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The matrix effect limits the accuracy of quantitation of the otherwise popular metabolomics technique liquid chromatography coupled to mass spectrometry (LC-MS). The gold standard to correct for this phenomenon, whereby compounds coeluting with the analyte of interest cause ionization enhancement or suppression, is to quantify an analyte based on the peak area ratio with an isotopologue added to the sample as an internal standard. However, these stable isotopes are expensive and sometimes unavailable. Here, we describe an alternative approach: matrix effect correction and quantifying analytes using a signal ratio with a postcolumn infused standard (PCIS). Using an LC-MS/MS method for eight endocannabinoids and related metabolites in plasma, we provide strategies to select, optimize, and evaluate PCIS candidates. Based on seven characteristics, the structural endocannabinoid analogue arachidonoyl-2'-fluoroethylamide was selected as a PCIS. Three methods to evaluate the PCIS correction vs no correction showed that PCIS correction improved values for the matrix effect, precision, and dilutional linearity of at least six of the analytes to within acceptable ranges. PCIS correction also resulted in parallelization of calibration curves in plasma and neat solution, for six of eight analytes even with higher accuracy than peak area ratio correction with their stable isotope labeled internal standard, i.e., the gold standard. This enables quantification based on neat solutions, which is a significant step toward absolute quantification. We conclude that PCIS has great, but so far underappreciated, potential in accurate LC-MS quantification.

This pilot dose-escalation study evaluated the absorption and metabolism of a novel fasting mimetic formulation containing spermidine, nicotinamide, palmitoylethanolamide (PEA), and oleoylethanolamide (OEA) taken as oral supplements in young adults. Five healthy men consumed a standardized breakfast, followed by control (wheat flour) or low, medium, or high doses of supplements containing spermidine, nicotinamide, PEA, and OEA 2 hours later. Blood was drawn at 0, 1, 2, and 4 hours after the supplement (2, 3, 4, and 6 hours postprandial). Plasma concentrations of spermidine, 1-methylnicotinamide, PEA and OEA were quantified by liquid chromatography-mass spectrometry. The secretion of tumor necrosis factor alpha and production of reactive oxygen species by stimulated macrophages incubated with plasma, and cholesterol efflux capacity of plasma were analyzed. Plasma 1-methylnicotinamide, PEA, and OEA concentrations increased after supplement intake (P < .05). Spermidine concentrations decreased in the control arm (P < .05) but not the supplement arms. Net incremental area under the curve for tumor necrosis factor alpha and reactive oxygen species in stimulated macrophages decreased when incubated with plasma following supplement intake (P < .05). Intake of the combined supplements showed they were bioavailable and increased in plasma in a dose-dependent manner and provide preliminary data showing enhanced plasma anti-inflammatory and antioxidant functions. This trial was registered at clinicaltrials.gov (NCT05017428)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Evidence from preclinical animal models suggests that the stress-buffering function of the endocannabinoid (eCB) system may help protect against stress-related reductions in hippocampal volume, as is documented in major depressive disorder (MDD). However, stress exposure may also lead to dysregulation of this system. Thus, pathways from marked stress histories, such as childhood maltreatment (CM), to smaller hippocampal volumes and MDD in humans may depend on dysregulated versus intact eCB functioning. We examined whether the relation between MDD and peripheral eCB concentrations would vary as a function of CM history. Further, we examined whether eCBs moderate the relation of CM/MDD and hippocampal volume. Ninety-one adults with MDD and 62 healthy comparison participants (HCs) were recruited for a study from the Canadian Biomarker Integration Network in Depression program (CAN-BIND-04). The eCBs, anandamide (AEA) and 2-arachidonylglycerol (2-AG), were assessed from blood plasma. Severe CM history was assessed retrospectively via contextual interview. MDD was associated with eCBs, though not all associations were moderated by CM or in the direction expected. Specifically, MDD was associated with higher AEA compared to HCs regardless of CM history, a difference that could be attributed to psychotropic medications. MDD was also associated with higher 2-AG, but only for participants with CM. Consistent with hypotheses, we found lower left hippocampal volume in participants with versus without CM, but only for those with lower AEA, and not moderate or high AEA. Our study presents the first evidence in humans implicating eCBs in stress-related mechanisms involving reduced hippocampal volume in MDD., (© 2024. The Author(s).)

Multiple sclerosis (MS) is a complex chronic neuroinflammatory disease characterized by demyelination leading to neuronal dysfunction and neurodegeneration manifested by various neurological impairments. The endocannabinoid system (ECS) is a lipid signalling network, which plays multiple roles in the central nervous system and the periphery, including synaptic signal transmission and modulation of inflammation. The ECS has been identified as a potential target for the development of novel therapeutic interventions in MS patients. It remains unclear whether ECS-associated metabolites are changed in MS and could serve as biomarkers in blood or cerebrospinal fluid (CSF). In this retrospective study we applied targeted lipidomics to matching CSF and serum samples of 74 MS and 80 non-neuroinflammatory control patients. We found that MS-associated lipidomic changes overall did not coincide between CSF and serum. While glucocorticoids correlated positively, only the endocannabinoid (eCB) 2-arachidonoyl glycerol (2-AG) showed a weak positive correlation (r = 0.3, p < 0.05) between CSF and serum. Peptide endocannabinoids could be quantified for the first time in CSF but did not differ between MS and controls. MS patients showed elevated levels of prostaglandin E2 and steaorylethanolamide in serum, and 2-oleoylglycerol and cortisol in CSF. Sex-specific differences were found in CSF of MS patients showing increased levels of 2-AG and glucocorticoids in males only. Overall, arachidonic acid was elevated in CSF of males. Interestingly, CSF eCBs correlated positively with age only in the control patients due to the increased levels of eCBs in young relapsing-remitting MS patients. Our findings reveal significant discrepancies between CSF and serum, underscoring that measuring eCBs in blood matrices is not optimal for detecting MS-associated changes in the central nervous system. The identified sex and age-specific changes of analytes of the stress axis and ECS specifically in the CSF of MS patients supports the role of the ECS in MS and may be relevant for drug development strategies., (© 2024. The Author(s).)

Background: Abnormalities in biochemical parameters and changes in eating habits are considered complications of obesity. Oleoylethanolamide (OEA), an endocannabinoid-like compound, has been shown to have protective effects on many metabolic disorders. Given this evidence, the present study aimed to assess the effects of OEA on lipid profile parameters, fasting blood sugar (FBS), and dietary habits in healthy obese people., Methods: In this randomized, double-blind, placebo-controlled clinical trial, which was carried out in 2016 in Tabriz, Iran, 60 obese people were enrolled in the study based on inclusion criteria. The intervention group consumed 125 mg of OEA capsules, and the placebo group received the same amount of starch twice for 8 weeks. Blood samples (5 mL) were taken at baseline and the end of the study in a fasting state. Serum concentrations of FBS, triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and total cholesterol (TC) were measured by enzymatic methods using commercial kits. The low-density lipoprotein cholesterol (LDL-C) concentration was obtained using the Friede-Wald formula. To assess dietary habits, a food frequency questionnaire (147 items) was used at baseline and the end of the study. A value less than < 0.05 was considered to indicate statistical significance., Results: The TG concentration decreased significantly in the intervention group (mean (SD): 166.29 (70.01) mg/dL to 142.22 (48.05) mg/dL, p = 0.047). Changes in the placebo group were not significant (p > 0.05). After adjusting for baseline values and demographic characteristics, the difference in TG between groups remained significant (p = 0.044). Changes in other biochemical parameters were not significant. There was no significant difference between or within groups in terms of food groups., Conclusion: OEA, as a complementary agent, plays a protective role in TG regulation. However, future studies with longer durations are needed to explore the impact of OEA on regulating dietary habits and to identify the mechanisms related to metabolic abnormalities in obese people., Trial Registration: The study was registered in the Iranian Registry of Clinical Trials (IRCT) center as IRCT201607132017N30 with URL. www.IRCT.IR in date 03/10/2016., (© 2024. The Author(s).)

Major advances have been made in obesity treatment, focusing on restoring disturbances along the gut-brain axis. The endocannabinoid system (ECS) is a neuromodulatory signaling system, present along the entire gut-brain axis, that plays a critical role in central and peripheral regulation of food intake and body weight. Evidence on the impact of weight loss on the ECS is, however, more limited. Therefore, we set out to review the existing literature for changes in central and circulating endocannabinoid levels after bariatric surgery and other weight loss strategies in humans. The PubMed, Embase and Web of Science databases were searched for relevant articles. Fifty-six human studies were identified. Most studies measuring circulating 2-arachidonoylglycerol (2-AG) found no difference between normal weight and obesity, or no correlation with BMI. In contrast, studies measuring circulating arachidonoylethanolamine (AEA) found an increase or positive correlation with BMI. Two studies found a negative correlation between BMI and cannabinoid receptor type 1 (CB1) receptor availability in the brain. Only one study investigated the effect of pharmacological weight management on circulating endocannabinoid concentrations and found no effect on AEA concentrations. So far, six studies investigated potential changes in circulating endocannabinoids after bariatric surgery and reported conflicting results. Available evidence does not univocally support that circulating endocannabinoids are upregulated in individuals with obesity, which may be explained by variability across studies in several potential confounding factors (e.g. age and sex) as well as heterogeneity within the obesity population (e.g. BMI only vs. intra-abdominal adiposity). While several studies investigated the effect of lifestyle interventions on the circulating ECS, more studies are warranted that focus on pharmacologically and surgically induced weight loss. In addition, we identified several research needs which should be fulfilled to better understand the role of the ECS in obesity and its treatments., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background and Purpose: Preclinical studies of amyotrophic lateral sclerosis (ALS) have shown altered endocannabinoid (eCB) signalling that may contribute to the disease. Results from human studies are sparse and inconclusive. The aim of this study was to determine the association between serum levels of eCBs or their congeners, the so-called endocannabinoidome, and disease status and activity in ALS patients., Methods: Serum concentrations of 2-arachidonoylglycerol and N-arachidonoylethanolamine (AEA), and AEA congeners palmitoylethanolamide (PEA), oleoylethanolamide (OEA), eicosapentaenoylethanolamide (EPEA), 2-docosahexaenoylglycerol (2-DHG) and docosahexaenoylethanolamide (DHEA) were measured in samples from 65 ALS patients, 32 healthy controls (HCs) and 16 neurological disease controls (NALS). A subset of 46 ALS patients underwent a longitudinal study. Disease activity and progression were correlated with eCB and congener levels., Results: Most circulating mediators were higher in ALS than HCs (all p < 0.001), but not NALS. Across clinical stages, ALS patients showed increased levels of PEA, OEA and EPEA (all p < 0.02), which were confirmed by the longitudinal study (all p < 0.03). Serum PEA and OEA levels were independent predictors of survival and OEA levels were higher in patients complaining of appetite loss. Cluster analysis revealed two distinct profiles of circulating mediators associated with corresponding patterns of disease activity (severe vs. mild). Patients belonging to the 'severe' cluster showed significantly higher levels of OEA and PEA and lower levels of 2-DHG compared to NALS and HCs., Conclusion: Circulating endocannabinoidome profiles are indicative of disease activity, thus possibly paving the way to a personalized, rather than a 'one-fits-all', therapeutic approach targeting the endocannabinoidome., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Endocannabinoids (ECs), such as anandamide and 2-arachidonyl glycerol (2-AG), contribute to the pathology of inflammatory, malignant, cardiovascular, metabolic and mental diseases. The reliability of quantitative analyses in biological fluids of ECs and endocannabinoid-like (EC-like) substances depends on pre-analytical conditions such as temperature and "time-to-centrifugation". Standardization of these parameters is critical for valid quantification and implementation in clinical research. In this study, we compared concentrations obtained with GlucoEXACT blood collection tubes versus K3EDTA tubes and employed the optimized procedure to assess ECs profiles in patients with inflammatory skin disease and healthy controls. A UHPLC-MS/MS method was validated for human plasma from GlucoEXACT blood collection tubes according to EMA and FDA guidelines, and pre-analytical conditions were systematically modified to assess analyte stability and optimize the procedures. The results showed significantly lower concentrations of ECs and EC-like substance concentrations with GlucoEXACT tubes compared with K3EDTA tubes, and GlucoEXACT extended the time window of stable concentrations. The strongest method-disagreement occurred for 1/2-AG suggesting that GlucoEXACT delayed ex vivo isomer rearrangement. Hence, GlucoExact tubes were superior in terms of stability and reliability. However, although absolute concentrations obtained with GlucoExact and K3EDTA differed, linear regression studies showed high agreement (except for 1/2-AG), and both methods showed similar EC profiles and similar disease-dependent pro-inflammatory patterns in dermatology patients. Hence, despite the obstacles in EC analyses, implementation of optimized pre-analytical blood collection and sample processing procedures provide reliable insight into peripheral ECs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Dysregulation of the endocannabinoid (eCB) system is implicated in various stress-related neuropsychiatric disorders (SRDs), including anxiety, depression, and post-traumatic stress disorder (PTSD). In this systematic review and meta-analysis, our objectives were to characterize circulating anandamide (AEA) and 2-arachidonoylglycerol (2-AG) concentrations at rest and in response to acute laboratory-based psychosocial stress in individuals with SRDs and without (controls). Our primary aims were to assess the effects of acute psychosocial stress on eCB concentrations in controls (Aim 1), compare baseline (prestress) eCB concentrations between individuals with SRDs and controls (Aim 2), and explore differential eCB responses to acute psychosocial stress in individuals with SRDs compared with controls (Aim 3). Methods: On June 8, 2023, a comprehensive review of the MEDLINE (PubMed) database was conducted to identify original articles meeting inclusion criteria. A total of 1072, 1341, and 400 articles were screened for inclusion in Aims 1, 2, and 3, respectively. Results: Aim 1, comprised of seven studies in controls, revealed that most studies reported stress-related increases in AEA (86%, with 43% reporting statistical significance) and 2-AG (83%, though none were statistically significant except for one study in saliva). However, meta-analyses did not support these patterns ( p' s>0.05). Aim 2, with 20 studies, revealed that most studies reported higher baseline concentrations of both AEA (63%, with 16% reporting statistical significance) and 2-AG (60%, with 10% reporting statistical significance) in individuals with SRDs compared with controls. Meta-analyses confirmed these findings ( p' s<0.05). Aim 3, which included three studies, had only one study that reported statistically different stress-related changes in 2-AG (but not AEA) between individuals with PTSD (decrease) and controls (increase), which was supported by the meta-analysis ( p <0.001). Meta-analyses showed heterogeneity across studies and aims ( I 2 =14-97%). Conclusion: Despite substantial heterogeneity in study characteristics, samples, and methodologies, consistent patterns emerged, including elevated baseline AEA and 2-AG in individuals with SRDs compared with controls, as well as smaller stress-related increases in 2-AG in individuals with SRDs compared with controls. To consider eCBs as reliable biomarkers and potential intervention targets for SRDs, standardized research approaches are needed to clarify the complex relationships between eCBs, SRDs, and psychosocial stress.

Opioid-related overdose deaths are still on the rise in North America, emphasizing the need to better understand the underlying neurobiological mechanisms regarding the development of opioid use disorder (OUD). Recent evidence from preclinical and clinical studies indicate that the endocannabinoid system (ECS) may play a crucial role in stress and reward, both involved in the development and maintenance of substance use disorders. Animal models demonstrate a specific crosstalk between the ECS and the endogenous opioid system. However, translational studies in humans are scarce. Here, we investigated basal plasma levels of the endocannabinoids anandamide (AEA) and 2-arachidonoyglycerol (2-AG), and eight endocannabinoid-related lipids, including oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), as well as whole blood fatty acid amide hydrolase (FAAH) activity in chronic non-medical prescription opioid users (NMPOU; n = 21) compared to opioid-naïve healthy controls (n = 29) considering age, sex, and cannabis use as potential confounders. Additionally, the association of endocannabinoids and related lipids with the participants' response to experimentally induced social exclusion was examined. We found significantly elevated basal AEA, OEA, and PEA levels in NMPOU compared to controls, but no differences in FAAH activity, 2-AG, or other endocannabinoid-related lipids. Within NMPOU, higher AEA levels were associated with lower perception of social exclusion. Robust positive correlations within N-acylethanolamines (i.e., AEA, OEA, and PEA) indicate strong metabolic associations. Together with our recent findings of elevated basal 2-AG levels in dependent cocaine users, present results indicate substance-specific alterations of the ECS that may have implications in the search for novel therapeutic interventions for these populations., (© 2024. The Author(s).)

Background: Schizophrenia (SCZ) is a severe mental disorder, but its pathogenesis is still unknown, and its clinical treatment effect is very limited. Transient receptor potential vanilloid 1 (TRPV1) channel and the Endocannabinoid System (ECS)have been confirmed to be involved in the pathogenesis of SCZ, although their actions have not been fully clarified yet. The objective is to examine TRPV1 and ECS expression in the blood of schizophrenia patients and investigate their correlation with disease severity., Methods: This is a cross-sectional investigation. Peripheral blood samples were gathered from normal controls (NC, n=37), as well as individuals with schizophrenia, including first episode (n=30) and recurrent (n=30) cases. We employed western blot and ELISA techniques to quantify TRPV1, cannabinoid receptors 1(CB1), anandamide (AEA), and 2-arachidonoylglycerol (2-AG), and assess the severity of the patient's symptoms by means of the PANSS scale., Results: Compared to NC, TRPV1 levels showed a noticeable decrease in both first episode schizophrenia (f-SCZ group) and recurrent schizophrenia (r-SCZ group) subjects. Additionally, CB1 levels appeared increased in f-SCZ group. Furthermore, 2-AG levels were found to be elevated in both f-SCZ group and r-SCZ group compared to NC, whereas AEA levels were decreased in f-SCZ group but increased in r-SCZ group. Moreover, among schizophrenia patients, TRPV1 demonstrated a negative correlation with negative symptoms. Within r-SCZ subjects, CB1 displayed a negative correlation with relapse number, while 2-AG showed a correlation in the opposite direction., Conclusions: This study provides initial clinical evidence of changed TRPV1 expression in schizophrenia, potentially linked to negative symptoms. These results suggest a possible dysfunction of TRPV1 and the endocannabinoid system (ECS), which might offer new avenues for medical interventions., Competing Interests: Declaration of Competing Interest The authors have declared that there are no conflicts of interest in relation to the subject of this study., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Both endocannabinoid (EC) and endogenous opioid systems are involved in nociceptive processing and may work together synergistically based on preclinical models. This study evaluated the interactive effects of preoperative beta-endorphin (BE) concentrations (a key analgesic endogenous opioid) in cerebrospinal fluid (CSF) and ECs (CSF and plasma 2-arachidonoylglycerol and plasma anandamide) on postoperative opioid use and pain intensity in a prospective cohort of n = 112 pregnant patients undergoing scheduled cesarean delivery. Maternal blood and CSF samples were collected preoperatively for BE and EC assays. Patients completed measures of outpatient opioid use (number of tablets used and days of use) and average pain intensity at 2 weeks postoperatively. Results of general linear model analyses controlling for maternal age, body mass index at time of delivery, and race revealed significant multiplicative interactions between EC and BE concentrations on number of opioid tablets used (based on pill count), days of opioid use, and total milligram morphine equivalents used in the 2-week follow-up period. Elevated preoperative plasma and CSF 2-arachidonoylglycerol predicted reduced outpatient opioid analgesic use, particularly for patients low in CSF BE. Similar analyses for pain intensity at 2-week follow-up indicated a significant interaction (P < .02) characterized by higher preoperative BE concentrations being associated with lower subsequent pain only for individuals with low preoperative plasma anandamide concentrations. Further exploration of interactions between EC and endogenous opioid inhibitory systems as they influence responses to opioid analgesics in other clinical pain populations may help guide the development of precision pain management approaches. PERSPECTIVE: In the postoperative setting of patients undergoing cesarean delivery, elevated ECs were linked to reduced outpatient opioid analgesic use in individuals who had low endogenous opioid concentrations in CSF. Further exploration of interactions between these 2 inhibitory systems as they impact responses to pain management interventions appears warranted., (Copyright © 2024 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The mental health benefits of cannabidiol (CBD) are promising but can be inconsistent, in part due to challenges in defining an individual's effective dosage. In schizophrenia, alterations in anandamide (AEA) concentrations, an endocannabinoid (eCB) agonist of the eCB system, reflect positively on treatment with CBD. Here, we expanded this assessment to include eCBs alongside AEA congeners, comparing phytocannabinoids and dosage in a clinical setting., Methods: Liquid chromatography-tandem mass spectrometry quantified changes in serum levels of AEA, 2-arachidonoylglycerol (2-AG), alongside AEA-related compounds oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), which were attained from two independent, parallel-designed, clinical trials investigating single, oral CBD (600 or 800 mg), delta-9-tetrahydrocannabinol (Δ 9 -THC, 10 or 20 mg) and combination administration (CBD|800 mg+Δ 9 -THC|20 mg) in healthy volunteers (HVs, n=75). Concentrations were measured at baseline (t=0), 65 and 160 min post administration., Results: CBD-led increases in AEA (1.6-fold), OEA and PEA (1.4-fold) were observed following a single 800 mg (p corr <0.05) but not 600 mg dosage. Declining AEA was observed with Δ 9 -THC at 10 mg (-1.3-fold) and 20 mg (-1.4-fold) but restored to baseline levels by 160 min. CBD+Δ 9 -THC yielded the highest increases in AEA (2.1-fold), OEA (1.9-fold) and PEA (1.8-fold) without reaching a maximal response., Conclusion: CBD-administered effects towards AEA, OEA and PEA are consistent with phase II trials reporting clinical improvement for acute schizophrenia (CBD≥800 mg). Including Δ 9 -THC appears to enhance the CBD-induced response towards AEA and its congeners. Our results warrant further investigations into the potential of these lipid-derived mediators as metabolic measures for CBD dose prescription and co-cannabinoid administration., Competing Interests: Competing interests: FML and DK are shareholders of curantis UG (Ltd.). CR is a shareholder of lero bioscience UG (Ltd.). CR, CB, ID, and AEH are employees of Endosane Pharmaceuticals GmbH. FML received an Investigator Initiated Trial Grant from Endosane Pharmaceuticals GmbH. All other authors have nothing to disclose., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Plasma levels of endocannabinoids (eCBs) are very dynamic and variable in different circumstances and pathologies. The aim of the study was to determine the levels of the main eCBs and N-acylethanolamines (NAEs) in COVID-19 patients during the acute and post-acute phase of SARS-CoV-2 infection. Samples collected before December 31, 2020 were used for the determination of circulating eCB levels by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The association between plasma eCB measurements and biochemical and hematological parameters, as well as serum IL-6 levels, was evaluated. Samples of 64 individuals were analysed, n = 18 healthy donors, n = 30 acute, and n = 16 post-acute patients. Plasma levels of 2-arachidonoylglycerol (2-AG), were significantly elevated in COVID-19 patients when compared to healthy individuals. Plasma N-palmitoylethanolamide (PEA) and N-arachidonoylethanolamide (AEA) levels were found to be decreased in post-acute patient samples. These results suggest that 2-AG plays an important role in the inflammatory cascade in COVID-19 disease; in addition, eCBs might be involved in the post-acute pathogenesis of COVID-19. This study provides evidence of altered levels of circulating eCBs as a consequence of SARS-CoV-2 infection., (© 2024. The Author(s).)

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., (© 2024. The Author(s).)

Our laboratory previously developed a method for assessing experimentally induced pain perception through a 2-min constant heat pain stimulation. However, the traditional analysis relying on group means struggles to interpret the considerable inter-individual variability due to the dynamic nature of the response. Recently, trajectory analysis techniques based on extended mixed models have emerged, providing insights into distinct response profiles. Notably, these methods have never been applied to pain paradigms before. Furthermore, various socio-demographic and neurobiological factors, including endocannabinoids, may account for these inter-individual differences. This study aims to apply the novel analysis to dynamic pain responses and investigate variations in response profiles concerning socio-demographic, psychological, and blood endocannabinoid concentrations. 346 pain-free participants were enrolled in a psychophysical test involving a continuous painful heat stimulation lasting for 2 min at a moderate intensity. Pain perception was continuously recorded using a computerized visual scale. Dynamic pain response analyses were conducted using the innovative extended mixed model approach. In contrast to the traditional group-mean analysis, the extended mixed model revealed three pain response trajectories. Trajectory 1 is characterized by a delay peak pain. Trajectory 2 is equivalent to the classic approach (peak pain follow by a constant and moderate increase of pain perception). Trajectory 3 is characterized by extreme responses (steep peak pain, decrease, and increase of pain perception), Furthermore, age and blood anandamide levels exhibited significant variations among these three trajectories. Using an innovative statistical approach, we found that a large proportion of our sample had a response significantly different from the average expected response. Endocannabinoid system seems to play a role in pain response profile., (© 2024. The Author(s).)

Linoleic acid (LA) is required for neuronal development. We have previously demonstrated sex-specific changes in cardiovascular and hepatic function in rat offspring from mothers consuming a high-LA diet, with some effects associated with reduced LA concentration in the postnatal diet. At this time, the impact of a high-maternal-LA diet on offspring brain development and the potential for the postnatal diet to alter any adverse changes are unknown. Rat offspring from mothers fed low- (LLA) or high-LA (HLA) diets during pregnancy and lactation were weaned at postnatal day 25 (PN25) and fed LLA or HLA diets until sacrifice in adulthood (PN180). In the offspring's brains, the postnatal HLA diet increased docosapentaenoate in males. The maternal HLA diet increased LA, arachidonate, docosapentaenoate, C18:0 dimethylacetal (DMA), C16:0 DMA, C16:0 DMA/C16:0, and C18:0 DMA/C18:0, but decreased eoicosenoate, nervoniate, lignocerate, and oleate in males. Maternal and postnatal HLA diets reduced oleate and vaccenate and had an interaction effect on myristate, palmitoleate, and eicosapentaenoate in males. In females, maternal HLA diet increased eicosadienoate. Postnatal HLA diet increased stearate and docosapentaenoate. Maternal and postnatal HLA diets had an interaction effect on oleate, arachidate, and docosahexaenoic acid (DHA)/omega (n)-6 docosapentaenoic acid (DPA) in females. Postnatal HLA diet decreased DHA/n-6 DPA in males and females. Postnatal HLA diet increased plasma endocannabinoids (arachidonoyl ethanolamide and 2-arachidonoyl glycerol), as well as other N-acyl ethanolamides and testosterone. HLA diet alters brain fatty acids, plasma endocannabinoids, and plasmalogen concentrations in a development-specific and sex-specific manner.

Background: Interactions between the endocannabinoid system (ECS) and neurotransmitter systems might mediate the risk of developing a schizophrenia spectrum disorder (SSD). Consequently, we investigated in patients with SSD and healthy controls (HC) the relations between (1) plasma concentrations of two prototypical endocannabinoids (N-arachidonoylethanolamine [anandamide] and 2-arachidonoylglycerol [2-AG]) and (2) striatal dopamine synthesis capacity (DSC), and glutamate and y-aminobutyric acid (GABA) levels in the anterior cingulate cortex (ACC). As anandamide and 2-AG might reduce the activity of these neurotransmitters, we hypothesized negative correlations between their plasma levels and the abovementioned neurotransmitters in both groups., Methods: Blood samples were obtained from 18 patients and 16 HC to measure anandamide and 2-AG plasma concentrations. For all subjects, we acquired proton magnetic resonance spectroscopy scans to assess Glx (i.e. glutamate plus glutamine) and GABA + (i.e. GABA plus macromolecules) concentrations in the ACC. Ten patients and 14 HC also underwent [ 18 F]F-DOPA positron emission tomography for assessment of striatal DSC. Multiple linear regression analyses were used to investigate the relations between the outcome measures., Results: A negative association between 2-AG plasma concentration and ACC Glx concentration was found in patients ( p = 0.008). We found no evidence of other significant relationships between 2-AG or anandamide plasma concentrations and dopaminergic, glutamatergic, or GABAergic measures in either group., Conclusions: Our preliminary results suggest an association between peripheral 2-AG and ACC Glx levels in patients.

The role of the endocannabinoid system (ECS) in depression and suicidality has recently emerged. The purpose of the study was to identify changes in plasma endocannabinoid concentrations of several endocannabinoids and correlate them with depressive symptoms and suicidality in patients with severe major depression undergoing electroconvulsive therapy (ECT). The study included 17 patients that were evaluated in four visits at different stages of therapy. At each visit depression, anxiety and suicidality symptoms were assessed and blood samples collected. Several endocannabinoid concentrations increased following six sessions of ECT, as 2-AG (p < 0.05) and LEA (p < 0.01), and following twelve sessions of ECT, as 2-AG (p < 0.05), AEA (p < 0.05), LEA (p < 0.05) and DH-Gly (p < 0.05). Endocannabinoids also correlated with symptoms of depression, anxiety and suicidality at baseline and at the sixth ECT session. Finally, we found one endocannabinoid, l-Gly, that differentiated between remitted and not-remitted patients at the seventh and thirteenth ECT sessions (p < 0.05). Our findings suggest that depression is markedly related to imbalance of the endocannabinoid system, and further regulated by ECT. Plasma endocannabinoids could be promising biomarkers for detection of depression response and remission., Competing Interests: Declaration of competing interest None of the authors reports any financial or other conflict of interest with regard to this study. The authors furthermore confirm that this manuscript or parts thereof have not been published and are not under consideration for publication elsewhere. They also confirm that all of them contributed significantly to the study. They furthermore, confirm giving their approval to all statements and declarations included in this submission., (Copyright © 2024. Published by Elsevier B.V.)

Introduction: Cyclic vomiting syndrome (CVS) is a disorder of gut-brain interaction often triggered by stress. Interventions such as meditation may improve psychological outcomes and health-related quality of life (HRQoL), but their efficacy and the underlying mechanism are unknown., Methods: We conducted a 6-week single-arm pilot study to assess the effects of heartfulness meditation (HFM) in CVS using a custom-designed meditation app. Primary outcomes included state and trait anxiety and mood state changes pre vs post-meditation, and secondary outcomes were psychological distress, coping, sleep quality, and HRQoL at baseline and at weeks 3 and 6. Serum concentrations of endocannabinoids N -arachidonylethanolamine and 2-arachidonoylglycerol and related lipids were measured pre- and post-HFM at baseline and week 6., Results: In 30 treatment completers, there was a significant improvement in state anxiety ( P < 0.001), total mood disturbance ( P < 0.001), and other mood states (all P values < 0.05) across the 3 time points. Trait anxiety was also improved at week 6. There was a significant improvement in psychological distress (Global Severity Index), sleep quality (daytime dysfunction), coping (using religion/spirituality), and HRQoL (mental and physical) across the 3 time points (all P < 0.05). Significant increases in N -arachidonylethanolamine and related lipids N -oleoylethanolamine and palmitoylethanolamide post vs pre-HFM were observed at week 6 ( P < 0.001, 0.002, 0.003, respectively). No adverse effects were noted., Discussion: App-delivered HFM is feasible, safe, and effective and improves psychological outcomes and augments endocannabinoids. This provides insight into the mechanism underlying HFM and has potential for widespread use as a digital therapeutic in CVS and other disorder of gut-brain interaction., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Objective: Endocannabinoids and their N -acyl-ethanolamines (NAEs) and 2monoacyl-glycerols (2-MAGs) congeners are involved in the central and peripheral regulation of energy homeostasis, they are present in human milk and are associated with obesity. Infants exposed in utero to gestational diabetes mellitus (GDM) are more likely to develop obesity. The objective of this cross-sectional study is to compare the profile of eCBome mediators in milk of women with gestational diabetes (GDM+) and without (GDM-) and to assess the association with offspring growth. The hypothesis is that the eCBome of GDM+ human milk is altered and associated with a difference in infant growth., Methods: Circulating eCBome mediators were measured by LC-MS/MS in human milk obtained at 2 months postpartum from GDM+ (n=24) and GDM- (n=29) women. Infant weight and height at 2 months were obtained from the child health record. Z-scores were calculated., Results: Circulating Npalmitoylethanolamine (PEA) was higher in human milk of GDM+ women than in GDM- women (4.9 ± 3.2 vs. 3.3 ± 1.7, p=0.04). Higher levels were also found for several 2monoacyl-glycerols (2-MAGs) (p<0.05). The levels of NAEs (β=-4.6, p=0.04) and especially non-omega-3 NAEs (B=-5.6, p=0.004) in human milk were negatively correlated with weight-for-age z-score of GDM+ offspring., Conclusion: The profile of eCBome mediators in human milk at 2 months postpartum was different in GDM+ compared to GDM- women and was associated with GDM+ offspring growth at 2 months., Clinical Trial Registration: ClinicalTrials.gov, identifier (NCT04263675 and NCT02872402)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fradet, Castonguay-Paradis, Dugas, Perron, St-Arnaud, Marc, Doyen, Flamand, Dahhani, Di Marzo, Veilleux and Robitaille.)

Background: The Mediterranean diet (MedDiet) has demonstrated efficacy in preventing age-related cognitive decline and modulating plasma concentrations of endocannabinoids (eCBs) and N-acylethanolamines (NAEs, or eCB-like compounds), which are lipid mediators involved in multiple neurological disorders and metabolic processes. Hypothesizing that eCBs and NAEs will be biomarkers of a MedDiet intervention and will be related to the cognitive response, we investigated this relationship according to sex and apolipoprotein E (APOE) genotype, which may affect eCBs and cognitive performance., Methods: This was a prospective cohort study of 102 participants (53.9% women, 18.8% APOE-ɛ4 carriers, aged 65.6 ± 4.5 years) from the PREDIMED-Plus-Cognition substudy, who were recruited at the Hospital del Mar Research Institute (Barcelona). All of them presented metabolic syndrome plus overweight/obesity (inclusion criteria of the PREDIMED-Plus) and normal cognitive performance at baseline (inclusion criteria of this substudy). A comprehensive battery of neuropsychological tests was administered at baseline and after 1 and 3 years. Plasma concentrations of eCBs and NAEs, including 2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and N-docosahexaenoylethanolamine (DHEA), were also monitored. Baseline cognition, cognitive changes, and the association between eCBs/NAEs and cognition were evaluated according to gender (crude models), sex (adjusted models), and APOE genotype., Results: At baseline, men had better executive function and global cognition than women (the effect size of gender differences was - 0.49, p = 0.015; and - 0.42, p = 0.036); however, these differences became nonsignificant in models of sex differences. After 3 years of MedDiet intervention, participants exhibited modest improvements in memory and global cognition. However, greater memory changes were observed in men than in women (Cohen's d of 0.40 vs. 0.25; p = 0.017). In men and APOE-ε4 carriers, 2-AG concentrations were inversely associated with baseline cognition and cognitive changes, while in women, cognitive changes were positively linked to changes in DHEA and the DHEA/AEA ratio. In men, changes in the OEA/AEA and OEA/PEA ratios were positively associated with cognitive changes., Conclusions: The MedDiet improved participants' cognitive performance but the effect size was small and negatively influenced by female sex. Changes in 2-AG, DHEA, the OEA/AEA, the OEA/PEA and the DHEA/AEA ratios were associated with cognitive changes in a sex- and APOE-dependent fashion. These results support the modulation of the endocannabinoid system as a potential therapeutic approach to prevent cognitive decline in at-risk populations., Trial Registration: ISRCTN89898870., (© 2024. The Author(s).)

The endocannabinoid system (ECS) is dysregulated during obesity and metabolic disorders. Weight loss favours the re-establishment of ECS homeostatic conditions, but also the fatty acid composition of the diet can modulate endocannabinoid profiles. However, the combined impact of nutrient quality and energy restriction on the ECS remains unclear. In this 12 weeks randomized controlled trial, men and women (40-70 years) with obesity (BMI: 31.3 ± 3.5 kg/ m 2 ) followed either a low nutrient quality 25% energy-restricted (ER) diet (n=39) high in saturated fats and fructose, or a high nutrient quality ER diet (n=34) amongst others enriched in n-3 polyunsaturated fatty acids (PUFAs) or kept their habitual diet (controls). Profiles of plasma- and adipose N-acylethanolamines and mono-acyl glycerol esters were quantified using LC-MS/MS. Gene expression of ECS-related enzymes and receptors was determined in adipose tissue. Measurements were performed under fasting conditions before and after 12 weeks. Our results showed that plasma level of the DHA-derived compound docosahexaenoylethanolamide (DHEA) was decreased in the low nutrient quality ER diet (P<0.001) compared with the high nutrient quality ER diet, whereas anandamide (AEA) and arachidonoylglycerol (2-AG) levels were unaltered. However, adipose tissue gene expression of the 2-AG synthesizing enzyme diacylglycerol lipase alpha (DAGL-α) was increased following the low nutrient quality ER diet (P<.009) and differed upon intervention with both other diets. Concluding, nutrient quality of the diet affects N-acylethanolamine profiles and gene expression of ECS-related enzymes and receptors even under conditions of high energy restriction in abdominally obese humans. ClinicalTrials.gov NCT02194504., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

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) ( F 1,34 =5.337, p =0.027) and oleoylethanolamide (OEA) ( F 1,34 =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.

Objective: N-acylethanolamines (NAEs) include endocannabinoid (EC) and EC-related molecules that impact the anti-obesity and anti-diabetic efficacy of glucagon-like peptide-1 receptor agonists (GLP-1RA) in animal studies. However, the clinical relevance of these findings remains to be determined. Here, we tested whether GLP-1RA treatment affects circulating NAE levels and whether NAEs may predict the efficacy of GLP-1RA treatment in humans with obesity undergoing weight loss maintenance., Materials and Methods: We profiled plasma levels of NAEs in participants with obesity undergoing weight loss maintenance with (n = 23)/or without (n = 20) treatment with the GLP-1RA liraglutide. NAE levels were measured at three different time points: before the start of the study, at the end of the diet-induced weight loss, and after 52-weeks treatment. Linear regression analyses were used to investigate whether pharmacological responses could be predicted by NAEs levels., Results: Liraglutide treatment reduced plasma concentrations of the NAE and oleoyl-ethanolamide (OEA), without altering arachidonoyl-ethanolamide (AEA) levels and palmitoyl-ethanolamide (PEA) levels. High pre-treatment levels of OEA were predictive of superior compound-mediated effects on fasting insulin and triglyceride levels. High pre-treatment PEA and AEA levels were also predictive of superior Liraglutide-mediated effects on triglyceride levels., Conclusions: Our data suggests that specific NAEs such as OEA and AEA are promising biomarkers of GLP-1RA metabolic efficacy in humans with obesity during weight loss maintenance. Plasma profiling of EC-related molecules may be a promising strategy to tailor GLP-1R-based therapies to individual needs in obesity and diabetes management., (© 2023. The Author(s), under exclusive licence to Italian Society of Endocrinology (SIE).)

Endocannabinoids (ECs) are potent lipid mediators with high physiological relevance. They are involved in a wide variety of diseases like depression or multiple sclerosis and are closely connected to metabolic parameters in humans. Therefore, their suitability as a biomarker in different (patho-)physiological conditions is discussed intensively and predominantly investigated by analyzing systemic concentrations in easily accessible matrices like blood. Carefully designed pre-analytical sample handling is of major importance for high-quality data, but harmonization is not achieved yet. Whole blood is either processed to serum or plasma before the onset of analytical workflows and while knowledge about pre-analytical challenges in plasma handling is thorough they were not systematically investigated for serum. Therefore, the ECs AEA and 2-AG, and closely related EC-like substances 1-AG, DHEA, and PEA were examined by LC-MS/MS in serum samples of nine healthy volunteers employing different pre-analytical sample handling protocols, including prolonged coagulation, and storage after centrifugation at room temperature (RT) or on ice. Furthermore, all analytes were also assessed in plasma samples obtained from the same individuals at the same time points to investigate the comparability between those two blood-based matrices regarding obtained concentrations and their 2-AG/1-AG ratio. This study shows that ECs and EC-like substances in serum samples were significantly higher than in plasma and are especially prone to ex vivo changes during initial and prolonged storage for coagulation at RT. Storage on ice after centrifugation is less critical. However, storage at RT further increases 1-AG and 2-AG concentrations, while also lowering the already reduced 2-AG/1-AG ratio due to isomerization. Thus, avoidance of prolonged processing at RT can increase data quality if serum as the matrix of choice is unavoidable. However, serum preparation in itself is expected to initiate changes of physiological concentrations as standard precautionary measures like fast and cooled processing can only be utilized by using plasma, which should be the preferred matrix for analyses of ECs and EC-like substances., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Agricultural workers, especially those who work in swine confinement facilities, are at increased risk for developing pulmonary diseases including asthma, chronic obstructive pulmonary disease, and chronic bronchitis due to exposures to fumes, vapors, and organic dust. Repetitive exposure to agricultural dust leads to unresolved inflammation, a common underlying mechanism that worsens lung disease. Besides occupational exposure to dusts, diet also significantly contributes to inflammation and disease progression. Since DHA (docosahexaenoic acid), a polyunsaturated omega-3 fatty acid and its bioactive metabolites have key roles in inflammation resolution, we rationalized that individuals chronically exposed to organic dusts can benefit from dietary modifications. Here, we evaluated the role of DHA in modifying airway inflammation in a murine model of repetitive exposure to an aqueous extract of agricultural dust (three-week exposure to swine confinement dust extract, HDE) and after a one-week resolution/recovery period. We found that mice fed a high DHA diet had significantly increased bronchoalveolar lavage fluid (BALF) levels of DHA-derived resolvins and lower TNFα along with altered plasma levels of endocannabinoids and related lipid mediators. Following the one-week recovery we identified significantly reduced BALF cellularity and cytokine/chemokine release along with increased BALF amphiregulin and resolvins in DHA diet-fed versus control diet-fed mice challenged with HDE. We further report observations on the effects of repetitive HDE exposure on lung Ym1+ and Arg-1+ macrophages. Overall, our findings support a protective role for DHA and identify DHA-derived resolvins and endocannabinoids among the potential mediators of DHA in altering airway inflammation in chronic agricultural dust exposure., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

The endocannabinoid system (ECS) plays a pivotal role in the complex control and regulation of food intake. Pharmacological ECS activation could improve health in energy-deficient stages by increasing food intake, at least in intermittent feeders. However, knowledge of the mechanism regulating appetite in species with continued nutrient delivery is incomplete. The objectives of this pilot study were to investigate the effect of the intraperitoneal (i.p.) administration of the endocannabinoids (ECs) anandamide (AEA) and 2-arachidonoylglycerol (2-AG) on food intake, plasma EC concentrations and hypothalamic orexigenic signaling, and to study how the circulatory EC tone changes in response to short-term food deprivation in dairy cows, a species with continuous nutrient delivery. The administration of EC resulted in higher food intake during the first hour after treatment. Plasma AEA concentrations were significantly increased 2.5 h after AEA injection, whereas plasma 2-AG concentrations remained unchanged 2.5 h after 2-AG injection. The hypothalamic immunoreactivity of cannabinoid receptor 1, agouti-related protein, and orexin-A was not affected by either treatment; however, neuropeptide Y and agouti-related protein mRNA abundances were downregulated in the arcuate nucleus of AEA-treated animals. Short-term food deprivation increased plasma 2-AG, while plasma AEA remained unchanged. In conclusion, i.p.-administered 2-AG and AEA increase food intake in the short term, but only AEA accumulates in the circulation. However, plasma 2-AG concentrations are more responsive to food deprivation than AEA.

Lipid bioactivity is a result of direct action and the action of lipid mediators including oxylipins, endocannabinoids, bile acids and steroids. Understanding the factors contributing to biological variation in lipid mediators may inform future approaches to understand and treat complex metabolic diseases. This research aims to determine the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism. This study recruited 138 monozygotic (MZ) and dizygotic (DZ) twins aged 18-65 years and measured serum oxylipins, endocannabinoids, bile acids and steroids using liquid chromatography mass-spectrometry (LC-MS). In this classic twin design, the similarities and differences between MZ and DZ twins are modelled to estimate the contribution of genetic and environmental influences to variation in lipid mediators. Heritable lipid mediators included the 12-lipoxygenase products 12-hydroxyeicosatetraenoic acid [0.70 (95% CI: 0.12,0.82)], 12-hydroxyeicosatetraenoic acid [0.73 (95% CI: 0.30,0.83)] and 14‑hydroxy-docosahexaenoic acid [0.51 (95% CI: 0.07,0.71)], along with the endocannabinoid docosahexaenoy-lethanolamide [0.52 (95% CI: 0.15,0.72)]. For others such as 13-hydroxyoctadecatrienoic acid and lithocholic acid the contribution of environment to variation was stronger. With increased understanding of lipid mediator functions in health, it is important to understand the factors contributing to their variance. This study provides a comprehensive analysis of lipid mediators and extends pre-existing knowledge of the genetic and environmental influences on the human lipidome., (Copyright © 2021. Published by Elsevier Ltd.)

Cognitive decline is associated with both normal aging and early pathologies leading to dementia. Here we used quantitative profiling of metabolites involved in the regulation of inflammation, vascular function, neuronal function and energy metabolism, including oxylipins, endocannabinoids, bile acids, and steroid hormones to identify metabolic biomarkers of mild cognitive impairment (MCI). Serum samples (n = 212) were obtained from subjects with or without MCI opportunistically collected with incomplete fasting state information. To maximize power and stratify the analysis of metabolite associations with MCI by the fasting state, we developed an algorithm to predict subject fasting state when unknown (n = 73). In non-fasted subjects, linoleic acid and palmitoleoyl ethanolamide levels were positively associated with perceptual speed. In fasted subjects, soluble epoxide hydrolase activity and tauro-alpha-muricholic acid levels were negatively associated with perceptual speed. Other cognitive domains showed associations with bile acid metabolism, but only in the non-fasted state. Importantly, this study shows unique associations between serum metabolites and cognitive function in the fasted and non-fasted states and provides a fasting state prediction algorithm based on measurable metabolites., (© 2021. The Author(s).)

Background: Inflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders. The endocannabinoid system may have a role in the pathogenesis of IBD. We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients., Methods: Blood samples and biopsies were taken from IBD patients treated by either cannabis or placebo for 8 weeks. Immunohistochemistry for N -acyl-phosphatidylethanolamine-selective phospholipase D (NAPE-PLD) and fatty acid amide hydrolase (FAAH) expression was done on colon biopsies, and sample levels of anandamide (AEA), eCB2-arachidonylglycerol (2-AG), arachidonic acid (AA), palmitoylethanolamine (PEA), and oleoylethanolamine (OEA) were measured in patient's sera before and after cannabis treatment. Caco-2 cells were cultured with extracts of cannabis with/without tetrahydrocannabinol (THC) and their proteins extracted, and Western blotting for NAPE-PLD and FAAH expression was done., Results: Thirteen patients with Crohn's disease (CD) and nine patients with ulcerative colitis (UC) were treated with cannabis. Seventeen patients with CD and 10 with UC served as placebo groups. In all CD patients, the levels of eCBs remained unaltered during the treatment period. In UC patients treated with placebo, but not in those treated with cannabis, the levels of PEA, AEA, and AA decreased significantly. The percent reduction in bowel movements was negatively correlated with changes observed in the circulating AEA and OEA, whereas improvement in quality of life was positively correlated with the levels of 2-AG. In the biopsies from UC patients, FAAH levels increased over the study period. In Caco-2 cells, both cannabis extracts increased NAPE-PLD levels but reduced FAAH expression levels., Conclusion: Our study supports the notion that cannabis use affects eCB "tone" in UC patients and may have beneficial effects on disease symptoms in UC patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tartakover Matalon, Azar, Meiri, Hadar, Nemirovski, Abu Jabal, Konikoff, Drucker, Tam and Naftali.)

The endocannabinoid system (ECS) is a complex cell-signaling system. To address the growing need of analytics capturing endocannabinoid levels to investigate the ECS, we developed and validated an assay for the quantitative analysis of 14 endocannabinoids and congeners. A simple extraction using protein precipitation with acetonitrile followed by online-trapping high-performance liquid chromatography-tandem mass spectrometry (LC/LC-MS/MS) was used to monitor the levels of 14 endocannabinoids in plasma. The assay was validated and intra-run and inter-run accuracies and imprecisions as well as matrix effects, recoveries, and sample stabilities were determined. As a proof of concept, a subset of study samples after naturalistic administration of Cannabis flower and concentrate was analyzed. With the exception of N-oleoyl dopamine and oleamide, all endocannabinoids fulfilled the predefined acceptance criteria. Reproducible recoveries and no significant matrix effects were observed. Sample stability was an issue. Analysis of the proof-of-concept study samples revealed a significantly (p = 0.006) higher concentration of docosatetraenoyl ethanolamide in concentrate users (300 ± 13 pg/mL) compared to flower users (252 ± 11 pg/mL). A robust, sensitive high-throughput assay for the quantitation of 14 endocannabinoids and congeners was successfully validated. Our study showed that it is mandatory to (A) appropriately stabilize samples and (B) separate and separately quantify 1-AG and 2-AG; otherwise, study results are unreliable. The analysis of study samples from Cannabis flower users versus Cannabis concentrate users revealed higher levels of docosatetraenoyl ethanolamide and anandamide (n.s.) in high THC concentrate users in accordance with the existing literature, supporting the validity of the assay measurements. Graphical abstract.

Repetitive transcranial magnetic stimulation (rTMS) is an effective and well tolerable biological intervention in major depressive disorder (MDD) contributing to rapid symptom improvement. Molecular mechanisms underpinning the therapeutic effects of rTMS have still not been clarified. Recently published animal data implicated relevant associations with changes in endocannabinoid (eCB) brain levels during rTMS treatment, human studies, however, have not been published. In our study we assessed the detailed phenotypic spectrum of MDD and serum 2-arachidnoylglycerol (2-AG) and anandamide (AEA) levels in 18 patients with treatment-resistant depression before, immediately following, and two weeks after completion of a 10-day rTMS treatment. We found significant associations between serum 2-AG level changes from pretreatment to 2 weeks after treatment and symptom reduction. The greater the increase of 2-AG levels, the greater the improvement of depressive (p = 0.031), anxious (p = 0.007) and anhedonia symptoms (p = 0.047). Here we report for the first time a significant association of human circulating eCB and antidepressant effect of rTMS. Our data may indicate that direct stimulation of targeted brain areas can rapidly alleviate depressive complaints via activation of the eCB system.

Akkermansia muciniphila is considered as one of the next-generation beneficial bacteria in the context of obesity and associated metabolic disorders. Although a first proof-of-concept of its beneficial effects has been established in the context of metabolic syndrome in humans, mechanisms are not yet fully understood. This study aimed at deciphering whether the bacterium exerts its beneficial properties through the modulation of the endocannabinoidome (eCBome). Circulating levels of 25 endogenous endocannabinoid-related lipids were quantified by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in the plasma of overweight or obese individuals before and after a 3 months intervention consisting of the daily ingestion of either alive or pasteurized A. muciniphila . Results from multivariate analyses suggested that the beneficial effects of A. muciniphila were not linked to an overall modification of the eCBome. However, subsequent univariate analysis showed that the decrease in 1-Palmitoyl-glycerol (1-PG) and 2-Palmitoyl-glycerol (2-PG), two eCBome lipids, observed in the placebo group was significantly counteracted by the alive bacterium, and to a lower extent by the pasteurized form. We also discovered that 1- and 2-PG are endogenous activators of peroxisome proliferator-activated receptor alpha (PPARα). We hypothesize that PPARα activation by mono-palmitoyl-glycerols may underlie part of the beneficial metabolic effects induced by A. muciniphila in human metabolic syndrome.

In this study, a novel approach was developed to quantify endocannabinoids (eCBs), and was based on the liquid biosensor BIONOTE. This device is composed of a probe that can be immersed in a solution, and an electronic interface that can record a current related to the oxy-reductive reactions occurring in the sample. The two most representative members of eCBs have been analysed in vitro by BIONOTE: anandamide ( N -arachidonoylethanolamine, AEA) and 2-arachidonoylglycerol (2-AG). Bovine serum albumin was used to functionalize the probe and improve the sensibility of the whole analytical system. We show that BIONOTE is able to detect both AEA and 2-AG at concentrations in the low nanomolar range, and to discriminate between these eCBs and their moieties arachidonic acid, ethanolamine and glycerol. Notably, BIONOTE distinguished these five different molecules, and it was also able to quantify AEA in human plasma. Although this is just a proof-of-concept study, we suggest BIONOTE as a cheap and user-friendly prototype sensor for high throughput quantitation of eCB content in biological matrices, with an apparent diagnostic potential for tomorrow's medicine.

The global obesity epidemic continues to rise worldwide. In this context, unraveling new interconnections between biological systems involved in obesity etiology is highly relevant. Dysregulation of the endocannabinoidome (eCBome) is associated with metabolic complications in obesity. This study aims at deciphering new associations between circulating endogenous bioactive lipids belonging to the eCBome and metabolic parameters in a population of overweight or obese individuals with metabolic syndrome. To this aim, we combined different multivariate exploratory analysis methods: canonical correlation analysis and principal component analysis, revealed associations between eCBome subsets, and metabolic parameters such as leptin, lipopolysaccharide-binding protein, and non-esterified fatty acids (NEFA). Subsequent construction of predictive regression models according to the linear combination of selected endocannabinoids demonstrates good prediction performance for NEFA. Descriptive approaches reveal the importance of specific circulating endocannabinoids and key related congeners to explain variance in the metabolic parameters in our cohort. Analysis of quartiles confirmed that these bioactive lipids were significantly higher in individuals characterized by important levels for aforementioned metabolic variables. In conclusion, by proposing a methodology for the exploration of large-scale data, our study offers additional evidence of the existence of an interplay between eCBome related-entities and metabolic parameters known to be altered in obesity.

Background: The goals of this study were to determine whether serum concentrations of endocannabinoids (eCB) and related lipids predict disease status in patients with amyotrophic lateral sclerosis (ALS) relative to healthy controls, and whether concentrations correlate with disease duration and severity., Methods: Serum concentrations of the eCBs 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA), and related lipids palmitoylethanolamine (PEA), oleoylethanolamine (OEA), and 2-oleoylglycerol (2-OG), were measured in samples from 47 patients with ALS and 19 healthy adults. Hierarchical binary logistic and linear regression analyses assessed whether lipid concentrations predicted disease status (ALS or healthy control), duration, or severity., Results: Binary logistic regression revealed that, after controlling for age and gender, 2-AG, 2-OG and AEA concentrations were unique predictors of the presence of ALS, demonstrating odds ratios of 0.86 (P = .039), 1.03 (P = .023), and 42.17 (P = .026), respectively. When all five lipids and covariates (age, sex, race, ethnicity, body mass index, presence of a feeding tube) were included, the resulting model had an overall classification accuracy of 92.9%. Hierarchical linear regression analyses indicated that in patients with ALS, AEA and OEA inversely correlated with disease duration (P = .030 and .031 respectively), while PEA demonstrated a positive relationship with disease duration (P = .013). None of the lipids examined predicted disease severity., Conclusions: These findings support previous studies indicating significant alterations in concentrations of circulating lipids in patients with ALS. They suggest that arachidonic and oleic acid containing small lipids may serve as biomarkers for identifying the presence and duration of this disease., (© 2020 Wiley Periodicals LLC.)

Background: Patients with ESRD on maintenance hemodialysis (MHD) are particularly susceptible to dysregulation of energy metabolism, which may manifest as protein energy wasting and cachexia. In recent years, the endocannabinoid system has been shown to play an important role in energy metabolism with potential relevance in ESRD. N-acylethanolamines are a class of fatty acid amides which include the major endocannabinoid ligand, anandamide, and the endogenous peroxisome proliferator-activated receptor-α agonists, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA)., Methods: Serum concentrations of OEA and PEA were measured in MHD patients and their correlations with various clinical/laboratory indices were examined. Secondarily, we evaluated the association of circulating PEA and OEA levels with 12-month all-cause mortality., Results: Both serum OEA and PEA levels positively correlated with high-density lipoprotein-cholesterol levels and negatively correlated with body fat and body anthropometric measures. Serum OEA levels correlated positively with serum interleukin-6 (IL-6) (rho = 0.19; p = 0.004). Serum PEA and IL-6 showed a similar but nonsignificant trend (rho = 0.12; p = 0.07). Restricted cubic spline analyses showed that increasing serum OEA and PEA both trended toward higher mortality risk, and these associations were statistically significant for PEA (PEA ≥4.7 pmol/mL; reference: PEA <4.7 pmol/mL) after adjustments in a Cox model (hazard ratio 2.99; 95% confidence interval 1.04, 8.64)., Conclusions: In MHD patients, OEA and PEA are significantly correlated with variables related to lipid metabolism and body mass. Additionally, higher serum levels of PEA are associated with mortality risk. Future studies are needed to examine the potential mechanisms responsible for these findings and their clinical implications., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

Background: Gastroparesis (GP) is a motility disorder of the stomach presenting with upper gastrointestinal symptoms in the setting of delayed gastric emptying. Endocannabinoids are involved in the regulation of GI function including motility. However, their role in the pathophysiology of GP has not been sufficiently investigated. Our goal was to compare the circulating levels of endocannabinoids and cannabimimetic fatty acid derivatives in GP versus control subjects., Methods: The study compared plasma concentrations of endocannabinoids and their lipoamine and 2-acyl glycerol congeners, measured by high-pressure liquid chromatography/tandem mass spectrometry (HPLC-MS-MS), in adult patients with diabetic gastroparesis (DM-GP; n = 24; n = 16 female), idiopathic gastroparesis (ID-GP; n = 19; n = 11 female), diabetic patients without GP (DM; n = 19; n = 10 female), and healthy controls (HC; n = 18; n = 10 female). Data, presented as mean ± SEM, were analyzed with ANOVA (Sidak post hoc)., Key Results: Endocannabinoids anandamide (AEA: 0.5 ± 0.1 nMol/L) and 2-arachidonoyl glycerol (2-AG: 2.6 ± 0.7 nMol/L) were significantly lower in female DM-GP patients vs. DM females (AEA: 2.5 ± 0.7 nMol/L and 2-AG: 9.4 ± 3.3 nMol/L). Other monoacylglycerols including 2-palmitoyl glycerol and 2-oleoyl glycerol were also lower in female DM-GP patients compared to DM females. No changes were observed in men., Conclusions & Inferences: Endocannabinoids and other fatty acid derivatives with cannabimimetic properties are reduced in female DM-GP patients. Since GP, particularly with diabetic etiology, is more prevalent among women and since cannabinoids are antiemetic, this decrease in levels may contribute to symptom development in these subjects. Targeting the endocannabinoid system may be a future therapeutic option in DM-GP patients., (© 2020 John Wiley & Sons Ltd.)

Background: The development and maintenance of anxiety disorders is not fully understood. There is consensus in the literature that in addition to genetic factors, social, psychological and neurobiological factors are of crucial importance. The present exploratory study investigates the influence of the endocannabinoids (EC) and related N-acylethanolamines (NA) on the maintenance of panic disorder (PD)., Methods: A total of n = 36 PD and n = 26 healthy controls (HC) were included in the study. Baseline characteristics showed no differences between the two groups. The participants were exposed to the Trier Social Stress Test (TSST) for reliable laboratory stress induction. Blood samples were taken during the TSST by an intravenous catheter to examine the endocannabinoid (EC) stress response. Repeated measures ANOVA was conducted to test for main effects of time and group as well as the respective interaction., Results: Participants with PD consistently had significantly higher EC and NA blood levels than HC. The consistently high EC and NA levels barely showed any reactivity as indicated by a lack of statistical variance. In line with these findings no reaction to the psychosocial stressor TSST could be detected., Conclusion: Our main results show significant differences in EC concentrations between participants with PD and HC. These findings suggest that an imbalance in the ECS contributes to the maintenance of PD. Increased endocannabinoid levels may have important implications for organic diseases such as cardiovascular disorders. The limitations of the study as well as implications for further investigations are discussed., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Binge eating disorder (BED) is known as the most common eating disorder with both psychosocial and biological factors involved. In this regard, there is a need to recognize probable disturbances in substances involved in food intake regulation in BED. In this study, we hypothesized that the levels of endocannabinoids, fatty acid amid hydrolase (FAAH) gene polymorphisms, and appetite regulatory substances are different in overweight and obese women with and without BED. A Binge Eating Scale was used to estimate the prevalence of BED in 180 women classified as overweight or obese. The levels of anandamide (AEA), 2-arachidonoylglycerol (2-AG), leptin, insulin, and orexin-A were measured by enzyme-linked immunosorbent assay kits. The subjects were genotyped for polymorphisms of FAAH gene using amplification refractory mutation system-polymerase chain reaction. Data were analyzed using SPSS software. About 41.6% (n = 75) of the subjects were diagnosed with BED. Women with BED exhibited significantly higher levels of AEA, 2-AG, leptin, and insulin compared to non-BED women (P < .05). Binary logistic regression analysis also showed that AEA, leptin, and insulin were the predictors of having BED after adjusting for body mass index (P < .05). In addition, the frequency of A allele of FAAH gene was higher in women with BED compared to women without BED; however, there were no significant differences between these 2 groups (P = .08). These results supported our hypothesis in the cases of AEA, 2-AG, leptin, and insulin but not orexin and FAAH gene polymorphisms. The findings of the current study provide further evidence concerning the role of these substances in BED., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The endocannabinoid system (ECS) has been shown to play a critical role in the regulation of alcohol intake and alcohol-related behaviors. However, there are discrepancies between studies examining the interaction of the ECS and alcohol administration due to different experimental procedures. The present study aims at clarifying the time course effects of acute alcohol consumption on the ECS in the peripheral circulatory systems and central nervous systems of the same cohort of subjects. We have closely monitored the critical indicators reflecting changes of the ECS during the entire process from alcohol absorption to its metabolization, after acute alcohol (4.5 g/kg) intake by intragastric administration, including two key endocannabinoids (arachidonoylethanolamide and 2-arachidonoylglycerol) and their hydrolytic enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) in blood and three brain regions, as well as a crucial and abundant receptor (cannabinoid 1 receptor) of the ECS in the three brain regions. Our results indicate that acute alcohol consumption inhibits endocannabinoid (eCB) production in the blood and in the prefrontal cortex of the brain, whereas the reverse was observed in the brain regions of the hippocampus and striatum. The variation between levels of two hydrolytic enzymes in the blood and in the three brain regions failed to reach statistical significance. After acute alcohol consumption, CB1R levels in striatum, hippocampus, and prefrontal cortex showed a similar trend of increasing, while the significant changes occurred at different time points. The present findings reveal different ligand-receptor changing patterns in the blood and in different brain regions, supporting the notion that the ECS plays a vital role in acute alcohol intoxication. Additionally, the temporal effects of alcohol on key elements of the ECS of blood and different brain nuclei were different. Our investigation may lead to a deeper understanding of the effect of acute alcohol consumption on the ECS., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The search for a biomarker for suicide risk is a longstanding pursuit in clinical psychiatry. Literature addressing the role of endocannabinoids in suicide attempters (SA) is sparse. This cross-sectional study is aimed at comparing 8 AM serum concentrations of 4 endogenous cannabinoids (anandamide, AEA; 2-arachidonoylglycerol, 2-AG; N-palmitoiletanolamida, PEA; and oleoylethanolamide, OEA) in 30 suicide attempters (SA) and 12 psychiatric controls (PC). 8 AM AEA and PEA serum levels were higher in SA compared to PC without controlling for cannabis use (n = 42) (3.58 ± 5.77 vs. 1.62 ± 2.49, F = 3.04, P = 0.089; and 3.31 ± 4.82 vs. 1.21 ± 1.20, F = 6.22, p = 0.017, respectively). Serum ACTH was higher in PC compared to SA (32.11 ± 21.60 vs. 20.05 ± 9.96, F = 9.031, p = 0.0.005). After controlling for cannabis use in the urine test (n = 28), 8 AM AEA and PEA serum levels remained higher in SA compared to PC (4.57 ± 6.38 vs. 0.64 ± 1.11, F = 4.852, P = 0.037; and 4.35 ± 5.46 vs. 1.21 ± 1.25, F = 4.125, p = 0.053, respectively). The present study offers preliminary evidence about the role of AEA and PEA in suicidal behavior (SB). Furthermore, in the context of the mental pain model of SB, our findings suggest that some endocannabinoids may play a role in the pathophysiology of SB. Our pilot study deserves replication by other studies with bigger sample sizes., Competing Interests: Conflict of Interest In the last 24 months, Hilario Blasco-Fontecilla received lecture fees from Shire. He is Principal Investigator (PI) of an iPFIS research contract (www.isciii.es; IFI16/00,039) and co-PI of a MINECO research grant (RTI2018–101,857-B-I00); recipient of: 1) a FIPSE Grant, and 2) an IDIPHIPSA intensification Grant; involved in two clinical trials (MENSIA KOALA, NEWROFEED Study; ESKETSUI2002); member of the Advisory Board of ITA Salud Mental. Fernando Sanchez is an employee of TEA ediciones. Maria Rodrigo Yanguas is the recipient of an iPFS research contract (www.isciii.es). The remaining authors do not have any conflict of interest regarding the publication of this manuscript., (Copyright © 2020. Published by Elsevier B.V.)

Bereavement is one of the most intense, distressing, and traumatic events an elderly person will experience. The symptom responses to bereavement vary, particularly during the first year. However, the neurobiology underlying the symptom variance in grief is poorly understood. The endocannabinoid signaling (ECS) system is stress-responsive; mounting evidence implicates the central ECS in psychopathology. The current study aimed to investigate the hypothesis that the ECS is abnormal in grief, using circulating eCB concentrations as a biomarker of central ECS. A predominantly older sample of grief participants, within 13 months following the death of a loved one, and healthy comparison (HC) participants were studied. Associations of circulating eCBs with symptom variance in grievers were also examined. A total of 61 (grief: n = 44; HC: n = 17) adults completed cross-sectional clinical assessments and a fasting blood draw. Assessments included the Inventory of Complicated Grief scale; the 17-item Hamilton Depression Rating Scale; and the Hamilton Anxiety scale. Serum eCB concentrations (i.e., N-arachidonoylethanolamine [AEA] and 2-arachidonoylglycerol [2-AG]) were quantified using isotope dilution, liquid chromatography-mass spectrometry. Relative to HC participants, grievers had significantly elevated serum AEA but similar 2-AG concentrations. In grievers, serum AEA concentrations were positively associated with depressive and anxiety symptoms, but only in those with low grief symptoms. These novel findings indicate that elevated circulating eCB concentrations are found following bereavement. The eCB signaling response varies based on the degree of grief severity. Circulating eCB measures may have the potential to serve as biomarkers of prolonged grief disorder., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The endocannabinoidome encompasses several fatty acid (FA)-derived mediators, including the endocannabinoid anandamide (AEA) and 2-arachidonoyl-glycerol (2-AG), which served as targets for anti-obesity drug development, and their congener N-acyl-ethanolamines (NAEs) and 2-monoacyl-glycerols (2‑MAGs), which are involved in food intake and energy metabolism. Body weight and fat distribution have been suggested as determinants of peripheral endocannabinoid levels. We aimed at investigating factors, beyond body fat composition, that are associated with circulating NAE and 2-MAG levels in a heterogeneous human population. Plasma NAEs and 2-MAGs were measured using LC-MS/MS in a cross-sectional sample of healthy men and women (n = 195) covering a wide range of BMI and individuals before and after a 2-day Mediterranean diet (n = 21). Circulating levels of all 2-MAGs and NAEs, other than N-oleoyl-ethanolamine (OEA), correlated with body fat mass and visceral adipose tissue (0.26 < r < 0.54). NAE levels were elevated in individuals with elevated fat mass, while 2-MAGs were increased in individuals with predominantly visceral body fat distribution. Dietary intakes of specific FAs were associated with 2-AG and omega-3-FA-derived NAEs or 2-MAGs, irrespective of the body fat distribution. Some gut bacterial families (e.g. Veillonellaceae, Peptostreptococcaceae and Akkermansiaceae) were associated with variations in most NAEs or omega-3-FA-derived 2‑MAGs, independently of fat mass and dietary FA intake. Finally, a 2-day Mediterranean diet intervention increased circulating levels of NAEs and 2-MAGs in agreement with changes in FA intake (p < 0.01). Self-reported intake and short-term dietary intervention increased in oleic acid and EPA and DHA intake as well as certain gut microbiota taxa are associated to circulating NAEs and 2‑MAGs independently of adiposity measures, thus highlighting the potential importance of these variables in determining endocannabinoidome signaling in humans.

Acute physical exercise improves memory functions by increasing neural plasticity in the hippocampus. In animals, a single session of physical exercise has been shown to boost anandamide (AEA), an endocannabinoid known to promote hippocampal plasticity. Hippocampal neuronal networks encode episodic memory representations, including the temporal organization of elements, and can thus benefit motor sequence learning. While previous work established that acute physical exercise has positive effects on declarative memory linked to hippocampal plasticity mechanisms, its influence on memory for motor sequences, and especially on neural mechanisms underlying possible effects, has been less investigated. Here we studied the impact of acute physical exercise on motor sequence learning, and its underlying neurophysiological mechanisms in humans, using a cross-over randomized within-subjects design. We measured behavior, fMRI activity, and circulating AEA levels in fifteen healthy participants while they performed a serial reaction time task before and after a short period of exercise (moderate or high intensity) or rest. We show that exercise enhanced motor sequence memory, significantly for high intensity exercise and tending towards significance for moderate intensity exercise. This enhancement correlated with AEA increase, and dovetailed with local increases in caudate nucleus and hippocampus activity. These findings demonstrate that acute physical exercise promotes sequence learning, thus attesting the overarching benefit of exercise to hippocampus-related memory functions.

Traumatic brain injury (TBI) is a frequent cause of chronic headache, fatigue, insomnia, hyperactivity, memory deficits, irritability and posttraumatic stress disorder. Recent evidence suggests beneficial effects of pro-cannabinoid treatments. We assessed in mice levels of endocannabinoids in association with the occurrence and persistence of comparable sequelae after controlled cortical impact in mice using a set of long-term behavioral observations in IntelliCages, motor and nociception tests in two sequential cohorts of TBI/sham mice. TBI mice maintained lower body weights, and they had persistent low levels of brain ethanolamide endocannabinoids (eCBs: AEA, OEA, PEA) in perilesional and subcortical ipsilateral brain tissue (6 months), but rapidly recovered motor functions (within days), and average nociceptive responses were within normal limits, albeit with high variability, ranging from loss of thermal sensation to hypersensitivity. TBI mice showed persistent non-goal directed nighttime hyperactivity, i.e. they visited rewarding and non-rewarding operant corners with high frequency and random success. On successful visits, they made more licks than sham mice resulting in net over-licking. The lower the eCBs the stronger was the hyperactivity. In reward-based learning and reversal learning tasks, TBI mice were not inferior to sham mice, but avoidance memory was less stable. Hence, the major late behavioral TBI phenotype was non-goal directed nighttime hyperactivity and "over-licking" in association with low ipsilateral brain eCBs. The behavioral phenotype would agree with a "post-TBI hyperactivity disorder". The association with persistently low eCBs in perilesional and subcortical regions suggests that eCB deficiency contribute to the post-TBI psychopathology.

Background: A role for endocannabinoids in the male and female reproductive systems has been highlighted during the recent decades. Some of these compounds bind the cannabinoid CB1 receptor, which is abundantly expressed in the central nervous system but also present in the reproductive system, while others act as 'entourage compounds' modulators., Objectives: The present study aimed at evaluating the relationship between sperm quality and endocannabinoid profiles in a cohort of 200 young Swiss men and whether the presence of specific xenobiotics could influence these profiles., Materials and Methods: Semen analysis was performed according to WHO guidelines. Endocannabinoid profiles in blood and semen, as well as bisphenol A and S in urine, were determined by LC-MSMS methods. The presence of selected drugs was tested in urine by immunological screening, and urinary tetrahydrocannabinol (THC) metabolites were quantified by GC-MS., Results: Anandamide concentrations in seminal fluid and oleoylethanolamide (OEA) concentrations in blood serum appeared inversely correlated with sperm motility, while semen palmytoylethanolamide (PEA) was positively linked to sperm concentration. Moreover, OEA and PEA in seminal fluid were associated with better sperm morphology. Interestingly, the concentrations of the same endocannabinoids measured in both blood and semen were not correlated, and the presence of THC metabolites in some individuals was linked to lower concentrations of endocannabinoids., Conclusions: In the context of the general decline of the sperm count observed within the male population, endocannabinoids in semen constitute a class of promising biochemical markers that open new perspectives as a complement for the usual evaluation of semen quality or for the toxicological screening of individuals' exposure to putative endocrine disruptors., (© 2020 American Society of Andrology and European Academy of Andrology.)

Acute liver injury (ALI) is a highly destructive and potentially life-threatening condition, exacerbated by physical and psychological stress. The endocannabinoid system plays a key role in modulating stress and hepatic function. The aim of this study was to examine the development of acute liver injury in the genetically susceptible stress-sensitive Wistar-Kyoto (WKY) rat compared with normo-stress-sensitive Sprague Dawley (SD) rats, and associated changes in the endocannabinoid system. Administration of the hepatotoxin lipopolysaccharide/D-Galactosamine (LPS/GalN) resulted in marked liver injury in WKY, but not SD rats, with increased alanine aminotransferase (ALT), aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) plasma levels, significant histopathological changes, increased hepatic pro-inflammatory cytokine expression and caspase-3 activity and expression and reduced Glutathione (GSH) activity. Furthermore, compared to SD controls, WKY rats display increased anandamide and 2-Arachidonoylglycerol levels concurrent with decreased expression of their metabolic enzymes and a decrease in cannabinoid (CB) 1 receptor expression following LPS/GalN. CB 1 antagonism with AM6545 or CB 2 agonism with JWH133 did not alter LPS/GalN-induced liver injury in SD or WKY rats. These findings demonstrate exacerbation of acute liver injury induced by LPS/GalN in a stress-sensitive rat strain, with effects associated with alterations in the hepatic endocannabinoid system. Further studies are required to determine if the endocannabinoid system mediates or modulates the exacerbation of liver injury in this stress-sensitive rat strain.