Search Results (169)

Objectives: To determine whether plasma concentrations of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are elevated in adults with prediabetes, we explored their association with tissue advanced glycation end-products (AGEs) and assessed the influence of Mediterranean diet adherence. Methods: This cross-sectional single-centre study included 92 adults with prediabetes and 86 age-/sex-matched normoglycaemic controls. Anthropometry, blood pressure, biochemical indices, and skin autofluorescence-derived AGEs were measured. Serum AEA and 2-AG were quantified by competitive ELISA, while Mediterranean diet adherence was assessed using the Mediterranean Diet Serving Score (MDSS). Results: Prediabetes was associated with higher AEA (p = 0.004) but not 2-AG (p = 0.520). Also, AEA correlated positively with AGE values (r = 0.36; p = 0.002) and increased across AGE-based cardiovascular risk categories. In multivariable models, both prediabetes status and AGE burden independently predicted AEA. Participants achieving MDSS ≥ 14 exhibited lower AEA (p = 0.038); 2-AG remained unaffected. Finally, the multivariable analysis confirmed that both prediabetes (β = 11.9; p = 0.005) and AGE values (β = 0.25; p = 0.003) are positively associated with plasma AEA levels, independent of age, sex, BMI, and fasting plasma glucose levels. Conclusions: Circulating AEA, but not 2-AG, is elevated in prediabetes and independently linked to cumulative AGE burden, suggesting early endocannabinoid activation contributes to cardiometabolic risk. High adherence to a Mediterranean diet may mitigate this dysregulation. Full article

Although it is more than a century since it was first marketed, acetaminophen remains one of the most popular analgesic agents. In addition, acetaminophen has recently been applied to multimodal analgesia in combination with non-steroidal anti-inflammatory drugs, and its consumption significantly increased during the pandemic of coronavirus disease 2019 as well as diclofenac and ibuprofen. However, the detailed mode of analgesic action of acetaminophen is still unclear. In the present study, we comprehensively discuss conventional, recognized, and postulated mechanisms of analgesic acetaminophen and highlight the current mechanistic concepts while comparing with diclofenac and ibuprofen. Acetaminophen inhibits cyclooxygenase with selectivity for cyclooxygenase-2, which is higher than that of ibuprofen but lower than that of diclofenac. In contrast to diclofenac and ibuprofen, however, anti-inflammatory effects of acetaminophen depend on the extracellular conditions of inflamed tissues. Since the discovery of cyclooxygenase-3 in the canine brain, acetaminophen had been hypothesized to inhibit such a cyclooxygenase-1 variant selectively. However, this hypothesis was abandoned because cyclooxygenase-3 was revealed not to be physiologically and clinically relevant to humans. Recent studies suggest that acetaminophen is deacetylated to 4-aminophenol in the liver and after crossing the blood–brain barrier, it is metabolically converted into N-(4-hydroxyphenyl)arachidonoylamide. This metabolite exhibits bioactivities by targeting transient receptor potential vanilloid 1 channel, cannabinoid receptor 1, Cav3.2 calcium channel, anandamide, and cyclooxygenase, mediating acetaminophen analgesia. These targets may be partly associated with diclofenac and ibuprofen. The perspective of acetaminophen as a prodrug will be crucial for a future strategy to develop analgesics with higher tolerability and activity. Full article

Inflammation is a complicated physiological process that contributes to a variety of disorders including osteoarthritis (OA) and rheumatoid arthritis (RA). Endocannabinoids and the endocannabinoid system (ECS) play a pivotal role in the physiological response to pain and inflammation. A clinical study to investigate the role of the endocannabinoid system and related lipids in pain and inflammation in OA and RA was performed. In total, 80 subjects, namely, 25 patients with RA, 18 with OA, and 37 healthy participants, were included. Sixteen endocannabinoids and congeners, as well as 129 oxylipins, were quantified in plasma using specific, quantitative LC-MS/MS assays. The endocannabinoid analysis revealed significantly lower levels of 2-arachidonoylglycerol (2-AG) in RA and OA patients compared to healthy participants. In contrast, the EC levels of the ethanolamide group (anandamide, docosahexaenoyl-EA, palmitoleoyl-EA, and other ethanolamides) were higher in the RA study cohort and to a lesser extent also in the OA cohort. This analysis of oxylipins revealed lower levels of the pro-resolving lipid 9-oxo-octadecadienoic acid (9-oxoODE) and the ω-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in RA compared to all other study cohorts. 2-AG is a key regulator of nociception and inflammation, and its relatively low levels might be a mechanistic contributor to residual pain and inflammation in RA and OA. Several changes in pro- and anti-inflammatory lipid mediators were detected, including lower levels of EPA and DHA in RA, which might reveal the potential for nutritional supplementation with these anti-inflammatory fatty acids. Full article

Adolescent binge drinking has lasting behavioral consequences by disrupting the endocannabinoid system (ECS) and depleting brain omega-3. The natural accumulation of omega-3 fatty acids in cell membranes is crucial for maintaining the membrane structure, supporting interactions with the ECS, and restoring synaptic plasticity and cognition impaired by prenatal ethanol (EtOH) exposure. However, it remains unclear whether omega-3 supplementation can mitigate the long-term effects on the ECS, endocannabinoid-dependent synaptic plasticity, and cognition following adolescent binge drinking. Here, we demonstrated that omega-3 supplementation during EtOH withdrawal increases CB1 receptors in hippocampal presynaptic terminals of male mice, along with the recovery of receptor-stimulated [³⁵S]GTPγS binding to Gαi/o proteins. These changes are associated with long-term potentiation (LTP) at excitatory medial perforant path (MPP) synapses in the dentate gyrus (DG), which depends on anandamide (AEA), transient receptor potential vanilloid 1 (TRPV1), and N-methyl-D-aspartate (NMDA) receptors. Finally, omega-3 intake following binge drinking reduced the time and number of errors required to locate the escape box in the Barnes maze test. Collectively, these findings suggest that omega-3 supplementation restores Barnes maze performance to levels comparable to those of control mice after adolescent binge drinking. This recovery is likely mediated by modulation of the hippocampal ECS, enhancing endocannabinoid-dependent excitatory synaptic plasticity. Full article

The anandamide (AEA) and lipopolysaccharide (LPS) interaction is gaining attention, but evidence on the influence of probiotics on endocannabinoid system (ECS) biomarkers remains limited. This study (NCT05567653) investigated the effects of 12-week supplementation with Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on AEA (main outcome) and inflammatory biomarkers in female dancers. Fifteen participants (5 probiotic, 10 placebo) were included in the final analysis. Serum levels of AEA, LPS, and cytokines (tumor necrosis factor-alpha—TNF-α, interleukin-1 beta—IL-1β, and interleukin-10—IL-10) were measured using an ELISA (enzyme-linked immunosorbent assay), and the psychological stress responses were evaluated using the Mini-COPE questionnaire. At the baseline, a correlation between AEA and LPS was observed (Spearman’s r = 0.9677, p < 0.05). After 12 weeks, no statistically significant differences in the AEA, LPS, cytokine levels, or stress-coping strategies were observed between the probiotic and placebo groups (LPS–probiotic: +3.48 EU/L, p = 0.9361; placebo: +56.98 EU/L, p = 0.0694; AEA–probiotic: −1.11 ng/mL, p = 0.9538; placebo: +14.08 ng/mL, p = 0.4749). The direction of change may indicate a trend toward increased inflammation in the absence of probiotics, consistent with patterns described in previous literature. However, these results should be viewed as hypothesis generating and warrant confirmation in larger trials. Full article

The paraventricular nucleus of the hypothalamus (PVN) regulates, among others, the stress response, sexual behavior, and energy metabolism through its magnocellular and parvocellular neurosecretory cells. Within the PVN, ensemble coordination occurs through the many long-range synaptic afferents, whose activity in time relies on retrograde neuromodulation by, e.g., endocannabinoids. However, the nanoarchitecture of endocannabinoid signaling in the PVN, especially during neuronal development, remains undescribed. By using single-cell RNA sequencing, in situ hybridization, and immunohistochemistry during fetal and postnatal development in mice, we present a spatiotemporal map of both the 2-arachidonoylglycerol (2-AG) and anandamide (AEA) signaling cassettes, with a focus on receptors and metabolic enzymes, in both molecularly defined neurons and astrocytes. We find type 1 cannabinoid receptors (Cnr1), but neither Cnr2 nor Gpr55, expressed in neurons of the PVN. Dagla and Daglb, which encode the enzymes synthesizing 2-AG, were found in all neuronal subtypes of the PVN, with a developmental switch from Daglb to Dagla. Mgll, which encodes an enzyme degrading 2-AG, was only found sporadically. Napepld and Faah, encoding enzymes that synthesize and degrade AEA, respectively, were sparsely expressed in neurons throughout development. Notably, astrocytes expressed Mgll and both Dagl isoforms. In contrast, mRNA for any of the three major cannabinoid-receptor subtypes could not be detected. Immunohistochemistry validated mRNA expression and suggested that endocannabinoid signaling is configured to modulate the activity of afferent inputs, rather than local neurocircuits, in the PVN. Full article

Neurogenesis is considered the most robust form of plasticity in the adult brain. To better decipher this process, we evaluated the potential crosstalk of Kisspeptin and Endocannabinoid Systems (KPS and ECS, respectively) on hippocampal neurogenesis. Male adolescent rats were exposed to kisspeptin-10 (KP10) and the endocannabinoid anandamide (AEA) administered alone or in combination with the type 1 cannabinoid receptor (CB1R) antagonist SR141716A. The expression of Kiss1 and Kisspeptin receptor (Kiss1R) has been characterized for the first time in rat hippocampus together with the expression of the CB1R and the Transient Receptor Potential Vanilloid 1 ion channel receptor (TRPV1). Results show that both systems inhibit neurogenesis by reducing the extracellular signal-regulated kinase (ERK) signaling. Despite little differences in the expression of Kiss1R and CB1R, TRPV1 is enhanced by both KP10 and AEA treatments, suggesting TRPV1 as a common thread. KP10 administration reduces CB1R expression in the dentate gyrus, while AEA does not. KPS, unlike ECS, promotes the expression of estrogen receptor α (ER-α) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), also upregulating sirtuin 1 (SIRT1), brain-derived-neurotrophic factor (BDNF), and c-Jun. These findings suggest that the interaction between ECS and KPS could be involved in the fine-tuning of neurogenesis, highlighting a novel role for KPS. Full article

The endocannabinoid system is a complex communication system involved in maintaining homeostasis in various physiological processes, including metabolism, immune response, pain modulation, and neuroprotection. Endocannabinoids, mainly anandamide and 2-arachidonoylglycerol, are natural ligands of the cannabinoid receptors CB1 and CB2, which are widely distributed throughout the central nervous system and peripheral tissues. Their biosynthesis, degradation, and interaction with other signaling pathways play crucial roles in both health and disease. This article provides a comprehensive overview of the physiological and pathological roles of endocannabinoids, discusses their potential as therapeutic targets, and highlights recent advances in endocannabinoid-based treatments. Full article

Background/Objectives: Endocannabinoids are endogenous bioactive lipids that promote neurodevelopment and positive energy balance. Increased levels of endocannabinoids are associated with obesity, but the effect of maternal obesity on breast milk endocannabinoids across lactation is mostly unknown. Methods: Women from Rio de Janeiro (Brazil) (n = 92) were followed from the third trimester of pregnancy to 119 days postpartum, and milk samples were analyzed in the postpartum days 2–8 (T1), 28–47 (T2), and 88–119 (T3). We assessed the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) by high-performance liquid chromatography–mass spectrometry, leptin and insulin by immunoassay, and macronutrients by colorimetric assays in milk samples. Results: Milk AEA concentration was higher in T2 compared with T1 or T3, while 2-AG levels were higher in T2 and T3 compared with T1. Milk endocannabinoids were directly correlated with pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and milk triglycerides. Triglyceride and leptin levels were higher in mature milk (T2 and T3) of women with BMI > 25 or excessive GWG. Adjusted linear regression models showed a positive association between excessive GWG and milk 2-AG (β = 1629; 95% CI: 467–2792; p = 0.008). Conclusions: The endocannabinoid levels are higher in mature milk from women with obesity or excessive GWG, which may impact offspring development and metabolism. Full article

The endocannabinoid system (ECS) plays a crucial role in maintaining homeostasis by regulating immune response, energy metabolism, cognitive functions, and neuronal activity. It consists of endocannabinoids (eCBs), cannabinoid receptors (CBRs), and enzymes involved in eCB biosynthesis and degradation. Increasing evidence highlights the involvement of the ECS under several pathological conditions, making it a promising therapeutic target. Recent research efforts have focused on modulating endogenous eCB levels, particularly through the inhibition of fatty acid amide hydrolase (FAAH), the main catabolic enzyme of the major eCB anandamide. Natural substances, including plant extracts and purified compounds, can inhibit FAAH and represent a promising area of pharmacological research. Natural FAAH inhibitors are particularly attractive due to their potentially lower toxicity compared to synthetic compounds, making them safer candidates for therapeutic applications. Phytocannabinoids, flavonoids, and flavolignans have been shown to efficiently inhibit FAAH. The structural diversity and bioactivity of these natural substances provide a valuable alternative to synthetic inhibitors, and may open new avenues for developing innovative pharmacological tools. Full article

The transient receptor potential vanilloid 1 receptor (TRPV1) is a calcium-sensitive membrane receptor activated by capsaicin and the endocannabinoid, anandamide (AEA). Once activated in vitro, endometrial cancer (EC) cell growth appears to be inhibited through increased apoptosis, but the mechanism remains unclear. Our aim was to investigate the expression and distribution of TRPV1 in normal and cancerous endometria and to determine the precise in vitro mechanism of decreased EC cellular growth. TRPV1 expression in patients with endometrial carcinoma (15 Type 1 EC, six Type 2 EC) and six normal patients (atrophic endometria) was assessed using quantitative RT-PCR and immunohistochemistry (IHC). Additionally, immunohistochemical staining for the proliferation marker Ki-67, the pro-apoptotic marker BAX and the anti-apoptotic marker Bcl-2 were explored. TRPV1 transcript (p = 0.0054) and immunoreactive protein (p < 0.0001) levels were significantly reduced in all EC tissues when compared to control (atrophic) endometria. The almost 50% reduction in TRPV1 transcript levels was mirrored by an almost complete loss of immunoreactive TRPV1 protein. The increased proliferation (Ki-67) of EC tissues correlated with the expression of mutated BAX and inversely correlated to Bcl-2, but only in Type 2 EC samples. In vitro, AEA caused a decrease in Ishikawa cell numbers, whilst capsaicin did not, suggesting the anti-proliferative effect of AEA in EC cells is not via the TRPV1 receptor. In conclusion, the loss of TRPV1 expression in vivo plays a role in the aetiopathogenesis of EC. Activation of cells by AEA also probably promotes EC cell loss through a pro-apoptotic mechanism not involving TRPV1. Full article

Some musculoskeletal disorders, including osteoarthritis; arthrosis; post-traumatic injuries; and other inflammatory tendon, joint and muscular afflictions, still represent unmet medical needs. Cetylated fatty acids (CFAs) are key components of widely distributed over-the-counter products, especially for topical use, which are intended to reduce symptoms associated with these conditions. Nevertheless, the mechanism of action of CFAs’ analgesic and anti-inflammatory properties has not yet been clearly established. Endocannabinoids, such as 2-arachidonoylglycerol (2-AG) and anandamide (AEA), are known to produce analgesic and anti-inflammatory effects. These compounds undergo physiological inactivation operated by several enzymes, including monoacylglycerol lipase (MAGL). We herein demonstrate for the first time that the therapeutic effects of CFAs may be attributable, at least in part, to their MAGL inhibition activities, which induce a local increase in analgesic/anti-inflammatory endocannabinoids in close proximity to the site of administration. These findings pave the way for the development of new potent local analgesic agents, whose action is based on an indirect cannabinoid effect. Full article

Gastric cancer is one of the most common forms of cancer worldwide. A growing number of studies have addressed the anti-proliferative effects of cannabinoids on several tumor cells. The molecular mechanisms underlying the anti-proliferative effects of the endogenous cannabinoid anandamide (AEA) on gastric tumor cell lines have yet to be characterized. Here, we investigated the anti-proliferative mechanisms elicited by AEA on the AGS human gastric cancer cell line employing an Oncoprint database, Western blotting, and immunofluorescence. We observed that AEA (5 µM) inhibited phosphorylated AKT’s expression level. This point is relevant because AKT is mutated in AGS cells, according to Oncoprint. In addition, AEA induced the up-regulation of phosphorylated ERK and, in turn, inhibited Bcl-2 expression and activated pro-apoptotic signals induced by pro-apoptotic Bax and Bak, which resulted in caspase-3 activation. The effect of anandamide on phosphorylated AKT was dependent on cannabinoid receptor 2 activation (CB2R) as revealed by the selective inverse agonist JTE-907, which reverted the anandamide-induced expression in the phosphorylated AKT/total AKT ratio. In contrast, changes in phosphorylated ERK evoked an increase in pro-apoptotic pathways that culminated in cell death by caspase-3 activation. These results indicate that the endogenous cannabinoid anandamide in gastric cancer cells increases caspase-3 activity via mitochondrial pro-apoptotic Bax/Bak proteins and decreases viability through CB2R via AKT down-regulation’s trophic mechanisms. These effects constitute a promising tool for the design of gastric cancer therapies. Full article

Background and aims: Aframomum melegueta (A. melegueta) from the ginger family is appreciated for its pungent seeds widely used in African ethno-medicine. Among the several biological activities associated with the seed’s preparations, some preclinical studies suggest a set of neuroactive properties that have not been tested in humans to date. We performed a clinical trial to investigate the effects of A. melegueta seed extracts on anxiety, stress, mood, and sleep in healthy subjects with moderate anxiety levels. In vitro pharmacological assays targeting the endocannabinoid, serotoninergic, and GABAergic systems were conducted to elucidate the underlying mechanism of action. Methods: A. melegueta standardized to 10% total vanilloids (primarily 6-gingerol, 6-shogaol, and 6-paradol) was obtained after hydroalcoholic extraction and the spray-drying microencapsulation process. Subjects consumed 50, 100, or 150 mg of the extract daily for three days. A set of validated psychometric test questionnaires was collected before and 48 h after the first intake. A. melegueta extract interaction with canonical endocannabinoid receptors (hCB1R and hCB2R), the serotonin receptor (5HT1AR) and gamma-aminobutyric acid receptor (GABAA1R) was evaluated by the radioligand binding assay. Additionally, receptor functional assays and enzyme inhibition assays were conducted to test the extract’s functional activity on the non-canonical endocannabinoid receptor (TRPV1) and the cannabinoid fatty-acid amide hydrolase enzyme (FAAH), respectively. Results: In vitro pharmacological tests showed that the A. melegueta extract activated TRPV1, modulated both hCB2R and 5HT1AR and inhibited FAAH, which is the enzyme primarily responsible for hydrolyzing endogenous anandamide. After a 48 h intake period, the extract significantly reduced anxiety and tension related to stress, improved overall mood, and enhanced sleep quality in the participants at doses ranging from 50 to 150 mg, with no reported side effects. Conclusions: This study supports the potential of the A. melegueta extract for anxiety reduction, mood improvement, stress mitigation, and sleep enhancement. The in vitro tests suggest that the extract’s primary mechanism of action may involve the inhibition of FAAH, which is a key target in anxiety management. Full article

Background: The endocannabinoid system (ECS) is one of the most important systems modulating functions in the body. The ECS, via cannabinoid (CB: CB1 and CB2) receptors, endocannabinoids occurring in the brain (e.g., anandamide (AEA) and 2-arachidonoylglycerol (2-AG)) and enzymes degrading endocannabinoids in the brain (fatty-acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL)), plays a key role in the regulation of mood and anxiety. However, the effects of cannabinoid compounds on anxiety-related responses are complex and yield mixed results depending on the type of pharmacological manipulation (direct or indirect) of functions of the ECS, as well as the kinds of cannabinoids, dosage and procedure. Methods: The aim of this study was to determine and compare the influence of the direct (via CB receptors ligands) and indirect (via inhibition of enzymes degrading endocannabinoids in the brain) pharmacological modulation of ECS function on anxiety-like responses in mice in the elevated plus maze (EPM) test. For this purpose, in the first step of the experiments, we used selected ligands of CB1, CB1/CB2 and CB2 receptors to assess which types of CB receptors are involved in anxiety-related responses in mice. Next, we used inhibitors of FAAH (which breaks down AEA) or MAGL (which breaks down 2-AG) to assess which endocannabinoid is more responsible for anxiety-related behavior in mice. Results: The results of our presented research showed that an acute administration of CB1 receptor agonist oleamide (5–20 mg/kg) had no influence on anxiety-related responses and CB1 receptor antagonist AM 251 (0.25–3 mg/kg) had anxiogenic effects in the EPM test in mice. In turn, an acute administration of mixed CB1/CB2 receptor agonist WIN55,212-2 used at a dose of 1 mg/kg had an anxiolytic effect observed in mice in the EPM test. What is of interest is that both the acute administration of a CB2 receptor agonist (JWH 133 at the doses of 1 and 2 mg/kg) and antagonist (AM 630 at the doses of 0.5–2 mg/kg) had anxiogenic effects in this procedure. Moreover, we revealed that an acute administration of only FAAH inhibitor URB 597 (0.3 mg/kg) had an anxiolytic effect, while MAGL inhibitor JZL 184 (at any used doses (2–40 mg/kg)) after an acute injection had no influence on anxiety behavior in mice, as observed in the EPM test. Conclusions: In our experiments, we confirmed the clearly significant involvement of the ECS in anxiety-related responses. In particular, the pharmacological indirect manipulation of ECS functions is able to elicit promising anxiolytic effects. Therefore, the ECS could be a potential target for novel anxiolytic drugs; however, further studies are needed. Full article