Inhibitor Of Alcohol Dehydrogenase Research Articles

Abstracts of the Toxicology and Poisons Network Australasia (TAPNA) 2024 Annual Scientific Meeting (Melbourne, Victoria).

Background Toxic alcohol poisoning is uncommon in New South Wales (NSW). Inadequate treatment causes significant morbidity and mortality. Management priorities are diagnosis, and early treatment with alcohol dehydrogenase (ADH) blockade and extracorporeal treatments (ECTRs). Fomepizole is a potent ADH inhibitor available in Australia but its use and role, compared to ethanol, is uncertain. We describe the epidemiology, management and outcomes of suspected significant toxic alcohol poisonings in NSW. Methods We searched databases of the NSW Poisons Information Centre, five tertiary clinical toxicology services and Statewide retrieval services. We included all patients with known or suspected toxic alcohol poisoning referred to a clinical toxicologist and included all patients who received treatment with ADH blockade. Patients were subdivided on the basis of whether toxic alcohol poisoning was confirmed or excluded. Data extracted included demographics, details of the exposure, management (including treatment delays and monitoring of ethanol therapy (if received), outcomes and complications). Categorical data were described as frequencies and percentages, and continuous data were described as median and interquartile ranges. Results Among 198 patients between 2015 and 2023, 36 fulfilled inclusion criteria. Toxic alcohols ingested included ethylene glycol (29), diethylene glycol (5), and methanol (1); 12 co-ingested ethanol. Toxic alcohol poisoning was confirmed by history or specific assays in 35 cases. Delay to presentation was median 3 h (IQR 2–9; 20). Delay from hospital presentation to initiating ADH blockade was median 3 h (IQR 2–7; 27). Three were diagnosed after developing unexplained AKI. Four patients received fomepizole and 27 received ethanol therapy. In the 20 patients who received ethanol for ≥24 h, blood ethanol concentrations were measured median 5.5 times (IQR 4-11) in the first 24 h, and 9 had at least 2 subtherapeutic levels. 21 patients received ECTR, which was initiated within median 7 h (IQR 4-11). Excluding 3 patients who did not receive treatment due to delayed diagnosis, 18 developed complications (acute kidney injury 16, neurotoxicity 8, death 3). In 18 ethanol-treated patients, fomepizole would have offered key advantages, including avoiding ICU (9), facilitating transport (7), and delaying and/or foregoing ECTR (6). Discussion There are potential benefits of fomepizole use in NSW.

Computational identification of potential bioactive compounds from Triphala against alcoholic liver injury by targeting alcohol dehydrogenase.

Alcoholic liver injury resulting from excessive alcohol consumption is a significant social concern. Alcohol dehydrogenase (ADH) plays a critical role in the conversion of alcohol to acetaldehyde, leading to tissue damage. The management of alcoholic liver injury encompasses nutritional support and, in severe cases liver transplantation, but potential adverse effects exist, and effective medications are currently unavailable. Natural products with their potential benefits and historical use in traditional medicine emerge as promising alternatives. Triphala, a traditional polyherbal formula demonstrates beneficial effects in addressing diverse health concerns, with a notable impact on treating alcoholic liver damage through enhanced liver metabolism. The present study aims to identify potential active phytocompounds in Triphala targeting ADH to prevent alcoholic liver injury. Screening 119 phytocompounds from the Triphala formulation revealed 62 of them showing binding affinity to the active site of the ADH1B protein. Promising lipid-like molecule from Terminalia bellirica, (4aS, 6aR, 6aR, 6bR, 7R, 8aR, 9R, 10R, 11R, 12aR, 14bS)-7, 10, 11-trihydroxy-9-(hydroxymethyl)-2, 2, 6a, 6b, 9, 12a-hexamethyl-1, 3, 4, 5, 6, 6a, 7, 8, 8a, 10, 11, 12, 13, 14b-tetradecahydropicene-4a-carboxylic acid showed high binding efficiency to a competitive ADH inhibitor, 4-Methylpyrazole. Pharmacokinetic analysis further confirmed the drug-likeness and non-hepatotoxicity of the top-ranked compound. Molecular dynamics simulation and MM-PBSA studies revealed the stability of the docked complexes with minimal fluctuation and consistency of the hydrogen bonds throughout the simulation. Together, computational investigations suggest that (4aS, 6aR, 6aR, 6bR, 7R, 8aR, 9R, 10R, 11R, 12aR, 14bS)-7, 10, 11-trihydroxy-9-(hydroxymethyl)-2, 2, 6a, 6b, 9, 12a-hexamethyl-1, 3, 4, 5, 6, 6a, 7, 8, 8a, 10, 11, 12, 13, 14b-tetradecahydropicene-4a-carboxylic acid from the Triphala formulation holds promise as an ADH inhibitor, suggesting an alternative therapy for alcoholic liver injury.

Transcriptome Study of Bursaphelenchus xylophilus Treated with Fomepizole Reveals a Serine/Threonine-Protein Phosphatase Gene that Is Substantially Linked with Vitality and Pathogenicity.

Bursaphelenchus xylophilus, the pine wood nematode (PWN), is the causal agent of pine wilt disease (PWD), which causes enormous economic loss annually. According to our previous research, fomepizole, as a selective inhibitor of PWN alcohol dehydrogenase (ADH), has the potential to be a preferable lead compound for developing novel nematicides. However, the underlying molecular mechanism is still unclear. The result of molecular docking showed that the stronger interactions between fomepizole and PWN ADH at the active site of ADH were attributed to hydrogen bonds. Low-dose fomepizole had a substantial negative impact on the egg hatchability, development, oviposition, and lifespan of PWN. Transcriptome analysis indicated that 2,124 upregulated genes and 490 downregulated genes in fomepizole-treated PWN were obtained. Kyoto Encyclopedia of Genes and Genomes enrichment analysis of differentially expressed genes indicated that fomepizole could be involved in controlling PWN vitality mainly by regulating key signaling pathways, such as the ribosome, hippo signaling pathway, and lysosome. Remarkably, the results of RNA interference indicated that the downregulated serine/threonine-protein phosphatase gene (stpp) could reduce the egg hatchability, development, oviposition, and lifespan of PWN, which was closely similar to the consequences of nematodes with low-dose fomepizole treatment. In addition, the silencing of stpp resulted in weakness of PWN pathogenicity, which indicated that stpp could be a potential drug target to control PWN.

Preparation of Pueraria lobata Root-Derived Exosome-Like Nanovesicles and Evaluation of Their Effects on Mitigating Alcoholic Intoxication and Promoting Alcohol Metabolism in Mice.

Pueraria lobata (P. lobata), a dual-purpose food and medicine, displays limited efficacy in alcohol detoxification and liver protection, with previous research primarily focused on puerarin in its dried roots. In this study, we investigated the potential effects and mechanisms of fresh P. lobata root-derived exosome-like nanovesicles (P-ELNs) for mitigating alcoholic intoxication, promoting alcohol metabolism effects and protecting the liver in C57BL/6J mice. We isolated P-ELNs from fresh P. lobata root using differential centrifugation and characterized them via transmission electron microscopy, nanoscale particle sizing, ζ potential analysis, and biochemical assays. In Acute Alcoholism (AAI) mice pre-treated with P-ELNs, we evaluated their effects on the timing and duration of the loss of the righting reflex (LORR), liver alcohol metabolism enzymes activity, liver and serum alcohol content, and ferroptosis-related markers. P-ELNs, enriched in proteins, lipids, and small RNAs, exhibited an ideal size (150.7 ± 82.8 nm) and negative surface charge (-31 mV). Pre-treatment with 10 mg/(kg.bw) P-ELNs in both male and female mice significantly prolonged ebriety time, shortened sobriety time, enhanced acetaldehyde dehydrogenase (ALDH) activity while concurrently inhibited alcohol dehydrogenase (ADH) activity, and reduced alcohol content in the liver and serum. Notably, P-ELNs demonstrated more efficacy compared to P-ELNs supernatant fluid (abundant puerarin content), suggesting alternative active components beyond puerarin. Additionally, P-ELNs prevented ferroptosis by inhibiting the reduction of glutathione peroxidase 4 (GPX4) and reduced glutathione (GSH), and suppressing acyl-CoA synthetase long-chain family member 4 (ACSL4) elevation, thereby mitigating pathological liver lipid accumulation. P-ELNs exhibit distinct exosomal characteristics and effectively alleviate alcoholic intoxication, improve alcohol metabolism, suppress ferroptosis, and protect the liver from alcoholic injury. Consequently, P-ELNs hold promise as a therapeutic agent for detoxification, sobriety promotion, and prevention of alcoholic liver injury.

Molecular Docking and Dynamics Study of Compounds from Combretum indicum var. B Seeds as Alcohol Dehydrogenase Inhibitors

Molecular Docking and Dynamics Study of Compounds from Combretum indicum var. B Seeds as Alcohol Dehydrogenase Inhibitors

Preparation of Alcohol Dehydrogenase-Zinc Phosphate Hybrid Nanoflowers through Biomimetic Mineralization and Its Application in the Inhibitor Screening.

A biomimetic mineralization method was used in the facile and rapid preparation of nanoflowers for immobilizing alcohol dehydrogenase (ADH). The method mainly uses ADH as an organic component and zinc phosphate as an inorganic component to prepare flower-like ADH/Zn3(PO4)2 organic-inorganic hybrid nanoflowers (HNFs) with the high specific surface area through a self-assembly process. The synthesis conditions of the ADH HNFs were optimized and its morphology was characterized. Under the optimum enzymatic reaction conditions, the Michaelis-Menten constant (Km) of ADH HNFs (β-NAD+ as substrate) was measured to be 3.54 mM, and the half-maximal inhibitory concentration (IC50) of the positive control ranitidine (0.2-0.8 mM) was determined to be 0.49 mM. Subsequently, the inhibitory activity of natural medicine Penthorum chinense Pursh and nine small-molecule compounds on ADH was evaluated using ADH HNFs. The inhibition percentage of the aqueous extract of P. chinense is 57.9%. The vanillic acid, protocatechuic acid, gallic acid, and naringenin have obvious inhibitory effects on ADH, and their percentages of inhibition are 55.1%, 68.3%, 61.9%, and 75.5%, respectively. Moreover, molecular docking analysis was applied to explore the binding modes and sites of the four most active small-molecule compounds to ADH. The results of this study can broaden the application of immobilized enzymes through biomimetic mineralization, and provide a reference for the discovery of ADH inhibitors from natural products.

Acetaldehyde via CGRP receptor and TRPA1 in Schwann cells mediates ethanol-evoked periorbital mechanical allodynia in mice: relevance for migraine

BackgroundIngestion of alcoholic beverages is a known trigger of migraine attacks. However, whether and how ethanol exerts its pro-migraine action remains poorly known. Ethanol stimulates the transient receptor potential vanilloid 1 (TRPV1) channel, and its dehydrogenized metabolite, acetaldehyde, is a known TRP ankyrin 1 (TRPA1) agonist.MethodsPeriorbital mechanical allodynia following systemic ethanol and acetaldehyde was investigated in mice after TRPA1 and TRPV1 pharmacological antagonism and global genetic deletion. Mice with selective silencing of the receptor activated modifying protein 1 (RAMP1), a component of the calcitonin gene-related peptide (CGRP) receptor, in Schwann cells or TRPA1 in dorsal root ganglion (DRG) neurons or Schwann cells, were used after systemic ethanol and acetaldehyde.ResultsWe show in mice that intragastric ethanol administration evokes a sustained periorbital mechanical allodynia that is attenuated by systemic or local alcohol dehydrogenase inhibition, and TRPA1, but not TRPV1, global deletion, thus indicating the implication of acetaldehyde. Systemic (intraperitoneal) acetaldehyde administration also evokes periorbital mechanical allodynia. Importantly, periorbital mechanical allodynia by both ethanol and acetaldehyde is abrogated by pretreatment with the CGRP receptor antagonist, olcegepant, and a selective silencing of RAMP1 in Schwann cells. Periorbital mechanical allodynia by ethanol and acetaldehyde is also attenuated by cyclic AMP, protein kinase A, and nitric oxide inhibition and pretreatment with an antioxidant. Moreover, selective genetic silencing of TRPA1 in Schwann cells or DRG neurons attenuated periorbital mechanical allodynia by ethanol or acetaldehyde.ConclusionsResults suggest that, in mice, periorbital mechanical allodynia, a response that mimics cutaneous allodynia reported during migraine attacks, is elicited by ethanol via the systemic production of acetaldehyde that, by releasing CGRP, engages the CGRP receptor in Schwann cells. The ensuing cascade of intracellular events results in a Schwann cell TRPA1-dependent oxidative stress generation that eventually targets neuronal TRPA1 to signal allodynia from the periorbital area.

Awareness raising and dealing with methanol poisoning based on effective strategies

Intoxication with methanol most commonly occurs as a consequence of ingesting, inhaling, or coming into contact with formulations that include methanol as a base. Clinical manifestations of methanol poisoning include suppression of the central nervous system, gastrointestinal symptoms, and decompensated metabolic acidosis, which is associated with impaired vision and either early or late blindness within 0.5–4 h after ingestion. After ingestion, methanol concentrations in the blood that are greater than 50 mg/dl should raise some concern. Ingested methanol is typically digested by alcohol dehydrogenase (ADH), and it is subsequently redistributed to the body's water to attain a volume distribution that is about equivalent to 0.77 L/kg. Moreover, it is removed from the body as its natural, unchanged parent molecules. Due to the fact that methanol poisoning is relatively uncommon but frequently involves a large number of victims at the same time, this type of incident occupies a special position in the field of clinical toxicology. The beginning of the COVID-19 pandemic has resulted in an increase in erroneous assumptions regarding the preventative capability of methanol in comparison to viral infection. More than 1000 Iranians fell ill, and more than 300 of them passed away in March of this year after they consumed methanol in the expectation that it would protect them from a new coronavirus. The Atlanta epidemic, which involved 323 individuals and resulted in the deaths of 41, is one example of mass poisoning. Another example is the Kristiansand outbreak, which involved 70 people and resulted in the deaths of three. In 2003, the AAPCC received reports of more than one thousand pediatric exposures. Since methanol poisoning is associated with high mortality rates, it is vital that the condition be addressed seriously and managed as quickly as feasible. The objective of this review was to raise awareness about the mechanism and metabolism of methanol toxicity, the introduction of therapeutic interventions such as gastrointestinal decontamination and methanol metabolism inhibition, the correction of metabolic disturbances, and the establishment of novel diagnostic/screening nanoparticle-based strategies for methanol poisoning such as the discovery of ADH inhibitors as well as the detection of the adulteration of alcoholic drinks by nanoparticles in order to prevent methanol poisoning. In conclusion, increasing warnings and knowledge about clinical manifestations, medical interventions, and novel strategies for methanol poisoning probably results in a decrease in the death load.

Symbiosis between Dendrobium catenatum protocorms and Serendipita indica involves the plant hypoxia response pathway.

Mycorrhizae are ubiquitous symbioses established between fungi and plant roots. Orchids, in particular, require compatible mycorrhizal fungi for seed germination and protocorm development. Unlike arbuscular mycorrhizal fungi, which have wide host ranges, orchid mycorrhizal fungi are often highly specific to their host orchids. However, the molecular mechanism of orchid mycorrhizal symbiosis is largely unknown compared to that of arbuscular mycorrhizal and rhizobial symbiosis. Here, we report that an endophytic Sebacinales fungus, Serendipita indica, promotes seed germination and the development of protocorms into plantlets in several epiphytic Epidendroideae orchid species (6 species in 2 genera), including Dendrobium catenatum, a critically endangered orchid with high medicinal value. Although plant-pathogen interaction and high meristematic activity can induce the hypoxic response in plants, it has been unclear whether interactions with beneficial fungi, especially mycorrhizal ones, also involve the hypoxic response. By studying the symbiotic relationship between D. catenatum and S. indica, we determined that hypoxia-responsive genes, such as those encoding alcohol dehydrogenase (ADH), are highly induced in symbiotic D. catenatum protocorms. In situ hybridization assay indicated that the ADH gene is predominantly expressed in the basal mycorrhizal region of symbiotic protocorms. Additionally, the ADH inhibitors puerarin and 4-methylpyrazole both decreased S. indica colonization in D. catenatum protocorms. Thus, our study reveals that S. indica is widely compatible with orchids and that ADH and its related hypoxia-responsive pathway are involved in establishing successful symbiotic relationships in germinating orchids.

Mechanical and Heat Hyperalgesia upon Withdrawal From Chronic Intermittent Ethanol Vapor Depends on Sex, Exposure Duration, and Blood Alcohol Concentration in Mice

Approximately half of patients with alcohol use disorder report pain and this can be severe during withdrawal. Many questions remain regarding the importance of biological sex, alcohol exposure paradigm, and stimulus modality to the severity of alcohol withdrawal-induced hyperalgesia. To examine the impact of sex and blood alcohol concentration on the time course of the development of mechanical and heat hyperalgesia, we characterized a mouse model of chronic alcohol withdrawal-induced pain in the presence or absence the alcohol dehydrogenase inhibitor, pyrazole. Male and female C57BL/6J mice underwent chronic intermittent ethanol vapor ± pyrazole exposure for 4 weeks, 4 d/wk to induce ethanol dependence. Hind paw sensitivity to the plantar application of mechanical (von Frey filaments) and radiant heat stimuli were measured during weekly observations at 1, 3, 5, 7, 24, and 48 hours after cessation of ethanol exposure. In the presence of pyrazole, males developed mechanical hyperalgesia after the first week of chronic intermittent ethanol vapor exposure, peaking at 48 hours after cessation of ethanol. By contrast, females did not develop mechanical hyperalgesia until the fourth week; this also required pyrazole and did not peak until 48 hours. Heat hyperalgesia was consistently observed only in females exposed to ethanol and pyrazole; this developed after the first weekly session and peaked at 1 hour. We conclude that Chronic alcohol withdrawal-induced pain develops in a sex-, time-, and blood alcohol concentration-dependent manner in C57BL/6J mice. PerspectiveAlcohol withdrawal-induced pain is a debilitating condition in individuals with AUD. Our study found mice experience alcohol withdrawal-induced pain in a sex and time course specific manor. These findings will aid in elucidating mechanisms of chronic pain and AUD and will help individuals remain abstinent from alcohol.

Effect of ADHI on hepatic stellate cell activation and liver fibrosis in mice

The relationship between alcohol dehydrogenase (ADH) and liver fibrosis has been studied, but the mechanism of ADH involvement in liver fibrosis remains unclear. The aim of the present study was to explore the role of ADHI, the classical liver ADH, in hepatic stellate cell (HSC) activation and the effect of 4-methylpyrazole (4-MP), an ADH inhibitor, on liver fibrosis induced by carbon tetrachloride (CCl4) in mice. The results showed that overexpression of ADHI significantly increases proliferation, migration, adhesion and invasion rates of HSC-T6 cells as compared with controls. When HSC-T6 cells were activated by ethanol, TGF-β1 or LPS, the expression of ADHI was elevated significantly (P < 0.05). Overexpression of ADHI significantly increased the levels of COL1A1 and α-SMA, markers of HSC activation. Moreover, the expression of COL1A1 and α-SMA was decreased significantly by transfection of ADHI siRNA (P < 0.01). In a liver fibrosis mouse model ADH activity increased significantly and was highest in the 3rd week. The activity of ADH in the liver was correlated with its activity in the serum (P < 0.05). 4-MP significantly decreased ADH activity and ameliorated liver injury, and ADH activity was positively correlated with the Ishak score of liver fibrosis. In conclusion, ADHI plays an important role in the activation of HSC, and inhibition of ADH ameliorates liver fibrosis in mice.

Protective effect of methanolic extract of Areca catechu nut on ethanol withdrawal symptoms in mice

BackgroundThe purpose of the current study was to examine the potential impact of a methanolic extract of Areca catechu nut (MAN) on handling-induced convulsions (HIC), anxiety and anhedonia behaviour of alcohol-withdrawn mice. 30 female Swiss albino mice were divided into 5 groups, each with 6 animals. Group 1 (saline withdrawal) received saline during the 3-day alcohol/saline induction phase, while the other 4 groups (alcohol withdrawal) received 20% v/v ethanol (1.25 ml/100 g body weight, i.p.; 20% v/v ethanol was made from absolute ethanol with 79.9 ml saline + 0.1 ml fomepizole, an alcohol dehydrogenase inhibitor). Day four (test day) involved studying handling-induced convulsions; open field test (OFT), elevated plus maze test (EPM), marble burying test (MBT) for anxiety; 24-h sucrose preference test (SPT) for anhedonia in mice. On the test day, Group I and II (saline withdrawal and alcohol withdrawal) received oral treatments with 1% w/v sodium carboxyl methylcellulose 1 h prior to the behavioural testing. Group III received an injection of diazepam (1 mg/kg, i.p., 30 min prior) and Group IV and V were treated with two different doses of MAN (50 and 100 mg/kg, p.o.) 1 h prior to the behavioural test.ResultsAt doses of 50 and 100 mg/kg, p.o., the Areca catechu nut methanolic extract significantly reduced handling convulsions and anxiety, and had an anti-anhedonic effect using various evaluation criteria, such as convulsion score (HIC), no. of central and peripheral line crossings (OFT), % entries and time spent in open arms (EPM), no. of marbles buried (MBT), and sucrose intake ratio (SPT) in alcohol-withdrawn mice.ConclusionIn mice undergoing alcohol withdrawal, Areca catechu nut extract (MAN) greatly lessens handling-induced convulsions, anxiety and depression symptoms.Graphical

Carbon-deuterium bonds as reporters of electric fields in solvent and protein environments.

Use of vibrational probes to measure electric fields inside proteins has illuminated the role of electrostatics in biological applications ranging from binding interactions to enzyme catalysis. While prior work focused on strongly absorbing carbonyl and nitrile probes, more recent work has begun exploring weakly absorbing carbon-hydrogen bonds, beginning with measurements of electric fields inside oxidoreductases using the vibrational Stark effect (VSE). Originally, an alcohol dehydrogenase inhibitor containing a deuterated aldehyde was used to measure the field in two directions—on carbonyl and carbon-deuterium (C-D) bonds—in the enzyme active site. Now, several more distinct cases demonstrate how C-D probes map electric fields to vibrational frequency shifts, with new implications for our understanding of the VSE. To probe the field along a different dimension in oxidoreductases, we consider singly deuterated NAD(P)H which reports fields along the hydride transfer axis and whose frequency detection is facilitated by advancements in quantum cascade laser (QCL) technology for infrared spectroscopy. Unusually, the solvatochromic shift for this C-D probe appears opposite to that observed for carbonyls and nitriles; that is, the probe blueshifts in more polar solvents. In another example, the chromophore of green fluorescent protein (GFP) with a deuterated bridge carbon demonstrates similarly unusual frequency shifts in solvent and protein environments, with stronger fields parallel to the C-D dipole causing blueshifts. Observed Stark tuning rates for these molecules are recapitulated by in silico Stark calculations at the B3LYP or ωB97X-D/6-31+G(d) level. Stark tuning rate comparison with other C-D containing molecules including deuterated aldehydes and chloroform-d indicates a large sensitivity of the Stark tuning rate to molecular structure. We demonstrate how properly calibrated C-D probes can be effective reporters of electric fields in applications such as enzyme-catalyzed hydride transfer, biological photophysics and beyond.

Role of AMPK-SREBP Signaling in Regulating Fatty Acid Binding-4 (FABP4) Expression following Ethanol Metabolism.

Fatty acid binding protein-4 (FABP4) is not normally expressed in the liver but is induced in alcohol-dependent liver disease (ALD)). This study sought to identify mechanisms whereby ethanol (EtOH) metabolism alters triglyceride accumulation and FABP4 production. Human hepatoma cells which were stably transfected to express alcohol dehydrogenase (ADH) or cytochrome P4502E1 (CYP2E1) were exposed to EtOH in the absence/presence of inhibitors of ADH (4-methylpyrazole) or CYP2E1 (chlormethiazole). Cells were analyzed for free fatty acid (FFA) content and FABP4 mRNA, then culture medium assayed for FABP4 levels. Cell lysates were analyzed for AMP-activated protein kinase-α (AMPKα), Acetyl-CoA carboxylase (ACC), sterol regulatory element binding protein-1c (SREBP-1c), and Lipin-1β activity and localization in the absence/presence of EtOH and pharmacological inhibitors. CYP2E1-EtOH metabolism led to increased FABP4 mRNA/protein expression and FFA accumulation. Analysis of signaling pathway activity revealed decreased AMPKα activation and increased nuclear-SREBP-1c localization following CYP2E1-EtOH metabolism. The role of AMPKα-SREBP-1c in regulating CYP2E1-EtOH-dependent FFA accumulation and increased FABP4 was confirmed using pharmacological inhibitors and over-expression of AMPKα. Inhibition of ACC or Lipin-1β failed to prevent FFA accumulation or changes in FABP4 mRNA expression or protein secretion. These data suggest that CYP2E1-EtOH metabolism inhibits AMPKα phosphorylation to stimulate FFA accumulation and FABP4 protein secretion via an SREBP-1c dependent mechanism.

Microbiome-derived ethanol in nonalcoholic fatty liver disease.

To test the hypothesis that the gut microbiota of individuals with nonalcoholic fatty liver disease (NAFLD) produce enough ethanol to be a driving force in the development and progression of this complex disease, we performed one prospective clinical study and one intervention study. Ethanol was measured while fasting and 120 min after a mixed meal test (MMT) in 146 individuals. In a subset of 37 individuals and in an external validation cohort, ethanol was measured in portal vein blood. In an intervention study, ten individuals with NAFLD and ten overweight but otherwise healthy controls were infused with a selective alcohol dehydrogenase (ADH) inhibitor before an MMT. When compared to fasted peripheral blood, median portal vein ethanol concentrations were 187 (interquartile range (IQR), 17-516) times higher and increased with disease progression from 2.1 mM in individuals without steatosis to 8.0 mM in NAFL 21.0 mM in nonalcoholic steatohepatitis. Inhibition of ADH induced a 15-fold (IQR,1.6- to 20-fold) increase in peripheral blood ethanol concentrations in individuals with NAFLD, although this effect was abolished after antibiotic treatment. Specifically, Lactobacillaceae correlated with postprandial peripheral ethanol concentrations (Spearman's rho, 0.42; P &lt; 10^-5) in the prospective study. Our data show that the first-pass effect obscures the levels of endogenous ethanol production, suggesting that microbial ethanol could be considered in the pathogenesis of this highly prevalent liver disease.

Inhibition mechanism of baicalein against alcohol dehydrogenase in vitro via biological techniques, spectroscopy and computer simulation

• Baicalein entered coenzyme cavity spontaneously to form a stable complex. • Activity of ADH was inhibited by baicalein in a non-competitive mechanism. • Baicalein altered the secondary structure of ADH and induced functional variation. • Decreased ASA of amino acid residues was the reason for fluorescence quenching. • Hydrogen bonds had been attested to be the vital forces for binary complex. Baicalein is a dietary flavonoid with extensive biological activity. Alcohol dehydrogenase (ADH) is one of the pivotal enzymes for alcohol metabolism. This research intends to investigate the mechanism of inhibition of ADH by baicalein and evaluate their structure–activity relationship. Baicalein inhibited ADH activity in a non-competitive manner. The fluorescence intensity of ADH decreased because of the formation of ADH-baicalein complex. Hydrogen bonds and van der Waals forces were the main acting forces in stabilising the complex. At 298 K, the binding constant (K a ) of baicalein to ADH was 5.41 × 10 4 L·mol −1 with one binding stoichiometry, suggesting formation of binary complex. Molecular docking analysis revealed that the hydroxyl groups on the side chain of baicalein interacted with ADH through hydrogen bonds. The interaction between baicalein and Val292 (B) may partially explain the decreased activity of ADH. The effect of baicalein on the structure of ADH was confirmed by three-dimensional (3D) fluorescence spectroscopy, circular dichroism (CD) spectroscopy, fourier-transform infrared (FT-IR) spectroscopy experiments and computer simulations. Overall, this study could reveal a novel research perspective on the therapeutic effect of baicalein and its medicinal value.

Symptomatic Diethylene Glycol Ingestion Successfully Treated with Fomepizole Monotherapy

BackgroundDiethylene glycol (DEG) is an industrial solvent with many uses, including brake fluids. It has also caused mass poisonings after use as an inappropriate substitute for propylene glycol or glycerin, though individual ingestions are rare. Like other toxic alcohols, DEG is metabolized by alcohol dehydrogenase and aldehyde dehydrogenase, with toxicity likely mediated by the resulting metabolites. Fomepizole, an alcohol dehydrogenase inhibitor, is used to prevent metabolite formation with other toxic alcohol exposures. Fomepizole is recommended for DEG poisoning, though supporting clinical evidence is limited. Case ReportA 31-year-old man presented after ingestion of DEG-containing brake fluid and hydrocarbon-containing “octane booster.” He was noted to be clinically intoxicated, with a mildly elevated anion gap metabolic acidosis and no osmolar gap. DEG level was later found to be elevated, consistent with his ingestion. He was treated with fomepizole alone, with resolution of metabolic acidosis and clinical findings over the next 2 days. No delayed neurologic sequelae were present at 52-day follow-up. Our case provides additional evidence supporting the use of fomepizole for DEG poisoning. Consistent with other toxic alcohols, DEG poisoning, especially early presentations, may benefit from empiric fomepizole administration. Why Should an Emergency Physician Be Aware of This?DEG poisoning is potentially life threatening, but treatable if identified early. An ingestion can be toxic despite a normal osmolar gap, leading to false reassurance. Finally, it is rare, so emergency physicians must be made aware of its potential dangers.

In silico Investigations on Structure, Reactivity Indices, NLO properties, and Bio-evaluation of 1-benzyl-2-phenyl-1H-benzimidazole Derivatives using DFT and Molecular Docking Approaches

Six 1-benzyl-2-phenyl-1H-benzimidazole derivatives, A1-A6, were modeled computationally, and equilibrium optimization was carried out at the B3LYP/6-31G** level of theory. The geometrical parameters, IR, UV-Vis, and molecular reactive properties were predicted on the basis of density functional theory (DFT) calculations. The electron-donating/accepting power (𝜔−/𝜔+) calculated were 4.71/1.18, 5.675/1.766, and 4.785/1.210 eV for A1, A2, and A3, respectively, indicating good electron donors; while A4 and A5 were calculated to be 8.13/3.60 and 9.284/4.744 eV, respectively signifying good electron acceptors in line with chemical hardness (μ), electrophilicity (ω) values and MEP analysis. The NLO behavior of compounds A1-A3 was greater than that of the standard NLO material urea gives the most reactive sites in the molecules. Docking analysis revealed that binding affinities for the six compounds A1-A6 were -8.3 to -9.0 kcal/mol and -9.2 to -10.0 kcal/mol for APO-liver alcohol dehydrogenase inhibitor (PDB IP: 5ADH) and antihypertensive protein hydrolase inhibitor (PDB IP: 4XX3), respectively; thus could possess good antioxidant and antihypertensive properties.

TRPV6 channel mediates alcohol-induced gut barrier dysfunction and systemic response.

SUMMARYIntestinal epithelial tight junction disruption is a primary contributing factor in alcohol-associated endotoxemia, systemic inflammation, and multiple organ damage. Ethanol and acetaldehyde disrupt tight junctions by elevating intracellular Ca2+. Here we identify TRPV6, a Ca2+-permeable channel, as responsible for alcohol-induced elevation of intracellular Ca2+, intestinal barrier dysfunction, and systemic inflammation. Ethanol and acetaldehyde elicit TRPV6 ionic currents in Caco-2 cells. Studies in Caco-2 cell monolayers and mouse intestinal organoids show that TRPV6 deficiency or inhibition attenuates ethanol- and acetaldehyde-induced Ca2+ influx, tight junction disruption, and barrier dysfunction. Moreover, Trpv6−/− mice are resistant to alcohol-induced intestinal barrier dysfunction. Photoaffinity labeling of 3-azibutanol identifies a histidine as a potential alcohol-binding site in TRPV6. The substitution of this histidine, and a nearby arginine, reduces ethanol-activated currents. Our findings reveal that TRPV6 is required for alcohol-induced gut barrier dysfunction and inflammation. Molecules that decrease TRPV6 function have the potential to attenuate alcohol-associated tissue injury.

Ingestion of Alcohol-Based Hand Sanitizer: A case report

IntroductionAlcohol-based hand sanitizers containing ethanol or isopropanol are being used in order to prevent person-to-person transmission during the COVID-19. Early signs and symptoms of this ingestion include nausea, vomiting, headache, abdominal pain, blurred vision, loss of coordination, and decreased level of consciousness. After hand sanitizer ingestion we have to suspect about methanol poisoning, monitoring the start of anion-gap metabolic acidosis, seizures, and blindness is essential. Treatment includes supportive care, acidosis correction, and the administration of an alcohol dehydrogenase inhibitor. In servere cases hemodialysis may be required.Objectives To present a case of an 29-year-old woman who was taken to the emergency department after voluntary ingestion of alcohol-based hand sanitizer in a suicide attempt. To describe the most common side effects of hand sanitizer ingestion and the literature review.MethodsClinical case presentation and literature review of similar cases.ResultsA 29-year-old woman, with diagnosis of borderline personality disorder and previous suicide attempts was taken to the emergency department after 3 hours of voluntary ingestion of an unknown quantity of alcohol-based hand sanitizer. Initial laboratory findings showed laboratory a blood methanol concentration of 66 mg/dL, with an anion gap of 30 mEq/L, arterial blood pH of 7.2, serum bicarbonate concentration of 12 mEq/L. Patient complained of abdominal pain and nervoussness.ConclusionsMost common signs and symptoms of alcohol-based hand sanitizer ingestion include nausea, vomiting, headache, abdominal pain, blurred vision, loss of coordination, and decreased level of consciousness. Treatment includes supportive care, acidosis correction, the administration of an alcohol dehydrogenase inhibitor and sometimes may be required.DisclosureNo significant relationships.