Metabolite Of Ethanol Research Articles

Development and validation of LCMS method for determination of Ethyl Glucuronide (EtG) in urine

BackgroundEthyl glucuronide (EtG) is a phase II metabolite of ethanol and is an upcoming biomarker for recent alcohol intake. Monitoring of alcohol intake in case of alcohol-dependent syndrome is very useful for early intervention and preventing harmful effects. EtG has also been identified as a very useful marker in differentiating antemortem ingestion of alcohol from postmortem production of alcohol. This study was undertaken with an objective of developing a sensitive and specific method for determination of EtG in urine. MethodsTriple quadruple Liquid Chromatography (LC)-Mass Spectrometry (MS) with Electrospray Ionization (ESI) negative mode has been used for developing the multiple reaction monitoring method by using the Polaris 3 C 18-Ether analytical column. A simple sample preparation method was adopted using the Bond Elute Plexa PAX SPE cartridge. The developed method was also tested on actual urine samples from 15 individuals after consumption of 60 and 90 ml of whiskey at different time intervals. ResultsA simple method was developed for determination of EtG in urine, with a sensitivity of 100 ppb and a recovery of 75%. Validation of the method on urine samples revealed that EtG could be detected for up to 18 h in individuals who ingested 60 ml of whiskey and up to 24 h in those who ingested 90 ml of whiskey. ConclusionThe simple method was developed for determination of EtG in urine and validated on actual urine samples. This method can now be used in aircraft accident investigation to differentiate postmortem production of alcohol, and the method is also a very useful tool to monitor Alcohol dependent Syndrome (ADS) cases.

Spinal astrocyte aldehyde dehydrogenase-2 mediates ethanol metabolism and analgesia in mice

BackgroundLittle is known about the targets in the CNS that mediate ethanol analgesia. This study explores the role of spinal astrocyte aldehyde dehydrogenase-2 (ALDH2), a key ethanol-metabolising enzyme, in the analgesic effects of ethanol in mice. MethodsAstrocyte and hepatocyte ALHD2-deficient mice were generated and tested in acute and chronic pain models. Cell-type-specific distribution of ALDH2 was analysed by RNA in situ hybridisation in spinal slices from astrocytic ALDH2-deficient mice and their wild-type littermates. Spinal ethanol metabolites and γ-aminobutyric acid (GABA) content were measured using gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. ResultsALDH2 mRNA was expressed in both astrocytes and neurones in spinal cord slices. Astrocyte ALDH2-deficient mice had decreased expression of ALDH2 mRNA in astrocytes, but not in neurones. Astrocyte ALDH2 deficiency inhibited ethanol-derived acetate, but not acetaldehyde content in spinal cord tissues. Depletion of spinal astrocyte ALDH2 selectively inhibited ethanol-induced anti-nociceptive effect, but not the effect of ethanol, on motor function. Astrocyte ALDH2 deficiency abolished ethanol-induced GABA elevation. The ethanol metabolite acetate produced anti-nociception and increased GABA synthesis in a manner similar to ethanol. I.T. delivery of either GABAA or GABAB receptor antagonists prevented ethanol and acetate-induced analgesia. ConclusionsThese findings provide evidence that ALDH2 in spinal astrocytes mediates spinal ethanol metabolism and ethanol-induced analgesic effects by promoting GABA synthesis and GABAergic transmission in spinal cord.

Study of the Fermentation Kinetics and Secondary Metabolites of Torulaspora delbrueckii Yeasts from Different Substrates

Due to global competition and consumer demand for innovative products, the brewing industry is exploiting research to create new beer products with complex aromatic profiles. Recently, interest has been focused on non-Saccharomyces yeast strains, employed in the wine sector. In this study, the capability of two Torulaspora delbrueckii strains (T.d. 291 and T.d. Prelude) on metabolizing the basic sugars of wort was investigated and compared with a S. cerevisiae strain (S.c. US-05). More specifically, the consumption of wort sugars (glucose, fructose, maltose, and their mixtures) and the production of ethanol and secondary metabolites were studied, at two fermentation temperatures (20 °C and 13 °C). From the results of the fermentation kinetics, it was concluded that both T. delbrueckii yeasts are able to metabolize all sugars, produce a satisfactory amount of ethanol and grow at either temperature, although with a faster rate at 20 °C. The volatile compounds were significantly affected by the fermentation temperature and the sugar used. Both T. delbrueckii strains demonstrated potential for use in brewing.

Effects of acetate on cerebral blood flow, systemic inflammation, and behavior in alcohol use disorder.

Alcohol use disorders (AUDs) are associated with altered regulation of physiological processes in the brain. Acetate, a metabolite of ethanol, has been implicated in several processes that are disrupted in AUDs including transcriptional regulation, metabolism, inflammation, and neurotransmission. To further understand the effects of acetate on brain function in AUDs, we investigated the effects of acetate on cerebral blood flow (CBF), systemic inflammatory cytokines, and behavior in AUD. Sixteen participants with AUD were recruited from a nonmedical, clinically managed detoxification center. Each participant received acetate and placebo in a randomly assigned order of infusion and underwent 3T MR scanning using quantitative pseudo-continuous arterial spin labeling. Participants and the study team were blinded to the infusion. CBF values (ml/100g/min) extracted from thalamus were compared between placebo and acetate using a mixed effect linear regression model accounting for infusion order. Voxel-wise CBF comparisons were set at threshold of p<0.05 cluster-corrected for multiple comparisons, voxel-level p<0.0001. Plasma cytokine levels and behavior were also assessed between infusions. Fifteen men and 1 woman were enrolled with Alcohol Use Disorders Identification Test (AUDIT) scores between 13 and 38 with a mean of 28.3±9.1. Compared to placebo, acetate administration increased CBF in the thalamus bilaterally (Left: 51.2 vs. 68.8, p<0.001; Right: 53.7 vs. 69.6, p=0.001), as well as the cerebellum, brainstem, and cortex. Older age and higher AUDIT scores were associated with increases in acetate-induced thalamic blood flow. Cytokine levels and behavioral measures did not differ between placebo and acetate infusions. This pilot study in AUD suggests that during the first week of abstinence from alcohol, the brain's response to acetate differs by brain region and this response may be associated with the severity of alcohol dependence.

Phosphatidylethanol in whole blood of rhesus monkeys correlates with ethanol consumption.

Phosphatidylethanol (PEth) homologs are ethanol metabolites used to identify and monitor alcohol drinking in humans. In this study, we measured levels of the 2 most abundant homologs, PEth 16:0/18:1 and PEth 16:0/18:2, in whole blood samples from rhesus macaque monkeys that drank ethanol daily ad libitum to assess the relationship between PEth levels and recent ethanol exposure in this animal model. Blood samples were obtained from The Monkey Alcohol Tissue Research Resource. The monkeys were first induced to consume 4% (w/v) ethanol in water from a panel attached to their home cage. Then, monkeys were allowed to drink ethanol and water ad libitum 22h daily for 12months and the daily amount of ethanol each monkey consumed was measured. Whole, uncoagulated blood was collected from each animal at the end of the entire experimental procedure. PEth 16:0/18:1 and PEth 16:0/18:2 levels were analyzed by HPLC with tandem mass spectrometry, and the ethanol consumed during the preceding 14days was measured. Combined PEth was the sum of the concentrations of both homologs. Our results show that (1) PEth accumulates in the blood of rhesus monkeys after ethanol consumption; (2) PEth homolog levels were correlated with the daily average ethanol intake during the 14-day period immediately preceding blood collection; (3) the application of established human PEth 16:0/18:1 cutoff concentrations indicative of light social or no ethanol consumption (<20ng/ml), moderate ethanol consumption (≥ 20 and < 200ng/ml) and heavy ethanol consumption (≥ 200ng/ml) predicted significantly different ethanol intake in these animals. PEth homologs were not detected in ethanol-naïve controls. This study confirms that PEth is a sensitive biomarker for ethanol consumption in rhesus macaque monkeys. This nonhuman primate model may prove useful in evaluating sources of variability previously shown to exist between ethanol consumption and PEth homolog levels among humans.

Brain ethanol metabolism by astrocytic ALDH2 drives the behavioural effects of ethanol intoxication.

Alcohol is among the most widely used psychoactive substances worldwide. Ethanol metabolites such as acetate, thought to be primarily the result of ethanol breakdown by hepatic aldehyde dehydrogenase 2 (ALDH2), contribute to alcohol's behavioural effects and alcoholism. Here, we show that ALDH2 is expressed in astrocytes in the mouse cerebellum and that ethanol metabolism by astrocytic ALDH2 mediates behavioural effects associated with ethanol intoxication. We show that ALDH2 is expressed in astrocytes in specific brain regions and that astrocytic, but not hepatocytic, ALDH2 is required to produce ethanol-derived acetate in the mouse cerebellum. Cerebellar astrocytic ALDH2 mediates low-dose ethanol-induced elevation of GABA levels, enhancement of tonic inhibition and impairment of balance and coordination skills. Thus, astrocytic ALDH2 controls the production, cellular and behavioural effects of alcohol metabolites in a brain-region-specific manner. Our data indicate that astrocytic ALDH2 is an important, but previously under-recognized, target in the brain to alter alcohol pharmacokinetics and potentially treat alcohol use disorder.

Lycopene Inhibits Oxidative Stress-Mediated Inflammatory Responses in Ethanol/Palmitoleic Acid-Stimulated Pancreatic Acinar AR42J Cells.

High alcohol intake results in the accumulation of non-oxidative ethanol metabolites such as fatty acid ethyl esters (FAEEs) in the pancreas. High FAEE concentrations mediate pancreatic acinar cell injury and are associated with alcoholic pancreatitis. Treatment with ethanol and the fatty acid palmitoleic acid (EtOH/POA) increased the levels of palmitoleic acid ethyl ester and induced zymogen activation and cytokine expression in pancreatic acinar cells. EtOH/POA induces nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mediated reactive oxygen species (ROS) production and pancreatic acinar cell injury. Lycopene, a bright-red carotenoid, is a potent antioxidant due to its high number of conjugated double bands. This study aimed to investigate whether lycopene inhibits the EtOH/POA-induced increase in ROS production, zymogen activation, and expression of the inflammatory cytokine IL-6 in EtOH/POA-stimulated pancreatic acinar AR42J cells. EtOH/POA increased the ROS levels, NADPH oxidase and NF-κB activities, zymogen activation, IL-6 expression, and mitochondrial dysfunction, which were inhibited by lycopene. The antioxidant N-acetylcysteine and NADPH oxidase 1 inhibitor ML171 suppressed the EtOH/POA-induced increases in ROS production, NF-κB activation, zymogen activation, and IL-6 expression. Therefore, lycopene inhibits EtOH/POA-induced mitochondrial dysfunction, zymogen activation, and IL-6 expression by suppressing NADPH oxidase-mediated ROS production in pancreatic acinar cells.

Clearing up the Confusion: What to Do with Ethanol and Ethanol Metabolites in Urine Drug Screens.

Clearing up the Confusion: What to Do with Ethanol and Ethanol Metabolites in Urine Drug Screens.

Inflammatory response of ethanol and its metabolites in human primary bronchial epithelial cells pre-stimulated with LPS

Previous in vitro studies have shown that ethanol metabolites directly causes toxicity to the respiratory tract including alveolar macrophages and primary airway smooth muscle cells. We hypothesize that oxidative and non-oxidative metabolites of ethanol would influence cytokine secretion and cellular metabolism to a greater degree than would EtOH alone in human bronchial epithelial cells (hBEC).

Clinical usefulness of a urine dipstick to detect ethyl glucuronide (EtG): A quantitative clinical study in healthy young female volunteers.

The metabolite of ethanol, ethyl glucuronide (EtG), reflects alcohol intake longer than ethanol and is used as a biomarker in clinical settings to detect alcohol use. We aimed to assess the clinical usefulness in a low-to-moderate alcohol intake setting and validate a new urine EtG dipstick. A three-way, open, cross-over trial was conducted. Data were collected from January to June 2019. Among 12 healthy female volunteers, we quantified urine EtG and used a dipstick following intake of either one, two or four units of alcohol. Main outcomes were concentrations of EtG in urine and serum, and creatinine and ethanol in serum. EtG in urine was determined dichotomously by dipsticks at two different thresholds and by mass spectrometry used as gold standard. EtG in urine was quantifiable up to 24hours after alcohol intake. In some individual cases, EtG was quantifiable up to 72hours at low concentrations. The dipstick detected EtG in urine up to 24hours. At thresholds of 1000 and 1500ng/mL, the dipsticks had a specificity of 100% (both), while sensitivity was 84% and 69%, respectively. The sensitivity of the dipsticks was insufficient to support a screening purpose in this setting of low-to-moderate alcohol intake.

Investigation of Fermentation Regimes for the Production of Low-alcohol and Non-alcohol Beers

The combination of modified mashing method and arrested fermentation for the production of low-alcohol and non-alcohol beers was studied. Therefore, five regimes for fermentation of wort with reduced fermentable sugar content with top-fermenting yeast strain at low temperatures and pitching rates were investigated. According to the fermentation dynamic results the decrease in the fermentation temperature from 10 °C to 5 °C at pitching rate of 109 Colony Forming Units cm−3 ( CFU cm−3 ) led to significantly reduced concentrations of ethanol and secondary metabolites in beer. The temperature decrease from 10 °C to 7 °C at pitching rate of 107 CFU cm−3 resulted in a decrease in the alcohol concentration and increase in all the secondary metabolite concentrations except for the vicinal diketones concentration. Data show that yeast biomass does not grow at 5 °C and at inoculum concentration of 107 CFU cm−3, which makes fermentation impossible. Fermentation kinetics using Monod's model supplemented with product inhibition was also investigated. Up to 1.7 % of alcohol accumulates in the beer in some of the variants within 7 days. At low fermentation temperatures, yeast biomass utilizes part of the substrate to maintain its vital activity under stress fermentation conditions, which leads to a reduction in the amount of alcohol synthesized. The synthesis and reduction of the secondary metabolites was delayed compared to conventional beer fermentation. The sensory evaluation of the beers produced showed that the most appealing beer was the one produced at 10 °C and pitching rate of 109 CFU cm−3.

The ethanol metabolite acetic acid activates mouse nucleus accumbens shell medium spiny neurons.

Although ethanol consumption leads to an array of neurophysiological alterations involving the neural circuits for reward, the underlying mechanisms remain unclear. Acetic acid is a major metabolite of ethanol with high bioactivity and potentially significant pharmacological importance in regulating brain function. Yet, the impact of acetic acid on reward circuit function has not been well explored. Given the rewarding properties associated with ethanol consumption, we investigated the acute effects of ethanol and/or acetic acid on the neurophysiological function of medium spiny neurons of the nucleus accumbens shell, a key node in the mammalian reward circuit. We find that acetic acid, but not ethanol, provided a rapid and robust boost in neuronal excitability at physiologically relevant concentrations, whereas both compounds enhanced glutamatergic synaptic activity. These effects were consistent across both sexes in C57BL/6J mice. Overall, our data suggest acetic acid is a promising candidate mediator for ethanol effects on mood and motivation that deserves further investigation.NEW & NOTEWORTHY Ethanol consumption disrupts many neurophysiological processes leading to alterations in behavior and physiological function. The possible involvement of acetic acid, produced via ethanol metabolism, has been insufficiently explored. Here, we demonstrate that acetic acid contributes to rapid neurophysiological alterations in the accumbens shell. These findings raise the interesting possibility that ethanol may serve as a prodrug-generating acetic acid as a metabolite-that may influence ethanol consumption-associated behaviors and physiological responses by altering neurophysiological function.

Rutin inhibits DRP1-mediated mitochondrial fission and prevents ethanol-induced hepatotoxicity in HepG2 cells and zebrafish

ABSTRACT Excessive alcohol consumption causes the cellular and tissue damage. The toxic metabolites of ethanol are harmful to multiple organ systems, such as the central nervous system, skeletal muscles, and liver, and cause alcohol-induced diseases like cancer, as well as induce hepatotoxicity, and alcoholic myopathy. Alcohol exposure leads to a surge in hepatic alcohol metabolism and oxygen consumption, a decrease in hepatic ATP, and the rapid accumulation of lipid within hepatocytes. Several pathologies are closely linked to defective mitochondrial dynamics triggered by abnormal mitochondrial function and cellular homeostasis, raising the possibility that novel drugs targeting mitochondrial dynamics may have therapeutic potential in restoring cellular homeostasis in ethanol-induced hepatotoxicity. Rutin is a phytochemical polyphenol known to protect cells from cytotoxic chemicals. We investigated the effects of rutin on mitochondrial dynamics induced by ethanol. We found that rutin enhances mitochondrial dynamics by suppressing mitochondrial fission and restoring the balance of the mitochondrial dynamics. Mitochondrial elongation following rutin treatment of ethanol exposed cells was accompanied by reduced DRP1 expression. These data suggest that rutin plays an important role in remodeling of mitochondrial dynamics to alleviate hepatic steatosis and enhance mitochondrial function and cell viability.

Estimates of Non-Alcoholic Food-Derived Ethanol and Methanol Exposure in Human.

Food-derived alcohol is almost not in question due to its low concentration. Nevertheless, could it pose a problem for some risk groups and forensic cases? To answer this, we aimed to simultaneously evaluate ethanol and methanol ingredients of a variety of non-alcoholic foods in two different countries and estimate their possible health and forensic consequences. Alcohols in foods were analysed by headspace gas chromatography (HS-GC). Human average acute daily food consumptions and food-derived blood alcohol concentrations (BAC) were determined by using the data of the EFSA Nutrition Survey. Methanol and ethanol ingredients of similar foods varied between the two cities. Most foods produce higher methanol concentrations than the Maximum Allowable Dose Level (23 mg). Especially fruit juices lead to the critical level of ethanol for children (6.0 mg/kg bw). Based on the results, adult daily intake of selected food groups does not bear ethanol that exceeds the legal limit of BAC or the limit not allowed by the religious and does not lead to acute alcohol toxicity. But these low levels of ethanol and methanol consumed via non-alcoholic foods for life can raise the vulnerability to chronic health problems (cancer, liver cirrhosis, Alzheimer's disease, autism, ocular toxicity, alterations in fetal development), and may lead to positive ethanol metabolite results (e. g. Ethyl glucuronide) when a low cut-off level is used. Therefore, studies on the alcohol contents of various natural and processed non-alcoholic foods along with their effects on humans, and new regulations on labeling the food products and conscious food consumption are in particular importance. It would also be important to consider unintentional alcohol consumption via non-alcoholic foods in the evaluation of clinical and forensic cases.

Fatty acid ethyl esters in meconium and substance use in adolescence

Prenatal alcohol exposure (PAE) continues to be a serious public health problem, yet no reliable clinical tools are available for assessing levels of drinking during pregnancy. Fatty acid ethyl esters (FAEEs), the nonoxidative metabolites of ethanol measured in meconium, are potential biomarkers to quantify the level of PAE. The association between the concentrations of FAEEs from meconium and adolescent substance use and related problems was examined in a prospective birth-cohort of adolescents exposed to alcohol and drugs in utero. FAEEs were quantified with gas chromatography via a flame ionization detector. Meconium was analyzed for FAEEs in 216 newborns; 183 of them (81 boys, 102 girls) were assessed at age 15 for alcohol, tobacco, and marijuana use using biologic assays and self-report. Substance use problems were assessed using the Problem Oriented Screening Instrument for Teenagers. Findings from multivariable logistic regression analyses indicated that, after controlling for other prenatal drug exposure and covariates, higher concentrations of FAEEs (ethyl myristate, ethyl palmitate, ethyl oleate, ethyl linoleate, ethyl linolenate, and ethyl arachidonate) were related to a greater likelihood of marijuana use and experiencing substance use problems, but not tobacco or alcohol use, at age 15. Elevated levels of FAEEs in meconium may be promising markers for PAE, identifying newborns at risk for early substance use and developing substance use problems.

Ethyl Glucuronide and Ethyl Sulphate in Urine: Caution in their use as markers of recent alcohol use.

To clarify the role of the ethanol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS), in monitoring alcohol consumption. We recruited 7 female and 17 male volunteers who were instructed to consume a quantity of beer (containing 48 gm ethanol) with food in one session. We examined urinary excretion of EtG and EtS over time and looked for correlations between the concentrations of the metabolites EtG and EtS. EtG concentrations in urine varied between 0.026 and 430.372μg/ml with average values between 11.85μg/ml (SD 19.75), 30min after alcohol intake, and 100.39μg/ml (SD 101.34), 4.5h after alcohol intake. EtS urinary concentration ranged from 0.006 to 101.432μg/ml with average values between 4.77μg/ml (SD 5.42), 30min after alcohol intake, and 30.14μg/ml (SD 27.20), 4.5h after alcohol intake. Spearman's test showed that urinary EtG and EtS correlated significantly at several time points. The great interindividual variability in their excretion suggests caution in the use of urinary measurement of these metabolites in forensic investigations.

Ethyl glucuronide and ethanol concentrations in femoral blood, urine and vitreous humor from 117 autopsy cases

BackgroundVitreous humor (VH) is a specimen of great value in forensic investigations and is being used for evaluating possible post-mortem formation of ethanol. Ethyl glucuronide (EtG) is an ethanol metabolite that has found interest for the same purpose. Both compounds can be measured in VH and because of differences in rate of distribution and elimination they may offer complementary information. MethodsVH, femoral blood (FB) and urine were collected from 117 autopsy cases for forensic investigation. Ethanol was measured with headspace gas chromatography, while EtG was measured with liquid chromatography – tandem mass spectrometry. Results and conclusionEthanol was detected in all matrices in 39 cases, while EtG was present in 62 cases. The VH-FB and the VH-urine ethanol concentrations in the 39 cases were statistically correlated (p < 0.00001). In one case with an ethanol concentration of 0.11 g/L in FB, no ethanol was detected in VH and urine, and no EtG in any specimen, indicating a possible post-mortem formation. EtG was present in VH in more cases than in FB and urine. The correlation between the EtG concentrations in VH and FB was statistically significant (p < 0.0003) as was the case also for VH and urine (p < 0.001). The combined information on ethanol and EtG concentrations in the three matrices can be used to interpret alcohol drinking habit before death. This study confirms the value of using VH as a specimen in forensic investigations regarding recent exposure to ethanol. EtG can be used not only for investigating post-mortem ethanol formation but also for estimating recent alcohol drinking.

Effect of silibinin on ethanol- or acetaldehyde-induced damge of mouse primary hepatocytes in vitro

Silibinin, one of the flavonoids isolated from milk thistle seeds of Silybum marianum, has hepatoprotective properties against toxins in clinical. However, the detailed mechanisms have remained unclear. This study investigates the underlying mechanism of silibinin in the protection against ethanol- or acetaldehyde-induced damage of neonatal mouse primary hepatocytes in vitro. The results show that ethanol inhibited proliferation of hepatocytes in a time (12, 24, 36 h) and dose-dependent (0–800 mM) manner. However, silibinin did not show protective effect on ethanol (500 mM)-induced suppression of hepatocyte proliferation. Acetaldehyde, the toxic metabolite of ethanol, appearing immediately in individuals after drink also inhibited the proliferation of hepatocytes in a dose-dependent (0–12 mM) manner. Surprisingly, silibinin significantly increased the cell viability and reduced the leakage of alanine amino transferase (ALT) and aspartate amino transferase (AST) in acetaldehyde-treated hepatocytes, suggesting that silibinin protected cell injury caused by acetaldehyde treatment. The apoptosis-inducing effect of acetaldehyde was demonstrated by the increased number of cells in sub-G1 phase as well as caspase-3 activation. Further study shows that acetaldehyde induced autophagy in the hepatocytes. The autophagy inhibitors, 3-Methyladenine (3-MA) and chloroquine (CQ), further decreased the viability of cells treated with acetaldehyde, suggesting that autophagy plays a protective role against apoptosis. Consistently, silibinin (20 μM) significantly reduced the activation of caspase 3 or apoptosis and increased the conversion of LC3-I to LC3-II or autophagy. Taken together, it is concluded that silibinin does not repress the ethanol- induced hepatocyte injury, whereas silibinin reduces acetaldehyde-caused hepatocyte injury through down-regulation of apoptosis and up-regulation of autophagy.

The Effect of Ethanol Consumption on Composition and Morphology of Femur Cortical Bone in Wild-Type and ALDH2*2-Homozygous Mice.

ALDH2 inactivating mutation (ALDH2*2) is the most abundant mutation leading to bone morphological aberration. Osteoporosis has long been associated with changes in bone biomaterial in elderly populations. Such changes can be exacerbated with elevated ethanol consumption and in subjects with impaired ethanol metabolism, such as carriers of aldehyde dehydrogenase 2 (ALDH2)-deficient gene, ALDH2*2. So far, little is known about bone compositional changes besides a decrease in mineralization. Raman spectroscopic imaging has been utilized to study the changes in overall composition of C57BL/6 female femur bone sections, as well as in compound spatial distribution. Raman maps of bone sections were analyzed using multilinear regression with these four isolated components, resulting in maps of their relative distribution. A 15-week treatment of both wild-type (WT) and ALDH2*2/*2 mice with 20% ethanol in the drinking water resulted in a significantly lower mineral content (p < 0.05) in the bones. There was no significant change in mineral and collagen content due to the mutation alone (p > 0.4). Highly localized islets of elongated adipose tissue were observed on most maps. Elevated fat content was found in ALDH2*2 knock-in mice consuming ethanol (p < 0.0001) and this effect appeared cumulative. This work conclusively demonstrates that that osteocytes in femurs of older female mice accumulate fat, as has been previously theorized, and that fat accumulation is likely modulated by levels of acetaldehyde, the ethanol metabolite.

Does Eumelanin Oxidation Play a Role on the Photostability of Ethyl Glucuronide in Hair Exposed to Simulated Solar Radiation?

The action of solar radiation on the concentration of the ethanol metabolite ethyl glucuronide (EtG) in 40 hair samples of nonabstinent subjects was investigated. Hair samples of different colors were analyzed before and after irradiation with artificial sunlight under a light dose corresponding to 3 months of sun exposure. After irradiation, an increase of EtG concentration was detected in 55% of the samples ranging from 5% to 141%. In 16 cases, a concentration reduction ranging from -2% to -74% was observed. The measure of the level of pyrrole-2,3,5-tricarboxylic acid (PTCA), a marker of eumelanin oxidation, demonstrated the largest increase in oxidation in light brown hair where the greatest degradation of EtG was observed after irradiation. However, the rise of PTCA in all hair tested was accompanied by increase in EtG concentration in 8/10 samples and by decrease in 2/10, suggesting no correlation between the two markers. To verify if hair structure was modified by light, scanning electron microscopy (SEM) analysis was performed on irradiated hair of different colors and compared with the dark samples. SEM revealed modification of hair structure in all samples showing partial shaft exfoliation and reduction of hair thickness under the treatment with solar radiation.