Identification of synthetic cathinone positional isomers using electron activated dissociation mass spectrometry.

BACKGROUND: Synthetic cathinones (SCs) are a large category of new psychoactive substances (NPS), which pose a serious threat to public health due to limited information about their toxicology and pharmacology. Many SCs are closely related in their chemical structures, with some substances being positional isomers. In this study, we propose a new workflow for the identification of SC isomers using liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS2) combined with electron activated dissociation (EAD) and chemometrics. Differentiation between isomeric SCs is essential for both legislative and public safety reasons, since minor differences in their molecular structures may change their legal status and pharmacological profiles. RESULTS: The workflow was optimized using ring-substituted isomers of methylmethcathinones, methylethcathinones, and chloromethcathinones. The kinetic energy in the EAD cell was investigated at three levels (i.e., 15, 18, and 20 eV) for each group. Two data analysis methods (i.e., t-distributed stochastic neighbor embedding [t-SNE] and a Random Forest [RF] algorithm) were applied using the obtained EAD mass spectral data. The three sets of ring-substituted SCs were clearly distinguished using t-SNE and an RF algorithm. Moreover, the RF approach resulted in a 97 % classification accuracy for isomer identification using various combinations of compounds, isomers, and electron kinetic energies. This workflow was subsequentially applied to the analysis of 26 blind street samples, resulting in a 92 % classification accuracy for isomer identification. However, the accuracy varied based on the kinetic electron energy. A subset of the original data set, focusing on 15-eV data only, was used, resulting in a classification accuracy of 100 %. SIGNIFICANCE: This study presents the first LC-HRMS2 workflow based on EAD and chemometrics, which resulted in a classification accuracy of 100 % of authentic street samples. The developed LC-HRMS2 workflow demonstrates that EAD product ions and their characteristic ion ratios can be successfully used to identify ring-substituted positional isomers of SCs.

Cold-induced changes in plasma signaling lipids are associated with a healthier cardiometabolic profile independently of brown adipose tissue.

Cold exposure activates brown adipose tissue (BAT) and potentially improves cardiometabolic health through the secretion of signaling lipids by BAT. Here, we show that 2 h of cold exposure in young adults increases the levels of omega-6 and omega-3 oxylipins, the endocannabinoids (eCBs) anandamide and docosahexaenoylethanolamine, and lysophospholipids containing polyunsaturated fatty acids. Contrarily, it decreases the levels of the eCBs 1-LG and 2-LG and 1-OG and 2-OG, lysophosphatidic acids, and lysophosphatidylethanolamines. Participants overweight or obese show smaller increases in omega-6 and omega-3 oxylipins levels compared to normal weight. We observe that only a small proportion (∼4% on average) of the cold-induced changes in the plasma signaling lipids are slightly correlated with BAT volume. However, cold-induced changes in omega-6 and omega-3 oxylipins are negatively correlated with adiposity, glucose homeostasis, lipid profile, and liver parameters. Lastly, a 24-week exercise-based randomized controlled trial does not modify plasma signaling lipid response to cold exposure.

Higher Plasma Levels of Endocannabinoids and Analogues Correlate With a Worse Cardiometabolic Profile in Young Adults.

CONTEXT: The endocannabinoid system (ECS) is a signaling system composed of endocannabinoids (eCBs), their receptors, and the enzymes involved in their synthesis and metabolism. Alterations in the ECS are linked to the development of cardiometabolic diseases. OBJECTIVE: Here, we investigated the relationship between plasma levels of eCBs and their analogues with body composition and cardiometabolic risk factors. METHODS: The study included 133 young adults (age 22.1 ± 2.2 years, 67% women). Fasting plasma levels of eCBs and their analogues were measured using liquid chromatography-tandem mass spectrometry. Body composition, brown adipose tissue (BAT) volume, glucose uptake, and traditional cardiometabolic risk factors were measured. RESULTS: Plasma levels of eCBs and several eCB analogues were positively correlated with adiposity and traditional cardiometabolic risk factors (eg, serum insulin and triacylglyceride levels, all r ≥ 0.17 and P ≤ .045). Plasma levels of 2-arachidonoyl glycerol and N-pentadecenoylethanolamine were negatively correlated with BAT volume and glucose uptake (all r ≤ -0.17 and P ≤ .047). We observed that the plasma levels of eCBs and their analogues were higher in metabolically unhealthy overweight-obese participants than in metabolically healthy overweight-obese participants. CONCLUSION: Our findings show that the plasma levels of eCBs and their analogues are related to higher levels of adiposity and worse cardiometabolic profile.

Electron activated dissociation - a complementary fragmentation technique to collision-induced dissociation for metabolite identification of synthetic cathinone positional isomers.

Over the last decade, a remarkable number of new psychoactive substances (NPS) have emerged onto the drug market, resulting in serious threats to both public health and society. Despite their abundance and potential toxicity, there is little information available on their metabolism, a crucial piece of information for clinical and forensic purposes. NPS metabolism can be studied using in vitro models, such as liver microsomes, cytosol, hepatocytes, etc. The tentative structural elucidation of metabolites of NPS formed using in vitro models is typically carried out using liquid chromatography combined with high-resolution tandem mass spectrometry (LC-HRMS2) with collision-induced dissociation (CID) as a fragmentation method. However, the thermally-excited ions produced with CID may not be sufficient for unambiguous identification of metabolites or their complete characterization. Electron-activated dissociation (EAD), a relatively new fragmentation approach that can be used to fragment singly-charged ions, may provide complementary structural information that can be used to further improve the confidence in metabolite identification. The aim of this study was to compare CID and EAD as fragmentation methods for the characterization and identification of synthetic cathinone positional isomers and their metabolites. The in vitro metabolism of 2-methylethcathinone (2-MEC), 3-methylethcathinone (3-MEC) and 4-methylethcathinone (4-MEC) was investigated with both CID and EAD methods using LC-HRMS2. Four, seven and six metabolites were tentatively identified for the metabolism of 2-MEC, 3-MEC and 4-MEC, respectively. Here, the metabolism of 3-MEC and 2-MEC is reported for the first time. The EAD product ion mass spectra showed different fragmentation patterns compared to CID, where unique and abundant product ions were observed in EAD but not in CID. More importantly, certain EAD exclusive product ions play a significant role in structural elucidation of some metabolites. These results highlight the important role that EAD fragmentation can play in metabolite identification workflows, by providing additional fragmentation data compared with CID and, thus, enhancing the confidence in structural elucidation of drug metabolites.

In vitro metabolism of cathinone positional isomers: does sex matter?

Synthetic cathinones, one of the most prevalent categories of new psychoactive substances, have been posing a serious threat to public health. Methylmethcathinones (MMCs), notably 3-MMC, have seen an alarming increase in their use in the last decade. The metabolism and toxicology of a large majority of synthetic cathinones, including 3-MMC and 2-MMC, remain unknown. Traditionally, male-derived liver materials have been used as in vitro metabolic incubations to investigate the metabolism of xenobiotics, including MMCs. Therefore, little is known about the metabolism in female-derived in vitro models and the potential sex-specific differences in biotransformation. In this study, the metabolism of 2-MMC, 3-MMC, and 4-MMC was investigated using female rat and human liver microsomal incubations, as well as male rat and human liver microsomal incubations. A total of 25 phase I metabolites of MMCs were detected and tentatively identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Seven sex-specific metabolites were detected exclusively using pooled male rat liver microsomal incubations. In addition, the metabolites generated from the sex-dependent in vitro metabolic incubations that were present in both male and female rat liver microsomal incubations showed differences in relative abundance. Yet, neither sex-specific metabolites nor significant differences in relative abundance were observed from pooled human liver microsomal incubations. This is the first study to report the phase I metabolic pathways of MMCs using in vitro metabolic incubations for both male and female liver microsomes, and the relative abundance of the metabolites observed from each sex.

The relative abundance of fecal bacterial species belonging to the Firmicutes and Bacteroidetes phyla is related to plasma levels of bile acids in young adults.

BACKGROUND: Gut bacteria play a crucial role in the metabolism of bile acids (BA). Whether an association exists between the fecal microbiota composition and circulating BA levels in humans is poorly understood. Here, we investigated the relationship between fecal microbiota diversity and composition with plasma levels of BA in young adults. METHODS: Fecal microbiota diversity/composition was analyzed with 16S rRNA sequencing in 80 young adults (74% women; 21.9 ± 2.2 years old). Plasma levels of BA were measured using liquid chromatography-tandem mass spectrometry. PERMANOVA and Spearman correlation analyses were used to investigate the association between fecal microbiota parameters and plasma levels of BA. RESULTS: Fecal microbiota beta (P = 0.025) and alpha diversity indexes of evenness (rho = 0.237, P = 0.033), Shannon (rho = 0.313, P = 0.004), and inverse Simpson (rho = 0.283, P = 0.010) were positively associated with plasma levels of the secondary BA glycolithocholic acid (GLCA). The relative abundance of genera belonging to the Firmicutes and Bacteroidetes phyla was positively correlated with plasma levels of GLCA (all rho ≥ 0.225, P ≤ 0.049). However, the relative abundance of species from Firmicutes and Bacteroidetes phyla were negatively correlated with plasma levels of primary and secondary BA (all rho ≤ - 0.220, P ≤ 0.045), except for the relative abundance of Bacteroides vulgatus, Alistipes onderdonkii, and Bacteroides xylanisolvens species (Bacteroidetes phylum) that were positively correlated with the plasma levels of GLCA. CONCLUSIONS: The relative abundance of specific fecal bacteria species is associated with plasma levels of BA in young adults. However, further investigations are required to validate whether the composition of the gut microbiota can regulate the plasma concentrations of BA in humans.

A bout of endurance and resistance exercise transiently decreases plasma levels of bile acids in young, sedentary adults.

Circulating bile acids (BA) are signaling molecules that control glucose and lipid metabolism. However, the effects of acute exercise on plasma levels of BA in humans remain poorly understood. Here, we evaluate the effects of a bout of maximal endurance exercise (EE) and resistance exercise (RE) on plasma levels of BA in young, sedentary adults. Concentration of eight plasma BA was measured by liquid chromatography-tandem mass spectrometry before and 3, 30, 60, and 120 min after each exercise bout. Cardiorespiratory fitness (CRF) was assessed in 14 young adults (21.8 ± 2.5 yo, 12 women); muscle strength was assessed in 17 young adults (22.4 ± 2.5 yo, 11 women). EE transiently decreased plasma levels of total, primary, and secondary BA at 3 and 30 min after exercise. RE exerted a prolonged reduction in plasma levels of secondary BA (p < 0.001) that lasted until 120 min. Primary BA levels of cholic acid (CA) and chenodeoxycholic acid (CDCA) were different across individuals with low/high CRF levels after EE (p ≤ 0.044); CA levels were different across individuals with low/high handgrip strength levels. High CRF individuals presented higher levels of CA and CDCA 120 min after exercise vs baseline (+77% and +65%) vs the low CRF group (-5% and -39%). High handgrip strength levels individuals presented higher levels of CA 120 min after exercise versus baseline (+63%) versus the low handgrip strength group (+6%). The study findings indicate that an individual's level of physical fitness can influence how circulating BA respond to both endurance and resistance exercise. Additionally, the study suggests that changes in plasma BA levels after exercising could be related to the control of glucose homeostasis in humans.

Trapped ion mobility mass spectrometry of new psychoactive substances: Isomer-specific identification of ring-substituted cathinones.

New psychoactive substances (NPS) are synthetic derivatives of illicit drugs designed to mimic their psychoactive effects. NPS are typically not controlled under drug acts or their legal status depends on their molecular structure. Discriminating isomeric forms of NPS is therefore crucial for forensic laboratories. In this study, a trapped ion mobility spectrometry time-of-flight mass spectrometry (TIMS-TOFMS) approach was developed for the identification of ring-positional isomers of synthetic cathinones, a class of compounds representing two-third of all NPS seized in Europe in 2020. The optimized workflow features narrow ion-trapping regions, mobility calibration by internal reference, and a dedicated data-analysis tool, allowing for accurate relative ion-mobility assessment and high-confidence isomer identification. Ortho-, meta- and para-isomers of methylmethcathinone (MMC) and bicyclic ring isomers of methylone were assigned based on their specific ion mobilities within 5 min, including sample preparation and data analysis. The resolution of two distinct protomers per cathinone isomer added to the confidence in identification. The developed approach was successfully applied to the unambiguous assignment of MMC isomers in confiscated street samples. These findings demonstrate the potential of TIMS-TOFMS for forensic case work requiring fast and highly-confident assignment cathinone-drug isomers in confiscated samples.

Altered methionine-sulfone levels are associated with impaired growth in HIV-exposed-uninfected children.

OBJECTIVE: To determine immune-metabolic dysregulation in children born to women living with HIV. METHODS: Longitudinal immune-metabolomic analyses of plasma of 32 pregnant women with HIV (WHIV) and 12 uninfected women and their children up to 1.5 years of age were performed. RESULTS: Using liquid chromatography-mass spectrometry and a multiplex bead assay, 280 metabolites (57 amino acids, 116 positive lipids, 107 signalling lipids) and 24 immune mediators (e.g. cytokines) were quantified. combinational antiretroviral therapy (cART) exposure was categorized as cART initiation preconception (long), cART initiation postconception up to 4 weeks before birth (medium) and cART initiation within 3 weeks of birth (short). Plasma metabolite profiles differed between HIV-exposed-uninfected (HEU)-children with long cART exposure compared to HIV-unexposed-children (HUU). Specifically, higher levels of methionine-sulfone, which is associated with oxidative stress, were detected in HEU-children with long cART exposure compared to HUU-children. High infant methionine-sulfone levels were reflected by high prenatal plasma levels in the mother. Increased methionine-sulfone levels in the children were associated with decreased growth, including both weight and length. CONCLUSION: These findings based on longitudinal data demonstrate that dysregulation of metabolite networks associated with oxidative stress in children born to WHIV is associated with restricted infant growth.

High omega-6/omega-3 fatty acid and oxylipin ratio in plasma is linked to an adverse cardiometabolic profile in middle-aged adults.

Omega-6 and omega-3 oxylipins may be surrogate markers of systemic inflammation, which is one of the triggers for the development of cardiometabolic disorders. In the current study, we investigated the relationship between plasma levels of omega-6 and omega-3 oxylipins with body composition and cardiometabolic risk factors in middle-aged adults. Seventy-two 72 middle-aged adults (39 women; 53.6±5.1 years old; 26.7±3.8 kg/m2) were included in this cross-sectional study. Plasma levels of omega-6 and omega-3 fatty acids and oxylipins were determined using targeted lipidomic. Body composition, dietary intake, and cardiometabolic risk factors were assessed with standard methods. The plasma levels of the omega-6 fatty acids and derived oxylipins, the hydroxyeicosatetraenoic acids (HETEs; arachidonic acid (AA)-derived oxylipins) and dihydroxy-eicosatrienoic acids (DiHETrEs; AA-derived oxylipins), were positively associated with glucose metabolism parameters (i.e., insulin levels and homeostatic model assessment of insulin resistance index (HOMA); all r≥0.21, P<.05). In contrast, plasma levels of omega-3 fatty acids and derived oxylipins, specifically hydroxyeicosapentaenoic acids (HEPEs; eicosapentaenoic acid-derived oxylipins), as well as series-3 prostaglandins, were negatively associated with plasma glucose metabolism parameters (i.e., insulin levels, HOMA; all r≤0.20, P<.05). The plasma levels of omega-6 fatty acids and derived oxylipins, HETEs and DiHETrEs were also positively correlated with liver function parameters (i.e., glutamic pyruvic transaminase, gamma-glutamyl transferase (GGT), and fatty liver index; all r≥0.22 and P<.05). In addition, individuals with higher omega-6/omega-3 fatty acid and oxylipin ratio showed higher levels of HOMA, total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and GGT (on average +36%), as well as lower levels of high-density lipoprotein cholesterol (-13%) (all P<.05). In conclusion, the omega-6/omega-3 fatty acid and oxylipin ratio, as well as specific omega-6 and omega-3 oxylipins plasma levels, reflect an adverse cardiometabolic profile in terms of higher insulin resistance and impaired liver function in middle-aged adults.

The Evolution Toward Designer Benzodiazepines in Drug-Facilitated Sexual Assault Cases.

Drug-facilitated sexual assault (DFSA) is a crime where the victim is unable to provide sexual consent due to incapacitation resulting from alcohol or drug consumption. Due to the large number of substances possibly used in DFSA, including illicit, prescription and over-the-counter drugs, DFSA faces many toxicological challenges. Benzodiazepines (BZDs) are ideal candidates for DFSA, as they are active at low doses, have a fast onset of action and can be easily administered orally. The last decade has seen the emergence of designer benzodiazepines (DBZDs), which show slight modifications compared with BZDs and similar pharmacological effects but are not controlled under the international drug control system. DBZDs represent an additional challenge due to the number of new entities regularly appearing in the market, their possibly higher potency and the limited knowledge available on their pharmacokinetic and pharmacodynamics properties. Many BZDs and DBZDs have a short half-life, leading to rapid metabolism and excretion. The low concentrations and short time windows for the detection of BZD in body fluids require the use of highly sensitive analysis methods to enable the detection of drugs and their respective metabolites. This review discusses the current state of the toxicological analysis of BZDs and DBZDs in forensic casework and their pharmacokinetic properties (i.e., absorption, distribution, metabolism, and elimination), as well as their analysis in biosamples typically encountered in DFSA (i.e., blood, urine and hair).

Urinary Metabolic Profiling in Volunteers Undergoing Malaria Challenge in Gabon.

The interaction of malaria parasites with their human host is extensively studied, yet only few studies reported how P. falciparum infection affects urinary metabolite profiles and how this is associated with immunity. We present a longitudinal study of the urinary metabolic profiles of twenty healthy Africans with lifelong exposure to malaria and five malaria-naïve Europeans, who were all challenged with direct venous inoculation of live P. falciparum sporozoïtes (PfSPZ) and followed up until they developed symptoms or became thick blood smear positive (TBS). Urine samples were collected before and at 2, 5, 9 and 11 days post challenge and were analysed. Upon infection, all Europeans became TBS positive, while Africans showed either a delay in time to parasitaemia or controlled infection. Our metabolic data showed that Europeans and Africans had distinct alterations in metabolite patterns, with changes mostly seen on days 5 and 9 post PfSPZ infection, and more prominently in Europeans. Within the African group, the levels of formate, urea, trimethylamine, threonine, choline, myo-inositol and acetate were significantly higher in TBS positive whereas the levels of pyruvate, 3-methylhistidine and dimethylglycine were significantly lower in individuals who remained TBS negative. Notably, before inoculation with PfSPZ, a group of metabolites including phenylacetylglutamine can potentially be used to predict parasitaemia control among Africans. Taken together, this study highlights the difference in urinary metabolic changes in response to malaria infection as a consequence of lifelong exposure to malaria and that change detectable before challenge might predict the control of parasitaemia in malaria-endemic areas.

Plasma Levels of Omega-3 and Omega-6 Derived Oxylipins Are Associated with Fecal Microbiota Composition in Young Adults.

Pre-clinical studies suggest that circulating oxylipins, i.e., the oxidation products of polyunsaturated fatty acids (PUFAs), modulate gut microbiota composition in mice, but there is no information available in humans. Therefore, this study aimed to investigate the relationship between omega-3 and omega-6 derived oxylipins plasma levels and fecal microbiota composition in a cohort of young adults. 80 young adults (74% women; 21.9 ± 2.2 years old) were included in this cross-sectional study. Plasma levels of oxylipins were measured using liquid chromatography-tandem mass spectrometry. Fecal microbiota composition was analyzed by V3-V4 16S rRNA gene sequencing. We observed that plasma levels of omega-3 derived oxylipins were positively associated with the relative abundance of Clostridium cluster IV genus (Firmicutes phylum; rho ≥ 0.415, p ≤ 0.009) and negatively associated with the relative abundance of Sutterella genus (Proteobacteria phylum; rho ≥ -0.270, p ≤ 0.041), respectively. Moreover, plasma levels of omega-6 derived oxylipins were negatively associated with the relative abundance of Acidaminococcus and Phascolarctobacterium genera (Firmicutes phylum; all rho ≥ -0.263, p ≤ 0.024), as well as Sutterella, Succinivibrio, and Gemmiger genera (Proteobacteria phylum; all rho ≥ -0.263, p ≤ 0.024). Lastly, the ratio between omega-6 and omega-3 oxylipins plasma levels was negatively associated with the relative abundance of Clostridium cluster IV genus (Firmicutes phylum; rho = -0.334, p = 0.004) and Butyricimonas genus (Bacteroidetes phylum; rho = -0.292, p = 0.014). In conclusion, our results show that the plasma levels of omega-3 and omega-6 derived oxylipins are associated with the relative abundance of specific fecal bacteria genera.

Acute and long-term exercise differently modulate plasma levels of oxylipins, endocannabinoids, and their analogues in young sedentary adults: A sub-study and secondary analyses from the ACTIBATE randomized controlled-trial.

BACKGROUND: Fatty acid-derived lipid mediators including oxylipins, endocannabinoids (eCBs), and their analogues, have emerged as key metabolites in the inflammatory and immune response to physiological stressors. METHODS: This report was based on a sub-study and secondary analyses the ACTIBATE single-center unblinded randomized controlled trial (ClinicalTrials.gov ID: NCT02365129). The study was performed in the Sport and Health University Research Institute and the Virgen de las Nieves University Hospital of the University of Granada. Eligible participants were young, sedentary adults with no chronic diseases. Here, we performed both an acute endurance and resistance exercise sub-studies (n.ß=.ß14 and 17 respectively), and a 24-week supervised exercise intervention, combining endurance and resistance exercise training at moderate-intensity (MOD-EX) or vigorous-intensity (VIG-EX) exercise groups, in young sedentary adults. Randomization was performed by unrestricted randomization. Plasma levels of oxylipins, eCBs, and their analogues were measured using liquid chromatography-tandem mass spectrometry. FINDINGS: Both endurance and resistance exercise increased by.ß+50% the plasma levels of dihomo-..-linolenic acid and arachidonic acid (AA) omega-6 derived oxylipins, as well as eicosapentaenoic acid and docosahexaenoic acid omega-3 derived after 3 and 120.ßmin of the bout of exercise (all ..2.ß....ß0.219 and P.ß..±.ß0.039). These exercise modalities also increased the levels of anandamide and eCBs analogues (+25%). 145 young sedentary adults were assigned to a control (CON, n.ß=.ß54), a MOD-EX (n.ß=.ß48) or a VIG-EX (n.ß=.ß43). 102 participants were included in the final long-term analyses (CON, n.ß=.ß36; MOD-EX, n.ß=.ß33; and VIG-EX, n.ß=.ß33) of the trial. After 24-week of supervised exercise, MOD-EX decreased plasma levels of omega-6 oxylipins, concretely linoleic acid (LA) and adrenic acid derived oxylipins, and the eCBs analogues OEA and LEA in comparison to the CON (all P.ß..±.ß0.021). VIG-EX decreased LA-derived oxylipins and LEA compared to CON. No relevant adverse events were recorded. INTERPRETATION: Endurance and resistance exercises acutely increased plasma levels of oxylipins, eCBs, and their analogues, whereas 24 weeks of exercise training decreased fasting plasma levels of omega-6 oxylipins, and eCBs analogues in young, sedentary adults. FUNDING: See Acknowledgments section.

Linoleic acid-derived oxylipins and isoprostanes plasma levels are influenced by 1,25-Dihydroxyvitamin D levels in middle-aged sedentary adults: The FIT-AGEING study.

INTRODUCTION: Vitamin D - concretely its active form 1,25-dihydroxyvitamin D (1,25(OH)2D) - maintains several physiological processes. Oxylipins are oxidized lipids derived from ω-6 and ω-3 polyunsaturated fatty acids involved in inflammation. Little is known about the association of 1,25(OH)2D with inflammatory parameters in middle-aged populations - who could be at risk of vitamin D deficiency -. The aim of this study was to investigate the relationship between 1,25(OH)2D plasma levels with circulating white blood cells, platelets counts and oxylipins levels. MATERIALS AND METHODS: A total of 74 (53 % women) middle-aged (40-65 years old) adults were recruited for this cross-sectional study. 1,25(OH)2D plasma levels were measured using an immunochemiluminometric assay. White blood cells and platelets were analyzed by hemocytometry. ω-6 and ω-3 oxylipins plasma levels were measured using liquid chromatography - tandem mass spectrometry. Simple and multiple linear regression models, and Pearson correlation analyses, were performed to study the association of 1,25(OH)2D levels with WBC and platelets counts, and oxylipins, respectively. RESULTS: 1,25(OH)2D plasma levels were positively related with linoleic acid-derived oxylipins and isoprostanes plasma levels, whereas an inverse relationship with dihomo-γ-linolenic acid/linoleic acid and arachidonic acid/linoleic acid ratios was unveiled. No significant associations were observed for circulating ω-3 oxylipins, white blood cells levels or platelets count. CONCLUSIONS: Linoleic acid-derived oxylipins and isoprostanes plasma levels may be influenced by 1,25(OH)2D plasma levels. Further investigations are needed to elucidate the impact of other vitamin D forms upon circulating oxylipins levels.

Plasma Levels of Endocannabinoids and Their Analogues Are Related to Specific Fecal Bacterial Genera in Young Adults: Role in Gut Barrier Integrity.

OBJECTIVE: To investigate the association of plasma levels of endocannabinoids with fecal microbiota. METHODS: Plasma levels of endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), as well as their eleven analogues, and arachidonic acid (AA), were measured using liquid chromatography-tandem mass spectrometry in 92 young adults. DNA extracted from stool samples was analyzed using 16S rRNA gene sequencing. Lipopolysaccharide levels were measured in plasma samples. RESULTS: Plasma levels of endocannabinoids and their analogues were not related to beta or alpha diversity indexes. Plasma levels of AEA and related N-acylethanolamines correlated positively with the relative abundance of Faecalibacterium genus (all rho ≥ 0.26, p ≤ 0.012) and Akkermansia genus (all rho ≥ 0.22, p ≤ 0.036), and negatively with the relative abundance of Bilophila genus (all rho ≤ -0.23, p ≤ 0.031). Moreover, plasma levels of 2-AG and other acylglycerols correlated positively with the relative abundance of Parasutterella (all rho ≥ 0.24, p ≤ 0.020) and Odoribacter genera (all rho ≥ 0.27, p ≤ 0.011), and negatively with the relative abundance of Prevotella genus (all rho ≤ -0.24, p ≤ 0.023). In participants with high lipopolysaccharide values, the plasma levels of AEA and related N-acylethanolamines, as well as AA and 2-AG, were negatively correlated with plasma levels of lipopolysaccharide (all rho ≤ -0.24, p ≤ 0.020). CONCLUSION: Plasma levels of endocannabinoids and their analogues are correlated to specific fecal bacterial genera involved in maintaining gut barrier integrity in young adults. This suggests that plasma levels of endocannabinoids and their analogues may play a role in the gut barrier integrity in young adults.

Quantification of endocannabinoids in human cerebrospinal fluid using a novel micro-flow liquid chromatography-mass spectrometry method.

The endocannabinoid system (ECS) is implicated in various brain disorders. Changes in the composition of the cerebrospinal fluid (CSF) may be associated with ECS-related pathologies. Endocannabinoids (eCBs) and their analogues are present at low concentrations in human CSF, which hampered the investigation of the ECS in this body fluid. In this study, we developed a highly sensitive and selective micro-flow liquid chromatography-tandem mass spectrometry (micro-LC-MS/MS) method for the analysis of eCBs and eCB analogues in human CSF. The developed method allowed for the quantitative analysis of 16 eCBs and their analogues in human CSF. Micro-LC-MS/MS analyses were performed at a flow-rate of 4 µL min-1 with a 0.3-mm inner diameter column. A minor modification of a novel spray needle was carried out to improve the robustness of our method. By using an injection volume of 3 µL, our method reached limits of detection in the range from 0.6 to 1293.4 pM and limits of quantification in range from 2.0 to 4311.3 pM while intra- and interday precisions were below 13.7%. The developed workflow was successfully used for the determination of eCBs in 288 human CSF samples. It is anticipated that the proposed approach will contribute to a deeper understanding of the role of ECS in various brain disorders.

Effect of Different Exercise Training Modalities on Fasting Levels of Oxylipins and Endocannabinoids in Middle-Aged Sedentary Adults: A Randomized Controlled Trial.

This study aimed to investigate the effects of different exercise training programs on fasting plasma levels of oxylipins, endocannabinoids (eCBs), and eCBs-like molecules in middle-aged sedentary adults. A 12-week randomized controlled trial was conducted using a parallel group design. Sixty-five middle-aged adults (40-65 years old) were randomly assigned to: (a) no exercise (control group), (b) concurrent training based on international physical activity recommendations (PAR group), (c) high-intensity interval training (HIIT group), and (d) HIIT together with whole-body electromyostimulation (HIIT + EMS group). Plasma levels of oxylipins, eCBs, and eCBs-like molecules were determined in plasma samples before and after the intervention using targeted lipidomics. Body composition was assessed through dual-energy X-ray absorptiometry, and dietary intake through a food frequency questionnaire and three nonconsecutive 24-hr recalls. The physical activity recommendations, HIIT, and HIIT-EMS groups showed decreased plasma levels of omega-6 and omega-3-derived oxylipins, and eCBs and eCBs-like molecules after 12 weeks (all Δ ≤ -0.12; all p < .05). Importantly, after Bonferroni post hoc corrections, the differences in plasma levels of omega-6 and omega-3 oxylipins were not statistically significant compared with the control group (all p > .05). However, after post hoc corrections, plasma levels of anandamide and oleoylethanolamide were increased in the physical activity recommendations group compared with the control group (anandamide: Δ = 0.05 vs. -0.09; oleoylethanolamide: Δ = -0.12 vs. 0.013, all p ≤ .049). In conclusion, this study reports that a 12-week exercise training intervention, independent of the modality applied, does not modify fasting plasma levels of omega-6 and omega-3 oxylipins, eCBs, and eCBs-like molecules in middle-aged sedentary adults.

Changes in Plasma Lipid Levels Following Cortical Spreading Depolarization in a Transgenic Mouse Model of Familial Hemiplegic Migraine.

Metabolite levels in peripheral body fluids can correlate with attack features in migraine patients, which underscores the potential of plasma metabolites as possible disease biomarkers. Migraine headache can be preceded by an aura that is caused by cortical spreading depolarization (CSD), a transient wave of neuroglial depolarization. We previously identified plasma amino acid changes after CSD in familial hemiplegic migraine type 1 (FHM1) mutant mice that exhibit increased neuronal excitability and various migraine-related features. Here, we aimed to uncover lipid metabolic pathways affected by CSD, guided by findings on the involvement of lipids in hemiplegic migraine pathophysiology. Using targeted lipidomic analysis, we studied plasma lipid metabolite levels at different time points after CSD in wild-type and FHM1 mutant mice. Following CSD, the most prominent plasma lipid change concerned a transient increase in PGD2, which lasted longer in mutant mice. In wild-type mice only, levels of anti-inflammatory lipid mediators DPAn-3, EPA, ALA, and DHA were elevated 24 h following CSD compared to Sham-treated animals. Given the role of PGs and neuroinflammation in migraine pathophysiology, our findings underscore the potential of monitoring peripheral changes in lipids to gain insight in central brain mechanisms.

Plasma Levels of Bile Acids Are Related to Cardiometabolic Risk Factors in Young Adults.

CONTEXT: Bile acids (BA) are known for their role in intestinal lipid absorption and can also play a role as signaling molecules to control energy metabolism. Prior evidence suggests that alterations in circulating BA levels and in the pool of circulating BA are linked to an increased risk of obesity and a higher incidence of type 2 diabetes in middle-aged adults. OBJECTIVE: We aimed to investigate the association between plasma levels of BA with cardiometabolic risk factors in a cohort of well-phenotyped, relatively healthy young adults. METHODS: Body composition, brown adipose tissue, serum classical cardiometabolic risk factors, and a set of 8 plasma BA (including glyco-conjugated forms) in 136 young adults (age 22.1 ± 2.2 years, 67% women) were measured. RESULTS: Plasma levels of chenodeoxycholic acid (CDCA) and glycoursodeoxycholic acid (GUDCA) were higher in men than in women, although these differences disappeared after adjusting for body fat percentage. Furthermore, cholic acid (CA), CDCA, deoxycholic acid (DCA), and glycodeoxycholic acid (GDCA) levels were positively, yet weakly associated, with lean body mass (LBM) levels, while GDCA and glycolithocholic acid (GLCA) levels were negatively associated with 18F-fluorodeoxyglucose uptake by brown adipose tissue. Interestingly, glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), and GUDCA were positively associated with glucose and insulin serum levels, HOMA index, low-density lipoprotein cholesterol, tumor necrosis factor alpha, interleukin (IL)-2, and IL-8 levels, but negatively associated with high-density lipoprotein cholesterol, ApoA1, and adiponectin levels, yet these significant correlations partially disappeared after the inclusion of LBM as a confounder. CONCLUSION: Our findings indicate that plasma levels of BA might be sex dependent and are associated with cardiometabolic and inflammatory risk factors in young and relatively healthy adults.