Liver Alcohol Dehydrogenase Activity Research Articles

Effects of Chronic Alcohol Consumption and Iron Deficiency on Maternal Folate Status and Reproductive Outcome in Mice

The influence of chronic alcohol consumption with or without iron deficiency on reproductive performance and folate status was studied. Female CBA/J mice were fed isocaloric liquid diets prior to and during pregnancy. A 2 × 2 factorial design was employed with ethanol-derived calories (EDC) and iron (Fe) as dietary variables. Groups received 0% EDC and 30 ppm Fe (CA); 0% EDC and 2 ppm Fe (CD); 20% EDC and 30 ppm Fe (EA); and 20% EDC and 2 ppm Fe (ED). Animals were killed on day 18 of gestation. Mean body weights were reduced in CD, EA and ED groups, while daily caloric intakes reduced only in CD and ED groups. Maternal values for hemoglobin, transferrin saturation and red cell folates decreased with iron deficiency and/or 20% EDC; hematocrit, serum iron and serum folates decreased only with iron deficiency. Blood ethanol levels were similar in EA and ED groups. Maternal liver total lipids and alcohol dehydrogenase activity increased only with 20% EDC, while dihydrofolate reductase activity decreased with iron deficiency and/or 20% EDC. Iron deficiency and/or 20% EDC adversely affected gestational performances in mice as indicated by increased resorptions and decreased percentages of live fetuses/litters and live fetal weights. Data indicate that iron deficiency and/or chronic ethanol consumption induce adverse effects on maternal reproductive performance of CBA/J mice possibly via alteration of folate metabolism.

The mitigative effect of lotus root (Nelumbo nucifera Gaertn) extract on acute alcoholism through activation of alcohol catabolic enzyme, reduction of oxidative stress, and protection of liver function.

Lotus root (Nelumbo nucifera Gaertn) is a common medicinal-food dual-use vegetable. In this study, the effects of lotus root extract on acute alcoholism were investigated. The Walle-Hoch method was used to determine the ADH activity of lotus root extracts in vitro. Lotus root methanol extract were identified by UPLC-QTOF-MS/MS based metabolomics analysis. Then 109 active ingredients with achievable oral doses and drug-like properties were explored using the TCMSP platform. SwissTargetPrediction Database to predict lotus root treatment targets for acute alcoholismSTRING database (https://www.string-db.org/) was used to construct protein-protein interaction network graphs. Gene ontology (GO) functional, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of genes common to lotus root and alcoholism by Metascap database. Molecular docking simulations were performed using AutoDock 1.5.6 software. Animal experiments verified the relieving effect of lotus root extract on acute alcoholism after intervention. Results indicated the methanol extract of lotus root showed the highest activation rate of ethanol dehydrogenase in vitro (18.87%). The 433 compounds of lotus root methanol extract were identified by UPLC-QTOF-MS/MS based metabolomics analysis. Bioinformatics analysis indicate that there were 224 intersectioning targets between lotus root extract and acute alcoholism. KEGG enrichment analysised shows that lotus root extract may play a role in treating acute alcoholism by intervening with the neuroactive ligand-receptor interaction pathway. The protein-protein interaction network (PPI) analysis found that HSP90AA1, MAPK1 and STAT3 played a key role in lotus root extract-modulated PPI networks. Molecular docking showed that (7R, 8S)-dihydrodihydrodipine cypressol had the best binding ability with MAPK1. Experiments in mice indicate that lotus root extract improved the activity of liver alcohol dehydrogenase (ADH), acetaldehyde dehydrogenase (ALDH), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), increase glutathione (GSH) and reduce malondialdehyde (MDA) levels, decrease glutamate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (AKP) in the serum of mice with acute alcoholism, and accelerate the metabolic rate of alcohol after drinking. This study reveals the mechanism of lotus root to alleviate acute alcoholism, which provides a basis for further research on functional foods using lotus root and offers new possibilities for the treatment of acute alcoholism. The results of the current study showed that the methanolic extract of lotus root had the highest activation rate of ethanol dehydrogenase. Network pharmacology results suggest that lotus root extract may play a role in the treatment of alcoholism by regulating signaling pathways, such as neuroactive ligand-receptor interactions, as well as biological processes, such as regulation of secretion, regulation of ion transport, response to lipopolysaccharides, and response to alcohol. Animal experiments confirmed the therapeutic effect of lotus root on acute alcoholism mechanistically through activation of alcohol catabolic enzyme, reduction of oxidative stress and protection of liver function.

Effect of water-soluble propolis administration on the ethanol-induced hangover in rats.

Water soluble propolis was prepared using β-cyclodextrin, and its effect on an ethanol-induced hangover was examined in Sprague-Dawley (SD) rats fed with ethanol. When SD rats were administrated with propolis 30min after ethanol feeding, ethanol content in the rat serum decreased 2.1 times 1h after ethanol feeding. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in rat liver increased 3.0 and 4.4 times, respectively, 1h after ethanol feeding and administration of propolis 30min after ethanol feeding. There were no differences in the expression of ADH and ALDH genes regardless of propolis administration. These results indicated that a decrease in ethanol content in the serum was not due to an increase in the expression of ADH or ALDH genes but rather, an increase in activities of ADH and ALDH.

Boletus aereus protects against acute alcohol-induced liver damage in the C57BL/6 mouse via regulating the oxidative stress-mediated NF-κB pathway

Context Alcoholic liver disease, caused by abuse and consumption of alcohol, exhibits high morbidity and mortality. Boletus aereus Bull. (Boletaceae) (BA) shows antioxidant, anti-inflammatory and antimicrobial effects. Objectives To investigate the hepatoprotective effects of BA using an acute alcohol-induced hepatotoxicity mice model. Materials and methods The composition of BA fruit body was first systematically analyzed. Subsequently, a C57BL/6 mice model of acute alcohol-induced liver injury was established by intragastrically administration of alcohol, which was intragastrically received with BA powder at 200 mg/kg and 800 mg/kg for 2 weeks, 60 mg/kg silybin treatment was used as positive control group. By employing the pathological examination, ELISA, RT-PCR and western blot, the regulation of BA on oxidative stress signals was investigated. Results The LD50 of BA was much higher than 4 g/kg/p.o. In acute alcohol-damaged mice, BA reduced the levels of alanine aminotransferase (>18.3%) and aspartate aminotransferase (>27.6%) in liver, increased the activity of liver alcohol dehydrogenase (>35.0%) and serum acetaldehyde dehydrogenase (>18.9%). BA increased the activity of superoxide dismutase (>13.4%), glutathione peroxidase (>11.0%) and 800 mg/kg BA strongly reduced chemokine (C-X-C motif) ligand 13 (14.9%) and chitinase-3 like-1 protein (13.4%) in serum. BA reversed mRNA over-expression (>70%) and phosphor-stimulated expression (>45.0%) of an inhibitor of nuclear factor κ-B kinase (NF-κB, an inhibitor of nuclear factor κ-B α and nuclear factor κ-B in the liver. Conclusions BA is effective in ameliorating alcohol-induced liver injury through regulating oxidative stress-mediated NF-κB signalling, which provides a scientific basis for further research on its clinical applications.

Higher Activity of Alcohol Dehydrogenase Is Correlated with Hepatic Fibrogenesis.

Hepatofibrosis can progress to cirrhosis and hepatocellular carcinoma (HCC). Prevention, stabilization, and reversal of disease progression are vital for patients with hepatofibrosis, and identifying the risk factors for hepatofibrosis is urgently needed. In this study, we examined the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the fibrotic livers of HCC patients (n = 88) and comparied these results with activities in patients with normal livers (n = 74). A fibrosis-carcinoma rat model was used to study the activity of ADH in fibrosis and HCC and the relationship between innate ADH activity and the extent of hepatofibrosis or HCC. Substantial interindividual variations were found in the activities of ADH and ALDH in normal livers. The activity levels of total ADH, ADHI, and ADHII in fibrotic livers were significantly higher than those in normal livers (P < 0.001), whereas the activity of ALDH was slightly greater. The positive rates of ADHI and ADHII were 84.1% and 77.3%, respectively; the areas under the receiver operator characteristics (ROC) curve were 0.943 and 0.912, respectively. For the rat model compared with controls, ADH activity in liver was significantly increased at the fibrotic and HCC stages, and no significant difference was noted between ADH activity in the liver at these two stages. The innate activity of ADH in serum was well correlated with the extent of hepatofibrosis as indicated by Masson area%, Ki67+%, proliferating cell nuclear antigen +%, and GST-p average density at fibrotic stage but not at HCC stage. A higher level of activity of ADH is a risk factor for hepatofibrogenesis and might be a prevention target for hepatofibrosis.

Ethylene glycol poisoning

Ethylene glycol poisoning

Ethanol metabolism varies with hypoxia tolerance in ten cyprinid species.

During periods of severe hypoxia or anoxia, Carassius spp. are known for their ability to produce ethanol as their anaerobic end product, which diffuses into the environment thereby reducing the osmotic and acidotic load associated with "anaerobic" glycolysis. However, the relationship between alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities, key ethanol metabolizing enzymes, and hypoxia tolerance among Carassius spp. and their closely related non-ethanol-producing cyprinids remains unclear. To address this, we quantified the activity levels of key anaerobic enzymes in liver and muscle in species of cyprinids over 48h of severe hypoxia exposure (0.7kPa). As predicted, muscle ADH activity was highest in the two most hypoxia-tolerant species (Carassius spp.), with very low levels present in the other species examined. However, liver ADH activities showed an inverse relationship with hypoxia tolerance, with the most hypoxia-tolerant fish having the lowest ADH activity. There was no correlation between hypoxia tolerance and ALDH and LDH activities in muscle or liver. All species produced lactate, reaching their highest levels after 8h, but returning to near-baseline levels by 48h of sustained exposure to hypoxia, suggesting lactate oxidation or depressed ATP demand. Liver glycogen content was not affected by 48h hypoxia exposure in the most hypoxia-tolerant species, whereas the least tolerant species consumed the majority of the liver glycogen stores, which is probably due to the greater relative hypoxia exposure experienced by these species. Our findings that liver ADH activities were inversely related to hypoxia tolerance suggests that in all but Carassius spp., the ethanol metabolizing pathways in cyprinids is largely similar to that observed in other vertebrates and plays a role in the detoxification of ethanol. Furthermore, conservation of glycogen stores may be the result of metabolic-depressing pathways in the more tolerant species, regardless of the ability to produce ethanol, or adaptations that improve oxygen uptake to reduce metabolic demands due to hypoxia.

Ethanol-Induced ADH Activity in Zebrafish: Differential Concentration-Dependent Effects on High- Versus Low-Affinity ADH Enzymes

Zebrafish express enzymes that metabolize ethanol in a manner comparable to that of mammals, including humans. We previously demonstrated that acute ethanol exposure increases alcohol dehydrogenase (ADH) activity in an inverted U-shaped dose-dependent manner. It was hypothesized that the biphasic dose-response was due to the increased activity of a high-affinity ADH isoform following exposure to low concentrations of ethanol and increased activity of a low-affinity ADH isoform following exposure to higher concentrations of ethanol. To test this hypothesis, we exposed zebrafish to different concentrations of ethanol (0%, 0.25%, 0.5%, and 1.0% v/v) for 30 min and measured the total ADH activity in the zebrafish liver. However, we also repeated this enzyme activity assay using a low concentration of the substrate (ethanol) to determine the activity of high-affinity ADH isoforms. We found that total ADH activity in response to ethanol induces an inverted U-shaped dose-response similar to our previous study. Using a lower substrate level in our enzyme assay targeting high-affinity isozymes, we found a similar dose-response. However, the difference in activity between the high and low substrate assays (high substrate activity - low substrate activity), which provide an index of activity for low-affinity ADH isoforms, revealed no significant effect of ethanol exposure. Our results suggest that the inverted U-shaped dose-response for total ADH activity in response to ethanol is driven primarily by high-affinity isoforms of ADH.

Compromised zinc status of experimental rats as a consequence of prolonged iron & calcium supplementation.

Background & objectives:Iron supplementation is usually given to pregnant and lactating women who may also have marginal deficiency of zinc. The negative impact of supplemental iron and calcium on zinc status is a cause of concern. The present investigation was undertaken to examine the effect of inclusion of iron and calcium in the diet at supplementary levels on zinc status of experimental rats.Methods:Groups of experimental rats were maintained on diets supplemented with iron (Molar ratio - Zn:Fe 1:30) and calcium (Molar ratio - Zn:Ca 1:667) both individually and in combination for six weeks. Zinc status of these rats was assessed by determining zinc concentration in circulation and in organs, and the activities of zinc containing enzymes in serum and liver.Results:The zinc status of experimental rats receiving supplemental levels of iron and calcium was significantly compromised. Zinc concentration in serum, kidney, spleen and liver was reduced significantly by both these minerals. Six weeks of supplementation of iron and calcium individually, significantly reduced the activity of liver and serum superoxide dismutase and alkaline phosphatase. Activity of liver alcohol dehydrogenase was lowered in calcium supplemented group and in calcium + iron supplemented group, while that of carbonic anhydrase was significantly reduced by iron, calcium and their combination.Interpretation & conclusions:Supplemental levels of iron and calcium, both individually and in combination, significantly compromised the zinc status of experimental rats. This negative effect of these two minerals was more prominent when these were supplemented for a period of six weeks.

Investigation of liver alcohol dehydrogenase catalysis using an NADH biomimetic and comparison with a synthetic zinc model complex

We have compared the catalytic activity of horse liver alcohol dehydrogenase (LADH) with a synthetic zinc model complex in the presence of N-benzyl-1,4-dihydronicotinamide (BNAH), a cofactor which serves as a biomimetic for the natural cofactor NADH. We have used five different substrates (benzaldehyde, p-anisaldehyde, 4-nitrobenzaldehyde, 2-pyridine carboxaldehyde, and 5-pyrimidine carboxaldehyde) in this study. These substrates vary in their substituent inductive effect, which is the ability to donate or withdraw electron density away from their carbonyl-functional group. Our results reveal that in the presence of NADH, geometric factors (induced fit of the substrate and cofactor in the enzyme active site) are vital. However, reactivity assays show that in the presence of BNAH, there is a strong correlation between substrate electronic environment and the observed catalytic rate, i.e. the more electron withdrawn the substrate, the greater the speed at which the reduction reaction occurs. NMR spectroscopy reveals that a synthetic zinc model complex catalyzes the reduction of substrates in a manner consistent with LADH enzyme.

Acute and chronic ethanol exposure differentially alters alcohol dehydrogenase and aldehyde dehydrogenase activity in the zebrafish liver.

Chronic ethanol exposure paradigms have been successfully used in the past to induce behavioral and central nervous system related changes in zebrafish. However, it is currently unknown whether chronic ethanol exposure alters ethanol metabolism in adult zebrafish. In the current study we examine the effect of acute ethanol exposure on adult zebrafish behavioral responses, as well as alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in the liver. We then examine how two different chronic ethanol exposure paradigms (continuous and repeated ethanol exposure) alter behavioral responses and liver enzyme activity during a subsequent acute ethanol challenge. Acute ethanol exposure increased locomotor activity in a dose-dependent manner. ADH activity was shown to exhibit an inverted U-shaped curve and ALDH activity was decreased by ethanol exposure at all doses. During the acute ethanol challenge, animals that were continuously housed in ethanol exhibited a significantly reduced locomotor response and increased ADH activity, however, ALDH activity did not change. Zebrafish that were repeatedly exposed to ethanol demonstrated a small but significant attenuation of the locomotor response during the acute ethanol challenge but ADH and ALDH activity was similar to controls. Overall, we identified two different chronic ethanol exposure paradigms that differentially alter behavioral and physiological responses in zebrafish. We speculate that these two paradigms may allow dissociation of central nervous system-related and liver enzyme-dependent ethanol induced changes in zebrafish.

Effects of the extracts and an active compound curcumenone isolated from Curcuma zedoaria rhizomes on alcohol-induced drunkenness in mice

The Curcuma zedoaria rhizome has been used traditionally to treat gastrointestinal diseases as an aromatic stomachic drug, and this is currently used to treat alcohol-induced loss of appetite and nausea in Japan. We examined the effects of various fractions and isolated compounds on alcohol-induced drunkenness and blood alcohol concentrations in mice. The 30% ethanol-extract (1000mg/kg) of C. zedoaria rhizome prevented drunkenness 60 and 120min after 40% alcohol administration. The n-hexane-soluble fraction (300mg/kg) and an isolated compound (3, 10 or 30mg/kg) prevented drunkenness at 30, 60 or 120min. The extract, n-hexane-soluble fraction and isolated compound reduced the elevation in blood alcohol concentrations 30 and 60min after 40% alcohol administration. The isolated compound (10 and 30mg/kg) enhanced liver ADH activity 30 and 60min after 40% alcohol administration. The compound was identified as curcumenone by a direct comparison of 1H- and 13C-NMR spectral data. In conclusion, the protective effect of the C. zedoaria extract on drunkenness might be due to an active substance, curcumenone, and decreases in the elevation of blood alcohol concentrations through increased liver alcohol dehydrogenase activity.

Screening of the inhibitory effect of xenobiotics on alcohol metabolism using S9 rat liver fractions

The purpose of this work was to develop and optimize a simple and suitable method to detect the potential inhibitory effect of drugs and medicines on alcohol dehydrogenase (ADH) activity in order to evaluate the possible interactions between medicines and alcohol metabolism. Commonly used medicines that are often involved in court litigations related with driving under the influence of alcohol were selected. Alprazolam, flunitrazepam and tramadol were tested as drugs with no known effect on ADH activity. Cimetidine, reported previously as having inhibitory effect on ADH, and 4-methylpyrazole (4-MP), a well known ADH inhibitor, were tested as positive controls. Apart from 4-MP, tramadol was identified as having the higher inhibitory effect with an IC50 of 44.7×10−3mM, followed by cimetidine (IC50 of 122.9×10−3mM). Alprazolam and flunitrazepam also reduced liver ADH activity but to a smaller extent (inhibition of 11.8±5.0% for alprazolam 1.0mM and 34.5±7.1% for flunitrazepam 0.04mM). Apart from cimetidine, this is the first report describing the inhibitory effect of these drugs on ethanol metabolism. The results also show the suitability of the method to screen for inhibitory effect of drugs on ethanol metabolism helping to identify drugs for which further study is justified.

Preventive effects of Flos Perariae (Gehua) water extract and its active ingredient puerarin in rodent alcoholism models

BackgroundRadix Puerariae is used in Chinese medicine to treat alcohol addiction and intoxication. The present study investigates the effects of Flos puerariae lobatae water extract (FPE) and its active ingredient puerarin on alcoholism using rodent models.MethodsAlcoholic animals were given FPE or puerarin by oral intubation prior or after alcohol treatment. The loss of righting reflex (LORR) assay was used to evaluate sedative/hypnotic effects. Changes of gama-aminobutyric acid type A receptor (GABAAR) subunits induced by alcohol treatment in hippocampus were measured with western blot. In alcoholic mice, body weight gain was monitored throughout the experiments. Alcohol dehydrogenase (ADH) levels in liver were measured.ResultsFPE and puerarin pretreatment significantly prolonged the time of LORR induced by diazepam in acute alcoholic rat. Puerarin increased expression of gama-aminobutyric acid type A receptor alpha1 subunit and decreased expression of alpha4 subunit. In chronic alcoholic mice, puerarin pretreatment significantly increased body weight and liver ADH activity in a dose-dependent manner. Puerarin pretreatment, but not post-treatment, can reverse the changes of gama-aminobutyric acid type A receptor subunit expression and increase ADH activity in alcoholism models.ConclusionThe present study demonstrates that FPE and its active ingredient puerarin have preventive effects on alcoholism related disorders.

알코올 대사 효소 alcohol dehydrogenase (ADH) 및 acetaldehyde dehydrogenase (ALDH) 활성에 미치는 아미노산의 영향

본 연구에서는 숙취해소에 좋은 것으로 알려진 식품 소재의 주요 아미노산을 포함하여 효소 활성에 영향을 미치는 것으로 알려진 아미노산을 선택하였고, 효소 활성도가 상대적으로 높은 yeast와 rat liver 유래의 ADH 및 ALDH 효소를 대상으로 알코올 대사에 관련된 효소 활성의 촉진 효과에 대하여 검토하였다. Rat liver 유래의 ADH 활성은 처리한 아미노산 중에서 arginine에서 가장 높았다. Arginine의 첨가 농도를 달리하여 효소 활성을 측정한 결과 <TEX>$10{\sim}50\;mg$</TEX>/ml 농도에서 <TEX>$118{\sim}120.6%$</TEX>로 양성대조구의 90.6% 보다 약간 높은 것으로 나타났다. 또한, yeast 유래의 ADH 활성은 methionine에서 가장 높은 활성을 보였고, methionine의 처리 농도를 달리한 경우에서는 첨가 농도 의존적으로 높은 활성을 보였다. Rat liver 유래의 ALDH 활성은 methionine이 가장 높은 활성을 보였다. Methionine의 첨가 농도별 측정에서는 10 mg/ml에서 30 및 50 mg/ml 첨가 농도에서 보다 높은 활성을 보였으며, 이들 모든 처리 농도에서 양성대조구 보다 상당히 높은 활성을 보였다. 한편 yeast 유래의 ALDH 활성은 각 아미노산별 큰 차이는 없었으나, arginine에서 높은 활성을 보였다. Arginine의 첨가 농도별 측정에서는 처리 농도 의존적으로 활성이 약간씩 증가하는 경향을 보였으며, 양성대조구 보다 높은 활성을 나타내었다. 효모 유래 ALDH 및 rat liver 유래 ADH 효소 활성을 촉진시키는 작용을 가진 arginine을 효모 배양에 첨가시킬 경우 세포 내 ALDH 및 ADH 활성 염색 정도가 증가함으로써 arginine은 ALDH 및 ADH 활성을 촉진시키는 효능이 in vivo 실험계에서도 확인되었다. 이상의 실험 결과에서 아미노산 중에서는 arginie과 methionine이 ADH 및 ALDH 활성을 촉진시키는 작용에 의해 알코올 분해뿐만 아니라 acetaldehyde의 분해도 촉진시킬 가능성이 높아 숙취해소 효과는 물론 간 보호 효과도 동시에 있을 것으로 시사 되어 진다. 따라서 arginine과 methionine과 같은 아미노산을 주류 제품에 첨가하게 될 경우 숙취해소 경감과 간 보호 효능을 어느 정도 나타낼 수 있을 가능성이 제기되었다. The present study examined the comparative effects of various amino acids on the alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities of yeast Saccharomyces cereviciae and rat liver homogenate in vitro. Methionine showed the highest activity in yeast ADH among the amino acids used in this study, but this was not higher than that of the hangover product, Condition-Power (CP) used as positive control. Methionine was also found to be the best amino acid in terms of the ALDH activity in rat liver homogenate among the treatment amino acids, which was comparatively higher than that of positive control CP. It was chosen for further experiments and yeast ADH activity increased in parallel with increased methionine concentration, but not rat liver ALDH activity, and it was comparatively higher than those of the positive control. Arginine showed the highest values in yeast ALDH and rat liver ADH activities among amino acids, and it was chosen for further experiments. Yeast ALDH activity increased in parallel with increased arginine concentration, which was higher than that of positive control CP, and rat liver ADH activity was also comparatively higher in all treatment concentrations of arginine than that of positive control CP. The native electrophoresis of ADH and ALDH from cell-free extracts of yeast Saccharomyces cerevisiae cultured in the growth medium containing various arginine concentrations by <TEX>$0{\sim}0.1%$</TEX> showed two active bands upon zymogram staining analysis, and the straining intensity of ADH and ALDH active bands in arginine treatment yeast was stronger than that of non-yeast or low treatment yeast. These results indicate that alcohol metabolizing enzyme activities can be enhanced by arginine and methionine, suggesting that arginine and methionine have potent ethanol-metabolizing activities.

The Effect of Plant Compounds from Whisky Cask on Horse Liver Alcohol Dehydrogenase Activity

Aged whisky contains many plant derived compounds from oak wood cask, and the color of whisky gradually changes to deep amber. More than 500 kinds of compounds are known as minor components in aged whisky. The taste of whisky becomes smooth with aging, and we can sober up feeling good. However, detail effect of these plant derived components from whisky cask on alcohol metabolism has not been clarified. In this experiment, we investigated the relation between the structure of components and the rate of ethanol oxidation reaction by using 26 kinds of plant derived components from oak wood cask and its derivatives. All the compounds which we used have a benzene ring as a basic frame, and have a hydroxyl group, an aldehyde group, and a carboxyl group further. All 26 compounds from oak wood cask and its derivatives used in this experiment were inhibited the ethanol oxidation. Interestingly, the relative activity of compound with an aldehyde group (Benzaldehyde and its derivatives) inhibited most strongly to be 30~40%. However, the relative activity of Benzaldehyde with one hydroxyl group had about 70% of relative activity and it had only one hydroxyl group, it clarified that the inhibition effect becomes weaker. The inhibition effect of compounds with calboxyl group (Benzoic acid and its derivatives) was weak and showed 90% of re lative activity. However, in contrast to the case of Benzaldehyde, the inhabitation effect of Benzoic acid only with one hydroxyl group becomes strong. From these results, it is clarified that many compounds from oak wood cask inhibite the ethanol oxidation. But the mechanism of inhabitation is complex and the additivity of the functional group contribution is not applied simply.

Maturation of Whisky Changes Ethanol Elimination Kinetics and Neural Effects by Increasing Nonvolatile Congeners

The maturation of distilled spirits is known to change constituent congeners to improve the qualities of smell and taste. However, it has been largely unknown how maturation modifies the pharmacokinetics or neuropharmacological effects of ethanol. We used single malt whiskies to investigate the effects of spirit maturation on ethanol metabolism and drunkenness. Mice were injected with 5-year (5-y) or 20-year (20-y) aged single malt whisky with a concentration of 20% (w/v) ethanol at a dose of 3 g/kg. The concentrations of ethanol and its metabolites in the blood and the duration of loss of righting reflex (LORR) were compared between the 2 whisky groups. In addition, the effects of nonvolatile congeners in whisky on the biomedical reactivities of ethanol were investigated by administering a nonvolatile fraction added to a 20% ethanol solution, whose fraction was prepared by evaporating 16-y whisky. Liver alcohol dehydrogenase (ADH) activity was measured with whisky as the substrate or in the presence of nonvolatile congeners with ethanol as the substrate. The rate of ethanol elimination (mmol/kg/h) was smaller in the 20-y whisky group than in the 5-y group (p<0.01 by Fisher's protected least significant difference), which resulted in lower concentrations of blood acetaldehyde and acetate in the former group than in the latter group (p<0.01 by ANOVA). Nonvolatile congeners added to the ethanol solution also depressed the rate of ethanol elimination in mice. In vitro studies demonstrated that liver ADH activity measured with whisky as the substrate was decreased as a function of the age of the whisky, and that the activity measured with ethanol as the substrate was strongly inhibited by nonvolatile congeners. The duration of LORR was longer in the 20-y group than in the 5-y group (p<0.01). Nonvolatile congeners also prolonged the duration of ethanol-induced LORR, when administered together with ethanol. Maturation of whisky delayed ethanol metabolism to lower the level of blood acetaldehyde and acetate with increasing inhibition of liver ADH activity by nonvolatile congeners. It also prolonged drunkenness by enhancing the neurodepressive effects of ethanol, due to increases in the amount of nonvolatile congeners. These biomedical effects of whisky maturation may reduce aversive reactions and cytotoxicity due to acetaldehyde, and may also limit overdrinking with the larger neurodepression.

Involvement of alcohol and aldehyde dehydrogenase activities on hepatic retinoid metabolism and its possible participation in the progression of rat liver regeneration

Liver alcohol dehydrogenase (ADH) activity is decreased towards exogenous substrates after partial hepatectomy (PH), probably due to putative endogenous substrates acting as ADH inhibitors. Hence, retinoids could be suitable candidates as such endogenous substrates. Therefore, cytosolic ADH kinetic analysis using several substrates, liver cytosolic and mitochondrial aldehyde dehydrogenase (ALDH) activities, retinal and retinol content, as well as expression of proteins for ADH and CRBPI (a retinol carrier protein) were determined in liver samples, at two stages of liver regeneration (one- or two-thirds PH). The effect of inhibiting in vivo liver ADH by 4-methylpyrazole (4-MP) was also evaluated after 70%-PH. With 70%-PH, in vitro ADH activity towards exogenous alcohols and aldehydes was diminished, but retinol oxidation was increased and retinal reduction was decreased. These activities that be due to the participation of an ADH type which did not correlate with the amount of immunoreactive ADH protein. Cytosolic and mitochondrial ALDH activities oxidized actively retinal, whereas retinol and CBRP-I expression were reduced in these animals. With 30%-PH, these changes were less evident and sometimes opposite to those found with 70%-PH. In addition, retinol readily inhibited ADH-mediated ethanol oxidation. Interestingly, in vivo 4-MP administration inhibited ADH activity in a dose-dependent manner correlating with a progressive inhibition of liver regeneration. In conclusion, PH-induced inhibition of ADH (mainly type I) seems to be related to ADH-mediated retinoid metabolism during liver proliferation. Thus, results suggest a role of ADH in retinoid metabolism, which is apparently required during rat liver regeneration.

Effect of leptin on liver alcohol dehydrogenase

The effect of leptin on liver alcohol dehydrogenase (ADH) was determined in male rats. Administration of one or three daily doses of leptin (1 μg/g of body weight intraperitoneally) increased ADH activity. Leptin enhanced ADH synthesis without an effect on ADH degradation. Leptin did not change ADH mRNA, indicating that the effect of leptin in enhancing ADH occurs at the post-transcriptional level. Leptin increased eukaryotic initiation factor (eIF) 2α, eIF2B activity, and the eIF4E–eIF4G complex, while it decreased the inhibitory complex of eIF4E with the eIF4E-binding protein-1 (4E-BP1). Leptin increased mammalian target of rapamycin (mTor) that phosphorylates 4E-BP1. In conclusion, leptin increases liver ADH activity and ADH protein due to an increase in synthesis which occurs at the post-transcriptional level. The effect of leptin in enhancing translational initiating factors may be of significance in the regulation not only of ADH but also of many other proteins.

Inhibition of Horse Liver Alcohol Dehydrogenase by Methyltin Compounds

The study of inorganic tin (SnCl2, SnCl4) and methyltin compounds (MeSnCl3, Me2SnCI2, Me3SnCl) effects on the enzymatic activity of alcohol dehydrogenase (ADH) in the reaction of ethanol oxidation has been carried out. The experimental results of the study show that inorganic tin and methyltin substances induce slight inhibition of the catalytic activity of horse liver alcohol dehydrogenase (HLADH), unable to be improved during pre-incubation with the enzyme. The conditions for carrying out the kinetic investigation of the mentioned phenomenon were optimized and as it turned out the mechanism of methyltin trichloride action, as the most effective methyltin inhibitor, is more complex than the proposed interaction of the metal atom with SH-groups of the enzyme protein. It was demonstrated that the tin compounds act in the same manner as methylmercury compounds and might serve as oxidative agents towards the co-enzyme NADH. Kinetic data on MeSnCl3 were calculated. Data acquired on NAD-dependent ADH from horse liver and those regarding NAD-dependent LDH from sturgeon liver were compared.