Chloroform-based liquid-liquid extraction and LC-MS/MS quantification of endocannabinoids, cortisol and progesterone in human hair

Sex-Specific Changes to Brain Fatty Acids, Plasmalogen, and Plasma Endocannabinoids in Offspring Exposed to Maternal and Postnatal High-Linoleic-Acid Diets

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.

A Gold Nanoparticle-Based Cortisol Aptasensor for Non-Invasive Detection of Fish Stress

Cortisol is a key stress biomarker in humans and animals, including fishes. In aquafarming, stress monitoring using cortisol quantification can help to optimize aquaculture practices for welfare and productivity enhancement. However, most current methods for cortisol detection rely on invasive tissue sampling. In this work, we developed a gold nanoparticle (AuNP)-based cortisol sensor to address the demand of detecting picomolar ranges of cortisol from complex fish tank water matrices as a non-invasive alternative for more effective stress monitoring. We first identified a DNA aptamer with effective binding to cortisol and then conjugated the thiol-labelled aptamer to AuNPs together with a blocker molecule (CALNN) to form an Au-Apt-CALNN conjugate that is stable in fish tank water. The cortisol detection principle is based on magnesium chloride (MgCl2)-induced particle aggregation, where the cortisol-bound aptamer on the AuNPs folds into a tertiary structure and provides greater protection for Au-Apt-CALNN against MgCl2-induced aggregation due to steric stabilization. At an optimum MgCl2 concentration, the differential stability of particles with and without cortisol binding offers a limit of detection (LOD) of 100 pM for cortisol within a 35 min reaction. The aptasensor has been validated on recirculating aquaculture system (RAS) fish tank water samples by the HPLC method and was able to detect changes in water cortisol induced by two different stress paradigms. This on-site deployable and non-invasive sensor offers opportunities for more efficient and real-time fish stress monitoring for the optimization of aquaculture practices.

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.

Trauma film viewing and intrusive memories: Relationship between salivary alpha amylase, endocannabinoids, and cortisol

The endogenous cannabinoid (ECB) system is a small molecule lipid signalling system that is involved in stress response activation and is associated with PTSD, but it is unclear whether salivary ECBs are part of the sympathetic nervous system response to stress. We conducted an adapted trauma film paradigm, where participants completed a cold pressor test (or control) while watching a 10-minute trauma film. We also collected saliva and hair samples and tested them for ECBs, cortisol, and salivary alpha amylase (sAA). As hypothesised, there were significant positive correlations between sAA activity and salivary ECB levels, particularly 2-arachidonoyl glycerol (2-AG), though ECBs were not correlated with sAA stress reactivity. Participants who had a significant cortisol response to the trauma film/stressor reported less intrusive memories, which were also less distressing and less vivid. This effect was moderated by arachidonoyl ethanolamide (AEA), where decreases in AEA post-stress were associated with more intrusive memories in cortisol non-responders only. This study provides new evidence for the role of ECBs in the sympathetic nervous system.

Cyanoacetohydrazide as a Novel Derivatization Agent for the Determination of UHPLC-HRMS Steroids in Urine

The possibility of cyanoacetohydrazide usage as a novel derivatizing agent is demonstrated in the presented article, and a comparison with hydroxylamine as the most commonly used reagent is provided. Optimal conditions for steroid derivatization with cyanoacetohydrazide are provided. According to the collected data, the maximum yield of derivatives was observed at pH 2.8 within 70 min at 40 °C with 5 ng/mL limit of detection for all investigated analytes. It was shown that cyanoacetohydrazide derivatives produces both syn- and anti-forms as well as hydroxylamine, and their ratios were evaluated and shown in presented work. An efficiency enchantment from two to up to five times was achieved with a novel derivatization reagent. Its applicability for qualitative analysis of steroids in urine was presented at real samples. Additionally, the reproducible fragmentation of the derivatizing agent in collision-induced dissociation offers opportunities for simplified non-targeted steroidomic screening. Furthermore, cyanoacetohydrazide increases ionization efficiency in positive mode, which can eliminate the need for redundant high-resolution instrument runs required for both positive and negative mode analyses.

Sex-dimorphism in human serum endocannabinoid and n-acyl ethanolamine concentrations across the lifespan

The endocannabinoid (ECB) system has recently been considered a potential treatment target for various clinical disorders. However, research around age- and sex-related changes within the ECB system is relatively limited. To improve our understanding of these changes, the current study measured arachidonoyl ethanolamide (AEA), 2-arachidonoyl glycerol (2-AG), oleoylethanolamine (OEA), palmitoylethanolamine (PEA), arachidonic acid (AA), cortisol, and progesterone in pooled serum samples stratified by sex (male and female) and age groups (5-15; 15-30; 30-45; 45-60; 60-75; 85+), using liquid-chromatography tandem mass spectrometry. Serum progesterone levels significantly increased in females of the 15-30 and 30-45 age groups, before declining. Significantly higher cortisol, AEA, 2-AG, OEA, and PEA were found in males and in older age, while significantly higher AA was found in females. Our results indicate that ECBs and related hormones exhibit sexual dimorphism in the age ranges that correspond with female pregnancy, menopause, and post menopause. Male testosterone levels most likely influences male ECB changes throughout the lifespan. Future research could capitalise on these findings by performing repeated measurements in individuals in a longitudinal style, to further refine the temporal profile of age-specific changes to the ECB system identified here.

Fear conditioning depends on the nature of the unconditional stimulus and may be related to hair levels of endocannabinoids

The replicability of fear conditioning research has come under recent scrutiny, with increasing acknowledgment that the use of differing materials and methods may lead to incongruent results. Direct comparisons between the main two unconditional stimuli used in fear conditioning - an electric shock or a loud scream-are scarce, and yet these stimuli are usually used interchangeably. In the present study, we tested whether a scream, a shock, or an unpredictable combination of the two affected fear acquisition, extinction, and return of fear amongst healthy participants (N = 109, 81 female). We also collected hair samples and tested the relationship between fear conditioning and hair endocannabinoid levels. Our findings suggest that, although subjective ratings of pleasantness, arousal, and anxiety were similar regardless of the unconditional stimuli used, skin conductance responses were significantly lower for stimuli paired with the scream compared to a shock alone. Further, reducing the predictability of the unconditional stimulus reduced habituation of skin conductance responses during acquisition and reacquisition, but did not produce stronger conditioning compared to shock alone. Exploratory analyses suggested that hair endocannabinoids were associated with overall physiological arousal during fear conditioning, as well as higher return of fear to the threat cue, but not to the safety cue. These findings have multiple implications for the design and replicability of fear conditioning research and provide the first evidence for an association between hair levels of endocannabinoids and human fear conditioning.

Hair endocannabinoids predict physiological fear conditioning and salivary endocannabinoids predict subjective stress reactivity in humans

On the basis of substantial preclinical evidence, the endogenous cannabinoid system has been proposed to be closely involved in stress reactivity and extinction of fear. Existing human research supports this proposal to some extent, but existing studies have used only a narrow range of tools and biomatrices to measure endocannabinoids during stress and fear experiments. In the present study we collected hair and saliva samples from 99 healthy participants who completed a fear conditioning and intrusive memory task. Subjective, physiological and biological stress reactivity to a trauma film, which later served as unconditional stimulus during fear conditioning, was also measured. We found that salivary endocannabinoid concentrations predicted subjective responses to stress, but not cortisol stress reactivity, and replicated previous findings demonstrating a sex dimorphism in hair and salivary endocannabinoid levels. Hair 2-arachidonoyl glycerol levels were significantly associated with better retention of safety learning during extinction and renewal phases of fear conditioning, while hair concentrations of oleoylethanolamide and palmitoylethanolamide were associated with overall physiological arousal, but not conditional learning, during fear conditioning. This study is the first to test the relationship between hair and salivary endocannabinoids and these important psychological processes. Our results suggest that these measures may serve as biomarkers of dysregulation in human fear memory and stress.

Applied Clinical Tandem Mass Spectrometry-Based Quantification Methods for Lipid-Derived Biomarkers, Steroids and Cannabinoids: Fit-for-Purpose Validation Methods

The emergence of metabolomics and quantification approaches is revealing new biomarkers applied to drug discovery. In this context, tandem mass spectrometry is the method of choice, requiring a specific validation process for preclinical and clinical applications. Research on the two classes of lipid mediators, steroids and cannabinoids, has revealed a potential interaction in cannabis addiction and metabolism-related disorders. Here we present the development of GC-MS/MS and LC-MS/MS methods for routine quantification of targeted steroids and cannabinoids, respectively. The methods were developed using an isotopic approach, including validation for linearity, selectivity, LLOQ determination, matrix effect, carryover, between- and within-run accuracy and precision, and stability tests to measure 11 steroids and seven cannabinoids in human plasma. These methods were satisfactory for most validity conditions, although not all met the acceptance criteria for all analytes. A comparison of calibration curves in biological and surrogate matrices and in methanol showed that the latter condition was more applicable for our quantification of endogenous compounds. In conclusion, the validation of our methods met the criteria for GLP-qualified rather than GLP-validated methods, which can be used for routine analytical studies for dedicated preclinical and clinical purposes, by combining appropriate system suitability testing, including quality controls in the biological matrix.

Translation of animal endocannabinoid models of PTSD mechanisms to humans: Where to next?

The endocannabinoid system is known to be involved in mechanisms relevant to PTSD aetiology and maintenance, though this understanding is mostly based on animal models of the disorder. Here we review how human paradigms can successfully translate animal findings to human subjects, with the view that substantially increased insight into the effect of endocannabinoid signalling on stress responding, emotional and intrusive memories, and fear extinction can be gained using modern paradigms and methods for assessing the state of the endocannabinoid system in PTSD.

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.

Fast accurate quantification of salivary cortisol and cortisone in a large-scale clinical stress study by micro-UHPLC-ESI-MS/MS using a surrogate calibrant approach

Cortisol and cortisone are common markers for stress and thus preferentially analyzed in matrices that allow non-invasive sampling such as saliva. Though the major drawback of immunoassays is lack of specificity due to cross reactivities, they are still most commonly used for quantification of steroid hormones. To overcome such problems, sensitive methods based on liquid chromatography-mass spectrometry are becoming more and more accepted as the golden standard for steroid bioanalysis as they achieve accurate quantification at trace levels for multiple analytes in the same run. Along this line, the aim of this study was the development of a new microflow UHPLC-ESI-MS/MS method for the measurement of salivary cortisol and cortisone, which due to its microflow regime provides enhanced sensitivity and is more ecofriendly. The developed method implemented sample preparation by Solid-Phase Extraction (SPE) in a 96-well plate format. Data acquisitions were carried out in MRM (multiple reaction monitoring) mode. The quantitative determination of endogenous compounds in saliva remains a challenge since analyte-free matrix is lacking. Hence, a surrogate calibrant approach with cortisol-d₄ andcortisone-¹³C₃ was applied for the target compounds in the presented method. A number of factors were optimized and the method validated. The lower limit of quantitation (LLOQ) was 72 and 62 pg mL^-1for cortisol and cortisone, respectively. Linear calibration was achieved in the range from 0.062 to 75.5 ng mL^-1for cortisol-d₄ and 0.072 to 44 ng mL^-1forcortisone-¹³C₃. The performance of the method was also evaluated via proficiency test for salivary cortisol. Finally, it was applied successfully to evaluate cortisol and cortisone concentrations in multiple batches in routine clinical stress study samples (4056 total injections with 1983 study samples). Moreover, the instrument performance (in particular retention time variability) within each batch, between different batches and lot-to-lot of 5 investigated capillary columns over time is described. The work documents that micro-UHPLC-ESI-MS/MS is suitable and robust enough to carry out a full clinical study with greater than 1000s of samples over an extended period if adequate internal standards can be used.