Oleoylethanolamide, Neuroinflammation, and Alcohol Abuse

Oleoylethanolamide ameliorates allergic asthma and atopic dermatitis via activation of GPR119

Serum levels of oleoylethanolamide (OEA) have been associated with the severity of pulmonary diseases, and augmented levels of epidermal OEA have been observed in response to low-grade inflammation in human skin. OEA acts as an endogenous ligand for GPR119; thus, the functional roles of GPR119 were investigated using two murine models. We tested effects of OEA and AR231453, a selective synthetic GPR119 agonist on ovalbumin (OVA)-induced allergic asthma and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis-like models in GPR119 wild-type (WT) and deficient mice. In OVA-induced allergic asthma model, administration of OEA or AR231453 reduced allergic feature, including airway hyperresponsiveness, eosinophil accumulation in bronchoalveolar lavage fluid, airway inflammation, and mucin secretion in the lungs, and both ameliorated DNCB-induced atopic dermatitis-like skin lesions, such as hypertrophy and mast cell accumulation, in GPR119 wild-type (WT) mice, but not in GPR119-deficient mice. OEA or AR231453 treatment reduced OVA-induced increase in pro-inflammatory cytokine expression, and type 2 innate lymphoid cells in the lungs, and both significantly suppressed the DNCB-induced lymph node enlargement and inflammatory Th2/1/17 cells in GPR119 WT mice, but not in GPR119-deficient mice. In RBL-2H3 mast cells, OEA or AR231453 suppressed degranulation and Th2 cytokine expression. These findings suggest that OEA functions to protect against allergic asthma and atopic dermatitis via GPR119 activation by suppressing immune responses in the lungs, lymph nodes, and skin, highlighting GPR119 activation as a therapeutic target for allergic and inflammatory diseases.

The Relationship Between Alcohol Consumption and Frailty Among Older Adults in China: Results From the Chinese Longitudinal Healthy Longevity Survey

INTRODUCTION

Alcohol consumption has an impact on the frailty, but current research in China lacks a detailed classification of alcohol use. This study aimed to explore the relationship between different drinking patterns and frailty in older adults.

METHODOLOGY

The data came from the 2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS) study, which included older adults (aged ≧ 60). Their demographic data, drinking status, and frailty index were collected in CLHLS. Through logistic regression models to analyze the correlation between alcohol consumption and frailty.

RESULTS

A total of 14,931 participants were included in the analysis. The prevalence of frailty was 29.1%, 35.2%, and 14.9% among risk-free, past risky, and now risky drinkers, respectively. After adjusting for covariates, past risky drinking was a risk factor for frailty (p = .003).

DISCUSSION

High-risk alcohol consumption is positively correlated with frailty. Prevention and reduction of risky drinking in older adults may help protect them from developing frailty.

Region-Specific Gene Expression Changes Associated with Oleoylethanolamide-Induced Attenuation of Alcohol Self-Administration

Oleoylethanolamide (OEA) is a lipid with anti-inflammatory activity that modulates multiple reward-related behaviors. Previous studies have shown that OEA treatment reduces alcohol self-administration (SA) while inhibiting alcohol-induced inflammatory signaling. Nevertheless, the specific mechanisms that OEA targets to achieve these effects have not been widely explored. Here, we tested the effects of OEA treatment during alcohol SA, extinction or previous to cue-induced reinstatement of alcohol seeking. In addition, we measured gene expression changes in the striatum and hippocampus of relevant receptors for alcohol consumption (Drd1, Drd2, Cnr1, Oprm) as well as immune-related proteins (Il-6, Il-1β, Tlr4) and the brain-derived neurotrophic factor (Bdnf). Our results confirmed that when administered contingently, systemic OEA administration reduced alcohol SA and attenuated cue-induced reinstatement. Interestingly, we also observed that OEA treatment reduced the number of sessions needed for the extinction of alcohol seeking. Biochemical analyses showed that OEA induced gene expression changes in dopamine and cannabinoid receptors in the striatum and hippocampus. In addition, OEA treatment modulated the long-term immune response and increased Bdnf expression. These results suggest that boosting OEA levels may be an effective strategy for reducing alcohol SA and preventing relapse.

Peripheral endocannabinoids in major depressive disorder and alcohol use disorder: a systematic review

BACKGROUND

Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD) are two high-prevalent conditions where the Endocannabinoid system (ECS) is believed to play an important role. The ECS regulates how different neurotransmitters interact in both disorders, which is crucial for controlling emotions and responses to stress and reward stimuli. Measuring peripheral endocannabinoids (eCBs) in human serum and plasma can help overcome the limitations of detecting endocannabinoid levels in the brain. This systematic review aims to identify levels of peripheral eCBs in patients with MDD and/or AUD and find eCBs to use as diagnostic, prognostic biomarkers, and potential therapeutic targets.

METHODS

We conducted a systematic literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines from the earliest manuscript until October 22, 2023, in three electronic databases. We included studies of human adults who had a current diagnosis of AUD and/or MDD and evaluated plasma or serum endocannabinoids. We carefully considered known variables that may affect endocannabinoid levels.

RESULTS

We included 17 articles in this systematic review, which measured peripheral eCBs in 170 AUD and 359 MDD patients. Stressors increase peripheral 2-arachidonyl-glycerol (2-AG) concentrations, and 2-AG may be a particular feature of depression severity and chronicity. Anxiety symptoms are negatively correlated with anandamide (AEA) concentrations, and AEA significantly increases during early abstinence in AUD. Studies suggest a negative correlation between Oleoylethanolamide (OEA) and length of abstinence in AUD patients. They also show a significant negative correlation between peripheral levels of AEA and OEA and fatty acid amide hydrolase (FAAH) activity. Eicosapentaenoylethanolamide (EPEA) is correlated to clinical remission rates in depression. Included studies show known variables such as gender, chronicity, symptom severity, comorbid psychiatric symptoms, length of abstinence in the case of AUD, and stress-inducibility that can affect peripheral eCBs.

CONCLUSIONS

This systematic review highlights the important role that the ECS plays in MDD and AUD. Peripheral eCBs appear to be useful biomarkers for these disorders, and further research may identify potential therapeutic targets. Using accessible biological samples such as blood in well-designed clinical studies is crucial to develop novel therapies for these disorders.

Bilirubin, once a toxin but now an antioxidant alleviating non-alcoholic fatty liver disease in an autophagy-dependent manner in high-fat diet-induced rats: a molecular and histopathological analysis

Background and purpose

As an endogenous antioxidant, bilirubin has surprisingly been inversely correlated with the risk of non-alcoholic fatty liver disease (NAFLD). Thereupon, the current evaluation was designed to assess the positive effects of bilirubin on the autophagy flux, as well as the other pathogenic processes and parameters involved in the expansion of NAFLD.

Experimental approach

Thirty adult male rats weighing 150-200 g with free access to sucrose solution (18%) were randomly subdivided into 5 groups (n = 6). Subsequently, the animals were euthanized, and their blood specimens and liver tissue samples were collected to measure serum biochemical indices, liver histopathological changes, intrahepatic triglycerides content, and tissue stereological alterations. Furthermore, the expression levels of autophagy-related genes (Atgs) were measured to assess the state of the autophagy flux.

Findings/Results

Fasting blood glucose, body weight, as well as liver weight, liver-specific enzyme activity, and serum lipid profile indices markedly decreased in rats that underwent a six-week bilirubin treatment compared to the control group. In addition, histopathological studies showed that hepatic steatosis, fibrosis, inflammation, and necrosis significantly decreased in the groups that received bilirubin compared to the control animals. Bilirubin also caused significant alterations in the expression levels of the Atgs, as well as the Beclin- 1 protein.

Conclusion and implication

Bilirubin may have potential ameliorative effects on NAFLD-associated liver damage. Moreover, the beneficial effects of bilirubin on intrahepatic lipid accumulation and steatosis were comparable with the group that did not ever receive bilirubin.

Epigenetic associations of GPNMB rs199347 variant with alcohol consumption in Parkinson's disease

Introduction

Alcohol consumption can induce a neuroinflammatory response and contribute to the progression of neurodegeneration. However, its association with Parkinson's disease (PD), the second most common neurodegenerative disorder, remains undetermined. Recent studies suggest that the glycoprotein non-metastatic melanoma protein B (GPNMB) is a potential biomarker for PD. We evaluated the association of rs199347, a variant of the GPNMB gene, with alcohol consumption and methylation upstream of GPNMB.

Methods

We retrieved genetic and DNA methylation data obtained from participants enrolled in the Taiwan Biobank (TWB) between 2008 and 2016. After excluding individuals with incomplete or missing information about potential PD risk factors, we included 1,357 participants in our final analyses. We used multiple linear regression to assess the association of GPNMB rs199347 and chronic alcohol consumption (and other potential risk factors) with GPNMB cg17274742 methylation.

Results

There was no difference between the distribution of GPNMB rs199347 genotypes between chronic alcohol consumers and the other study participants. A significant interaction was observed between the GPNMB rs199347 variant and alcohol consumption (p = 0.0102) concerning cg17274742 methylation. Compared to non-chronic alcohol consumers with the AA genotype, alcohol drinkers with the rs199347 GG genotype had significantly lower levels (hypomethylation) of cg17274742 (p = 0.0187).

Conclusion

Alcohol consumption among individuals with the rs199347 GG genotype was associated with lower levels of cg17274742 methylation, which could increase expression of the GPNMB gene, an important neuroinflammatory-related risk gene for PD.

Protective and curative effects of unconjugated bilirubin on gene expression of LOX-1 and iNOS in the heart of rats receiving high-fat diet and low dose streptozotocin: a histomorphometric approach

BACKGROUND

Atherosclerosis is a chronic inflammatory condition affecting the large arteries and is a major cause of cardiovascular diseases (CVDs) globally. Increased levels of adhesion molecules in cardiac tissue serve as prognostic markers for coronary artery occlusion risk. Given the antioxidant properties of bilirubin and its inverse correlation with atherosclerosis, this study aimed to assess the beneficial effects of bilirubin on atherosclerotic indices and heart structure in high-fat diet-fed diabetic rats with atherosclerosis.

METHODS

Atherosclerosis was induced in three out of five groups of adult male Sprague Dawley rats through a 14-week period of high-fat diet (HFD) consumption and a single low dose of streptozotocin (STZ) (35 mg/kg). The atherosclerotic rats were then treated with intraperitoneal administration of 10 mg/kg/day bilirubin for either 6 or 14 weeks (treated and protected groups, respectively), or the vehicle. Two additional groups served as the control and bilirubin-treated rats. Subsequently, the mRNA expression levels of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), lectin-like LDL receptor 1 (LOX-1), and the inducible nitric oxide synthase (iNOS) were analyzed using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Histopathological and stereological analyses were performed to assess changes in the heart structure.

RESULTS

Bilirubin significantly decreased the expression of VCAM-1, ICAM-1, LOX-1, and iNOS genes in the treated group. Moreover, bilirubin mitigated pathological damage in the left ventricle of the heart. Stereological analysis revealed a decrease in the left ventricle and myocardium volume, accompanied by an increase in vessel volume in rats treated with bilirubin.

CONCLUSION

These findings demonstrate that mild hyperbilirubinemia can protect against the progression of atherosclerosis and heart failure by improving lipid profile, modulating adhesion molecules, LOX-1, and iNOS gene expression levels.

Divergent Roles of APOAI and APOM in the Identification of Alcohol Use Disorder and Their Association With Inflammation and Cognitive Decline: A Pilot Study

BACKGROUND

Alcohol use disorder (AUD) courses with inflammation and cognitive decline. Apolipoproteins have emerged as novel target compounds related to inflammatory processes and cognition.

METHODS

A cross-sectional study was performed on abstinent AUD patients with at least 1 month of abstinence (n  = 33; 72.7% men) and healthy controls (n  = 34; 47.1% men). A battery of plasma apolipoproteins (APOAI, APOAII, APOB, APOCII, APOE, APOJ, and APOM), plasma inflammatory markers (LPS, LBP), and their influence on cognition and presence of the disorder were investigated.

RESULTS

Higher levels of plasma APOAI, APOB, APOE, and APOJ, as well as the proinflammatory LPS, were observed in the AUD group, irrespective of sex, whereas APOM levels were lower vs controls. Hierarchical logistic regression analyses, adjusting for covariates (age, sex, education), associated APOM with the absence of cognitive impairment in AUD and identified APOAI and APOM as strong predictors of the presence or absence of the disorder, respectively. APOAI and APOM did not correlate with alcohol abuse variables or liver status markers, but they showed an opposite profile in their associations with LPS (positive for APOAI; negative for APOM) and cognition (negative for APOAI; positive for APOM) in the entire sample.

CONCLUSIONS

The HDL constituents APOAI and APOM were differentially regulated in the plasma of AUD patients compared with controls, playing divergent roles in the disorder identification and associations with inflammation and cognitive decline.

Lipid metabolites and nitric oxide production in the cerebrospinal fluid and plasma of dogs with meningoencephalitis of unknown origin and idiopathic epilepsy: a pilot study

Introduction

Idiopathic epilepsy (IE) and meningoencephalomyelitis of unknown origin (MUO) are common causes of brain diseases leading to seizures in dogs. In this study, the concentrations of 196 lipid metabolites and nitrogen oxide (NO) production in the cerebrospinal fluid (CSF) and plasma of dogs with MUO or IE were measured using a LC-MS/MS and a NOx analyzer, respectively.

Methods

Nine clinically healthy dogs and 11 and 12 dogs with IE and MUO, respectively, were included in the study.

Results

Lipid analysis revealed variations in the levels of four and six lipid metabolites in CSF and plasma, respectively, between the groups. The levels of 6-keto-prostaglandin (PG) F1α (PGF1α), 20-carboxy arachidonic acid (20-carboxy-AA), 9-hydroxyoctadecadienoic acid, and lyso-platelet-activating factor were high in the CSF of dogs with MUO. In addition, the plasma levels of 11,12-dihydroxyeicosatrienoic acid, 20-carboxy-AA, and oleoylethanolamide were high in dogs with IE, and those of PGF1α were high in dogs with MUO. NO production levels were high in CSF but not in plasma in dogs with MUO or IE.

Discussion

It remains unknown whether these changes represent the cause or effect of diseases of the central nervous system; however, lipid metabolites and NO production in CSF and plasma may be used as diagnostic biomarkers and could be exploited for treating idiopathic or inflammatory epilepsy in dogs.

Unveiling the "hidden quality" of the walnut pellicle: a precious source of bioactive lipids

Tree nut consumption has been widely associated with various health benefits, with walnuts, in particular, being linked with improved cardiovascular and neurological health. These benefits have been attributed to walnuts' vast array of phenolic antioxidants and abundant polyunsaturated fatty acids. However, recent studies have revealed unexpected clinical outcomes related to walnut consumption, which cannot be explained simply with the aforementioned molecular hallmarks. With the goal of discovering potential molecular sources of these unexplained clinical outcomes, an exploratory untargeted metabolomics analysis of the isolated walnut pellicle was conducted. This analysis revealed a myriad of unusual lipids, including oxylipins and endocannabinoids. These lipid classes, which are likely present in the pellicle to enhance the seeds' defenses due to their antimicrobial properties, also have known potent bioactivities as mammalian signaling molecules and homeostatic regulators. Given the potential value of this tissue for human health, with respect to its "bioactive" lipid fraction, we sought to quantify the amounts of these compounds in pellicle-enriched waste by-products of mechanized walnut processing in California. An impressive repertoire of these compounds was revealed in these matrices, and in notably significant concentrations. This discovery establishes these low-value agriculture wastes promising candidates for valorization and translation into high-value, health-promoting products; as these molecules represent a potential explanation for the unexpected clinical outcomes of walnut consumption. This "hidden quality" of the walnut pellicle may encourage further consumption of walnuts, and walnut industries may benefit from a revaluation of abundant pellicle-enriched waste streams, leading to increased sustainability and profitability through waste upcycling.

Effects of novel GLT-1 modulator, MC-100093, on neuroinflammatory and neurotrophic biomarkers in mesocorticolimbic brain regions of male alcohol preferring rats exposed chronically to ethanol

Chronic ethanol consumption can lead to increased extracellular glutamate concentrations in key reward brain regions, such as medial prefrontal cortex (mPFC) and nucleus accumbens (NAc), and consequently leading to oxidative stress and neuroinflammation. Previous studies from our lab tested β-lactam antibiotics and novel beta-lactam non-antibiotic, MC-100093, and showed these β-lactam upregulated the major astrocytic glutamate transporter, GLT-1, and consequently reduced ethanol intake and normalized glutamate homeostasis. This present study tested the effects of novel synthetic β-lactam non-antibiotic drug, MC-100093, in chronic ethanol intake and neuroinflammatory and trophic factors in subregions of the NAc (NAc core and shell) and mPFC (Prelimbic, PL; and Infralimbic, IL) of male P rats. MC-100093 treatment reduced ethanol intake after 5-week drinking regimen. Importantly, MC-100093 attenuated ethanol-induced downregulation of brain derived neurotrophic factor (BDNF) expression in these brain regions. In addition, MC-100093 attenuated ethanol-induced upregulation of pro-inflammatory cytokines such as TNF-a and HMGB1 in all these brain regions. Furthermore, MC-100093 treatment attenuated ethanol-induced increase in RAGE in these brain regions. MC-100093 prevented neuroinflammation caused by ethanol intake as well as increased neurotrophic factor in mesocorticolimbic brain regions. MC-100093 treatment reduced ethanol intake and this behavioral effect was associated with attenuation of reduced trophic factors and increased pro-inflammatory factors. MC-100093 is considered a small molecule that may have potential therapeutic effects for the treatment of the effects of chronic exposure to ethanol.

Changes in Immune-Related Biomarkers and Endocannabinoids as a Function of Frequency of Cannabis Use in People Living With and Without HIV

Background: Cannabis use is common among people living with HIV (PLWH). Some observational studies of PLWH have linked cannabis use to lower immune markers; however, this is yet to be confirmed. In addition, whether HIV affects the endogenous cannabinoid system has not been studied. Our objective was to examine changes in immune-related biomarkers and endocannabinoids as a function of cannabis use frequency in people living with and without HIV. Materials and Methods: Data were obtained from a longitudinal study of men who have sex with men living in Los Angeles with, or at risk for, HIV. By design, half were PLWH. Those eligible for the parent study were willing and able to return for follow-up every 6 months. Those eligible for inclusion in this study reported varying levels of current cannabis use at follow-up. Specifically, one visit corresponded to a period of daily use and another to a period of infrequent use (weekly, monthly, or less than monthly). Banked serum from all eligible participants was analyzed for immune-related biomarkers, endocannabinoids, and paracannabinoids. Results: The analysis included 36 men, 19 of whom were PLWH. PLWH reported greater lifetime methamphetamine or amphetamine use (68% vs. 0%) and current cigarette use (55% vs. 20%) than people without HIV. Serum levels of HIV-related immune biomarkers including tumor necrosis factor receptor 2 (TNFR2; p=0.013) and CD27 (p=0.004) were greater in PLWH, alongside lower anandamide (AEA) (F1,34=5.337, p=0.027) and oleoylethanolamide (OEA) (F1,34=8.222, p=0.007) levels relative to people without HIV. Frequency of cannabis use did not impact the serum analytes in our study. Conclusions: Higher levels of TNFR2 and CD27 and lower levels of AEA and OEA in PLWH underscore the role of the TNF/TNFR superfamily in HIV, while highlighting a new role for the enzymatic activity of fatty acid amide hydrolase (the enzyme that hydrolyzes AEA and OEA) in HIV. Findings that cannabis frequency did not impact the immune phenotype may not generalize to other populations of PLWH. Additional work is required to further clarify the relationship between immune markers and endocannabinoids as a function of cannabis use frequency in PLWH. ClinicalTrials.gov ID: NCT01201083.

Bacterial lipopolysaccharide forms aggregates with apolipoproteins in male and female rat brains after ethanol binges

Alcohol binge drinking allows the translocation of bacterial lipopolysaccharide (LPS) from the gut to the blood, which activates the peripheral immune system with consequences in neuroinflammation. A possible access/direct signaling of LPS to/in the brain has not yet been described under alcohol abuse conditions. Apolipoproteins are compounds altered by alcohol with high affinity to LPS which may be involved in its transport to the brain or in its elimination. Here, we explored the expression of small components of LPS, in its free form or bound to apolipoproteins, in the brain of female and male rats exposed to alcohol binges. Animals received ethanol oral gavages (3 g/kg every 8 h) for 4 days. LPS or its components (Lipid A and core), LPS-binding protein, corticosterone, lipoproteins (HDL, LDL), apolipoproteins (ApoAI, ApoB, and ApoE), and their receptors were measured in plasma and/or in nonperfused prefrontal cortex (PFC) and cerebellum. Brain LipidA-apolipoprotein aggregates were determined by Western blotting and confirmed by co-immunoprecipitation. In animals exposed to alcohol binges: 1) plasma LPS-binding protein was elevated in both sexes; 2) females showed elevations in plasma ApoAI and corticosterone levels; 3) Lipid A formed aggregates with ApoAI in the female PFC and with ApoB in males, the latter showing Toll-like receptor 4 upregulation in PFC but not females. These results suggest that small bacterial components are present within the brain, forming aggregates with different apolipoproteins, depending on the sex, after alcohol binge intoxications. Results may have implications for the crosstalk between alcohol, LPS, and neuroinflammation.

Neuroimmune Activation and Microglia Reactivity in Female Rats Following Alcohol Dependence

The rates of alcohol use disorder among women are growing, yet little is known about how the female brain is affected by alcohol. The neuroimmune system, and specifically microglia, have been implicated in mediating alcohol neurotoxicity, but most preclinical studies have focused on males. Further, few studies have considered changes to the microglial phenotype when examining the effects of ethanol on brain structure and function. Therefore, we quantified microglial reactivity in female rats using a binge model of alcohol dependence, assessed through morphological and phenotypic marker expression, coupled with regional cytokine levels. In a time- and region-dependent manner, alcohol altered the microglial number and morphology, including the soma and process area, and the overall complexity within the corticolimbic regions examined, but no significant increases in the proinflammatory markers MHCII or CD68 were observed. The majority of cytokine and growth factor levels examined were similarly unchanged. However, the expression of the proinflammatory cytokine TNFα was increased, and the anti-inflammatory IL-10, decreased. Thus, female rats showed subtle differences in neuroimmune reactivity compared to past work in males, consistent with reports of enhanced neuroimmune responses in females across the literature. These data suggest that specific neuroimmune reactions in females may impact their susceptibility to alcohol neurotoxicity and other neurodegenerative events with microglial contributions.

Thirty Risk Factors for Alzheimer's Disease Unified by a Common Neuroimmune-Neuroinflammation Mechanism

One of the major obstacles confronting the formulation of a mechanistic understanding for Alzheimer's disease (AD) is its immense complexity-a complexity that traverses the full structural and phenomenological spectrum, including molecular, macromolecular, cellular, neurological and behavioural processes. This complexity is reflected by the equally complex diversity of risk factors associated with AD. However, more than merely mirroring disease complexity, risk factors also provide fundamental insights into the aetiology and pathogenesis of AD as a neurodegenerative disorder since they are central to disease initiation and subsequent propagation. Based on a systematic literature assessment, this review identified 30 risk factors for AD and then extended the analysis to further identify neuroinflammation as a unifying mechanism present in all 30 risk factors. Although other mechanisms (e.g., vasculopathy, proteopathy) were present in multiple risk factors, dysfunction of the neuroimmune-neuroinflammation axis was uniquely central to all 30 identified risk factors. Though the nature of the neuroinflammatory involvement varied, the activation of microglia and the release of pro-inflammatory cytokines were a common pathway shared by all risk factors. This observation provides further evidence for the importance of immunopathic mechanisms in the aetiopathogenesis of AD.

The endocannabinoid system as a putative target for the development of novel drugs for the treatment of psychiatric illnesses

Cannabis is well established to impact affective states, emotion and perceptual processing, primarily through its interactions with the endocannabinoid system. While cannabis use is quite prevalent in many individuals afflicted with psychiatric illnesses, there is considerable controversy as to whether cannabis may worsen these conditions or provide some form of therapeutic benefit. The development of pharmacological agents which interact with components of the endocannabinoid system in more localized and discrete ways then via phytocannabinoids found in cannabis, has allowed the investigation if direct targeting of the endocannabinoid system itself may represent a novel approach to treat psychiatric illness without the potential untoward side effects associated with cannabis. Herein we review the current body of literature regarding the various pharmacological tools that have been developed to target the endocannabinoid system, their impact in preclinical models of psychiatric illness and the recent data emerging of their utilization in clinical trials for psychiatric illnesses, with a specific focus on substance use disorders, trauma-related disorders, and autism. We highlight several candidate drugs which target endocannabinoid function, particularly inhibitors of endocannabinoid metabolism or modulators of cannabinoid receptor signaling, which have emerged as potential candidates for the treatment of psychiatric conditions, particularly substance use disorder, anxiety and trauma-related disorders and autism spectrum disorders. Although there needs to be ongoing clinical work to establish the potential utility of endocannabinoid-based drugs for the treatment of psychiatric illnesses, the current data available is quite promising and shows indications of several potential candidate diseases which may benefit from this approach.

Oleoylethanolamide ameliorates motor dysfunction through PPARα-mediates oligodendrocyte differentiation and white matter integrity after ischemic stroke

BACKGROUND AND AIM

Our previous study has revealed that OEA promotes motor function recovery in the chronic stage of ischemic stroke. However, the neuroprotective mechanism of OEA on motor function recovery after stroke still is unexplored. Therefore, the aim of this study was to explore the effects of OEA treatment on angiogenesis, neurogenesis, and white matter repair in the peri-infarct region after cerebral ischemia.

EXPERIMENTAL PROCEDURE

The adult male rats were subjected to 2 h of middle cerebral artery occlusion. The rats were treated with 10 and 30 mg/kg OEA or vehicle daily starting from day 2 after ischemia induction until they were sacrificed.

KEY RESULTS AND CONCLUSIONS

The results revealed that OEA increased cortical angiogenesis, neural progenitor cells (NPCs) proliferation, migration, and differentiation. OEA treatment enhanced the survival of newborn neurons and oligodendrogenesis, which eventually repaired the cortical neuronal injury and improved motor function after ischemic stroke. Meanwhile, OEA treatment promoted the differentiation of oligodendrocyte progenitor cells (OPCs) and oligodendrogenesis by activating the PPARα signaling pathway. Our results showed that OEA restores motor function by facilitating cortical angiogenesis, neurogenesis, and white matter repair in rats after ischemic stroke. Therefore, we demonstrate that OEA facilitates functional recovery after ischemic stroke and propose the hypothesis that the long-term application of OEA mitigates the disability after stroke.

Administration of Linoleoylethanolamide Reduced Weight Gain, Dyslipidemia, and Inflammation Associated with High-Fat-Diet-Induced Obesity

Acylethanolamides (NAEs) are bioactive lipids derived from diet fatty acids that modulate important homeostatic functions, including appetite, fatty acid synthesis, mitochondrial respiration, inflammation, and nociception. Among the naturally circulating NAEs, the pharmacology of those derived from either arachidonic acid (Anandamide), oleic acid (OEA), and palmitic acid (PEA) have been extensively characterized in diet-induced obesity. For the present work, we extended those studies to linoleoylethanolamide (LEA), one of the most abundant NAEs found not only in plasma and body tissues but also in foods such as cereals. In our initial study, circulating concentrations of LEA were found to be elevated in overweight humans (body mass index (BMI, Kg/m2) > 25) recruited from a representative population from the south of Spain, together with AEA and the endocannabinoid 2-Arachidonoyl glycerol (2-AG). In this population, LEA concentrations correlated with the circulating levels of cholesterol and triglycerides. In order to gain insight into the pharmacology of LEA, we administered it for 14 days (10 mg/kg i.p. daily) to obese male Sprague Dawley rats receiving a cafeteria diet or a standard chow diet for 12 consecutive weeks. LEA treatment resulted in weight loss and a reduction in circulating triglycerides, cholesterol, and inflammatory markers such as Il-6 and Tnf-alpha. In addition, LEA reduced plasma transaminases and enhanced acetyl-CoA-oxidase (Acox) and Uncoupling protein-2 (Ucp2) expression in the liver of the HFD-fed animals. Although the liver steatosis induced by the HFD was not reversed by LEA, the overall data suggest that LEA contributes to the homeostatic signals set in place in response to diet-induced obesity, potentially contributing with OEA to improve lipid metabolism after high fat intake. The anti-inflammatory response associated with its administration suggests its potential for use as a nutrient supplement in non-alcoholic steatohepatitis.

Fenofibrate Decreases Ethanol-Induced Neuroinflammation and Oxidative Stress and Reduces Alcohol Relapse in Rats by a PPAR-α-Dependent Mechanism

High ethanol consumption triggers neuroinflammation, implicated in sustaining chronic alcohol use. This inflammation boosts glutamate, prompting dopamine release in reward centers, driving prolonged drinking and relapse. Fibrate drugs, activating peroxisome proliferator-activated receptor alpha (PPAR-α), counteract neuroinflammation in other contexts, prompting investigation into their impact on ethanol-induced inflammation. Here, we studied, in UChB drinker rats, whether the administration of fenofibrate in the withdrawal stage after chronic ethanol consumption reduces voluntary intake when alcohol is offered again to the animals (relapse-type drinking). Furthermore, we determined if fenofibrate was able to decrease ethanol-induced neuroinflammation and oxidative stress in the brain. Animals treated with fenofibrate decreased alcohol consumption by 80% during post-abstinence relapse. Furthermore, fenofibrate decreased the expression of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukins IL-1β and IL-6, and of an oxidative stress-induced gene (heme oxygenase-1), in the hippocampus, nucleus accumbens, and prefrontal cortex. Animals treated with fenofibrate showed an increase M2-type microglia (with anti-inflammatory proprieties) and a decrease in phagocytic microglia in the hippocampus. A PPAR-α antagonist (GW6471) abrogated the effects of fenofibrate, indicating that they are dependent on PPAR-α activation. These findings highlight the potential of fenofibrate, an FDA-approved dyslipidemia medication, as a supplementary approach to alleviating relapse severity in individuals with alcohol use disorder (AUD) during withdrawal.

Oleoylethanolamide attenuates the stress-mediated potentiation of rewarding properties of cocaine associated with an increased TLR4 proinflammatory response

The lipid-derived messenger oleoylethanolamide (OEA) has been involved in multiple physiological functions including metabolism and the immune response. More recently, OEA has been observed to affect reward-related behavior. Stress is a major risk factor for drug use and a predictor of drug relapse. In the laboratory, social stress has been largely studied using the social defeat (SD) model. Here, we explored the effects of different OEA administration schedules on the increased rewarding properties of cocaine induced by SD. In addition, we evaluated the anti-inflammatory action of OEA pretreatment in TLR4 expression caused by SD in the cerebellum, a novel brain structure that has been involved in the development of cocaine addiction. Adult OF1 mice were assigned to an experimental group according to the stress condition (exploration or SD) and treatment (OEA before SD, OEA before conditioning or subchronic OEA treatment). Mice were administered with OEA i.p (10 mg/kg) 10 min previously to the corresponding event. Three weeks after the last SD encounter, conditioned place preference (CPP) was induced by a subthreshold cocaine dose (1 mg/kg). As expected, socially defeated mice presented greater vulnerability to the cocaine reinforcing effects and expressed CPP. Conversely, this effect was not observed under a non-stressed condition. Most importantly, we observed that OEA pretreatment before SD or before conditioning prevented cocaine CPP in defeated mice. Biochemical analysis showed that OEA administration before SD decreased proinflammatory TLR4 upregulation in the cerebellum caused by social stress. In summary, our results suggest that OEA may have a protective effect on stress-induced increased cocaine sensitivity by exerting an anti-inflammatory action.

A Review of the Characteristics of Clinical Trials and Potential Medications for Alcohol Dependence: Data Analysis from ClinicalTrials.gov

Objective. This study provides a comprehensive analysis of the characteristics of clinical trials related to alcohol dependence that are registered on ClinicalTrials.gov. Methods. All ClinicalTrials.gov trials registered up to 1 January 2023 were examined, focusing on trials that involved alcohol dependence. All 1295 trials were summarized by presenting their characteristics and results and reviewed most intervention drugs used in the treatment of alcohol dependence. Results. The study analysis identified a total of 1295 clinical trials registered on ClinicalTrials.gov that were focused on alcohol dependence. Of these, 766 trials had been completed, representing 59.15% of the total, while 230 trials were currently recruiting participants, accounting for 17.76% of the total. None of the trials had yet been approved for marketing. The majority of the studies included in this analysis were interventional studies (1145 trials, or 88.41%), which accounted for most of the patients enrolled in the trials. In contrast, observational studies represented only a small portion of the trials (150 studies, or 11.58%) and involved a smaller number of patients. In terms of geographic distribution, the majority of registered studies were located in North America (876 studies, or 67.64%), while only a small number of studies were registered in South America (7 studies, or 0.54%). Conclusions. The purpose of this review is to provide a basis for the treatment of alcohol dependence and prevention of its onset through an overview of clinical trials registered at ClinicalTrials.gov. It also offers essential information for future research to guide future studies.

Oleoylethanolamide attenuates cocaine-primed reinstatement and alters dopaminergic gene expression in the striatum

The lipid oleoylethanolamide (OEA) has been shown to affect reward-related behavior. However, there is limited experimental evidence about the specific neurotransmission systems OEA may be affecting to exert this modulatory effect. The aim of this study was to evaluate the effects of OEA on the rewarding properties of cocaine and relapse-related gene expression in the striatum and hippocampus. For this purpose, we evaluated male OF1 mice on a cocaine-induced CPP procedure (10 mg/kg) and after the corresponding extinction sessions, we tested drug-induced reinstatement. The effects of OEA (10 mg/kg, i.p.) were evaluated at three different timepoints: (1) Before each cocaine conditioning session (OEA-C), (2) Before extinction sessions (OEA-EXT) and (3) Before the reinstatement test (OEA-REINST). Furthermore, gene expression changes in dopamine receptor D1 gene, dopamine receptor D2 gene, opioid receptor µ, cannabinoid receptor 1, in the striatum and hippocampus were analyzed by qRT-PCR. The results obtained in the study showed that OEA administration did not affect cocaine CPP acquisition. However, mice receiving different OEA treatment schedules (OEA-C, OEA-EXT and OEA-REINST) failed to display drug-induced reinstatement. Interestingly, the administration of OEA blocked the increase of dopamine receptor gene D1 in the striatum and hippocampus caused by cocaine exposure. In addition, OEA-treated mice exhibited reduced striatal dopamine receptor gene D2 and cannabinoid receptor 1. Together, these findings suggest that OEA may be a promising pharmacological agent in the treatment of cocaine use disorder.

A review on the reciprocal interactions between neuroinflammatory processes and substance use and misuse, with a focus on alcohol misuse

Background: The last decade has witnessed a surge of findings implicating neuroinflammatory processes as pivotal players in substance use disorders. The directionality of effects began with the expectation that the neuroinflammation associated with prolonged substance misuse contributes to long-term neuropathological consequences. As the literature grew, however, it became evident that the interactions between neuroinflammatory processes and alcohol and drug intake were reciprocal and part of a pernicious cycle in which disease-relevant signaling pathways contributed to an escalation of drug intake, provoking further inflammation-signaling and thereby exacerbating the neuropathological effects of drug misuse.Objectives: The goal of this review and its associated special issue is to provide an overview of the emergent findings relevant to understanding these reciprocal interactions. The review highlights the importance of preclinical and clinical studies in testing and validation of immunotherapeutics as viable targets for curtailing substance use and misuse, with a focus on alcohol misuse.Methods: A narrative review of the literature on drug and neuroinflammation was conducted, as well as articles published in this Special Issue on Alcohol- and Drug-induced Neuroinflammation: Insights from Pre-clinical Models and Clinical Research.Results: We argue that (a) demographic variables and genetic background contribute unique sensitivity to drug-related neuroinflammation; (b) co-morbidities between substance use disorders and affect dysfunction may share common inflammation-related signatures that predict the efficacy of immunotherapeutic drugs; and (c) examination of polydrug interactions with neuroinflammation is a critical area where greater research emphasis is needed.Conclusions: This review provides an accessible and example-driven review of the relationship between drug misuse, neuroinflammatory processes, and their resultant neuropathological outcomes.

Bilirubin improves renal function by reversing the endoplasmic reticulum stress and inflammation in the kidneys of type 2 diabetic rats fed high-fat diet

Diabetic kidney disease (DKD), as a chronic diabetes-induced complication, is considered the most frequent leading cause of end-stage renal disease (ESRD). Regarding the observed protective effects of bilirubin, as a potential endogenous antioxidant/anti-inflammatory compound, against DKD progression, we planned to evaluate the effects of bilirubin administration on endoplasmic reticulum (ER) stress and inflammation in type 2 diabetic (T2D) rats fed high-fat diet (HFD). In this regard, thirty 8-week adult male Sprague Dawley rats were divided into five groups (n = 6). T2D and obesity were induced by streptozotocin (STZ) (35 mg/kg) and HFD (700 kcal/day), respectively. Bilirubin treatment was carried out for 6- and 14-week intervals (10 mg/kg/day), intraperitoneally. Then, the expression levels of ER stress-related genes (i.e. binding immunoglobulin protein (Bip), C/EBP homologous protein (Chop), and spliced x-box-binding protein 1 (sXbp1), as well as nuclear factor-κB (NF-κB) were analyzed using quantitative Real-time PCR experiments. Moreover, histopathological and stereological changes of kidney and its related structures were investigated for the studied rats. Bip, Chop, and NF-κB expression levels were significantly decreased under bilirubin treatment, while sXbp1 was up-regulated following the bilirubin administration. More interestingly, glomerular constructive damages seen in HFD-T2D rats, were considerably improved in the animals received bilirubin. Stereological assessments also revealed that bilirubin could desirably reverse the mitigation of kidney's total volume and its related structures, such as cortex, glomeruli, and convoluted tubules. Taken together, bilirubin has potential protective/ameliorative effects on DKD progression, especially through alleviating the renal ER stress and inflammatory responses in T2D rats with injured kidneys. In this era, clinical benefits of mild hyperbilirubinemia can be considered in human DKD.

Pathophysiological basis and promise of experimental therapies for Gulf War Illness, a chronic neuropsychiatric syndrome in veterans

This article describes the pathophysiology and potential treatments for Gulf War Illness (GWI), which is a chronic neuropsychiatric illness linked to a combination of chemical exposures experienced by service personnel during the first Gulf War in 1991. However, there is currently no effective treatment for veterans with GWI. The article focuses on the current status and efficacy of existing therapeutic interventions in preclinical models of GWI, as well as potential perspectives of promising therapies. GWI stems from changes in brain and peripheral systems in veterans, leading to neurocognitive deficits, as well as physiological and psychological effects resulting from multifaceted changes such as neuroinflammation, oxidative stress, and neuronal damage. Aging not only renders veterans more susceptible to GWI symptoms, but also attenuates their immune capabilities and response to therapies. A variety of experimental models are being used to investigate the pathophysiology and develop therapies that have the ability to alleviate devastating symptoms. Over two dozen therapeutic interventions targeting neuroinflammation, mitochondrial dysfunction, neuronal injury, and neurogenesis are being tested, including agents such as curcumin, curcumin nanoparticles, monosodium luminol, melatonin, resveratrol, fluoxetine, rolipram, oleoylethanolamide, ketamine, levetiracetam, nicotinamide riboside, minocycline, pyridazine derivatives, and neurosteroids. Preclinical outcomes show that some agents have promise, including curcumin, resveratrol, and ketamine, which are being tested in clinical trials in GWI veterans. Neuroprotectants and other compounds such as monosodium luminol, melatonin, levetiracetam, oleoylethanolamide, and nicotinamide riboside appear promising for future clinical trials. Neurosteroids have been shown to have neuroprotective and disease-modifying properties, which makes them a promising medicine for GWI. Therefore, accelerated clinical studies are urgently needed to evaluate and launch an effective therapy for veterans displaying GWI.

Irisin attenuates ethanol-induced behavioral deficits in mice through activation of Nrf2 and inhibition of NF-κB pathways

This study aims to investigate the effect of irisin on ethanol-induced behavioral deficits and explore the underlying mechanisms. A mouse model of ethanol addiction/withdrawal was constructed through chronic ethanol administration. Depressive-like behaviors were evaluated by the tail suspension test and forced swimming test, and anxiety-like behaviors were evaluated by the marble-burying test and elevated plus maze test. The expression of Nrf2 was measured by western blotting. Levels of inflammatory mediators (NF-κB, TNF-α, IL-1β and IL-6) and oxidative stress factors (ROS, MDA, GSH and SOD) were detected by ELISA. The ethanol-induced PC12/BV2 cell injury model was used to elucidate whether the effect of irisin on ethanol-induced neurological injury was related to anti-inflammatory and antioxidant mechanisms. Ethanol-induced ethanol preference and emotional deficits were improved by chronic irisin treatment; however, these improvements were partly reversed by cotreatment with the Nrf2 inhibitor ML385. Further results implied that the improvement effect of irisin on behavioral abnormalities may be related to its anti-inflammatory and antioxidant effects. In detail, irisin inhibited ethanol-induced abnormal expression of ROS and MDA and upregulated the expression of GSH and SOD. Meanwhile, irisin treatment inhibited ethanol-induced overexpression of NF-κB, TNF-α, IL-1β and IL-6 in the hippocampus and cerebral cortex. The regulation of oxidative stress factors by irisin was reversed after ML385 treatment. In the in vitro study, overexpression of oxidative stress factors in ethanol-treated PC12 cells was inhibited by irisin treatment; however, the prevention was reversed after the knockdown of Nrf2 siRNA. Moreover, ethanol-induced overexpression of inflammatory mediators in BV2 cells was also inhibited by irisin treatment. Irisin improved depressive and anxiety-like behaviors induced by ethanol addiction/withdrawal in mice, and this protection was greatly associated with the NF-κB-mediated anti-inflammatory signaling pathway and Nrf2-mediated antioxidative stress signaling pathway.

Microbiome Dysbiosis Shows Strong Association of Gut-Derived Altered Metabolomic Profile in Gulf War Chronic Multisymptom Illness Symptom Persistence Following Western Diet Feeding and Development of Obesity

The pathophysiology of Gulf War Illness (GWI) remains elusive even after three decades. The persistence of multiple complex symptoms along with metabolic disorders such as obesity worsens the health of present Gulf War (GW) Veterans often by the interactions of the host gut microbiome and inflammatory mediators. In this study, we hypothesized that the administration of a Western diet might alter the host metabolomic profile, which is likely associated with the altered bacterial species. Using a five-month symptom persistence GWI model in mice and whole-genome sequencing, we characterized the species-level dysbiosis and global metabolomics, along with heterogenous co-occurrence network analysis, to study the bacteriome-metabolomic association. Microbial analysis at the species level showed a significant alteration of beneficial bacterial species. The beta diversity of the global metabolomic profile showed distinct clustering due to the Western diet, along with the alteration of metabolites associated with lipid, amino acid, nucleotide, vitamin, and xenobiotic metabolism pathways. Network analysis showed novel associations of gut bacterial species with metabolites and biochemical pathways that could be used as biomarkers or therapeutic targets to ameliorate symptom persistence in GW Veterans.

Anandamide and other N-acylethanolamines: A class of signaling lipids with therapeutic opportunities

N-acylethanolamines (NAEs), including N-palmitoylethanolamine (PEA), N-oleoylethanolamine (OEA), N-arachidonoylethanolamine (AEA, anandamide), N-docosahexaenoylethanolamine (DHEA, synaptamide) and their oxygenated metabolites are a lipid messenger family with numerous functions in health and disease, including inflammation, anxiety and energy metabolism. The NAEs exert their signaling role through activation of various G protein-coupled receptors (cannabinoid CB₁ and CB₂ receptors, GPR55, GPR110, GPR119), ion channels (TRPV1) and nuclear receptors (PPAR-α and PPAR-γ) in the brain and periphery. The biological role of the oxygenated NAEs, such as prostamides, hydroxylated anandamide and DHEA derivatives, are less studied. Evidence is accumulating that NAEs and their oxidative metabolites may be aberrantly regulated or are associated with disease severity in obesity, metabolic syndrome, cancer, neuroinflammation and liver cirrhosis. Here, we comprehensively review NAE biosynthesis and degradation, their metabolism by lipoxygenases, cyclooxygenases and cytochrome P450s and the biological functions of these signaling lipids. We discuss the latest findings and therapeutic potential of modulating endogenous NAE levels by inhibition of their degradation, which is currently under clinical evaluation for neuropsychiatric disorders. We also highlight NAE biosynthesis inhibition as an emerging topic with therapeutic opportunities in endocannabinoid and NAE signaling.

Upregulation of TLR4/MyD88 pathway in alcohol-induced Wernicke’s encephalopathy: Findings in preclinical models and in a postmortem human case

Wernicke’s encephalopathy (WE) is a neurologic disease caused by vitamin B1 or thiamine deficiency (TD), being the alcohol use disorder its main risk factor. WE patients present limiting motor, cognitive, and emotional alterations related to a selective cerebral vulnerability. Neuroinflammation has been proposed to be one of the phenomena that contribute to brain damage. Our previous studies provide evidence for the involvement of the innate immune receptor Toll-like (TLR)4 in the inflammatory response induced in the frontal cortex and cerebellum in TD animal models (animals fed with TD diet [TDD] and receiving pyrithiamine). Nevertheless, the effects of the combination of chronic alcohol consumption and TD on TLR4 and their specific contribution to the pathogenesis of WE are currently unknown. In addition, no studies on TLR4 have been conducted on WE patients since brains from these patients are difficult to achieve. Here, we used rat models of chronic alcohol (CA; 9 months of forced consumption of 20% (w/v) alcohol), TD hit (TDD + daily 0.25 mg/kg i.p. pyrithiamine during 12 days), or combined treatment (CA + TDD) to check the activation of the proinflammatory TLR4/MyD88 pathway and related markers in the frontal cortex and the cerebellum. In addition, we characterized for the first time the TLR4 and its coreceptor MyD88 signature, along with other markers of this proinflammatory signaling such as phospo-NFκB p65 and IκBα, in the postmortem human frontal cortex and cerebellum (gray and white matter) of an alcohol-induced WE patient, comparing it with negative (no disease) and positive (aged brain with Alzheimer’s disease) control subjects for neuroinflammation. We found an increase in the cortical TLR4 and its adaptor molecule MyD88, together with an upregulation of the proinflammatory signaling molecules p-NF-ĸB and IĸBα in the CA + TDD animal model. In the patient diagnosed with alcohol-induced WE, we observed cortical and cerebellar upregulation of the TLR4/MyD88 pathway. Hence, our findings provide evidence, both in the animal model and the human postmortem brain, of the upregulation of the TLR4/MyD88 proinflammatory pathway in alcohol consumption–related WE.

The Impact of Alcohol-Induced Dysbiosis on Diseases and Disorders of the Central Nervous System

The human digestive tract contains a diverse and abundant microbiota that is important for health. Excessive alcohol use can disrupt the balance of these microbes (known as dysbiosis), leading to elevated blood endotoxin levels and systemic inflammation. Using QIAGEN Ingenuity Pathway Analysis (IPA) bioinformatics tool, we have confirmed that peripheral endotoxin (lipopolysaccharide) mediates various cytokines to enhance the neuroinflammation signaling pathway. The literature has identified alcohol-mediated neuroinflammation as a possible risk factor for the onset and progression of neurodegenerative diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD), and psychiatric disorders such as addiction to alcohol and other drugs. In this review, we discuss alcohol-use-induced dysbiosis in the gut and other body parts as a causal factor in the progression of Central Nervous System (CNS) diseases including neurodegenerative disease and possibly alcohol use disorder.

Possible therapeutic effects of boron citrate and oleoylethanolamide supplementation in patients with COVID-19: A pilot randomized, double-blind, clinical trial

BACKGROUND

The present study aimed to assess the therapeutic effects of boron citrate and oleoylethanolamide supplementation in patients with COVID-19.

METHODS

Forty adult patients with a diagnosis of COVID-19 were recruited in the present study. Patients were randomized in a 1:1:1:1 allocation ratio to 1of 4 treatment groups: (A) 5 mg of boron citrate twice a day, (B) 200 mg of oleoylethanolamide twice a day, (C) both therapies, or (D) routine treatments without any study medications. At pre-and post-intervention phase, some clinical and biochemical parameters were assessed.

RESULTS

Supplementation with boron citrate alone or in combination with oleoylethanolamide significantly improved O2 saturation and respiratory rate (p < 0.01). At the end of the study, significant increases in white blood cell and lymphocyte count were observed in the boron citrate and combined groups (p < 0.001). Boron citrate supplementation led to a significant decrease in serum lactate dehydrogenase (p = 0.026) and erythrocyte sedimentation rate (p = 0.014), compared with other groups. Furthermore, boron citrate in combination with oleoylethanolamide resulted in a significant reduction in the high-sensitivity C-reactive protein and interleukin-1β concentrations (p = 0.031 and p = 0.027, respectively). No significant differences were found among four groups post-intervention, in terms of hemoglobin concentrations, platelet count, and serum interleukin-6 levels. At the end of the study, common symptoms of COVID-19 including cough, fatigue, shortness of breath, and myalgia significantly improved in the supplemented groups, compared to the placebo (p < 0.05).

CONCLUSION

Supplementation with boron citrate alone or in combination with oleoylethanolamide could improve some clinical and biochemical parameters in COVID-19 patients.

Repeated Restraint Stress and Binge Alcohol during Adolescence Induce Long-Term Effects on Anxiety-like Behavior and the Expression of the Endocannabinoid System in Male Rats

(1) Background: Negative experiences during adolescence increase the vulnerability to develop mental disorders later in life. A better understanding of the mechanisms underlying these long-term alterations could help to identify better therapeutic interventions. (2) Methods: Adolescent male Wistar rats were used to explore the effects of repeated stress and alcohol exposure on anxiety-like behaviors, plasma corticosterone levels and the gene expression of the endocannabinoid system (ECS) and other relevant signaling systems (glutamatergic, corticotropin-releasing hormone (CRH) and neuropeptide Y (NPY)) in the amygdala and the medial prefrontal cortex (mPFC). (3) Results: Overall, both stress and alcohol induced anxiety-like behaviors, but only the alcohol-exposed rats displayed increased plasma levels of corticosterone. In the amygdala, there was a general deficit in the gene expression of the ECS and increases in the mRNA levels of certain subunits of glutamate receptors. Interestingly, there were significant interaction effects between stress and alcohol on the expression of the NMDA receptor subunits. In addition, increased mRNA levels of the CRH receptor were observed in alcohol-exposed rats. In the mPFC, alcohol exposure was associated with an increase in the gene expression of the ECS. By contrast, the combination of stress and alcohol produced opposite effects. (4) Conclusions: In summary, early stress and alcohol exposure induced long-term anxiety-like behavior in male rats but different mechanisms are involved in these maladaptive changes in the brain.

Acetylsalicylic Acid Suppresses Alcoholism-Induced Cognitive Impairment Associated with Atorvastatin Intake by Targeting Cerebral miRNA155 and NLRP3: In Vivo, and In Silico Study

Alcoholism is one of the most common diseases that can lead to the development of several chronic diseases including steatosis, and cognitive dysfunction. Statins are lipid-lowering drugs that are commonly prescribed for patients with fatty liver diseases; however, the exact effect of statins on cognitive function is still not fully understood. In the present study, we have investigated the molecular and microscopic basis of cognitive impairment induced by alcohol and/or Atorvastatin (ATOR) administration to male Wistar albino rats and explored the possible protective effect of acetylsalicylic acid (ASA). The biochemical analysis indicated that either alcohol or ATOR or together in combination produced a significant increase in the nucleotide-binding domain-like receptor 3 (NLRP3), interleukin-1β (IL-1β) miRNA155 expression levels in the frontal cortex of the brain tissue. The histological and morphometric analysis showed signs of degeneration in the neurons and the glial cells with aggregations of inflammatory cells and a decrease in the mean thickness of the frontal cortex. Immunohistochemical analysis showed a significant increase in the caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex. Interestingly, administration of ASA reversed the deleterious effect of the alcohol and ATOR intake and improved the cognitive function as indicated by biochemical and histological analysis. ASA significantly decreased the expression levels of miRNA155, NLRP3, and IL1B, and produced a significant decrease in caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex with a reduction in the process of neuroinflammation and neuronal damage. To further investigate these findings, we have performed an extensive molecular docking study to investigate the binding affinity of ASA to the binding pockets of the NLRP3 protein. Our results indicated that ASA has high binding scores toward the active sites of the NLRP3 NACHT domain with the ability to bind to the NLRP3 pockets by a set of hydrophilic and hydrophobic interactions. Taken together, the present study highlights the protective pharmacological effect of ASA to attenuate the deleterious effect of alcohol intake and long term ATOR therapy on the cognitive function via targeting miRNA155 and NLRP3 proteins.

Disinhibition-Like Behavior Correlates with Frontal Cortex Damage in an Animal Model of Chronic Alcohol Consumption and Thiamine Deficiency

Wernicke-Korsakoff syndrome (WKS) is induced by thiamine deficiency (TD) and mainly related to alcohol consumption. Frontal cortex dysfunction has been associated with impulsivity and disinhibition in WKS patients. The pathophysiology involves oxidative stress, excitotoxicity and inflammatory responses leading to neuronal death, but the relative contributions of each factor (alcohol and TD, either isolated or in interaction) to these phenomena are still poorly understood. A rat model was used by forced consumption of 20% (w/v) alcohol for 9 months (CA), TD hit (TD diet + pyrithiamine 0.25 mg/kg, i.p. daily injections the last 12 days of experimentation (TDD)), and both combined treatments (CA+TDD). Motor and cognitive performance and cortical damage were examined. CA caused hyperlocomotion as a possible sensitization of ethanol-induced excitatory effects and recognition memory deficits. In addition, CA+TDD animals showed a disinhibited-like behavior which appeared to be dependent on TDD. Additionally, combined treatment led to more pronounced alterations in nitrosative stress, lipid peroxidation, apoptosis and cell damage markers. Correlations between injury signals and disinhibition suggest that CA+TDD disrupts behaviors dependent on the frontal cortex. Our study sheds light on the potential disease-specific mechanisms, reinforcing the need for neuroprotective therapeutic approaches along with preventive treatments for the nutritional deficiency in WKS.

Effects of Alcohol Binge Drinking and Oleoylethanolamide Pretreatment in the Gut Microbiota

Introduction

Chronic alcohol consumption is known to cause gut dysbiosis (changes in microbiota composition and/or function, disruptive of the normal host–microbiota interactions). However, little is known about the changes that alcohol binge drinking induces in the gut microbiota. Here, we have tested the hypothesis that a protocol of alcohol binge drinking, known to induce neuroinflammation in previous studies, also promotes intestinal dysbiosis, and we explored how oleoylethanolamide (OEA, an acylethanolamide proven to counteract alcohol binge drinking-induced neuroinflammation) pretreatment modulates alcohol-induced dysbiosis.

Methods

Alcohol binges were forced by gavage three times per day during 4 consecutive days; OEA pretreatment (intraperitoneal or intragastric) was administered before each alcohol gavage. Stool microbiota composition was assessed by next-generation 16S rRNA gene sequencing, prior and after the 4-day alcohol binge protocol.

Results

Alcohol binge drinking reduced the richness of the gut microbiota and changed the microbial community, reducing Lactobacillus among other genera. Pretreatment with OEA in the alcohol-administered rats decreased the richness, evenness, and Shannon indices to a greater extent with respect to alcohol alone, also changing the community structure. Microbial interactions in the association network were further decreased following OEA administration in the alcohol group, with respect to the water administration. The synergistic interaction between alcohol binge and OEA was affected by the route of administration of OEA, since oral and i.p. administrations differently changed the community structure.

Conclusion

Results suggest that alcohol binge drinking produces a clear dysbiosis in animals; we observed that the well-known protective actions of OEA in the context of alcohol abuse might not be related to OEA-induced changes in alcohol-induced dysbiosis. These are observational results, and thus, further research will be needed for a complete understanding of the biological significance of the observed changes.

Alterations of Stress-Related Glucocorticoids and Endocannabinoids in Hair of Chronic Cocaine Users

BACKGROUND

Previous research in animals and humans has demonstrated a potential role of stress regulatory systems, such as the hypothalamic-pituitary-adrenal (HPA) axis and the endocannabinoid (eCB) system, in the development of substance use disorders. We thus investigated alterations of HPA and eCB markers in individuals with chronic cocaine use disorder by using an advanced hair analysis technique.

METHODS

We compared hair concentrations of glucocorticoids (cortisone, cortisol) and the eCBs 2-arachidonylglycerol, anandamide (AEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA) between 48 recreational cocaine users (RCU), 25 dependent cocaine users (DCU), and 67 stimulant-naïve controls. Self-reported substance use and hair concentrations of substances were also assessed.

RESULTS

Significantly higher concentrations of hair cortisone were found in RCU and DCU compared with controls. Hair concentrations of OEA and PEA were significantly lower in DCU compared with RCU and controls. Additionally, within cocaine users, elevated cocaine hair concentration was a significant predictor for increased glucocorticoid and decreased OEA hair levels. Moreover, higher 3,4-methyl​enedioxymethamphetamine hair concentration was correlated with elevated cortisone and AEA, OEA, and PEA levels in hair within cocaine users, whereas more self-reported cannabis use was associated with lower eCBs levels in hair across the total sample.

CONCLUSION

Our findings support the hypothesis that the HPA axis and eCB system might be important regulators for substance use disorders. The mechanistic understanding of changes in glucocorticoid and eCB levels in future research might be a promising pharmacological target to reduce stress-induced craving and relapse specifically in cocaine use disorder.

Obesity as a Condition Determined by Food Addiction: Should Brain Endocannabinoid System Alterations Be the Cause and Its Modulation the Solution?

Obesity is a complex disorder, and the number of people affected is growing every day. In recent years, research has confirmed the hypothesis that food addiction is a determining factor in obesity. Food addiction is a behavioral disorder characterized by disruptions in the reward system in response to hedonic eating. The endocannabinoid system (ECS) plays an important role in the central and peripheral control of food intake and reward-related behaviors. Moreover, both obesity and food addiction have been linked to impairments in the ECS function in various brain regions integrating peripheral metabolic signals and modulating appetite. For these reasons, targeting the ECS could be a valid pharmacological therapy for these pathologies. However, targeting the cannabinoid receptors with inverse agonists failed when used in clinical contexts as a consequence of the induction of affective disorders. In this context, new classes of drugs acting either on CB1 and/or CB2 receptors or on synthetic and degradation enzymes of endogenous cannabinoids are being studied. However, further investigation is necessary to find safe and effective treatments that can exert anti-obesity effects, normalizing reward-related behaviors without causing important adverse mood effects.

N-acylethanolamine regulation of TLR3-induced hyperthermia and neuroinflammatory gene expression: A role for PPARα

Increasing evidence suggests that SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is associated with increased risk of developing neurological or psychiatric conditions such as depression, anxiety or dementia. While the precise mechanism underlying this association is unknown, aberrant activation of toll-like receptor (TLR)3, a viral recognizing pattern recognition receptor, may play a key role. Synthetic cannabinoids and enhancing cannabinoid tone via inhibition of fatty acid amide hydrolase (FAAH) has been demonstrated to modulate TLR3-induced neuroimmune responses and associated sickness behaviour. However, the role of individual FAAH substrates, and the receptor mechanisms mediating these effects, are unknown. The present study examined the effects of intracerebral or systemic administration of the FAAH substrates N-oleoylethanolamide (OEA), N-palmitoylethanolamide (PEA) or the anandamide (AEA) analogue meth-AEA on hyperthermia and hypothalamic inflammatory gene expression following administration of the TLR3 agonist, and viral mimetic, poly I:C. The data demonstrate that meth-AEA does not alter TLR3-induced hyperthermia or hypothalamic inflammatory gene expression. In comparison, OEA and PEA attenuated the TLR3-induced hyperthermia, although only OEA attenuated the expression of hyperthermia-related genes (IL-1β, iNOS, COX2 and m-PGES) in the hypothalamus. OEA, but not PEA, attenuated TLR3-induced increases in the expression of all IRF- and NFκB-related genes examined in the hypothalamus, but not in the spleen. Antagonism of PPARα prevented the OEA-induced attenuation of IRF- and NFκB-related genes in the hypothalamus following TLR3 activation but did not significantly alter temperature. PPARα agonism did not alter TLR3-induced hyperthermia or hypothalamic inflammatory gene expression. These data indicate that OEA may be the primary FAAH substrate that modulates TLR3-induced neuroinflammation and hyperthermia, effects partially mediated by PPARα.

Alcohol induced impairment/abnormalities in brain: Role of MicroRNAs

Alcohol is a highly toxic substance and has teratogenic properties that can lead to a wide range of developmental disorders. Excessive use of alcohol can change the structural and functional aspects of developed brain and other organs. Which can further lead to significant health, social and economic implications in many countries of the world. Convincing evidence support the involvement of microRNAs (miRNAs) as important post-transcriptional regulators of gene expression in neurodevelopment and maintenance. They also show differential expression following an injury. MiRNAs are the special class of small non coding RNAs that can modify the gene by targeting the mRNA and fine tune the development of cells to organs. Numerous pieces of evidences have shown the relationship between miRNA, alcohol and brain damage. These studies also show how miRNA controls different cellular mechanisms involved in the development of alcohol use disorder. With the increasing number of research studies, the roles of miRNAs following alcohol-induced injury could help researchers to recognize alternative therapeutic methods to treat/cure alcohol-induced brain damage. The present review summarizes the available data and brings together the important miRNAs, that play a crucial role in alcohol-induced brain damage, which will help in better understanding complex mechanisms. Identifying these miRNAs will not only expand the current knowledge but can lead to the identification of better targets for the development of novel therapeutic interventions.

Inflammatory neuropsychiatric disorders and COVID-19 neuroinflammation

Neuropsychiatric sequalae to coronavirus disease 2019 (COVID-19) infection are beginning to emerge, like previous Spanish influenza and severe acute respiratory syndrome episodes. Streptococcal infection in paediatric patients causing obsessive compulsive disorder (PANDAS) is another recent example of an infection-based psychiatric disorder. Inflammation associated with neuropsychiatric disorders has been previously reported but there is no standard clinical management approach established. Part of the reason is that it is unclear what factors determine the specific neuronal vulnerability and the efficacy of anti-inflammatory treatment in neuroinflammation. The emerging COVID-19 data suggested that in the acute stage, widespread neuronal damage appears to be the result of abnormal and overactive immune responses and cytokine storm is associated with poor prognosis. It is still too early to know if there are long-term-specific neuronal or brain regional damages associated with COVID-19, resulting in distinct neuropsychiatric disorders. In several major psychiatric disorders where neuroinflammation is present, patients with abnormal inflammatory markers may also experience less than favourable response or treatment resistance when standard treatment is used alone. Evidence regarding the benefits of co-administered anti-inflammatory agents such as COX-2 inhibitor is encouraging in selected patients though may not benefit others. Disease-modifying therapies are increasingly being applied to neuropsychiatric diseases characterised by abnormal or hyperreactive immune responses. Adjunct anti-inflammatory treatment may benefit selected patients and is definitely an important component of clinical management in the presence of neuroinflammation.

Cerebellar and cortical TLR4 activation and behavioral impairments in Wernicke-Korsakoff Syndrome: Pharmacological effects of oleoylethanolamide

Wernicke-Korsakoff Syndrome (WKS) is a neuropsychiatric disorder whose etiology is a thiamine deficiency (TD), with alcoholism being the main underlying cause. Previous evidence suggests the presence of initial neuroinflammation and oxidative/nitrosative stress in the physiopathology, although the specific molecular mechanisms underlying TD-induced brain damage and behavioral disabilities are unknown. We explored the specific role of the innate immune receptor TLR4 in three murine models of WKS, based on the combination of a thiamine-deficient diet and pyrithiamine injections (0.25 mg/kg, i.p.) over time. The Symptomatic Model (SM) allowed us to describe the complete neurological/neurobehavioral symptomatology over 16 days of TD. Animals showed an upregulation of the TLR4 signaling pathway both in the frontal cortex (FC) and cerebellum and clear motor impairments related with cerebellar dysfunction. However, in the Pre-Symptomatic Model (PSM), 12 days of TD induced the TLR4 pathway upregulation in the FC, which correlated with disinhibited-like behavior, but not in the cerebellum, and no motor impairments. In addition, we tested the effects of the biolipid oleoylethanolamide (OEA, 10 mg/kg, i.p., once daily, starting before any symptom of the pathology is manifested) through the Glucose-Precipitated Model (GPM), which was generated by glucose loading (5 g/kg, i.v., last day) in thiamine-deficient animals to accelerate damage. Pretreatment with OEA prevented the TLR4-induced signature in the FC, as well as an underlying incipient memory disability and disinhibited-like behavior. This study suggests a key role for TLR4 in TD-induced neuroinflammation in the FC and cerebellum, and it reveals different vulnerability of these brain regions in WKS over time. Pre-treatment with OEA counteracts TD-induced TLR4-associated neuroinflammation and may serve as co-adjuvant therapy to prevent WKS-induced neurobehavioral alterations.

Mediterranean Diet and Neurodegenerative Diseases: The Neglected Role of Nutrition in the Modulation of the Endocannabinoid System

Neurodegenerative disorders are a widespread cause of morbidity and mortality worldwide, characterized by neuroinflammation, oxidative stress and neuronal depletion. The broad-spectrum neuroprotective activity of the Mediterranean diet is widely documented, but it is not yet known whether its nutritional and caloric balance can induce a modulation of the endocannabinoid system. In recent decades, many studies have shown how endocannabinoid tone enhancement may be a promising new therapeutic strategy to counteract the main hallmarks of neurodegeneration. From a phylogenetic point of view, the human co-evolution between the endocannabinoid system and dietary habits could play a key role in the pro-homeostatic activity of the Mediterranean lifestyle: this adaptive balance among our ancestors has been compromised by the modern Western diet, resulting in a “clinical endocannabinoid deficiency syndrome”. This review aims to evaluate the evidence accumulated in the literature on the neuroprotective, immunomodulatory and antioxidant properties of the Mediterranean diet related to the modulation of the endocannabinoid system, suggesting new prospects for research and clinical interventions against neurodegenerative diseases in light of a nutraceutical paradigm.

Differential stress response to psychological and physical stressors in children using spatial versus response-dependent navigation strategies

Previous work from our lab has shown that basal cortisol levels are different between healthy young adults who spontaneously use caudate nucleus-dependent response strategies compared to young adults who use hippocampus-dependent spatial navigation strategies. Young adults who use caudate nucleus dependent strategies display lower basal cortisol levels compared to those who use hippocampus-dependent strategies. In the current study, we assessed navigation strategies in children using a virtual navigation task and measured cortisol at baseline as well as cortisol reactivity to both a psychological and to a physical stressor. Replicating what is observed in adults, we found that children who used caudate nucleus-dependent navigation strategies displayed lower cortisol levels at baseline compared to those who used hippocampus-dependent strategies. The psychological stressor, knowledge that a blood draw would be performed by a nurse, caused a significant increase in cortisol uniquely in response learners. The physical stressor, the actual blood draw, produced a significant increase in cortisol amongst spatial learners that was then comparable to levels observed in response learners. Lower baseline cortisol and higher cortisol psychological stress response observed amongst children who used response strategies may therefore reflect early biological changes during development which may have an impact later in life when considering risk for neuropsychiatric disorders.

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Both adults and children rely of different navigation strategies to learn new environments.

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Cortisol levels differ between people dependent on spontaneous navigation strategy.

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We show a differential cortisol stress response in children dependent on navigational strategy.

Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities

Recent studies examining the neurobiology of substance abuse have revealed a significant role of neuroimmune signaling as a mechanism through which drugs of abuse induce aberrant changes in synaptic plasticity and contribute to substance abuse-related behaviors. Immune signaling within the brain and the periphery critically regulates homeostasis of the nervous system. Perturbations in immune signaling can induce neuroinflammation or immunosuppression, which dysregulate nervous system function including neural processes associated with substance use disorders (SUDs). In this review, we discuss the literature that demonstrates a role of neuroimmune signaling in regulating learning, memory, and synaptic plasticity, emphasizing specific cytokine signaling within the central nervous system. We then highlight recent preclinical studies, within the last 5 years when possible, that have identified immune mechanisms within the brain and the periphery associated with addiction-related behaviors. Findings thus far underscore the need for future investigations into the clinical potential of immunopharmacology as a novel approach toward treating SUDs. Considering the high prevalence rate of comorbidities among those with SUDs, we also discuss neuroimmune mechanisms of common comorbidities associated with SUDs and highlight potentially novel treatment targets for these comorbid conditions. We argue that immunopharmacology represents a novel frontier in the development of new pharmacotherapies that promote long-term abstinence from drug use and minimize the detrimental impact of SUD comorbidities on patient health and treatment outcomes.

Addiction and the kynurenine pathway: A new dancing couple?

Drug use poses a serious threat to health systems throughout the world and the number of consumers rises relentlessly every year. The kynurenine pathway, main pathway of tryptophan degradation, has drawn interest in this field due to its relationship with addictive behaviour. Recently it has been confirmed that modulation of kynurenine metabolism at certain stages of the pathway can reduce, prevent or abolish drug seeking-like behaviours in studies with several different drugs. In this review, we present an up-to-date summary of the evidences of a relationship between drug use and the kynurenine pathway, both the alterations of the pathway due to drug use as well as modulation of the pathway as a potential approach to treat drug addiction. The review discusses ethanol, nicotine, cannabis, amphetamines, cocaine and opioids and new prospects in the drug research field are proposed.

Endocannabinoid-Like Lipid Neuromodulators in the Regulation of Dopamine Signaling: Relevance for Drug Addiction

The family of lipid neuromodulators has been rapidly growing, as the use of different -omics techniques led to the discovery of a large number of naturally occurring N-acylethanolamines (NAEs) and N-acyl amino acids belonging to the complex lipid signaling system termed endocannabinoidome. These molecules exert a variety of biological activities in the central nervous system, as they modulate physiological processes in neurons and glial cells and are involved in the pathophysiology of neurological and psychiatric disorders. Their effects on dopamine cells have attracted attention, as dysfunctions of dopamine systems characterize a range of psychiatric disorders, i.e., schizophrenia and substance use disorders (SUD). While canonical endocannabinoids are known to regulate excitatory and inhibitory synaptic inputs impinging on dopamine cells and modulate several dopamine-mediated behaviors, such as reward and addiction, the effects of other lipid neuromodulators are far less clear. Here, we review the emerging role of endocannabinoid-like neuromodulators in dopamine signaling, with a focus on non-cannabinoid N-acylethanolamines and their receptors. Mounting evidence suggests that these neuromodulators contribute to modulate synaptic transmission in dopamine regions and might represent a target for novel medications in alcohol and nicotine use disorder.

Role of cannabinoids in alcohol-induced neuroinflammation

Alcohol is a psychoactive substance highly used worldwide, whose harmful use might cause a broad range of mental and behavioural disorders. Underlying brain impact, the neuroinflammatory response induced by alcohol is recognised as a key contributing factor in the progression of other neuropathological processes, such as neurodegeneration. These sequels are determined by multiple factors, including age of exposure. Strikingly, it seems that the endocannabinoid system modulation could regulate the alcohol-induced neuroinflammation. Although direct CB1 activation can worsen alcohol consequences, targeting other components of the expanded endocannabinoid system may counterbalance the pro-inflammatory response. Indeed, specific modulations of the expanded endocannabinoid system have been proved to exert anti-inflammatory effects, primarily through the CB2 and PPARγ signalling. Among them, some endo- and exogeneous cannabinoids can block certain pro-inflammatory mediators, such as NF-κB, thereby neutralizing the neuroinflammatory intracellular cascades. Furthermore, a number of cannabinoids are able to activate complementary anti-inflammatory pathways, which are necessary for the transition from chronically overactivated microglia to a regenerative microglial phenotype. Thus, cannabinoid modulation provides cooperative anti-inflammatory mechanisms that may be advantageous to resolve a pathological neuroinflammation in an alcohol-dependent context.

Oxytocin reverses ethanol consumption and neuroinflammation induced by social defeat in male mice

Oxytocin (OXT) modulates social interactions, attenuates stressful responses and can decrease drug-seeking and taking behaviors. In previous studies, we observed that social defeat (SD) induced a long-lasting increase in ethanol intake and neuroinflammation in male mice. We also know that OXT blocks the increase in cocaine reward induced by SD. Therefore, in the present study we aimed to evaluate the effect of 1 mg/kg of OXT administered 30 min before each episode of SD on ethanol consumption and the neuroinflammatory response in adult male mice. Three weeks after the last SD, mice underwent oral ethanol self-administration (SA) procedure, and striatal levels of the two chemokines CX3CL1 and CXCL12 were measured after the last SD and at the end of the ethanol SA. OXT administration blocked the increase in voluntary ethanol consumption observed in defeated mice, although it did not affect motivation for ethanol. An increase in the striatal levels of CX3CL1 and CXCL12 was observed in defeated animals immediately after the last defeat and after the ethanol SA. However, defeated mice treated with OXT did not show this increase in the neuroinflammatory response. In conclusion, OXT treatment can be a powerful therapeutic target to reduce the negative effects of social stress on ethanol consumption and the neuroinflammatory process.