G. (leaf), and Camellia sinensis (seed) (MIX) on acute ethanol-induced hangover in Sprague-Dawley rats. Plasma ethanol and acetaldehyde levels in MIX-treated rats significantly decreased at 3 h and 5 h after acute ethanol administration (25%, 3 g/kg body weight/d) as compared to ethanol-treated rats. Hepatic alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were significantly higher in MIXtreated rats than in ethanol-treated rats. MIX exhibited high ADH and ALDH activities on direct assays using S9 rat liver fraction for ethanol metabolic enzymes clearance action. These results suggest that MIX could alleviate ethanol-induced hangover symptoms by elevating activities related to hepatic ethanol-metabolizing enzymes against ethanol induced metabolites, and MIX should be further developed to be a new anti-hangover material.

Diet Supplementation with Allicin Protects against Alcoholic Fatty Liver Disease in Mice by Improving Anti-inflammation and Antioxidative Functions.

This study investigated the liver-protective effects of allicin, an active compound in fresh garlic, against alcoholic fatty liver disease (AFLD) and liver inflammation. Its effects were investigated in an AFLD model in male C57BL/6 mice, which were fed Lieber-DeCarli liquid diet containing ethanol. Allicin (5 and 20 mg/kg bw/day) was orally administered daily in the AFLD mice for 4 weeks. The results indicate that allicin promotes hepatoprotection by significantly reducing aspartate transaminase (AST) and alanine transaminase (ALT) levels (p < 0.05) in the plasma, which are key indicators of liver damage. Allicin reduced fat accumulation, increased glutathione and catalase levels, and decreased microsomal protein cytochrome P450 2E1 (CYP2E1) expression (p < 0.05) in the livers of the AFLD mice. Furthermore, allicin supplementation significantly decreased the levels of proinflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 and suppressed the expression of sterol regulatory element-binding protein-1 (SREBP-1) (p < 0.05). Additionally, it improved the hepatic alcohol dehydrogenase (ADH) activity (p < 0.05). Collectively, these findings demonstrate that allicin attenuates liver oxidative stress and inflammation.

Ethanol oxidation and the inhibition by drugs in human liver, stomach and small intestine: Quantitative assessment with numerical organ modeling of alcohol dehydrogenase isozymes

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for metabolism of ethanol. Human ADH constitutes a complex isozyme family with striking variations in kinetic function and tissue distribution. Liver and gastrointestinal tract are the major sites for first-pass metabolism (FPM). Their relative contributions to alcohol FPM and degrees of the inhibitions by aspirin and its metabolite salicylate, acetaminophen and cimetidine remain controversial. To address this issue, mathematical organ modeling of ethanol-oxidizing activities in target tissues and that of the ethanol–drug interactions were constructed by linear combination of the corresponding numerical rate equations of tissue constituent ADH isozymes with the documented isozyme protein contents, kinetic parameters for ethanol oxidation and the drug inhibitions of ADH isozymes/allozymes that were determined in 0.1 M sodium phosphate at pH 7.5 and 25 °C containing 0.5 mM NAD+. The organ simulations reveal that the ADH activities in mucosae of the stomach, duodenum and jejunum with ADH1C*1/*1 genotype are less than 1%, respectively, that of the ADH1B*1/*1–ADH1C*1/*1 liver at 1–200 mM ethanol, indicating that liver is major site of the FPM. The apparent hepatic KM and Vmax for ethanol oxidation are simulated to be 0.093 ± 0.019 mM and 4.0 ± 0.1 mmol/min, respectively. At 95% clearance in liver, the logarithmic average sinusoidal ethanol concentration is determined to be 0.80 mM in accordance with the flow-limited gradient perfusion model. The organ simulations indicate that higher therapeutic acetaminophen (0.5 mM) inhibits 16% of ADH1B*1/*1 hepatic ADH activity at 2–20 mM ethanol and that therapeutic salicylate (1.5 mM) inhibits 30–31% of the ADH1B*2/*2 activity, suggesting potential significant inhibitions of ethanol FPM in these allelotypes. The result provides systematic evaluations and predictions by computer simulation on potential ethanol FPM in target tissues and hepatic ethanol–drug interactions in the context of tissue ADH isozymes.