Analysis of 14 endocannabinoids and endocannabinoid congeners in human plasma using column switching high-performance atmospheric pressure chemical ionization liquid chromatography-mass spectrometry

The Interplay of Exogenous Cannabinoid Use on Anandamide and 2-Arachidonoylglycerol in Anxiety: Results from a Quasi-Experimental Ad Libitum Study

The public is increasingly reporting using cannabis for anxiety relief. Both cannabis use and the endocannabinoid system have been connected with anxiety relief/anxiolytic properties, but these relationships are complex, and the underlying mechanisms for them are unclear. Background/Objectives: Work is needed to understand how the endocannabinoid system, including the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), may be impacted by the main constituents of cannabis, Δ9-tetrahydrocannabinol (THC), and cannabidiol (CBD). Methods: The current study examined how the ab libitum use of products differing in THC and CBD affected AEA and 2-AG among 292 individuals randomly assigned to THC-dominant use (N = 92), CBD-dominant use (N = 97), THC + CBD use (N = 74), or non-use (N = 29). Results: The findings suggest that AEA levels do not change differently based on 4 weeks of cannabis use or by cannabinoid content, as AEA similarly increased across all conditions from study weeks 2 to 4. In contrast, AEA decreased at an acute administration session with product conditions containing any THC having greater AEA levels on average than the non-use condition. With regard to 2-AG, its levels appeared to primarily be affected by THC-dominant use, both acutely and over 4 weeks, when controlling for baseline cannabis use and examining study product use frequency among use conditions. Conclusions: Overall, the results continue to shed light on the complicated relationship between cannabinoid content and endocannabinoid production, and highlight the need for continued research on their interplay in human subjects.

Advances in targeted liquid chromatography-tandem mass spectrometry methods for endocannabinoid and N-acylethanolamine quantification in biological matrices: A systematic review

Liquid chromatography paired with tandem mass spectrometry (LC-MS/MS) is the gold standard in measurement of endocannabinoid concentrations in biomatrices. We conducted a systematic review of literature to identify advances in targeted LC-MS/MS methods in the period 2017-2024. We found that LC-MS/MS methods for endocannabinoid quantification are relatively consistent both across time and across biomatrices. Recent advances have primarily been in three areas: (1) sample preparation techniques, specific to the chosen biomatrix; (2) the range of biomatrices tested, recently favoring blood matrices; and (3) the breadth of endocannabinoid and endocannabinoid-like analytes incorporated into assays. This review provides a summary of the recent literature and a guide for researchers looking to establish the best methods for quantifying endocannabinoids in a range of biomatrices.

Endocannabinoid system alterations in schizophrenia: association with cannabis use and antipsychotic medication

Determining peripheral modulation of the endocannabinoid system (ECS) may be important for differentiating individuals with schizophrenia. Such differentiation can also be extended to subgroups of individuals, those who use cannabis and antipsychotic medications, particularly those who are treatment resistant. Patients and controls were recruited from the outpatient clinic of the Psychosis Group of the University of São Paulo, Brazil. A final sample of 93 individuals was divided into 3 groups: patients with schizophrenia using clozapine (treatment-resistant) (n = 29), patients with schizophrenia using another antipsychotic (n = 31), and controls (n = 33). By measuring the proteins and metabolites involved in the ECS pathways in the peripheral blood, AEA (anandamide), 2-AG (2-arachidonoyl ethanolamine), and CB2 receptor (peripheral) were quantified. Individuals reporting lifetime cannabis use had lower 2-AG plasma levels (p = 0.011). Regarding the CB2 receptor, the values of patients with schizophrenia and controls were similar, but those of patients using antipsychotics other than clozapine differed (p = 0.022). In generalized linear models to control for confounders, the use of cannabis remained the only factor that significantly influenced 2-AG levels. The relationship for non-clozapine antipsychotics as the only factor related to CB2 changes was marginally significant. We found for the first time that cannabis use and non-clozapine antipsychotic medication are potentially involved in the modulation of the ECS, specifically influencing 2-AG endocannabinoid and CB2 receptor levels. More studies regarding the ECS are needed since it has been increasingly related to the physiopathology of schizophrenia.

Microbiome metabolite quantification methods enabling insights into human health and disease

Many of the health-associated impacts of the microbiome are mediated by its chemical activity, producing and modifying small molecules (metabolites). Thus, microbiome metabolite quantification has a central role in efforts to elucidate and measure microbiome function. In this review, we cover general considerations when designing experiments to quantify microbiome metabolites, including sample preparation, data acquisition and data processing, since these are critical to downstream data quality. We then discuss data analysis and experimental steps to demonstrate that a given metabolite feature is of microbial origin. We further discuss techniques used to quantify common microbial metabolites, including short-chain fatty acids (SCFA), secondary bile acids (BAs), tryptophan derivatives, N-acyl amides and trimethylamine N-oxide (TMAO). Lastly, we conclude with challenges and future directions for the field.

β-Caryophyllene Inhibits Monoacylglycerol Lipase Activity and Increases 2-Arachidonoyl Glycerol Levels In Vivo: A New Mechanism of Endocannabinoid-Mediated Analgesia?

The mechanisms of β-caryophyllene (BCP)-induced analgesia are not well studied. Here, we tested the efficacy of BCP in an acute postsurgical pain model and evaluated its effect on the endocannabinoid system. Rats were treated with vehicle and 10, 25, 50, and 75 mg/kg BCP. Paw withdrawal responses to mechanical stimuli were evaluated using an electronic von Frey anesthesiometer. Endocannabinoids, including 2-arachidonoylglycerol (2-AG), were also evaluated in plasma and tissues using high-performance liquid chromatography-tandem mass spectrometry. Monoacylglycerol lipase (MAGL) activity was evaluated in vitro as well as ex vivo. We observed a dose-dependent and time-dependent alleviation of hyperalgesia in incised paws up to 85% of the baseline value at 30 minutes after administration of BCP. We also observed dose-dependent increases in the 2-AG levels of about threefold after administration of BCP as compared with vehicle controls. Incubations of spinal cord tissue homogenates from BCP-treated rats with isotope-labeled 2-arachidonoylglycerol-d8 revealed a reduced formation of the isotope-labeled MAGL product 2-AG-d8 as compared with vehicle controls, indicating MAGL enzyme inhibition. In vitro MAGL enzyme activity assessment using 2-AG as the substrate revealed an IC50 of 15.8 µM for MAGL inhibition using BCP. These data showed that BCP inhibits MAGL activity in vitro and in vivo, causing 2-AG levels to rise. Since the endocannabinoid 2-AG is a CB1 and CB2 receptor agonist, we propose that 2-AG-mediated cannabinoid receptor activation contributes to BCP's mechanism of analgesia. SIGNIFICANCE STATEMENT: β-Caryophyllene (BCP) consumption is relatively safe and is approved by the Food and Drug Administration as a flavoring agent, which can be used in cosmetic and food additives. BCP is a potent anti-inflammatory agent that showed substantial antihyperalgesic properties in this study of acute pain suggesting that BCP might be an alternative to opioids. This study shows an additive mechanism (monoacylglycerol lipase inhibition) by which BCP might indirectly alter CB1 and CB2 receptor activity and exhibit its pharmacological properties.

Quantification of Endocannabinoids in Human Plasma

The determination of the concentration of endocannabinoids and related compounds in human plasma has become a matter of interest due to their implication in physiological processes and, thus, their possible relation with physiological conditions or illnesses. The analysis of these compounds though has to be carefully designed as they are found in very low concentrations, and some of them degrade easily once blood is collected. In this chapter, a simple method based on a liquid-liquid extraction and analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) is described to determine the concentration of eight of the most relevant endocannabinoids in plasma.

Measuring the Content of Endocannabinoid-Like Compounds in Biological Fluids: A Critical Overview of Sample Preparation Methodologies

Different mass spectrometric techniques have been used over the past decade to quantify endocannabinoids (eCBs) and related lipids. Even with the level of molecular fingerprinting accuracy of an instrument like the most advanced triple quadrupole mass spectrometer, if one is not getting the most optimized sample to the detector in a way that this improved technology can be of use, then advancements can be stymied. Here, our focus is on review and discussion of sample preparation methodologies used to isolate the eCB anandamide and its close congeners N-acyl ethanolamines and structural congeners (i.e., lipo amino acids, lipoamines, N-acyl amides) in biological fluids. Most of our focus will be on the analysis of these lipids in plasma/serum, but we will also discuss how the same techniques can be used for the analysis of saliva and breast milk.

The Role of Cannabinoids in Bone Metabolism: A New Perspective for Bone Disorders

Novel interest has arisen in recent years regarding bone, which is a very complex and dynamic tissue deputed to several functions ranging from mechanical and protective support to hematopoiesis and calcium homeostasis maintenance. In order to address these tasks, a very refined, continuous remodeling process needs to occur involving the coordinated action of different types of bone cells: osteoblasts (OBs), which have the capacity to produce newly formed bone, and osteoclasts (OCs), which can remove old bone. Bone remodeling is a highly regulated process that requires many hormones and messenger molecules, both at the systemic and the local level. The whole picture is still not fully understood, and the role of novel actors, such as the components of the endocannabinoids system (ECS), including endogenous cannabinoid ligands (ECs), cannabinoid receptors (CBRs), and the enzymes responsible for endogenous ligand synthesis and breakdown, is extremely intriguing. This article reviews the connection between the ECS and skeletal health, supporting the potential use of cannabinoid receptor ligands for the treatment of bone diseases associated with accelerated osteoclastic bone resorption, including osteoporosis and bone metastasis.