Glutamatergic hyperfunctioning during alcohol withdrawal syndrome: therapeutic perspective with zinc and magnesium

Phytoceutical isoquercitrin and ethanolic extracts from pequi (Caryocar coriaceum Wittm) reverse alcohol withdrawal-induced anxiety in adult zebrafish (Danio rerio)

Pharmacotherapy in Alcohol Withdrawal Syndrome (AWS), which is a mental disorder, generally involves benzodiazepines due to their action via GABA, but their side effects, such as excessive sedation, mental confusion and risk of dependence, are considerable. It is important to investigate the anxiolytic potential of plants such as Caryocar coriaceum, due to the presence of secondary metabolic compounds, such as isoquercitrin, capable of promoting the reduction of anxiety during AWS. We evaluated the anxiolytic-like potential of ethanolic extracts from the leaves (EEPL) and pulp (EEPP) of C. coriaceum, and its major compound, isoquercitrin (IsoQuer), in adult zebrafish (Danio rerio) during alcohol withdrawal. Adult zebrafish (n = 8 per group) were treated (20 µL; p.o) with EEPL, or EEPP or IsoQuer (0.01 or 0.05 or 0.1 or 0.5 or 1.0 mg/mL) and submitted to the 96-hour acute toxicity test. Flumazenil in adult zebrafish and molecular Docking of IsoQuer were used to investigate the GABAergic involvement. Finally, the anxiolytic-like activity was evaluated during alcohol withdrawal in adult zebrafish. The results indicated that EEPL, EEPP and IsoQuer are safe and have no sedative effect on adult zebrafish. Furthermore, they demonstrated a pharmacological potential in the treatment of alcohol withdrawal-induced anxiety, mediated by the GABAergic system, evidenced in the in-silico study by the stable isoquercitrin-GABAA complex, the main constituent of the extracts. These findings suggest an anxiolytic herbal potential of C. coriaceum and isoquercitrin, providing an alternative for the treatment of anxiety associated with AWS.

Differential Effects of Intrahippocampal Administration of Ceftriaxone on Morphine Dependence and Withdrawal Syndrome in Rats

Glutamate is a key factor in opiate addiction. Glial glutamate transporter-1 (GLT-1) plays a prominent role in glutamate homeostasis. Therefore, different regimens of ceftriaxone as a GLT-1 activator were prescribed to determine whether modulating GLT-1 prevents morphine dependence or withdrawal syndrome. Rats received 10 mg/kg morphine subcutaneously for ten consecutive days. Intrahippocampal ceftriaxone (0.5 μL of 0.5 mM solution) was injected 30 min before morphine administration to assess its effect on dependence process. In the next experiment, after the animals became dependent, ceftriaxone was injected before or after the last morphine administration, and its effect on withdrawal symptoms was evaluated. The reversibility of developed dependence was evaluated in the conditions when morphine and ceftriaxone were administered simultaneously. Two hours after the last morphine injection, naloxone hydrochloride (1.5 mg/kg) was administered, and morphine withdrawal syndrome was recorded for 25 min. Ceftriaxone administration before each morphine injection caused a decrease in the occurrence of withdrawal symptoms. Single dose of ceftriaxone after or before the last dose of morphine did not change the withdrawal symptoms significantly. Ceftriaxone injection for 5 days after becoming dependent could decrease the occurrence of some withdrawal symptoms. Modulation of glutamate with ceftriaxone during morphine injection may be able to prevent dependence. However, a single dose of ceftriaxone after becoming dependent could not decrease withdrawal syndrome. More prolonged administration of ceftriaxone could alleviate the induced dependence.

Acetaldehyde-mediated increase in glutamatergic and N-acetylaspartate neurometabolite levels in the midcingulate cortex of ALDH2*1/*2 heterozygous young adults

BACKGROUND

To elucidate the neurobiology underlying alcohol's effect on the human brain, we examined the acute effects of moderate alcohol administration on levels of glutamatergic neurometabolites and N-acetylaspartate, an amino acid found in neurons, may reflect disordered neuronal integrity.

METHODS

Eighteen healthy Japanese participants (7 males/11 females) aged 20-30 years who were heterozygous for an inactive allele of acetaldehyde dehydrogenase-2 (ALDH/*1/*2) were included. Participants underwent an intravenous alcohol infusion using the clamp method at a target blood alcohol concentration (BAC) of 0.50 mg/mL for 90 min within a range of ±0.05 mg/mL. We examined glutamate + glutamine (Glx) and N-acetylaspartate N-acetylaspartylglutamate (NAA) levels in the midcingulate cortex (MCC) using 3 T 1 H-MRS PRESS at baseline, 90 min, and 180 min (i.e., 90 min after alcohol infusion was finished). A two-way repeated-measures analysis of variance was used to assess longitudinal changes in Glx and NAA levels, with time and sex as within- and between-subject factors, respectively. Pearson's correlation coefficients were calculated among neurometabolite levels and BAC or blood acetaldehyde concentration (BAAC).

RESULTS

Both Glx (F(2,32) = 8.15, p = 0.004, η2  = 0.15) and NAA (F(2,32) = 5.01, p = 0.04, η2  = 0.07) levels were increased after alcohol injection. There were no sex or time × sex interaction effects observed. NAA levels were positively correlated with BAAC at 90 min (r(13) = 0.77, p = 0.01). There were no associations between neurometabolite levels and BAC.

CONCLUSIONS

Both Glx and NAA levels in the MCC increased in response to the administration of moderate concentrations of alcohol. Given positive associations between NAA levels and BAAC and the hypothetical glutamate release via dopamine pathways, the effects of drinking on the MCC in the acute phase may be ascribed to acetaldehyde metabolized from alcohol.

Progenitor Cells Play a Role in Reinstatement of Ethanol Seeking in Adult Male and Female Ethanol Dependent Rats

Female and male glial fibrillary acidic protein-thymidine kinase (GFAP-TK) transgenic rats were made ethanol dependent via a six-week chronic intermittent ethanol vapor (CIE) and ethanol drinking (ED) procedure. During the last week of CIE, a subset of male and female TK rats was fed valcyte to ablate dividing progenitor cells and continued the diet until the end of this study. Following week six, all CIE rats experienced two weeks of forced abstinence from CIE-ED, after which they experienced relapse to drinking, extinction, and reinstatement of ethanol seeking sessions. CIE increased ED in female and male rats, with females having higher ethanol consumption during CIE and relapse sessions compared with males. In both sexes, valcyte reduced the levels of Ki-67-labeled progenitor cells in the subgranular zone of the dentate gyrus and did not alter the levels in the medial prefrontal cortex (mPFC). Valcyte increased ED during relapse, increased lever responses during extinction and, interestingly, enhanced latency to extinguish ethanol-seeking behaviors in males. Valcyte reduced the reinstatement of ethanol-seeking behaviors triggered by ethanol cues in females and males. Reduced seeking by valcyte was associated with the normalization of cytokines and chemokines in plasma isolated from trunk blood, indicating a role for progenitor cells in peripheral inflammatory responses. Reduced seeking by valcyte was associated with increases in tight junction protein claudin-5 and oligodendrogenesis in the dentate gyrus and reduction in microglial activity in the dentate gyrus and mPFC in females and males, demonstrating a role for progenitor cells in the dentate gyrus in dependence-induced endothelial and microglial dysfunction. These data suggest that progenitor cells born during withdrawal and abstinence from CIE in the dentate gyrus are aberrant and could play a role in strengthening ethanol memories triggered by ethanol cues via central and peripheral immune responses.

Magnesium in the treatment of alcohol withdrawal syndrome: a multicenter randomized controlled trial

OBJECTIVE

Alcohol withdrawal syndrome (AWS) is a frequent and potentially life-threatening condition experienced in alcohol use disorder. Since hypomagnesemia is involved in AWS's severity, we conducted a multicenter double-blind randomized placebo-controlled trial to examine the efficacy of oral magnesium supplementation as an adjuvant therapy of AWS.

MATERIAL AND METHODS

Inpatients were recruited in six different centers if they had a baseline score higher than eight on the Revised Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar). The experimental treatment was magnesium lactate dehydrate, administrated three times per day providing a total of 426.6 mg per day and up to 15 days. The primary endpoint was the significant between-group difference of the CIWA-Ar total score change from baseline to 3 days later. The treatment group and baseline score were introduced as covariables in an analysis of covariance.

RESULTS

A total of 98 inpatients were included {71.4% of men; mean age of 49.1 years [standard deviation (SD): 10.3]}. In the intention-to-treat population, the mean reduction of the CIWA-Ar score in the experimental group between baseline and 3 days later was 10.1 (SD: 5.2), whereas it was 9.2 (SD: 3.9) in the control group. The absolute difference of the adjusted mean in the experimental group compared with the control group was -0.69 (SD: 0.72), which did not correspond to a significant between-group difference (P = 0.34). Per-protocol analysis and sensitivity analyses also supported this result. Supplementary analyses found no significant difference regarding benzodiazepine consumption, magnesium blood concentration, and satisfaction to care.

CONCLUSIONS

The present study does not support the rationale of systematic oral magnesium supplementation in patients with AWS.

A Novel Sulfonamide, 4-FS, Reduces Ethanol Drinking and Physical Withdrawal Associated With Ethanol Dependence

Carbonic anhydrase (CA) is abundant in glial cells in the brain and CA type II isoform (CA II) activity in the hippocampus plays an important role in buffering extracellular pH transients produced by neural activity. Chronic ethanol exposure results in respiratory and metabolic acidosis, producing shifts in extracellular pH in the brain and body. These neurophysiological changes by ethanol are hypothesized to contribute to the continued drinking behavior and physical withdrawal behavior in subjects consuming ethanol chronically. We explored whether chronic ethanol self-administration (ethanol drinking, 10% v/v; ED) without or under the influence of chronic intermittent ethanol vapor (CIE-ED) experience alters the expression of CA II in the hippocampus. Postmortem hippocampal tissue analyses demonstrated that CA II levels were enhanced in the hilus region of the hippocampus in ED and CIE-ED rats. We used a novel molecule-4-fluoro-N-(4-sulfamoylphenyl) benzenesulfonamide (4-FS)-a selective CA II inhibitor, to determine whether CA II plays a role in ethanol self-administration in ED and CIE-ED rats and physical withdrawal behavior in CIE-ED rats. 4-FS (20 mg/kg, i.p.) reduced ethanol self-administration in ED rats and physical withdrawal behavior in CIE-ED rats. Postmortem hippocampal tissue analyses demonstrated that 4-FS reduced CA II expression in ED and CIE-ED rats to control levels. In parallel, 4-FS enhanced GABAA receptor expression, reduced ratio of glutamatergic GluN2A/2B receptors and enhanced the expression of Fos, a marker of neuronal activation in the ventral hippocampus in ED rats. These findings suggest that 4-FS enhanced GABAergic transmission and increased activity of neurons of inhibitory phenotypes. Taken together, these findings support the role of CA II in assisting with negative affective behaviors associated with moderate to severe alcohol use disorders (AUD) and that CA II inhibitors are a potential therapeutic target to reduce continued drinking and somatic withdrawal symptoms associated with moderate to severe AUD.

On the Neurobiological Role of Oxidative Stress in Alcohol-Induced Impulsive, Aggressive and Suicidal Behavior

Objectives: Alcohol abuse is known to result in behavioral impairments (such as increased impulsivity, aggressive, and suicidal behavior), but the neurobiological basis for these behavioral impairments remains unknown. The objective of this review is to propose a neurobiological basis for alcohol-induced aggression, impulsivity, and suicidal behavior. Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(Alcohol OR Alcoholism* OR Alcohol Abuse) AND (Behavior* OR Behavioral Impairment or Disorder) AND (Oxidative Stress OR Reactive Oxygen Species)." The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and May 31, 2019. The search was limited to studies published in English and other languages involving both animal and human subjects. Articles selected included randomized clinical trials (RCTs), observational studies, meta-analyses, and both systemic and narrative reviews, providing both quantitative and qualitative information with a measure of alcohol abuse or alcoholism as an outcome. Exclusion criteria were unpublished data of any form, including conference proceedings and dissertation. New key terms were identified (new term included: "Antioxidants, Neurotransmitters, Dopamine, Serotonin, GABA, Glutamate. Aggression, Impulsivity, Suicidal Behavior, hippocampus, prefrontal cortex, limbic system, psychiatric disorders, PTSD, Anxiety, Depression. These new terms were searched with Alcohol or Alcoholism or Alcohol Abuse and Oxidative Stress separately resulting in the identification of over 3000 articles. 196 were included in this article. Results: Multiple lines of evidence indicate that oxidative stress (OS) plays a critical underlying role in alcohol toxicity and behavioral impairments. Conclusions/Importance: People diagnosed with PTSD, anxiety disorder, depression, and those with a personality high in psychoticism as measured by the P Scale of the Eysenck Personality Questionnaire, with comorbid alcohol abuse or alcohol use disorder (AUD), may display increased impulsivity, aggression, and suicidal behavior because of the potentiating effect of alcohol-induced OS on their elevated brain oxidative status. Antioxidant therapy should be an integral part of acute alcohol intoxication and AUD treatment. Further research is necessary to fully understand the relationship between OS and alcohol-induced behavioral impairments.

Alcohol withdrawal syndrome: mechanisms, manifestations, and management

The alcohol withdrawal syndrome is a well‐known condition occurring after intentional or unintentional abrupt cessation of heavy/constant drinking in patients suffering from alcohol use disorders (AUDs). AUDs are common in neurological departments with patients admitted for coma, epileptic seizures, dementia, polyneuropathy, and gait disturbances. Nonetheless, diagnosis and treatment are often delayed until dramatic symptoms occur. The purpose of this review is to increase the awareness of the early clinical manifestations of AWS and the appropriate identification and management of this important condition in a neurological setting.

The Effect of Chronic Alprazolam Intake on Memory, Attention, and Psychomotor Performance in Healthy Human Male Volunteers

Alprazolam is used as an anxiolytic drug for generalized anxiety disorder and it has been reported to produce sedation and anterograde amnesia. In the current study, we randomly divided 26 healthy male volunteers into two groups: one group taking alprazolam 0.5 mg and the other taking placebo daily for two weeks. We utilized the Cambridge Neuropsychological Test Automated Battery (CANTAB) software to assess the chronic effect of alprazolam. We selected Paired Associates Learning (PAL) and Delayed Matching to Sample (DMS) tests for memory, Rapid Visual Information Processing (RVP) for attention, and Choice Reaction Time (CRT) for psychomotor performance twice: before starting the treatment and after the completion of the treatment. We found statistically significant impairment of visual memory in one parameter of PAL and three parameters of DMS in alprazolam group. The PAL mean trial to success and total correct matching in 0-second delay, 4-second delay, and all delay situation of DMS were impaired in alprazolam group. RVP total hits after two weeks of alprazolam treatment were improved in alprazolam group. But such differences were not observed in placebo group. In our study, we found that chronic administration of alprazolam affects memory but attentive and psychomotor performance remained unaffected.

Influence of microelement concentration on the intensity of alcohol withdrawal syndrome

AIMS

To establish a nutritional and constitutional profile concerning the micronutrient plasma concentration of patients who suffer from AWS.

METHOD

Observational case control study to determine whether patients who exhibited symptoms of AWS (N = 60) had micronutrient plasmatic concentration deficiencies when compared with healthy controls (N = 34).

RESULTS

There were statistically significant differences between the concentrations of nutrients that are correlated with glutamate hyperactivity (zinc, magnesium and folate/vitamin B12/homocysteine).

CONCLUSION

Evidence from literature and our experiment suggests that brain activity, especially the glutamatergic system, might be directly involved in micronutrient concentrations. Therefore, their supplementation to the AWS patient might improve symptom evolution.

Gene expression in the addicted brain

Addiction is due to changes in the structure and function of the brain, including neuronal networks and the cells that comprise them. Within cells, gene expression changes can track and help explain their altered function. Transcriptional changes induced by addictive agents are dynamic and divergent and range from signal pathway-specific perturbations to widespread molecular and cellular dysregulation that can be measured by "omic" methods and that can be used to identify new pathways. The molecular effects of addiction depend on timing of exposure or withdrawal, the stage of adaptation, the brain region, and the behavioral model, there being many models of addiction. However, the molecular neural adaptations across different drug exposures, conditions, and regions are to some extent shared and can reflect common actions on pathways relevant to addiction. Epigenetic studies of DNA methylation and histone modifications and studies of regulatory RNA networks have been informative for elucidating the mechanisms of transcriptional change in the addicted brain.

Alcohol, nicotine, and iatrogenic withdrawals in the ICU

OBJECTIVES

The neurophysiology, risk factors, and screening tools associated with alcohol withdrawal syndrome in the ICU are reviewed. Alcohol withdrawal syndrome assessment and its treatment options are discussed. Description of nicotine withdrawal and related publications specific to the critically ill are also reviewed. A brief comment as to sedative and opiate withdrawal follows.

DATA AND SUMMARY

The role of currently published alcohol withdrawal syndrome pharmacologic strategies (benzodiazepines, ethanol, clomethiazole, antipsychotics, barbiturates, propofol, and dexmedetomidine) is detailed. Studies on nicotine withdrawal management in the ICU focus mainly on the safety (mortality) of nicotine replacement therapy. Study characteristics and methodological limitations are presented.

CONCLUSION

We recommend a pharmacologic regimen titrated to withdrawal symptoms in ICU patients with alcohol withdrawal syndrome. Benzodiazepines are a reasonable option; phenobarbital appears to confer some advantages in combination with benzodiazepines. Propofol and dexmedetomidine have not been rigorously tested in comparative studies of drug withdrawal treatment; their use as additional or alternative strategies for managing withdrawal syndromes in ICU patients should therefore be individualized to each patient. Insufficient data preclude recommendations as to nicotine replacement therapy and management of iatrogenic drug withdrawal in ICU patients.

Magnesium for alcohol withdrawal

BACKGROUND

Patients have been given magnesium to treat or prevent alcohol withdrawal syndrome (AWS). Evidence to support this practice is limited, and is often based on the controversial link between hypomagnesaemia and AWS.

OBJECTIVES

To assess the effects of magnesium for the prevention or treatment of AWS in hospitalised adults.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Register of Controlled Trials (August 2012), PubMed (from 1966 to August 2012 ), EMBASE (from 1988 to August 2012), CINAHL (from 1982 to March 2010), Web of Science (1965 to August 2012). We also carried out Internet searches.

SELECTION CRITERIA

Randomised or quasi-randomised trials of magnesium for hospitalised adults with, or at risk for, acute alcohol withdrawal.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data with a standardised data extraction form, contacting the correspondence investigator if the necessary information was not available in the reports. Dichotomous outcomes were analysed by calculating the risk ratio (RR) for each trial, with the uncertainty in each result expressed with a 95% confidence interval (CI). Continuous outcomes were to be analysed by calculating the standardised mean difference (SMD) with 95% CI. For outcomes assessed by scales we compared and pooled the mean score differences from the end of treatment to baseline (post minus pre) in the experimental and control groups.

MAIN RESULTS

Four trials involving 317 people met the inclusion criteria. Three trials studied oral magnesium, with doses ranging from 12.5 mmol/day to 20 mmol/day. One trial studied parenteral magnesium (16.24 mEq q6h for 24 hours). Each trial demonstrated a high risk of bias in at least one domain. There was significant clinical and methodological variation between trials.We found no study that measured all of the identified primary outcomes and met the objectives of this review. Only one trial measured clinical symptoms of seizure, delirium tremens or components of the Clinical Institute Withdrawal Assessment for Alcohol (CIWA) score. A single outcome (handgrip strength) in three trials (113 people), was amenable to meta-analysis. There was no significant increase in handgrip strength in the magnesium group (SMD 0.04; 95% CI -0.22 to 0.30). No clinically important changes in adverse events were reported.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether magnesium is beneficial or harmful for the treatment or prevention of alcohol withdrawal syndrome.

The Interplay between the Hippocampus and Amygdala in Regulating Aberrant Hippocampal Neurogenesis during Protracted Abstinence from Alcohol Dependence

The development of alcohol dependence involves elevated anxiety, low mood, and increased sensitivity to stress, collectively labeled negative affect. Particularly interesting is the recent accumulating evidence that sensitized extrahypothalamic stress systems [e.g., hyperglutamatergic activity, blunted hypothalamic-pituitary-adrenal (HPA) hormonal levels, altered corticotropin-releasing factor signaling, and altered glucocorticoid receptor signaling in the extended amygdala] are evident in withdrawn dependent rats, supporting the hypothesis that pathological neuroadaptations in the extended amygdala contribute to the negative affective state. Notably, hippocampal neurotoxicity observed as aberrant dentate gyrus (DG) neurogenesis (neurogenesis is a process where neural stem cells in the adult hippocampal subgranular zone generate DG granule cell neurons) and DG neurodegeneration are observed in withdrawn dependent rats. These correlations between withdrawal and aberrant neurogenesis in dependent rats suggest that alterations in the DG could be hypothesized to be due to compromised HPA axis activity and associated hyperglutamatergic activity originating from the basolateral amygdala in withdrawn dependent rats. This review discusses a possible link between the neuroadaptations in the extended amygdala stress systems and the resulting pathological plasticity that could facilitate recruitment of new emotional memory circuits in the hippocampus as a function of aberrant DG neurogenesis.