Intake of Lactobacillus rhamnosus GG (LGG) fermented milk before drinking alcohol reduces acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2: a randomized, blinded crossover controlled trial.

Alcohol consumption leads to acetaldehyde accumulation, especially in people with mutant aldehyde dehydrogenase 2 gene (ALDH2). Novel strategies to promote acetaldehyde detoxification are required to prevent alcohol-related toxicity. Probiotic bacteria such as Lactobacillus rhamnosus GG (LGG) were shown to have in vitro capacity to detoxify acetaldehyde. This randomized, blinded, placebo-controlled cross-over trial investigated the effect of LGG fermented milk in people with ALDH2 polymorphisms after moderate alcohol intake. Ten healthy wild-type and ten heterozygous mutant ALDH2 Thai men were block randomized into two groups. Each group consumed a different sequence of 150 mL fermented milk containing 108 CFU mL-1 LGG and lactic-acidified milk (placebo), followed by five glasses of beer (0.4 g ethanol per kg body weight), with a one-week wash-out. Consuming LGG fermented milk before alcohol reduced areas under the response curves of blood and salivary acetaldehyde in wild-type and heterozygous mutant ALDH2 individuals (p < 0.05 and p < 0.01, respectively). Interestingly, participants with mutant ALDH2 responded better than wild-type participants for salivary acetaldehyde (90% vs. 70%, p < 0.001). Their durations of flushing were reduced when consuming LGG milk. Regardless of ALDH2 status, 105 CFU mL-1 LGG was retained in saliva at least 3.5 h after milk consumption. In conclusion, intake of LGG fermented milk before drinking alcohol reduces blood and salivary acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2. The addition of exogenous capacity to detoxify acetaldehyde using the probiotic product could be a potential strategy to promote the alleviation of exposure to reactive and carcinogenic acetaldehyde associated with alcohol drinking in individuals with defective ALDH2 enzyme.

Regulation of Alcohol and Acetaldehyde Metabolism by a Mixture of Lactobacillus and Bifidobacterium Species in Human.

Excessive alcohol consumption is one of the most significant causes of morbidity and mortality worldwide. Alcohol is oxidized to toxic and carcinogenic acetaldehyde by alcohol dehydrogenase (ADH) and further oxidized to a non-toxic acetate by aldehyde dehydrogenase (ALDH). There are two major ALDH isoforms, cytosolic and mitochondrial, encoded by ALDH1 and ALDH2 genes, respectively. The ALDH2 polymorphism is associated with flushing response to alcohol use. Emerging evidence shows that Lactobacillus and Bifidobacterium species encode alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) mediate alcohol and acetaldehyde metabolism, respectively. A randomized, double-blind, placebo-controlled crossover clinical trial was designed to study the effects of Lactobacillus and Bifidobacterium probiotic mixture in humans and assessed their effects on alcohol and acetaldehyde metabolism. Here, twenty-seven wild types (ALDH2*1/*1) and the same number of heterozygotes (ALDH2*2/*1) were recruited for the study. The enrolled participants were randomly divided into either the probiotic (Duolac ProAP4) or the placebo group. Each group received a probiotic or placebo capsule for 15 days with subsequent crossover. Primary outcomes were measurement of alcohol and acetaldehyde in the blood after the alcohol intake. Blood levels of alcohol and acetaldehyde were significantly downregulated by probiotic supplementation in subjects with ALDH2*2/*1 genotype, but not in those with ALDH2*1/*1 genotype. However, there were no marked improvements in hangover score parameters between test and placebo groups. No clinically significant changes were observed in safety parameters. These results suggest that Duolac ProAP4 has a potential to downregulate the alcohol and acetaldehyde concentrations, and their effects depend on the presence or absence of polymorphism on the ALDH2 gene.

Fenofibrate -a PPARα agonist- increases alcohol dehydrogenase levels in the liver: implications for its possible use as an ethanol-aversive drug. / Fenofibrato -un agonista de PPARα- incrementa los niveles de la alcohol deshidrogenasa hepática: implicaciones para su posible uso como una droga de aversión al etanol.

After ethanol consumption, disulfiram increases blood-acetaldehyde levels, generating an aversive reaction that deters alcohol drinking. Given the major secondary effects of disulfiram, finding other effective drugs to reduce alcohol consumption in individuals with alcohol-use-disorder is highly desirable. It has been reported that administering fenofibrate to high-drinking rats increases hepatic catalase levels and blood acetaldehyde after administering ethanol and a 60-70% inhibition of voluntary alcohol intake. This work evaluated whether fenofibrate has an additional effect on the activity of other ethanol-metabolizing enzymes, which could contribute to the high acetaldehyde levels generated upon administering ethanol. Male high-drinker rats were allowed to voluntary drink 10% ethanol or water for 2 months. Subsequently, fenofibrate (100 mg/kg/day) or vehicle was administered orally for 14 days. Then, alcohol dehydrogenase (ADH1) and aldehyde dehydrogenase (ALDH2) protein levels and enzymatic activities in the livers were quantified. Fenofibrate treatment produced a marked increase in ADH1 protein levels (396% ± 18%, p < 0.001) and enzymatic activity (425% ± 25%, p < 0.001). Fenofibrate did not result in differences in ALDH2 activity or in ALDH2 protein levels. The studies show that treatment with fenofibrate not only increased the activity of catalase in the liver of alcohol-drinking rats, as reported earlier, but also increased the levels and enzymatic activity of ADH1, while ALDH2 remained unchanged. The increases in ADH1 contribute to explaining the remarkable effect of fenofibrate in raising blood levels of acetaldehyde in ethanol-consuming animals, in which a marked reduction of alcohol intake is recorded.

Tras consumir etanol, el disulfiram incrementa los niveles de acetaldehído en sangre y genera una reacción aversiva que desalienta el consumo de alcohol. Dados los importantes efectos secundarios del disulfiram, es altamente deseable hallar otros fármacos efectivos para tratar el trastorno por uso de alcohol. Se ha reportado que administrar fenofibrato a ratas altamente bebedoras de alcohol aumenta los niveles de catalasa hepática y acetaldehído en sangre después de la administración de etanol, y disminuye el consumo voluntario de alcohol (60-70%). Este trabajo evalúa si el fenofibrato tiene un efecto adicional sobre la actividad de otras enzimas en el metabolismo del etanol que podría contribuir a generar altos niveles de acetaldehído. Se permitió a ratas macho altamente bebedoras beber voluntariamente etanol 10% durante 2 meses. Después, se les administró oralmente fenofibrato (100 mg/kg/día) o solo vehículo durante 14 días. Tras eso, se midieron los niveles hepáticos y actividades enzimáticas de alcohol deshidrogenasa (ADH1) y de aldehído deshidrogenasa (ALDH2). El fenofibrato produjo un marcado aumento en los niveles proteicos de ADH1 (396% ± 18%, p < 0,001) y de actividad enzimática (425% ± 25%, p < 0,001) sin alterar los niveles protéicos ni la actividad de ALDH2. Los resultados muestran que el tratamiento con fenofibrato no solo aumenta la actividad de catalasa en el hígado de ratas bebedoras de alcohol, sino que también incrementa los niveles y la actividad de ADH1, sin alterar ALDH2. Esto contribuye a explicar el notable efecto del fenofibrato en aumentar los niveles de acetaldehído en sangre en animales bebedores de alcohol, en los que se registra una marcada reducción en la ingesta de etanol.

The association between alcohol metabolism and genetic variants of ADH1A, SRPRB, and PGM1 in Korea.

BACKGROUND: Excessive alcohol consumption is a major public health problem in East Asian countries. Alcohol use leads to a cascade of problems including increased chances of risky behavior and a wide range of negative health consequences, from alcoholic liver disease to upper gastric and liver cancer. These alcohol effects are known to be influenced by ethnic variability and genetics. METHODS: In this study, subjects were administered a single dose of alcohol (0.6 g/kg for men or 0.4 g/kg for women), and blood alcohol and acetaldehyde concentrations were measured eight times over 5 hours. To investigate genetically susceptible factors to alcohol metabolism, we selected single-nucleotide polymorphisms (SNP) of genes identified by prior genetic association studies for alcohol metabolism, alcohol consumption, alcohol dependence, and related traits, and performed genotyping on all subjects (n = 104). RESULTS: We identified variations in the ADH1A, SRPRB, and PGM1 genes, which are directly associated with blood alcohol or acetaldehyde concentrations. Namely, the T allele of SRPRB rs17376019 and the C allele of PGM1 rs4643 were associated with lower blood alcohol levels, while the ADH1 rs1229976 C allele group exhibited markedly higher blood acetaldehyde levels than those of the ADH1 rs1229976 T allele group. CONCLUSION: This study demonstrates that genetic variations in ADH1A, SRPRB, and PGM1 are associated with variations in blood alcohol and acetaldehyde concentration after alcohol intake.

[Alcoholic liver disease: the roles of genetic-epigenetic factors and the effect of abstinence]. / Alkoholos májbetegség: a genetikai-epigenetikai tényezok szerepe és az absztinencia hatása.

The pathogenesis of alcoholic liver disease depends not only on the toxic effects of alcohol, but also on the complex interaction of host's and environmental factors. Thus, the genetic pre-disposition, co-morbidities and behavioral factors all play a role in the individual variations in the disease outcomes. On the other hand, the essential part of the therapeutic strategy is the complete withdrawal of the harmful etiological agent. The present paper is devoted to overview the genetics, the environmental factors and the effects of abstinence in alcoholic liver disease. Genetic variants in two enzymes involved in the metabolism of ethanol, alcohol-dehydrogenase ADH1B *2 and aldehyde-dehydrogenase ALDH2 *2 through increasing the blood level of acetaldehyde, may play a "protective" role against alcoholism. The P450 CYP2E1 *5 c2, an inducible microsomal oxidase, upregulated by ethanol and by formation of acetaldehyde and reactive oxygen species, increases liver toxicity. Three novel gene polymorphisms - such as the patatin-like phospholipase domain-containing 3 (PNPLA3 I148M C>G), the transmembrane 6 superfamily member 2 (TM6SF2 E167K), and the membrane-bound O-acyltransferase domain-containing 7 (MB0AT7 rs641738 C>T) - have been proven as risk factors of steatosis, fibrosis and even hepatocellular carcinoma in both alcoholic and non-alcoholic fatty liver disease patients. Alcohol-induced epigenetic effects, reversible but inheritable gene expression alterations - as histon modulations, DNA methylation and micro-RNA-s - are of importance in the pathogenesis as well, and in the future, they may serve as diagnostic markers and therapeutic targets. Women are at greater risk of developing alcoholic cirrhosis, furthermore, malnutrition, obesity, diabetes, smoking, and hepatitis virus infections are also risk factors. Alcoholic liver disease should be regarded as a preventable disease. Several clinical studies revealed that abstinence may result in the regression of steatohepatitis and fibrosis, compensation of cirrhosis, improving disease outcome and increasing survival even in patients with advanced stages. Early diagnosis and multidisciplinary interventions are highly required to achieve long-term abstinence and to prevent alcoholic cirrhosis. Orv Hetil. 2019; 160(14): 524-532.

Effects of "Essential AD2" Supplement on Blood Acetaldehyde Levels in Individuals Who Have Aldehyde Dehydrogenase (ALDH2) Deficiency.

BACKGROUND: It is estimated that 1 billion people in the world have a point mutation in the gene encoding the aldehyde dehydrogenase 2 (ALDH2) enzyme, the primary enzyme responsible for the metabolism of acetaldehyde. The presence of this mutation is called ALDH2 deficiency. Because of limited ability to metabolize acetaldehyde, individuals with ALDH2 deficiency experience elevated levels of blood acetaldehyde after exposure to various common sources such as recreational alcohol. Because of higher levels of acetaldehyde, individuals with ALDH2 deficiency are at higher risk for numerous diseases, including liver cirrhosis, esophageal and gastric cancer, osteoporosis, and Alzheimer disease. STUDY QUESTION: The present trial was designed to study the effectiveness, safety, and tolerability of a nutritional supplement (Essential AD2). MEASURES AND OUTCOMES: The primary outcome was change in acetaldehyde levels in the blood after exposure to alcohol in individuals with ALDH2 deficiency before and after the use of study nutritional supplement. STUDY DESIGN: This was a 28-day open-label trial, comparing initial acetaldehyde levels after alcohol ingestion to levels after 28 days of a nutritional supplement (Essential AD2). The study consisted of 12 subjects genotyped to be heterozygous for the ALDH2 gene mutation. RESULTS AND CONCLUSIONS: ALDH2 deficient subjects showed a significant decrease in average blood acetaldehyde level 20 minutes after alcohol consumption (from 0.91 mg/dL to 0.71 mg/dL, P value = 0.02) after receiving 28 days of the nutritional supplement. Acetaldehyde levels taken at 10 minutes and 40 minutes also showed a decrease, although they were not statistically significant. In addition, safety tests looking at liver function tests showed a decrease in aspartate transaminase and alanine transaminase liver proteins from 27.3 to 15.2 and 20.9 to 13.2, respectively, over the 28 days. The treatment was well tolerated and no significant side effects were noted.

Clove Bud Polyphenols Alleviate Alterations in Inflammation and Oxidative Stress Markers Associated with Binge Drinking: A Randomized Double-Blinded Placebo-Controlled Crossover Study.

Acetaldehyde, the major cytotoxin formed by the metabolism of alcohol, is responsible for liver injury, extracellular matrix alterations, inflammation, and hangover in heavy drinkers. This study aimed to demonstrate the efficacy of a standardized polyphenolic extract of clove buds (Clovinol) in ameliorating the oxidative stress and inflammation caused by the accumulation of acetaldehyde after binge drinking. We used a randomized, double-blinded crossover study with 16 male social drinkers. The subjects were randomized into two groups of eight subjects and received either placebo or Clovinol in a single hard shell gelatin capsule (250 mg × 1) per day. The dosage of alcohol was 1 g/kg body weight/day. After 2 weeks of washout period, the treatment regime was reversed. Blood samples were drawn at 0, 0.5, 2, 4, and 12 h after treatment with either placebo or Clovinol, and biochemical parameters were analyzed. Hangover severity score was determined by using a validated questionnaire as reported earlier. Results showed faster elimination of blood acetaldehyde with significant decreases in oxidative stress, lipid peroxidation, C-reactive protein, interleukin-6, and significant enhancement in glutathione and superoxide dismutase as compared with placebo along with an overall reduction of 55.34% in hangover severity in Clovinol-treated subjects. This study demonstrated the efficacy of clove bud polyphenols for alleviating alcohol-related side effects among social drinkers at the studied dose.

S-Allyl-L-cysteine sulfoxide, a garlic odor precursor, suppresses elevation in blood ethanol concentration by accelerating ethanol metabolism and preventing ethanol absorption from gut.

Alcoholic beverages are enjoyed together with meals worldwide, but their excessive intake is associated with an increased risk of various diseases. We investigated whether S-allyl-L-cysteine sulfoxide (ACSO), a sulfuric odor precursor of garlic, suppresses elevation in plasma ethanol concentration by accelerating ethanol metabolism and preventing ethanol absorption from the gut in rats. ACSO and garlic extract with a high ACSO content (Garlic-H) suppressed elevation in concentrations of ethanol and acetaldehyde in plasma and promoted the activities of alcohol dehydrogenase and aldehyde dehydrogenase. However, ACSO and Garlic-H did not affect plasma acetate so much. Furthermore, we examined the change in plasma ethanol concentration by injecting ACSO or Garlic-H into the ligated stomach or jejunum together with ethanol solution. ACSO and Garlic-H suppressed the absorption of ethanol from the stomach and jejunum, but suppression in the jejunum was less than in the stomach. In conclusion, ACSO inhibits ethanol absorption and accelerates ethanol metabolism.

Effect of alcohol dehydrogenase-1B and -7 polymorphisms on blood ethanol and acetaldehyde concentrations in healthy subjects with a history of moderate alcohol consumption.

This study aims to evaluate the effect of ADH1B and ADH7 genotypes on blood acetaldehyde and ethanol levels after alcohol ingestion, and to measure the genotoxic effect of smoking and ethanol on the buccal cells, also controlling for ADH variants. We recruited healthy Italian subjects with at least a moderate history of alcohol consumption. All subjects were given an alcoholic drink of 0.4 g ethanol /kg of body weight. Blood venous samples were collected at baseline, and 30, 60, 90, and 120 minutes after ingestion. Buccal cells were collected before ethanol ingestion. Sixty subjects were enrolled in the study. Individuals with the ADH1B GG genotype had median ethanol levels of 5.0mM (IQR 3.4-7.2), and those with the ADH1B GT/TT genotype had 4.7mM (IQR 4.2-4.8). Corresponding acetaldehyde levels were 1.5µM (IQR 0.7-2.6) for ADH1B GG genotype and 1.6µM (IQR 1.5-1.7) for ADH1B CG/GG genotype. Individuals with the ADH7 CC genotype had median ethanol levels of 5.0mM (IQR 3.3-7.2), while 5.0mM (IQR 4.7-5.6) was in those with the ADH7 CG/GG genotype. Corresponding acetaldehyde levels were 1.5 µM (IQR 0.7-2.6) for ADH7 CC genotype and 1.5 µM (IQR 1.4-1.6) for ADH7 CG/GG genotypes. A non-significant increase in the frequency of karyolitic and pyknotic cells was found in the group of heavy drinkers and current smokers, when compared to the moderate drinkers and the non-smokers. Our study does not support the hypothesis that ADH1B and ADH7 genotypes affect blood ethanol and acetaldehyde concentration.

Influence of Tiopronin on the Metabolism of Alcohol in Healthy Subjects.

Drug safety- and drug-alcohol interaction studies have mainly been conducted for frequently prescribed drugs with high financial interests. Orphan drugs such as tiopronin (ORPHA25073) are often neglected in terms of clinical research. Tiopronin is a drug that is mainly used for the treatment of cystinuria. In this study, the interaction of tiopronin regarding the metabolism of alcohol (primary objective), and the safety of tiopronin in combination with alcohol was tested in healthy volunteers.In this randomised, double-blind, cross-over study, 13 healthy subjects received 500 mg tiopronin or an identical looking placebo 1 h before the intake of 0.8 g of alcohol per kg of bodyweight. Blood alcohol concentrations were measured over the course of 12 h after consumption. The experiment was repeated 7 days later with the previous placebo group receiving the active drug and vice-versa. Changes in blood alcohol AUC and elimination rate k were analysed using a 2-tailed t-test. Further acetaldehyde concentrations were measured. Additionally, the concentration ability of the subjects was tested and any adverse effects were recorded.There was no significant change in blood alcohol or acetaldehyde concentration. Significant differences in concentration tests refer presumably to learning effects. No serious adverse event occurred. All adverse events were reversible and there was no significant difference in occurrence between drug and placebo group.It was demonstrated that tiopronin does not affect the metabolism of alcohol. Intake of tiopronin in combination with alcohol has no safety implications on healthy subjects.

Influence of tobacco smoke exposure on pharmacokinetics of ethyl alcohol in alcohol preferring and non-preferring rats.

BACKGROUND: A vast majority of people who abuse alcohol are also defined as "heavy smokers". Tobacco smokes induces CYP1A1, CYP1A2, CYP2A6 isoenzymes, but on the other hand, ethanol activates CYP2E1, which can be important during combined, chronic use of both of them. The aim of the study was to evaluate the influence of tobacco smoke xenobiotics on ethanol pharmacokinetics and the level of its metabolites in alcohol preferring and non-preferring rats. METHODS: Ethanol, acetaldehyde, methanol, n-propanol and n-butanol were determined in whole blood by means of gas chromatography. Cotinine in serum was determined by LC-MS/MS. A non-compartmental analysis (cotinine, acetaldehyde) and Widmark equation (ethanol) were used for pharmacokinetic parameters calculation. RESULTS: Ethanol levels were lower in animals exposed to tobacco smoke compared to rats receiving this xenobiotic, without a prior exposure to tobacco smoke. Lower values of the studied pharmacokinetic parameters were observed in the alcohol preferring males compared to the non-alcohol preferring rats. Both n-propanol and n-butanol had higher values of the pharmacokinetic parameters analyzed in the animals exposed to tobacco smoke and ethanol compared to those, which ethanol was administered only once. CONCLUSIONS: An increase in maximum concentration and the area under concentration-time curve for ethanol after its administration to rats preferring alcohol and exposed to tobacco smoke are accompanied by a decrease in the volume of distribution. The changes in the volume of distribution may be caused by an increase in the first-pass effect, in the intestinal tract and/or in the liver. The acetaldehyde elimination rate constant was significantly higher in alcohol-preferring animals.

Moderate ethanol administration accentuates cardiomyocyte contractile dysfunction and mitochondrial injury in high fat diet-induced obesity.

Light to moderate drinking confers cardioprotection although it remains unclear with regards to the role of moderate drinking on cardiac function in obesity. This study was designed to examine the impact of moderate ethanol intake on myocardial function in high fat diet intake-induced obesity and the mechanism(s) involved with a focus on mitochondrial integrity. C57BL/6 mice were fed low or high fat diet for 16 weeks prior to ethanol challenge (1g/kg/d for 3 days). Cardiac contractile function, intracellular Ca(2+) homeostasis, myocardial histology, and mitochondrial integrity [aconitase activity and the mitochondrial proteins SOD1, UCP-2 and PPARγ coactivator 1α (PGC-1α)] were assessed 24h after the final ethanol challenge. Fat diet intake compromised cardiomyocyte contractile and intracellular Ca(2+) properties (depressed peak shortening and maximal velocities of shortening/relengthening, prolonged duration of relengthening, dampened intracellular Ca(2+) rise and clearance without affecting duration of shortening). Although moderate ethanol challenge failed to alter cardiomyocyte mechanical property under low fat diet intake, it accentuated high fat diet intake-induced changes in cardiomyocyte contractile function and intracellular Ca(2+) handling. Moderate ethanol challenge failed to affect fat diet intake-induced cardiac hypertrophy as evidenced by H&E staining. High fat diet intake reduced myocardial aconitase activity, downregulated levels of mitochondrial protein UCP-2, PGC-1α, SOD1 and interrupted intracellular Ca(2+) regulatory proteins, the effect of which was augmented by moderate ethanol challenge. Neither high fat diet intake nor moderate ethanol challenge affected protein or mRNA levels as well as phosphorylation of Akt and GSK3ß in mouse hearts. Taken together, our data revealed that moderate ethanol challenge accentuated high fat diet-induced cardiac contractile and intracellular Ca(2+) anomalies as well as mitochondrial injury.

Human monoclonal Fab and human plasma antibodies to carbamyl-epitopes cross-react with malondialdehyde-adducts.

Oxidized low-density lipoprotein (OxLDL) plays a crucial role in the development of atherosclerosis. Carbamylated LDL has been suggested to promote atherogenesis in patients with chronic kidney disease. Here we observed that plasma IgG and IgM antibodies to carbamylated epitopes were associated with IgG and IgM antibodies to oxidation-specific epitopes (ρ = 0·65-0·86, P < 0·001) in healthy adults, suggesting a cross-reaction between antibodies recognizing carbamyl-epitopes and malondialdehyde (MDA)/malondialdehyde acetaldehyde (MAA) -adducts. We used a phage display technique to clone a human Fab antibody that bound to carbamylated LDL and other carbamylated proteins. Anti-carbamyl-Fab (Fab106) cross-reacted with oxidation-specific epitopes, especially with MDA-LDL and MAA-LDL. We showed that Fab106 bound to apoptotic Jurkat cells known to contain these oxidation-specific epitopes, and the binding was competed with soluble carbamylated and MDA-/MAA-modified LDL and BSA. In addition, Fab106 was able to block the uptake of carbamyl-LDL and MDA-LDL by macrophages and stained mouse atherosclerotic lesions. The observed cross-reaction between carbamylated and MDA-/MAA-modified LDL and its contribution to enhanced atherogenesis in uraemic patients require further investigation.

Simultaneous determination of methanol, acetaldehyde, acetone, and ethanol in human blood by gas chromatography with flame ionization detection.

BACKGROUND: Methanol, acetaldehyde, acetone, and ethanol, which are commonly used as biomarkers of several diseases, in acute intoxications, and forensic settings, can be detected and quantified in biological fluids. Gas chromatography (GC)-mass spectrometry techniques are complex, require highly trained personnel and expensive materials. Gas chromatographic determinations of ethanol, methanol, and acetone have been reported in one study with suboptimal accuracy. Our objective was to improve the assessment of these compounds in human blood using GC with flame ionization detection. METHODS: An amount of 50 µl of blood was diluted with 300 µl of sterile water, 40 µl of 10% sodium tungstate, and 20 µl of 1% sulphuric acid. After centrifugation, 1 µl of the supernatant was injected into the gas chromatograph. We used a dimethylpolysiloxane capillary column of 30 m × 0.25 mm × 0.25 µm. RESULTS: We observed linear correlations from 7.5 to 240 mg/l for methanol, acetaldehyde, and acetone and from 75 to 2400 mg/l for ethanol. Precision at concentrations 15, 60, and 120 mg/l for methanol, acetaldehyde, and acetone and 150, 600, and 1200 mg/ml for ethanol were 0.8-6.9%. Ranges of accuracy were 94.7-98.9% for methanol, 91.2-97.4% for acetaldehyde, 96.1-98.7% for acetone, and 105.5-111.6% for ethanol. Limits of detection were 0.80 mg/l for methanol, 0.61 mg/l for acetaldehyde, 0.58 mg/l for acetone, and 0.53 mg/l for ethanol. CONCLUSION: This method is suitable for routine clinical and forensic practices.

Subchronic exposure to ethyl tertiary butyl ether resulting in genetic damage in Aldh2 knockout mice.

Ethyl tertiary butyl ether (ETBE) is biofuel additive recently used in Japan and some other countries. Limited evidence shows that ETBE has low toxicity. Acetaldehyde (AA), however, as one primary metabolite of ETBE, is clearly genotoxic and has been considered to be a potential carcinogen. The aim of this study was to evaluate the effects of ALDH2 gene on ETBE-induced genotoxicity and metabolism of its metabolites after inhalation exposure to ETBE. A group of wild-type (WT) and Aldh2 knockout (KO) C57BL/6 mice were exposed to 500ppm ETBE for 1-6h, and the blood concentrations of ETBE metabolites, including AA, tert-butyl alcohol and 2-methyl-1,2-propanediol, were measured. Another group of mice of WT and KO were exposed to 0, 500, 1750, or 5000ppm ETBE for 6h/day with 5 days per weeks for 13 weeks. Genotoxic effects of ETBE in these mice were measured by the alkaline comet assay, 8-hydroxyguanine DNA-glycosylase modified comet assay and micronucleus test. With short-term exposure to ETBE, the blood concentrations of all the three metabolites in KO mice were significantly higher than the corresponding concentrations of those in WT mice of both sexes. After subchronic exposure to ETBE, there was significant increase in DNA damage in a dose-dependent manner in KO male mice, while only 5000ppm exposure significantly increased DNA damage in male WT mice. Overall, there was a significant sex difference in genetic damage in both genetic types of mice. These results showed that ALDH2 is involved in the detoxification of ETBE and lack of enzyme activity may greatly increase the sensitivity to the genotoxic effects of ETBE, and male mice were more sensitive than females.

Asiatic acid from Potentilla chinensis attenuate ethanol-induced hepatic injury via suppression of oxidative stress and Kupffer cell activation.

This study examined the effect of Asiatic acid from Potentilla chinensis (AAPC) on chronic ethanol-induced hepatic injury. Rats underwent intragastric administration of ethanol (5.0­9.0 g/kg) once a day for 12 weeks. A subset of rats were also intragastrically treated with AAPC (2, 4 or 8 mg/kg) once a day. In the end, AAPC treatment significantly protected against ethanol-induced liver injury, as evidenced by the decrease in serum alanine and aspartate aminotransferases levels and the attenuation of histopathological changes in rats. Additionally, AAPC significantly decreased blood alcohol and acetaldehyde concentrations by enhancing alcohol dehydrogenase and aldehyde dehydrogenase activities. Mechanistically, studies showed that AAPC remarkably alleviated the formations of malondialdehyde and myeloperoxidase, restored impaired antioxidants, including superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, and inhibited cytochrome P450 (CYP)2E1 activity. Moreover, the over-expression of cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), the elevated plasma endotoxin level and the up-regulated Toll-like receptor 4 (TLR4), CD14 and myeloid differentiation factor 88 (MyD88) as well as nuclear factor-κB were also suppressed by AAPC in ethanol-intoxicated rats. In conclusion, the protective effect of AAPC on ethanol-induced hepatotoxicity was mainly due to its ability to attenuate oxidative stress and inhibit Kupffer cell activation by decreasing the level of plasma endotoxin and the expression of TLR4, CD14 and MyD88.

Analysis of N(ε) -ethyllysine in human plasma proteins by gas chromatography-negative ion chemical ionization/mass spectrometry as a biomarker for exposure to acetaldehyde and alcohol.

BACKGROUND: N(ε) -ethyllysine (NEL) is a major stable adduct formed by the reaction of acetaldehyde (AA) with lysine residues in proteins. However, its occurrence and levels in biological specimens and its relationship with AA/alcohol exposure-associated disorders have not been fully elucidated. In this study, we have developed a sensitive and specific method to quantitate NEL levels in human plasma proteins. METHODS: The method consists of (1) purification of the protein fraction of interest by Sephadex G-15 to remove low molecular substances, (2) hydrolysis of proteins with Pronase E in the presence of stable isotope-labeled internal standards, (3) derivatization of amino acids with pentafluorobenzyl (PFB) bromide, and (4) quantification of the PFB derivatives of NEL and l-lysine using gas chromatography-negative ion chemical ionization/mass spectrometry in a selected ion monitoring mode. RESULTS: Using the above method, the NEL levels in human plasma proteins obtained from 10 each of control subjects and alcoholic patients were measured. NEL was detected in all samples analyzed, the average level of NEL in the plasma proteins of alcoholic patients (1.17 ± 0.36 NEL/1,000 l-lysine) being significantly higher than that of control subjects (0.26 ± 0.07 NEL/1,000 l-lysine). CONCLUSIONS: The method could be applied to molecular epidemiological studies to investigate possible associations between the NEL levels in human tissue proteins and human diseases associated with exposure to AA and alcohol.

Reduction of ethanol consumption in alcohol-preferring rats by dual expression gene transfer.

AIMS: To mimic, in an animal model of alcoholism, the protective phenotype against alcohol consumption observed in humans carrying a fast alcohol dehydrogenase (ADH1B*2) and an inactive aldehyde dehydrogenase (ALDH2*2). METHODS: We developed a multiple expression cassette adenoviral vector (AdV-ADH/asALDH2) encoding both a fast rat ADH and an antisense RNA against rat ALDH2. A control adenoviral vector (AdV-C) containing intronic non-coding DNA was also developed. These adenoviral vectors were administered intravenously to rats bred as high alcohol-drinkers (University of Chile bibulous) that were previously rendered alcohol dependent by a 75-day period of voluntary 10% ethanol intake. RESULTS: Animals administered AdV-ADH/asALDH2 showed a 176% increase in liver ADH activity, whereas liver ALDH2 activity was reduced by 24%, and upon the administration of a dose of ethanol (1 g/kg, i.p.), these showed arterial acetaldehyde levels that were 400% higher than those of animals administered AdV-C. Rats that received the AdV-ADH/asALDH2 vector reduced by 60% their voluntary ethanol intake versus controls. CONCLUSION: This study provides evidence that the simultaneous increase of liver ADH and a reduction of ALDH activity by gene transfer could constitute a potential therapeutic strategy for the treatment of alcoholism.

An optimized method for the measurement of acetaldehyde by high-performance liquid chromatography.

BACKGROUND: Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC). METHODS: We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood, and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent, time, and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DNP) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison with AcH-DNP standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol. RESULTS: Derivatization of acetaldehyde was performed at pH 4.0 with an 80-fold molar excess of DNPH. The reaction was completed in 40 minutes at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-minute chromatography program. Acetaldehyde detection was linear up to 80 µM. The recovery of acetaldehyde was >88% in culture media and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 µM. The accuracy of the method was <9% for intraday and <15% for interday measurements, in small volume (70 µl) plasma sampling. CONCLUSIONS: An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small-volume sampling of culture media and biological fluids.

Alcohol consumption and the risk of breast cancer

Epidemiologic studies addressing the association of alcohol consumption with breast cancer consistently suggest a modest association and a dose-response relationship. The epidemiologic evidence does not point to a single mechanism to explain the association, and several mechanisms have been proposed. Alcohol consumption is shown to increase levels of endogenous estrogens, known risk factors for breast cancer. This hypothesis is further supported by data showing that the alcohol-breast cancer association is limited to women with estrogen-receptor positive tumors. Products of alcohol metabolism are known to be toxic and are hypothesized to cause DNA modifications that lead to cancer. Recent research has focused on genes that influence the rate of alcohol metabolism, with genes that raise blood concentrations of acetaldehyde hypothesized to heighten breast cancer risk. Mounting evidence suggests that antioxidant intake(e.g.folate)mayreducealcohol-associatedbreast cancer risk, because it neutralizes reactive oxygen species, a second-stage product of alcohol metabolism. Diets lacking sufficient antioxidant intake, as a result, may further elevate the risk of breast cancer among alcohol consumers. Given that alcohol consumption is increasing worldwide and especially among women in countries of rapid economic growth, a greater understanding of the mechanisms underlying the known alcohol-breast cancer association is warranted.Avoiding overconsumption of alcohol is recommended, especially for women with known risk factors for breast cancer.

Diversos estudios epidemiológicos muestran la asociación del consumo de alcohol con el cáncer de mama de forma consistente, lo que sugiere una modesta asociación, y una relación de dosis-respuesta.La evidencia no apunta a un mecanismo único para explicar la asociación y varios mecanismos han sido propuestos. El consumo de alcohol incrementa los niveles endógenos de estrógeno, un riesgo conocido para cáncer de mama. Esta hipótesis es apoyada por información que muestra que la asociación entre el alcohol y el cáncer de mama está limitada a mujeres con tumores con receptores positivos de estrógeno. Es conocido que los derivados de la metabolización del alcohol son tóxicos, y se ha pensado que causan modificaciones en el DNA que llevan al cáncer. La investigación reciente se ha enfocado en genes que influencian la velocidad con la que se metaboliza el alcohol, y elevan las concentraciones de acetaldehído que se piensa puede aumentar el riesgo de cáncer de mama. La evidencia actual sugiere que la ingesta de antioxidantes (e.g. folato) puede reducirelriesgode cáncer asociadoalalcohol,porque neutraliza las especies reactivas de oxígeno, un producto de la segunda etapa del metabolismo del alcohol. Las dietas con ingesta insuficiente de antioxidantes,como resultado de esto, pueden elevar el riesgo de cáncer entre los consumidores de alcohol.Dado que el consumo de alcohol está incrementando en todo el mundo, especialmente en mujeres de países con rápido crecimiento económico, un mejor entendimiento de los mecanismos subyacentes a la asociación del cáncer de mama y el alcohol es necesario. Evitar el consumo excesivo es recomendado, especialmente para mujeres con factores de riesgo conocidos para cáncer de mama.