Leptin-regulated endocannabinoids are involved in maintaining food intake

Highly Selective Drug-Derived Fluorescent Probes for the Cannabinoid Receptor Type 1 (CB1R)

The cannabinoid receptor type 1 (CB1R) is pivotal within the endocannabinoid system regulating various signaling cascades with effects in appetite regulation, pain perception, memory formation, and thermoregulation. Still, understanding of CB1R's cellular signaling, distribution, and expression dynamics is very fragmentary. Real-time visualization of CB1R is crucial for addressing these questions. Selective drug-like CB1R ligands with a defined pharmacological profile were investigated for the construction of CB1R fluorescent probes using a reverse design-approach. A modular design concept with a diethyl glycine-based building block as the centerpiece allowed for the straightforward synthesis of novel probe candidates. Validated by computational docking studies, radioligand binding, and cAMP assay, this systematic approach allowed for the identification of novel pyrrole-based CB1R fluorescent probes. Application in fluorescence-based target-engagement studies and live cell imaging exemplify the great versatility of the tailored CB1R probes for investigating CB1R localization, trafficking, pharmacology, and its pathological implications.

Dissecting the role of cannabinoids in vascular health and disease

Cannabis, often recognized as the most widely used illegal psychoactive substance globally, has seen a shift in its legal status in several countries and regions for both recreational and medicinal uses. This change has brought to light new evidence linking cannabis consumption to various vascular conditions. Specifically, there is an association between cannabis use and atherosclerosis, along with conditions such as arteritis, reversible vasospasm, and incidents of aortic aneurysm or dissection. Recent research has started to reveal the mechanisms connecting cannabinoid compounds to atherosclerosis development. It is well known that the primary biological roles of cannabinoids operate through the activation of cannabinoid receptor types 1 and 2. Manipulation of the endocannabinoid system, either genetically or pharmacologically, is emerging as a promising approach to address metabolic dysfunctions related to obesity. Additionally, numerous studies have demonstrated the vasorelaxant properties and potential atheroprotective benefits of cannabinoids. In preclinical trials, cannabidiol is being explored as a treatment option for monocrotaline-induced pulmonary arterial hypertension. Although existing literature suggests a direct role of cannabinoids in the pathogenesis of atherosclerosis, the correlation between cannabinoids and other vascular diseases was only reported in some case series or observational studies, and its role and precise mechanisms remain unclear. Therefore, it is necessary to summarize and update previously published studies. This review article aims to summarize the latest clinical and experimental research findings on the relationship between cannabis use and vascular diseases. It also seeks to shed light on the potential mechanisms underlying these associations, offering a comprehensive view of current knowledge in this evolving field of study.

Implication of the endocannabidiome and metabolic pathways in fragile X syndrome pathophysiology

Fragile X Syndrome (FXS) results from the silencing of the FMR1 gene and is the most prevalent inherited cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorder. It is well established that Fragile X individuals are subjected to a wide array of comorbidities, ranging from cognitive, behavioural, and medical origin. Furthermore, recent studies have also described metabolic impairments in FXS individuals. However, the molecular mechanisms linking FMRP deficiency to improper metabolism are still misunderstood. The endocannabinoidome (eCBome) is a lipid-based signalling system that regulates several functions across the body, ranging from cognition, behaviour and metabolism. Alterations in the eCBome have been described in FXS animal models and linked to neuronal hyperexcitability, a core deficit of the disease. However, the potential link between dysregulation of the eCBome and altered metabolism observed in FXS remains unexplored. As such, this review aims to overcome this issue by describing the most recent finding related to eCBome and metabolic dysfunctions in the context of FXS. A better comprehension of this association will help deepen our understanding of FXS pathophysiology and pave the way for future therapeutic interventions.

Efficacy in diet-induced obese mice of the hepatotropic, peripheral cannabinoid 1 receptor inverse agonist TM38837

BACKGROUND AND PURPOSE

The cannabinoid CB1 receptor has a well-established role in appetite regulation. Drugs antagonizing central CB1 receptors, most notably rimonabant, induced weight loss and improved the metabolic profile in obese individuals but were discontinued due to psychiatric side effects. However, metabolic benefits were only partially attributable to weight loss, implying a role for peripheral receptors, and peripherally restricted CB1 receptor antagonists have since been of interest. Herein, we describe the evaluation of the peripherally restricted potent CB1 receptor inverse agonists TM38837 and TM39875, with acidic functionality, which were administered daily to diet-induced obese (DIO) mice for 5 weeks at doses for which CNS-mediated effects were minimal.

EXPERIMENTAL APPROACH

Compounds were tested in dose-response in acute studies to compare efficacy (gastric transport) and extent of CNS exposure (hypothermia and satiety sequence) to demonstrate peripheral restriction and select doses for the subsequent chronic DIO study.

KEY RESULTS

TM38837 but not TM39875 produced considerable (26%) weight loss, linked to a sustained reduction in food intake, together with improvements in plasma markers of inflammation and glucose homeostasis. Pharmacokinetic analysis indicated high plasma and low brain levels for both compounds with high liver levels for TM38837 (but not TM39875) due to hepatic uptake.

CONCLUSION AND IMPLICATIONS

Weight loss and metabolic benefits of TM38837 are likely not CNS-mediated but could be linked to enhanced liver exposure, which implicates intracellular CB1 receptors in hepatocytes as a possible driver of obesity and co-morbidities.

Cannabinoid Analgesia in Postoperative Pain Management: From Molecular Mechanisms to Clinical Reality

Postoperative pain (POP) is a challenging clinical phenomenon that affects the majority of surgical patients and demands effective management to mitigate adverse outcomes such as persistent pain. The primary goal of POP management is to alleviate suffering and facilitate a seamless return to normal function for the patient. Despite compelling evidence of its drawbacks, opioid analgesia remains the basis of POP treatment. Novel therapeutic approaches rely on multimodal analgesia, integrating different pharmacological strategies to optimize efficacy while minimizing adverse effects. The recognition of the imperative role of the endocannabinoid system in pain regulation has prompted the investigation of cannabinoid compounds as a new therapeutic avenue. Cannabinoids may serve as adjuvants, enhancing the analgesic effects of other drugs and potentially replacing or at least reducing the dependence on other long-term analgesics in pain management. This narrative review succinctly summarizes pertinent information on the molecular mechanisms, clinical therapeutic benefits, and considerations associated with the plausible use of various cannabinoid compounds in treating POP. According to the available evidence, cannabinoid compounds modulate specific molecular mechanisms intimately involved in POP. However, only two of the eleven clinical trials that evaluated the efficacy of different cannabinoid interventions showed positive results.

Overactivation of the Endocannabinoid System in Adolescence Disrupts Adult Adipose Organ Function in Mice

Cannabis use stimulates calorie intake, but epidemiological studies show that people who regularly use it are leaner than those who don't. Two explanations have been proposed for this paradoxical finding. One posits that Δ9-tetrahydrocannabinol (THC) in cannabis desensitizes adipose CB1 cannabinoid receptors, stopping their stimulating effects on lipogenesis and adipogenesis. Another explanation is that THC exposure in adolescence, when habitual cannabis use typically starts, produces lasting changes in the developing adipose organ, which impacts adult systemic energy use. Here, we consider these possibilities in the light of a study which showed that daily THC administration in adolescent mice produces an adult metabolic phenotype characterized by reduced fat mass, partial resistance to obesity and dyslipidemia, and impaired thermogenesis and lipolysis. The phenotype, whose development requires activation of CB1 receptors in differentiated adipocytes, is associated with overexpression of myocyte proteins in the adipose organ with unchanged CB1 expression. We propose that adolescent exposure to THC causes lasting adipocyte dysfunction and the consequent emergence of a metabolic state that only superficially resembles healthy leanness. A corollary of this hypothesis, which should be addressed in future studies, is that CB1 receptors and their endocannabinoid ligands may contribute to the maintenance of adipocyte differentiation during adolescence.

Bibliometric Analysis of Cannabis sativa Research: Trends, Challenges, and Future Directions

Introduction: The use of medical Cannabis remains unregulated in several countries due to the scarcity of clinical studies with high scientific evidence that establish safety and efficacy of Cannabis products. This study aimed to comprehensively analyze how knowledge has been created in this field, as well as perform a bibliographic mapping to identify knowledge gaps, and investigate key authors and journals that have significantly contributed to advancing our understanding of Cannabis. Method: The study protocol was registered in the International Prospective Register of Systematic Review (CRD42020223084). A systematic search was conducted in the Cochrane Central Register of Controlled Trials, Lilacs, Google Scholar, PubMed, SciELO, Scopus, and Web of Science databases. The bibliographic analysis and mapping were registered using the VOSviewer, Sci2tool, CiteSpace, and PoP software. Results: The systematic search identified 27,597 records, with 17,020 duplicates, resulting in a total of 10,577 articles included. The authors who published the most were Marilyn Ann Huestis (n=108) and Sagnik Bhattacharyya (n=71), while Elisaldo A. Carlini and Raphael Mechoulam published 8 and 22 articles, respectively. The journals Drug and Alcohol Dependence (n=297), Psychopharmacology (n=159) and Addictive Behaviors (n=150) were the ones that published the most on Cannabis. The journals suggest that the articles are correlated with the adverse and toxicological effects of recreational Cannabis use; however, most articles focus on medical Cannabis. The peak of publications was in 2021 (n=1,481). The countries that published the most were the United States (n=9,735), while Brazil occupied the 11th position (n=422). Most publications were carried out in "Pharmacology and Pharmacy" (11.31%), followed by "Psychiatry" (7.66%) and "Medicine" (5.80%). The areas of "Neurosciences" (1.59%), "Biochemistry," "Genetics," and "Molecular Biology" (0.79%) were little explored. Conclusion: This study captured the characteristics of publications about Cannabis and clinical studies in the scientific literature, yielding >10,000 articles, representing a large literature review, to date. Therefore, the most productive countries included the United States, the United Kingdom, and Canada, while the most productive authors were Marilyn Ann Huestis and Sagnik Bhattacharyya, with a peak of publications in 2021. Finally, the most chosen journals were Drug and Alcohol Dependence and Psychopharmacology.

Association between the FAAH C385A variant (rs324420) and obesity-related traits: a systematic review

BACKGROUND

Overweight and obesity are the consequence of a sustained positive energy balance. Twin studies show high heritability rates pointing to genetics as one of the principal risk factors. By 2022, genomic studies led to the identification of almost 300 obesity-associated variants that could help to fill the gap of the high heritability rates. The endocannabinoid system is a critical regulator of metabolism for its effects on the central nervous system and peripheral tissues. Fatty acid amide hydrolase (FAAH) is a key enzyme in the inactivation of one of the two endocannabinoids, anandamide, and of its congeners. The rs324420 variant within the FAAH gene is a nucleotide missense change at position 385 from cytosine to adenine, resulting in a non-synonymous amino acid substitution from proline to threonine in the FAAH enzyme. This change increases sensitivity to proteolytic degradation, leading to reduced FAAH levels and increased levels of anandamide, associated with obesity-related traits. However, association studies of this variant with metabolic parameters have found conflicting results. This work aims to perform a systematic review of the existing literature on the association of the rs324420 variant in the FAAH gene with obesity and its related traits.

METHODS

A literature search was conducted in PubMed, Web of Science, and Scopus. A total of 645 eligible studies were identified for the review.

RESULTS/CONCLUSIONS

After the identification, duplicate elimination, title and abstract screening, and full-text evaluation, 28 studies were included, involving 28 183 individuals. We show some evidence of associations between the presence of the variant allele and higher body mass index, waist circumference, fat mass, and waist-to-hip ratio levels and alterations in glucose and lipid homeostasis. However, this evidence should be taken with caution, as many included studies did not report a significant difference between genotypes. These discordant results could be explained mainly by the pleiotropy of the endocannabinoid system, the increase of other anandamide-like mediators metabolized by FAAH, and the influence of gene-environment interactions. More research is necessary to study the endocannabinoidomic profiles and their association with metabolic diseases.

GPR55 inhibits the pro-adipogenic activity of anandamide in human adipose stromal cells

The endocannabinoid anandamide (AEA) stimulates adipogenesis via the cannabinoid receptor CB1 in adipose stromal cells (ASCs). However, AEA interacts also with nonclassical cannabinoid receptors, including transient receptor potential cation channel (TRPV)1 and G protein-coupled receptor (GPR)55. Their roles in AEA mediated adipogenesis of human ASCs have not been investigated. We examined the receptor-expressions by immunostaining on human ASCs and tested their functionality by measuring the expression of immediate early genes (IEGs) related to the transcription factor-complex AP-1 upon exposition to receptor agonists. Cells were stimulated with increasing concentrations of specific ligands to investigate the effects on ASC viability (proliferation and metabolic activity), secretory activity, and AEA mediated differentiation. ASCs expressed both receptors, and their activation suppressed IEG expression. TRPV1 did not affect viability or cytokine secretion. GPR55 decreased proliferation, and it inhibited the release of hepatocyte growth factor. Blocking GPR55 increased the pro-adipogenic activity of AEA. These data suggest that GPR55 functions as negative regulator of cannabinoid mediated pro-adipogenic capacity in ASCs.

Crosstalk Between the Neuroendocrine System and Bone Homeostasis

The homeostasis of bone microenvironment is the foundation of bone health and comprises 2 concerted events: bone formation by osteoblasts and bone resorption by osteoclasts. In the early 21st century, leptin, an adipocytes-derived hormone, was found to affect bone homeostasis through hypothalamic relay and the sympathetic nervous system, involving neurotransmitters like serotonin and norepinephrine. This discovery has provided a new perspective regarding the synergistic effects of endocrine and nervous systems on skeletal homeostasis. Since then, more studies have been conducted, gradually uncovering the complex neuroendocrine regulation underlying bone homeostasis. Intriguingly, bone is also considered as an endocrine organ that can produce regulatory factors that in turn exert effects on neuroendocrine activities. After decades of exploration into bone regulation mechanisms, separate bioactive factors have been extensively investigated, whereas few studies have systematically shown a global view of bone homeostasis regulation. Therefore, we summarized the previously studied regulatory patterns from the nervous system and endocrine system to bone. This review will provide readers with a panoramic view of the intimate relationship between the neuroendocrine system and bone, compensating for the current understanding of the regulation patterns of bone homeostasis, and probably developing new therapeutic strategies for its related disorders.

Potential of dietary hemp and cannabinoids to modulate immune response to enhance health and performance in animals: opportunities and challenges

Cannabinoids are a group of bioactive compounds abundantly present in Cannabis sativa plant. The active components of cannabis with therapeutic potential are known as cannabinoids. Cannabinoids are divided into three groups: plant-derived cannabinoids (phytocannabinoids), endogenous cannabinoids (endocannabinoids), and synthetic cannabinoids. These compounds play a crucial role in the regulation various physiological processes including the immune modulation by interacting with the endocannabinoid system (A complex cell-signaling system). Cannabinoid receptor type 1 (CB1) stimulates the binding of orexigenic peptides and inhibits the attachment of anorexigenic proteins to hypothalamic neurons in mammals, increasing food intake. Digestibility is unaffected by the presence of any cannabinoids in hemp stubble. Endogenous cannabinoids are also important for the peripheral control of lipid processing in adipose tissue, in addition to their role in the hypothalamus regulation of food intake. Regardless of the kind of synaptic connection or the length of the transmission, endocannabinoids play a crucial role in inhibiting synaptic transmission through a number of mechanisms. Cannabidiol (CBD) mainly influences redox equilibrium through intrinsic mechanisms. Useful effects of cannabinoids in animals have been mentioned e.g., for disorders of the cardiovascular system, pain treatment, disorders of the respiratory system or metabolic disorders. Dietary supplementation of cannabinoids has shown positive effects on health, growth and production performance of small and large animals. Animal fed diet supplemented with hemp seeds (180 g/day) or hemp seed cake (143 g/kg DM) had achieved batter performance without any detrimental effects. But the higher level of hemp or cannabinoid supplementation suppress immune functions and reduce productive performance. With an emphasis on the poultry and ruminants, this review aims to highlight the properties of cannabinoids and their derivatives as well as their significance as a potential feed additive in their diets to improve the immune status and health performance of animals.

The effect of N-arachidonoylethanolamide administration on energy and fat metabolism of early lactating dairy cows

The aim of the study was to investigate the effect of N-arachidonoylethanolamide (AEA), an endocannabinoid with orexigenic characteristics, on plasma endocannabinoid concentrations, feed intake, energy balance, lipomobilisation, and hepatic lipid metabolism of early-lactating dairy cows. The experiment involved 10 pairs of Holstein half-sibling cows (end of 2nd-3rd pregnancy). Half-sibs of each pair were randomly assigned to either AEA (n = 10) or control (CON) group (n = 10). From day 1 to 30 postpartum, the AEA group received 5 intraperitoneal injections per week of 3 µg/kg body weight AEA and the CON group 0.9% NaCl. In week 1-3 postpartum, AEA administration had no effect on dry matter intake, body weight, or lipomobilisation, but increased plasma triglyceride concentration on d 21 p.p. and mRNA abundances of genes related to hepatic triglyceride synthesis. In week 4 postpartum, the AEA group showed reduced feed intake and whole-body carbohydrate oxidation, but increased whole-body fat oxidation and hepatic lipid accumulation, likely as a result of a counter-regulatory leptin increase. In conclusion, the present study shows a tissue-specific AEA insensitivity and may point to a leptin-controlled regulation of the ECS in early-lactation.

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients.

Novel N-Acylethanolamide Derivatives Affect Body Weight and Energy Balance

Introduction - The obesity pandemic is multifactorial. Nutritional, pharmacologic and surgical interventions are limited in reach and efficacy, raising need for new therapeutics. Aims - Characterization of anorexigenic and cognitive effect and central mechanism of action of novel N-acylethanolamide derivatives. Methods - Sabra mice divided to similar experimental groups, injected IP with: oleyl-L-leucinolamide (1 A), linoleyl-L-leucinolamide (4 A), linoleyl-L-valinolamide (5 A), oleyl-oxycarbonyl-L-valinolamide (1 B), oleyl-oxycarbonyl-D-valinolamide (2 B), oleylamine-carbonyl-L-valinolamide (3 B), oleylamine-carbonyl-D-valinolamide (4 B), and oleyl-L-hydroxyvalineamide (5 B). Control group with vehicle. Body weight and food consumption followed for 39 days. Motor activity and cognitive function by open field test and eight-arm maze. Mice sacrificed and mechanism of action investigated by qPCR. The genes analyzed involved in energy balance and regulation of appetite. Catecholamines and serotonin evaluated. Results - Compounds 1 A, 5 A, 1 B-4 B, caused significant weight loss of 4.2-5.6 % and 5 A, 1 B-4 B, improved cognitive function following 8 i. p. injections of 1 mg/kg during 39 days, by different mechanisms. 5 A, 3 B and 4 B decreased food consumption, whereas 1 A, 5 A and 2 B increased motor activity. 1 A, 4 A, 1 B and 3 B elevated SIRT-1, associated with survival. POMC upregulated by 1 B and 2 B, CART by 1 B, 2 B and 1 A. NPY and CAMKK2 downregulated by 5 A. 4 B enhanced 5-HT levels. 4 A, 5 A, 1 B, 4 B, 5 B decreased FAAH, showing long lasting effect. Conclusions - These new compounds might be developed for the treatment of obesity and for improved cognitive function.

Cannabinoid receptor type 1 (CB1R) inhibits hypothalamic leptin signaling via β-arrestin1 in complex with TC-PTP and STAT3

Molecular interactions between anorexigenic leptin and orexigenic endocannabinoids, although of great metabolic significance, are not well understood. We report here that hypothalamic STAT3 signaling in mice, initiated by physiological elevations of leptin, is diminished by agonists of the cannabinoid receptor 1 (CB1R). Measurement of STAT3 activation by semi-automated confocal microscopy in cultured neurons revealed that this CB1R-mediated inhibition requires both T cell protein tyrosine phosphatase (TC-PTP) and β-arrestin1 but is independent of changes in cAMP. Moreover, β-arrestin1 translocates to the nucleus upon CB1R activation and binds both STAT3 and TC-PTP. Consistently, CB1R activation failed to suppress leptin signaling in β-arrestin1 knockout mice in vivo, and in neural cells deficient in CB1R, β-arrestin1 or TC-PTP. Altogether, CB1R activation engages β-arrestin1 to coordinate the TC-PTP-mediated inhibition of the leptin-evoked neuronal STAT3 response. This mechanism may restrict the anorexigenic effects of leptin when hypothalamic endocannabinoid levels rise, as during fasting or in diet-induced obesity.

The Use of Cannabidiol in Metabolic Syndrome-An Opportunity to Improve the Patient's Health or Much Ado about Nothing?

Cannabis-derived therapies are gaining popularity in the medical world. More and more perfect forms of cannabinoids are sought, which could be used in the treatment of many common diseases, including metabolic syndrome, whose occurrence is also increasing. The purpose of this review was to investigate the usefulness of cannabinoids, mainly cannabidiol (CBD), in individuals with obesity, impaired glucose and lipid metabolism, high blood pressure, and non-alcoholic fatty liver disease (NAFLD). We summarised the most recent research on the broad topic of cannabis-derived influence on metabolic syndrome components. Since there is a lot of work on the effects of Δ9-THC (Δ9-tetrahydrocannabinol) on metabolism and far less on cannabidiol, we felt it needed to be sorted out and summarised in this review. The research results on the use of cannabidiol in obesity are contraindicatory. When it comes to glucose homeostasis, it appears that CBD maintains it, sensitises adipose tissue to insulin, and reduces fasting glucose levels, so it seems to be a potential target in this kind of metabolic disorder, but some research results are inconclusive. CBD shows some promising results in the treatment of various lipid disorders. Some studies have proven its positive effect by decreasing LDL and increasing HDL as well. Despite their probable efficacy, CBD and its derivatives will likely remain an adjunctive treatment rather than a mainstay of therapy. Studies have also shown that CBD in patients with hypertension has positive effects, even though the hypotensive properties of cannabidiol are small. However, CBD can be used to prevent blood pressure surges, stabilise them, and have a protective effect on blood vessels. Results from preclinical studies have shown that the effect of cannabidiol on NAFLD may be potentially beneficial in the treatment of the metabolic syndrome and its components. Nevertheless, there is limited data on CBD and NAFLD in human studies. Because of the numerous confounding factors, the conclusions are unclear, and more research in this field is required.

The Role of the Endocannabinoid System in Binge Eating Disorder

Eating disorders are multifactorial disorders that involve maladaptive feeding behaviors. Binge eating disorder (BED), the most prevalent of these in both men and women, is characterized by recurrent episodes of eating large amounts of food in a short period of time, with a subjective loss of control over eating behavior. BED modulates the brain reward circuit in humans and animal models, which involves the dynamic regulation of the dopamine circuitry. The endocannabinoid system plays a major role in the regulation of food intake, both centrally and in the periphery. Pharmacological approaches together with research using genetically modified animals have strongly highlighted a predominant role of the endocannabinoid system in feeding behaviors, with the specific modulation of addictive-like eating behaviors. The purpose of the present review is to summarize our current knowledge on the neurobiology of BED in humans and animal models and to highlight the specific role of the endocannabinoid system in the development and maintenance of BED. A proposed model for a better understanding of the underlying mechanisms involving the endocannabinoid system is discussed. Future research will be necessary to develop more specific treatment strategies to reduce BED symptoms.

The emerging role of the endocannabinoidome-gut microbiome axis in eating disorders

Among the sources of chemical signals regulating food intake, energy metabolism and body weight, few have attracted recently as much attention as the expanded endocannabinoid system, or endocannabinoidome (eCBome), and the gut microbiome, the two systems on which this review article is focussed. Therefore, it is legitimate to expect that these two systems also play a major role in the etiopathology of eating disorders (EDs), in particular of anorexia nervosa, bulimia nervosa and binge-eating disorder. The major mechanisms through which, also via interactions with other endogenous signaling systems, the eCBome, with its several lipid mediators and receptors, and the gut microbiome, via its variety of microbial kingdoms, phyla and species, and armamentarium of metabolites, intervene in these disorders, are described here, based on several published studies in either experimental models or patients. Additionally, in view of the emerging multi-faceted cross-talk mechanisms between these two complex systems, we discuss the possibility that the eCBome-gut microbiome axis is also involved in EDs.

A genetic variant of fatty acid amide hydrolase (FAAH) exacerbates hormone-mediated orexigenic feeding in mice

Fatty acid amide hydrolase (FAAH) degrades the endocannabinoid anandamide. A polymorphism in FAAH (FAAH C385A) reduces FAAH expression, increases anandamide levels, and increases the risk of obesity. Nevertheless, some studies have found no association between FAAH C385A and obesity. We investigated whether the environmental context governs the impact of FAAH C385A on metabolic outcomes. Using a C385A knock-in mouse model, we found that FAAH A/A mice are more susceptible to glucocorticoid-induced hyperphagia, weight gain, and activation of hypothalamic AMP-activated protein kinase (AMPK). AMPK inhibition occluded the amplified hyperphagic response to glucocorticoids in FAAH A/A mice. FAAH knockdown exclusively in agouti-related protein (AgRP) neurons mimicked the exaggerated feeding response of FAAH A/A mice to glucocorticoids. FAAH A/A mice likewise presented exaggerated orexigenic responses to ghrelin, while FAAH knockdown in AgRP neurons blunted leptin anorectic responses. Together, the FAAH A/A genotype amplifies orexigenic responses and decreases anorexigenic responses, providing a putative mechanism explaining the diverging human findings.

Investigation of the effects of atorvastatin and Lactobacillus acidophilus on some hormones and oxidative stress in experimental hypercholesterolemia

AIM

The investigation of serum leptin, ghrelin, insulin, seratonin hormones, NO, total oxidant/antioxidant status and brain cannaboid 1 receptor protein and apoptotic cell levels in atorvastatin and Lactobacillus acidophilus administrated experimental hypercholesterolemia was aimed in the project.

METHODS

In the study, 5 experimental groups were formed. Group 1 was fed with standard rat chow, and Group 2 was fed with 2% cholesterol added standard rat chow for 8 weeks. Group 3 was fed with 2% cholesterol feed and received atorvastatin (20 mg/kg/day) for the last 4 weeks. Group 4 was given L. acidophilus (2 ×10⁸ cfu/kg/day). Group 5 was given atorvastatin and L. acidophilus probiotic in the last 4 weeks of the experiment period. After the experimental period, blood samples were taken from each rat. Rats were sacrificed and brain tissues were taken for analyzes. In sera samples, leptin, ghrelin, insulin, serotonin hormones and NO levels were measured with ELISA. In brain samples, cannabinoid 1 receptor proteins and apoptosis levels were measured by ELISA. Total oxidant and antioxidant levels were investigated with using Rel Assay Kits.

RESULTS

The addition of cholesterol to feeds increased the levels of serum cholesterol, insulin and leptin levels; on the other hand, reduced the levels of serotonin and ghrelin. In hypercholesterolemia, total oxidant and NO levels were increased, and total antioxidant levels were decreased.

CONCLUSION

The results showed that administrations of L. acidophilus and atorvastatin might be recommended for treatment of hypercholesterolemia.

Endocannabinoid administration affects taste preference and the expression of cannabinoid and opioid receptors in the amygdala of early lactating cows

The aim of the study was to investigate the influence of intraperitoneal N-arachidonoylethanolamide (AEA) on taste preference for feed and water, tongue taste receptor signalling (TAS1R2, GNAT3), and endocannabinoid (CNR1, CNR2, GPR55) and opioid (OPRD1, OPRK1, OPRM1, OPRL1) receptors in the amygdala and nucleus accumbens in periparturient cows. We conducted taste preference tests using unaltered, umami-tasting, and sweet-tasting water and feed, before and after calving. After calving, eight cows received AEA injections (3 µg/(kg bodyweight × day), 25 days), whereas eight control (CON) cows received saline injections. Tissue was sampled 30 days after calving. Before calving, both cow groups preferred sweet-tasting feed and umami-tasting water. After calving, only the AEA-treated group preferred sweet-tasting feed, whereas the CON group showed no clear taste preference. In the amygdala, the mRNA expression of CNR1, OPRD1 (left hemisphere) and OPRK1 (right hemisphere) was lower in AEA animals than in CON animals, whereas no differences were found in the nucleus accumbens and tongue taste receptor expression. In conclusion, AEA administration enhanced existing taste preferences and reduced the expression of specific endocannabinoid and opioid receptors in the amygdala. The results support endocannabinoid-opioid interactions in the control of taste-dependent feed preference in early lactating cows.

Cannabidiol treatment improves metabolic profile and decreases hypothalamic inflammation caused by maternal obesity

Introduction

The implications of maternal overnutrition on offspring metabolic and neuroimmune development are well-known. Increasing evidence now suggests that maternal obesity and poor dietary habits during pregnancy and lactation can increase the risk of central and peripheral metabolic dysregulation in the offspring, but the mechanisms are not sufficiently established. Furthermore, despite many studies addressing preventive measures targeted at the mother, very few propose practical approaches to treat the damages when they are already installed.

Methods

Here we investigated the potential of cannabidiol (CBD) treatment to attenuate the effects of maternal obesity induced by a cafeteria diet on hypothalamic inflammation and the peripheral metabolic profile of the offspring in Wistar rats.

Results

We have observed that maternal obesity induced a range of metabolic imbalances in the offspring in a sex-dependant manner, with higher deposition of visceral white adipose tissue, increased plasma fasting glucose and lipopolysaccharides (LPS) levels in both sexes, but the increase in serum cholesterol and triglycerides only occurred in females, while the increase in plasma insulin and the homeostatic model assessment index (HOMA-IR) was only observed in male offspring. We also found an overexpression of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNFα), interleukin (IL) 6, and interleukin (IL) 1β in the hypothalamus, a trademark of neuroinflammation. Interestingly, the expression of GFAP, a marker for astrogliosis, was reduced in the offspring of obese mothers, indicating an adaptive mechanism to in utero neuroinflammation. Treatment with 50 mg/kg CBD oil by oral gavage was able to reduce white adipose tissue and revert insulin resistance in males, reduce plasma triglycerides in females, and attenuate plasma LPS levels and overexpression of TNFα and IL6 in the hypothalamus of both sexes.

Discussion

Together, these results indicate an intricate interplay between peripheral and central counterparts in both the pathogenicity of maternal obesity and the therapeutic effects of CBD. In this context, the impairment of internal hypothalamic circuitry caused by neuroinflammation runs in tandem with the disruptions of important metabolic processes, which can be attenuated by CBD treatment in both ends.

Loss of brain energy metabolism control as a driver for memory impairment upon insulin resistance

The pathophysiological mechanisms intersecting metabolic and neurodegenerative disorders include insulin resistance, which has a strong involvement of environmental factors. Besides central regulation of whole-body homeostasis, insulin in the central nervous system controls molecular signalling that is critical for cognitive performance, namely signalling through pathways that modulate synaptic transmission and plasticity, and metabolism in neurons and astrocytes. This review provides an overview on how insulin signalling in the brain might regulate brain energy metabolism, and further identified molecular mechanisms by which brain insulin resistance might impair synaptic fuelling, and lead to cognitive deterioration.

Endocannabinoid 2-Arachidonoylglycerol Levels in the Anterior Cingulate Cortex, Caudate Putamen, Nucleus Accumbens, and Piriform Cortex Were Upregulated by Chronic Restraint Stress

Endocannabinoid 2-arachidonoylglycerol (2-AG) has been implicated in habituation to stress, and its augmentation reduces stress-induced anxiety-like behavior. Chronic restraint stress (CRS) changes the 2-AG levels in some gross brain areas, such as the forebrain. However, the detailed spatial distribution of 2-AG and its changes by CRS in stress processing-related anatomical structures such as the anterior cingulate cortex (ACC), caudate putamen (CP), nucleus accumbens (NAc), and piriform cortex (PIR) are still unclear. In this study, mice were restrained for 30 min in a 50 mL-centrifuge tube for eight consecutive days, followed by imaging of the coronal brain sections of control and stressed mice using desorption electrospray ionization mass spectrometry imaging (DESI-MSI). The results showed that from the forebrain to the cerebellum, 2-AG levels were highest in the hypothalamus and lowest in the hippocampal region. 2-AG levels were significantly (p < 0.05) upregulated and 2-AG precursors levels were significantly (p < 0.05) downregulated in the ACC, CP, NAc, and PIR of stressed mice compared with control mice. This study provided direct evidence of 2-AG expression and changes, suggesting that 2-AG levels are increased in the ACC CP, NAc, and PIR when individuals are under chronic stress.

Role of the Endocannabinoid System in Metabolic Control Processes and in the Pathogenesis of Metabolic Syndrome: An Update

Metabolic syndrome is a complex disease state, which appears mostly as a consequence of an unhealthy, sedentary lifestyle. Metabolic complications include insulin resistance (IR), diabetes, dyslipidemia, hypertension, and atherosclerosis, impairing life standards and reducing life expectancy. The endocannabinoid system (ECS) has an important role in signalization processes, not only in the central nervous system, but also in the peripheral tissues. Several physiological functions are affected, and overexpression or downregulation contributes to several diseases. A better understanding of the functions of cannabinoid (CB) receptors may propose potential therapeutic effects by influencing receptor signaling and enzymes involved in downstream pathways. In this review, we summarize recent information regarding the roles of the ECS and the CB₁ receptor signaling in the physiology and pathophysiology of energy and metabolic homeostasis, in the development of obesity by enhancing food intake, upregulating energy balance and fat accumulation, increasing lipogenesis and glucose production, and impairing insulin sensitivity and secretion. By analyzing the roles of the ECS in physiological and pathophysiological mechanisms, we introduce some recently identified signaling pathways in the mechanism of the pathogenesis of metabolic syndrome. Our review emphasizes that the presence of such recently identified ECS signaling steps raises new therapeutic potential in the treatment of complex metabolic diseases such as diabetes, insulin resistance, obesity, and hypertension.

Hepatic targeting of the centrally active cannabinoid 1 receptor (CB1R) blocker rimonabant via PLGA nanoparticles for treating fatty liver disease and diabetes

Over-activation of the endocannabinoid/CB1R system is a hallmark feature of obesity and its related comorbidities, most notably type 2 diabetes (T2D), and non-alcoholic fatty liver disease (NAFLD). Although the use of drugs that widely block the CB1R was found to be highly effective in treating all metabolic abnormalities associated with obesity, they are no longer considered a valid therapeutic option due to their adverse neuropsychiatric side effects. Here, we describe a novel nanotechnology-based drug delivery system for repurposing the abandoned first-in-class global CB1R antagonist, rimonabant, by encapsulating it in polymeric nanoparticles (NPs) for effective hepatic targeting of CB1Rs, enabling effective treatment of NAFLD and T2D. Rimonabant-encapsulated NPs (Rimo-NPs) were mainly distributed in the liver, spleen, and kidney, and only negligible marginal levels of rimonabant were found in the brain of mice treated by iv/ip administration. In contrast to freely administered rimonabant treatment, no CNS-mediated behavioral activities were detected in animals treated with Rimo-NPs. Chronic treatment of diet-induced obese mice with Rimo-NPs resulted in reduced hepatic steatosis and liver injury as well as enhanced insulin sensitivity, which were associated with enhanced cellular uptake of the formulation into hepatocytes. Collectively, we successfully developed a method of encapsulating the centrally acting CB1R blocker in NPs with desired physicochemical properties. This novel drug delivery system allows hepatic targeting of rimonabant to restore the metabolic advantages of blocking CB1R in peripheral tissues, especially in the liver, without the negative CB1R-mediated neuropsychiatric side effects.

First Evidence of the Protective Effects of 2-Pentadecyl-2-Oxazoline (PEA-OXA) in In Vitro Models of Acute Lung Injury

Acute respiratory distress syndrome (ARDS) is a serious inflammatory lung disorder and a complication of SARS-CoV-2 infection. In patients with severe SARS-CoV-2 infection, the transition to ARDS is principally due to the occurrence of a cytokine storm and an exacerbated inflammatory response. The effectiveness of ultra-micronized palmitoylethanolamide (PEA-um) during the earliest stage of COVID-19 has already been suggested. In this study, we evaluated its protective effects as well as the effectiveness of its congener, 2-pentadecyl-2-oxazoline (PEA-OXA), using in vitro models of acute lung injury. In detail, human lung epithelial cells (A549) activated by polyinosinic-polycytidylic acid (poly-(I:C)) or Transforming Growth Factor-beta (TGF-β) were treated with PEA-OXA or PEA. The release of IL-6 and the appearance of Epithelial-Mesenchymal Transition (EMT) were measured by ELISA and immunofluorescence assays, respectively. A possible mechanism of action for PEA-OXA and PEA was also investigated. Our results showed that both PEA-OXA and PEA were able to counteract poly-(I:C)-induced IL-6 release, as well as to revert TGF-β-induced EMT. In addition, PEA was able to produce an "entourage" effect on the levels of the two endocannabinoids AEA and 2-AG, while PEA-OXA only increased PEA endogenous levels, in poly-(I:C)-stimulated A549 cells. These results evidence for the first time the superiority of PEA-OXA over PEA in exerting protective effects and point to PEA-OXA as a new promising candidate in the management of acute lung injury.

Endocannabinoid System Regulation in Female Rats with Recurrent Episodes of Binge Eating

Recurrent Binge Eating (BE) episodes characterize several eating disorders. Here, we attempted to reassemble a condition closer to BE disorder, and we analyzed whether recurrent episodes might evoke molecular alterations in the hypothalamus of rats. The hypothalamus is a brain region which is sensitive to stress and relevant in motivated behaviors, such as food intake. A well-characterized animal model of BE, in which a history of intermittent food restriction and stress induce binge-like palatable food consumption, was used to analyze the transcriptional regulation of the endocannabinoid system (ECS). We detected, in rats showing the BE behavior, an up-regulated gene expression of cannabinoid type-1 receptor (CB1), sn-1-specific diacylglycerol lipase, as well as fatty acid amide hydrolase (Faah) and monoacylglycerol lipase. A selective reduction in DNA methylation was also observed at the promoter of Faah, which is consistent with the changes in the gene expression. Moreover, BE behavior in rats was associated with an increase in anandamide (AEA) levels. Our findings support the relevant role of the ECS in the regulation of food intake in rats subjected to repeated BE episodes, and, in particular, on AEA signaling, acting via CB1 and FAAH modulation. Notably, the epigenetic regulation of the Faah gene might suggest this enzyme as a possible target for developing new therapeutical approaches.

Marijuana use and DNA methylation-based biological age in young adults

BACKGROUND

Marijuana is the third most commonly used drug in the USA and efforts to legalize it for medical and recreational use are growing. Despite the increase in use, marijuana's effect on aging remains understudied and understanding the effects of marijuana on molecular aging may provide novel insights into the role of marijuana in the aging process. We therefore sought to investigate the association between cumulative and recent use of marijuana with epigenetic age acceleration (EAA) as estimated from blood DNA methylation.

RESULTS

A random subset of participants from The Coronary Artery Risk Development in Young Adults (CARDIA) Study with available whole blood at examination years (Y) 15 and Y20 underwent epigenomic profiling. Four EAA estimates (intrinsic epigenetic age acceleration, extrinsic epigenetic age acceleration, PhenoAge acceleration, and GrimAge acceleration) were calculated from DNA methylation levels measured at Y15 and Y20. Ever use and cumulative marijuana-years were calculated from the baseline visit to Y15 and Y20, and recent marijuana use (both any and number of days of use in the last 30 days) were calculated at Y15 and Y20. Ever use of marijuana and each additional marijuana-year were associated with a 6-month (P < 0.001) and a 2.5-month (P < 0.001) higher average in GrimAge acceleration (GAA) using generalized estimating equations, respectively. Recent use and each additional day of recent use were associated with a 20-month (P < 0.001) and a 1-month (P < 0.001) higher GAA, respectively. A statistical interaction between marijuana-years and alcohol consumption on GAA was observed (P = 0.011), with nondrinkers exhibiting a higher GAA (β = 0.21 [95% CI 0.05, 0.36], P = 0.008) compared to heavy drinkers (β = 0.05 [95% CI - 0.09, 0.18], P = 0.500) per each additional marijuana-year. No associations were observed for the remaining EAA estimates.

CONCLUSIONS

These findings suggest cumulative and recent marijuana use are associated with age-related epigenetic changes that are related to lifespan. These observed associations may be modified by alcohol consumption. Given the increase in use and legalization, these findings provide novel insight on the effect of marijuana use on the aging process as captured through blood DNA methylation.

Up-regulation of CB1 cannabinoid receptors located at glutamatergic terminals in the medial prefrontal cortex of the obese Zucker rat

The present study describes a detailed neuroanatomical distribution map of the cannabinoid type 1 (CB₁) receptor, along with the biochemical characterization of the expression and functional coupling to their cognate G_i/o proteins in the medial prefrontal cortex (mPCx) of the obese Zucker rats. The CB₁ receptor density was higher in the prelimbic (PL) and infralimbic (IL) subregions of the mPCx of obese Zucker rats relative to their lean littermates which was associated with a higher percentage of CB₁ receptor immunopositive excitatory presynaptic terminals in PL and IL. Also, a higher expression of CB₁ receptors and WIN55,212-2-stimulated [³⁵S]GTPγS binding was observed in the mPCx but not in the neocortex (NCx) and hippocampus of obese rats. Low-frequency stimulation in layers II/III of the mPCx induced CB₁ receptor-dependent long-term synaptic plasticity in IL of area obese Zucker but not lean rats. Overall, the elevated 2-AG levels, up-regulation of CB₁ receptors, and increased agonist-stimulated [³⁵S]GTPγS binding strongly suggest that hyperactivity of the endocannabinoid signaling takes place at the glutamatergic terminals of the mPCx in the obese Zucker rat. These findings could endorse the importance of the CB₁ receptors located in the mPCx in the development of obesity in Zucker rats.

Yin and yang of cannabinoid CB1 receptor: CB1 deletion in immune cells causes exacerbation while deletion in non-immune cells attenuates obesity

While blockade of cannabinoid receptor 1 (CB1) has been shown to attenuate diet-induced obesity (DIO), its relative role in different cell types has not been tested. The current study investigated the role of CB1 in immune vs non-immune cells during DIO by generating radiation-induced bone marrow chimeric mice that expressed functional CB1 in all cells except the immune cells or expressed CB1 only in immune cells. CB1^−/− recipient hosts were resistant to DIO, indicating that CB1 in non-immune cells is necessary for induction of DIO. Interestingly, chimeras with CB1^−/− in immune cells showed exacerbation in DIO combined with infiltration of bone-marrow-derived macrophages to the brain and visceral adipose tissue, elevated food intake, and increased glucose intolerance. These results demonstrate the opposing role of CB1 in hematopoietic versus non-hematopoietic cells during DIO and suggests that targeting immune CB1 receptors provides a new pathway to ameliorate obesity and related metabolic disorders.

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Cannabinoid Receptor 1 (CB1), and not CB2, regulates diet-induced obesity (DIO)

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CB1 deficiency in non-immune cell types promotes DIO resistance

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CB1 deficiency in immune cells exacerbates DIO disease phenotype

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CB1 activation in immune cells is a potential therapeutic target for DIO attenuation

Cannabinoids and PPAR Ligands: The Future in Treatment of Polycystic Ovary Syndrome Women with Obesity and Reduced Fertility

Cannabinoids (CBs) are used to treat chronic pain, chemotherapy-induced nausea and vomiting, and multiple sclerosis spasticity. Recently, the medicinal use of CBs has attracted increasing interest as a new therapeutic in many diseases. Data indicate a correlation between CBs and PPARs via diverse mechanisms. Both the endocannabinoid system (ECS) and peroxisome proliferator-activated receptors (PPARs) may play a significant role in PCOS and PCOS related disorders, especially in disturbances of glucose-lipid metabolism as well as in obesity and fertility. Taking into consideration the ubiquity of PCOS in the human population, it seems indispensable to search for new potential therapeutic targets for this condition. The aim of this review is to examine the relationship between metabolic disturbances and obesity in PCOS pathology. We discuss current and future therapeutic interventions for PCOS and related disorders, with emphasis on the metabolic pathways related to PCOS pathophysiology. The link between the ECS and PPARs is a promising new target for PCOS, and we examine this relationship in depth.

Feed types affect the growth, nutrient utilization, digestive capabilities, and endocrine functions of Megalobrama amblycephala: a comparative study between pelleted and extruded feed

Nowadays, both pelleted feed (PF) and extruded feed (EF) have been widely adopted in the aquaculture industry. However, limited information is available comparing their utilization efficiencies and meanwhile interpreting the underlying mechanisms. This study aimed to compare the utilization efficiencies of both PF and EF by blunt snout bream (Megalobrama amblycephala) based on growth performance, digestive capacities, and endocrine functions. Two feeds with identical formulas were prepared and named PF and EF. Fish were randomly distributed into two groups, including one that fed the PF continuously, and one that offered the EF continuously. The whole feeding trail lasted 8 weeks. The results showed that the protein efficiency (PER), retention of nitrogen and energy (NRE and ERE), viscera index (VSI), apparent digestibility of dry matter, protein, carbohydrate, and gross energy, whole-body crude protein and energy contents, intestinal enzymatic activities of protease, amylase, and Na⁺,K⁺-ATPase, intestinal villi length, crypt depth, muscular layer thickness, and the transcriptions of leptin (LEP) and cholecystokinin (CCK) of the EF group were all significantly higher than those of the PF group, while the opposite was true for feed intake and feed conversion ratio. These findings suggested that compared with PF, EF could improve the feed utilization and nutrient retention of blunt snout bream by enhancing the intestinal digestive and absorptive functions but reduce the feed intake through the stimulation of both LEP and CCK.

Cross-Talk between Obesity and Diabetes: Introducing Polyphenols as an Effective Phytomedicine to Combat the Dual Sword Diabesity

: Obesity-associated diabetes mellitus, a chronic metabolic affliction accounting for 90% of all diabetic patients, has been affecting humanity extremely badly and escalating the risk of developing other serious disorders. It is observed that 0.4 billion people globally have diabetes, whose major cause is obesity. Currently, innumerable synthetic drugs like alogliptin and rosiglitazone are being used to get through diabetes, but they have certain complications, restrictions with severe side effects, and toxicity issues. Recently, the frequency of plant-derived phytochemicals as advantageous substitutes against diabesity is increasing progressively due to their unparalleled benefit of producing less side effects and toxicity. Of these phytochemicals, dietary polyphenols have been accepted as potent agents against the dual sword "diabesity". These polyphenols target certain genes and molecular pathways through dual mechanisms such as adiponectin upregulation, cannabinoid receptor antagonism, free fatty acid oxidation, ghrelin antagonism, glucocorticoid inhibition, sodium-glucose cotransporter inhibition, oxidative stress and inflammation inhibition etc. which sequentially help to combat both diabetes and obesity. In this review, we have summarized the most beneficial natural polyphenols along with their complex molecular pathways during diabesity.

The Role of Nutritional Status, Gastrointestinal Peptides, and Endocannabinoids in the Prognosis and Treatment of Children with Cancer

Neoplastic diseases in children are the second most frequent cause of death among the young. It is estimated that 400,000 children worldwide will be diagnosed with cancer each year. The nutritional status at diagnosis is a prognostic indicator and influences the treatment tolerance. Both malnutrition and obesity increase the risk of mortality and complications during treatment. It is necessary to constantly search for new factors that impair the nutritional status. The endocannabinoid system (ECS) is a signaling system whose best-known function is regulating energy balance and food intake, but it also plays a role in pain control, embryogenesis, neurogenesis, learning, and the regulation of lipid and glucose metabolism. Its action is multidirectional, and its role is being discovered in an increasing number of diseases. In adults, cannabinoids have been shown to have anti-cancer properties against breast and pancreatic cancer, melanoma, lymphoma, and brain tumors. Data on the importance of both the endocannabinoid system and synthetic cannabinoids are lacking in children with cancer. This review highlights the role of nutritional status in the oncological treatment process, and describes the role of ECS and gastrointestinal peptides in regulating appetite. We also point to the need for research to evaluate the role of the endocannabinoid system in children with cancer, together with a prospective assessment of nutritional status during oncological treatment.

Translational models of cannabinoid vapor exposure in laboratory animals

Cannabis is one of the most frequently used psychoactive substances in the world. The most common route of administration for cannabis and cannabinoid constituents such as Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) is via smoking or vapor inhalation. Preclinical vapor models have been developed, although the vaporization devices and delivery methods vary widely across laboratories. This review examines the emerging field of preclinical vapor models with a focus on cannabinoid exposure in order to (1) summarize vapor exposure parameters and other methodological details across studies; (2) discuss the pharmacological and behavioral effects produced by exposure to vaporized cannabinoids; and (3) compare behavioral effects of cannabinoid vapor administration with those of other routes of administration. This review will serve as a guide for past and current vapor delivery methods in animals, synergize findings across studies, and propose future directions for this area of research.

Integrative Hedonic and Homeostatic Food Intake Regulation by the Central Nervous System: Insights from Neuroimaging

Food intake regulation in humans is a complex process controlled by the dynamic interaction of homeostatic and hedonic systems. Homeostatic regulation is controlled by appetitive signals from the gut, adipose tissue, and the vagus nerve, while conscious and unconscious reward processes orchestrate hedonic regulation. On the one hand, sight, smell, taste, and texture perception deliver potent food-related feedback to the central nervous system (CNS) and influence brain areas related to food reward. On the other hand, macronutrient composition stimulates the release of appetite signals from the gut, which are translated in the CNS into unconscious reward processes. This multi-level regulation process of food intake shapes and regulates human ingestive behavior. Identifying the interface between hormones, neurotransmitters, and brain areas is critical to advance our understanding of conditions like obesity and develop better therapeutical interventions. Neuroimaging studies allow us to take a glance into the central nervous system (CNS) while these processes take place. This review focuses on the available neuroimaging evidence to describe this interaction between the homeostatic and hedonic components in human food intake regulation.

Masturbation in the Animal Kingdom

Masturbation is one of the most common sexual behaviors in humans. It is also a phylogenetically widespread trait of various other mammalian and some non-mammalian species. Several hypotheses have been proposed aiming to explain the function of masturbation in primates and other species. These were mainly based on observations of nonhuman primates such as rhesus macaques or bonobos and rodents such as African ground squirrels. Based on these observations various scholars suggested that masturbation improves ejaculate quality, decreases the risk of contracting sexually transmitted infections or is merely a by-product of sexual arousal and thus an alternate outlet to copulation. While these theories may explain some facets of masturbation in some species, they do not explain why masturbation is so widespread and has developed in various species as well as our hominid ancestors. Moreover, the research on which these theories are based is scarce and heavily focused on male masturbation, while female masturbation remains largely unexplored. This sex difference may be responsible for the one-sided theorizing that attributes a specific biological benefit to masturbation. We propose that the widespread prevalence of masturbation in the animal kingdom may be better explained by viewing masturbation as a primarily self-reinforcing behavior that promotes pleasure both in human and in nonhuman species.

Chemical Synthesis, Pharmacokinetic Properties and Biological Effects of JM-00266, a Putative Non-Brain Penetrant Cannabinoid Receptor 1 Inverse Agonist

Targeting cannabinoid 1 receptors (CB1R) with peripherally restricted antagonists (or inverse agonists) shows promise to improve metabolic disorders associated with obesity. In this context, we designed and synthetized JM-00266, a new CB1R blocker with limited blood–brain barrier (BBB) permeability. Pharmacokinetics were tested with SwissADME and in vivo in rodents after oral and intraperitoneal administration of JM-00266 in comparison with Rimonabant. In silico predictions indicated JM-00266 is a non-brain penetrant compound and this was confirmed by brain/plasma ratios and brain uptake index values. JM-00266 had no impact on food intake, anxiety-related behavior and body temperature suggesting an absence of central activity. cAMP assays performed in CB1R-transfected HEK293T/17 cells showed that the drug exhibited inverse agonist activity on CB1R. In addition, JM-00266 counteracted anandamide-induced gastroparesis indicating substantial peripheral activity. Acute administration of JM-00266 also improved glucose tolerance and insulin sensitivity in wild-type mice, but not in CB1R^−/− mice. Furthermore, the accumulation of JM-00266 in adipose tissue was associated with an increase in lipolysis. In conclusion, JM-00266 or derivatives can be predicted as a new candidate for modulating peripheral endocannabinoid activity and improving obesity-related metabolic disorders.

Serum lipid analysis and isotopic enrichment is suggestive of greater lipogenesis in young long-term cannabis users: A secondary analysis of a case-control study

Cannabis is now legal in many countries and while numerous studies have reported on its impact on cognition and appetite regulation, none have examined fatty acid metabolism in young cannabis users. We conducted an exploratory analysis to evaluate cannabis impact on fatty acid metabolism in cannabis users (n = 21) and non-cannabis users (n = 16). Serum levels of some saturated and monounsaturated fatty acids, including palmitic, palmitoleic, and oleic acids were higher in cannabis users compared to nonusers. As palmitic acid can be derived from diet or lipogenesis from sugars, we evaluated lipogenesis using a de novo lipogenesis index (palmitate/linoleic acid) and carbon-specific isotope analysis, which allows for the determination of fatty acid ¹³ C signature. The significantly higher de novo lipogenesis index in the cannabis users group along with a more enriched ¹³ C signature of palmitic acid suggested an increase in lipogenesis. In addition, while serum glucose concentration did not differ between groups, pyruvate and lactate were lower in the cannabis user group, with pyruvate negatively correlating with palmitic acid. Furthermore, the endocannabinoid 2-arachidonoylglycerol was elevated in cannabis users and could contribute to lipogenesis by activating the cannabinoid receptor 1. Because palmitic acid has been suggested to increase inflammation, we measured peripheral cytokines and observed no changes in inflammatory cytokines. Finally, an anti-inflammatory metabolite of palmitic acid, palmitoylethanolamide was elevated in cannabis users. Our results suggest that lipogenic activity is increased in cannabis users; however, future studies, including prospective studies that control dietary intake are required.

Lipid endocannabinoids in energy metabolism, stress and developmental programming

The endocannabinoid system (ECS) regulates brain development and function, energy metabolism and stress in a sex-, age- and tissue-dependent manner. The ECS comprises mainly the bioactive lipid ligands anandamide (AEA) and 2-aracdonoylglycerol (2-AG), cannabinoid receptors 1 and 2 (CB1 and CB2), and several metabolizing enzymes. The endocannabinoid tonus is increased in obesity, stimulating food intake and a preference for fat, reward, and lipid accumulation in peripheral tissues, as well as favoring a positive energy balance. Energy balance and stress responses share adaptive mechanisms regulated by the ECS that seem to underlie the complex relationship between feeding and emotional behavior. The ECS is also a key regulator of development. Environmental insults (diet, toxicants, and stress) in critical periods of developmental plasticity, such as gestation, lactation and adolescence, alter the ECS and may predispose individuals to the development of chronic diseases and behavioral changes in the long term. This review is focused on the ECS and the developmental origins of health and disease (DOHaD).

Mutual Links between the Endocannabinoidome and the Gut Microbiome, with Special Reference to Companion Animals: A Nutritional Viewpoint

There is growing evidence that perturbation of the gut microbiome, known as “dysbiosis”, is associated with the pathogenesis of human and veterinary diseases that are not restricted to the gastrointestinal tract. In this regard, recent studies have demonstrated that dysbiosis is linked to the pathogenesis of central neuroinflammatory disorders, supporting the existence of the so-called microbiome-gut-brain axis. The endocannabinoid system is a recently recognized lipid signaling system and termed endocannabinoidome monitoring a variety of body responses. Accumulating evidence demonstrates that a profound link exists between the gut microbiome and the endocannabinoidome, with mutual interactions controlling intestinal homeostasis, energy metabolism and neuroinflammatory responses during physiological conditions. In the present review, we summarize the latest data on the microbiome-endocannabinoidome mutual link in health and disease, focalizing the attention on gut dysbiosis and/or altered endocannabinoidome tone that may distort the bidirectional crosstalk between these two complex systems, thus leading to gastrointestinal and metabolic diseases (e.g., idiopathic inflammation, chronic enteropathies and obesity) as well as neuroinflammatory disorders (e.g., neuropathic pain and depression). We also briefly discuss the novel possible dietary interventions based not only on probiotics and/or prebiotics, but also, and most importantly, on endocannabinoid-like modulators (e.g., palmitoylethanolamide) for intestinal health and beyond.

Intestinal Barrier Function and Immune Homeostasis Are Missing Links in Obesity and Type 2 Diabetes Development

Noncommunicable diseases, such as type 2 diabetes (T2D), place a burden on healthcare systems worldwide. The rising prevalence of obesity, a major risk factor for T2D, is mainly attributed to the adoption of Westernized diets and lifestyle, which cause metabolic dysfunction and insulin resistance. Moreover, diet may also induce changes in the microbiota composition, thereby affecting intestinal immunity. The critical role of intestinal immunity and intestinal barrier function in the development of T2D is increasingly acknowledged, however, limited studies have investigated the link between intestinal function and metabolic disease. In this review, studies reporting specific roles of the intestinal immune system and intestinal epithelial cells (IECs) in metabolic disease are highlighted. Innate chemokine signaling, eosinophils, immunoglobulin A (IgA), T helper (Th) 17 cells and their cytokines were associated with obesity and/or dysregulated glucose homeostasis. Intestinal epithelial cells (IECs) emerged as critical modulators of obesity and glucose homeostasis through their effect on lipopolysaccharide (LPS) signaling and decontamination. Furthermore, IECs create a link between microbial metabolites and whole-body metabolic function. Future in depth studies of the intestinal immune system and IECs may provide new opportunities and targets to develop treatments and prevention strategies for obesity and T2D.

Selective measurement of NAPE-PLD activity via a PLA1/2-resistant fluorogenic N-acyl-phosphatidylethanolamine analog

N-acyl-phosphatidylethanolamine (NAPE)-hydrolyzing phospholipase D (NAPE-PLD) is a zinc metallohydrolase enzyme that converts NAPEs to bioactive N-acyl-ethanolamides. Altered NAPE-PLD activity may contribute to pathogenesis of obesity, diabetes, atherosclerosis, and neurological diseases. Selective measurement of NAPE-PLD activity is challenging, however, because of alternative phospholipase pathways for NAPE hydrolysis. Previous methods to measure NAPE-PLD activity involved addition of exogenous NAPE followed by TLC or LC/MS/MS, which are time and resource intensive. Recently, NAPE-PLD activity in cells has been assayed using the fluorogenic NAPE analogs PED-A1 and PED6, but these substrates also detect the activity of serine hydrolase-type lipases PLA1 and PLA2. To create a fluorescence assay that selectively measured cellular NAPE-PLD activity, we synthesized an analog of PED-A1 (flame-NAPE) where the sn-1 ester bond was replaced with an N-methyl amide to create resistance to PLA1 hydrolysis. Recombinant NAPE-PLD produced fluorescence when incubated with either PED-A1 or flame-NAPE, whereas PLA1 only produced fluorescence when incubated with PED-A1. Furthermore, fluorescence in HepG2 cells using PED-A1 could be partially blocked by either biothionol (a selective NAPE-PLD inhibitor) or tetrahydrolipstatin (an inhibitor of a broad spectrum of serine hydrolase-type lipases). In contrast, fluorescence assayed in HepG2 cells using flame-NAPE could only be blocked by biothionol. In multiple cell types, the phospholipase activity detected using flame-NAPE was significantly more sensitive to biothionol inhibition than that detected using PED-A1. Thus, using flame-NAPE to measure phospholipase activity provides a rapid and selective method to measure NAPE-PLD activity in cells and tissues.

Dronabinol inhibits alveolar bone remodeling in tooth movement of rats

INTRODUCTION

Orthodontic tooth movement is reliant on the process of bone remodeling, and a variety of medications impact the ability of teeth to move through bone. Marijuana is the most widely used recreational drug in the world, and early studies suggest the drug impacts bone remodeling as tetrahydrocannabinol binds to cannabinoid receptors which play a role in bone homeostasis. This study aimed to assess the impact of dronabinol on alveolar bone remodeling in rats with otherwise healthy tissue when subjected to orthodontic forces.

METHODS

Thirty male Sprague Dawley rats were equally allocated into 2 groups. Orthodontic appliances were placed in all animals, which consisted of a nickel-titanium coil ligated from the maxillary first molar to the central incisor. The appliance was activated to deliver a force to move teeth together. Over 21 days, daily injections of either dronabinol or the control (solvent) were given to the rats. Cephalometric analysis, histology, and bone remodeling profiles of both groups were analyzed and compared.

RESULTS

Teeth moved in both the dronabinol and control groups (P <0.05). Tooth movement in the control group followed the typical process of orthodontic tooth movement: periodontal width narrowing and bone resorption on the compression side of the tooth, with an overall decrease in the height of the alveolar bone. In contrast, the dronabinol group showed an abnormal response to tooth movement: no bone resorption on the compression side of the tooth, increased bone formation on the tension side, and the maintenance of the height of the alveolar crest. In the dronabinol group, there were also significantly more osteoclasts and osteoblasts in the alveolar bone than in the control group.

CONCLUSIONS

These results demonstrate that dronabinol attenuates orthodontic tooth movement by decreasing bone resorption, which could have implications for other bone-related recovery processes.

Transcriptional and functional divergence in lateral hypothalamic glutamate neurons projecting to the lateral habenula and ventral tegmental area

The lateral hypothalamic area (LHA) regulates feeding- and reward-related behavior, but because of its molecular and anatomical heterogeneity, the functions of defined neuronal populations are largely unclear. Glutamatergic neurons within the LHA (LHA^Vglut2) negatively regulate feeding and appetitive behavior. However, this population comprises transcriptionally distinct and functionally diverse neurons that project to diverse brain regions, including the lateral habenula (LHb) and ventral tegmental area (VTA). To resolve the function of distinct LHA^Vglut2 populations, we systematically compared projections to the LHb and VTA using viral tracing, single-cell sequencing, electrophysiology, and in vivo calcium imaging. LHA^Vglut2 neurons projecting to the LHb or VTA are anatomically, transcriptionally, electrophysiologically, and functionally distinct. While both populations encode appetitive and aversive stimuli, LHb projecting neurons are especially sensitive to satiety state and feeding hormones. These data illuminate the functional heterogeneity of LHA^Vglut2 neurons, suggesting that reward and aversion are differentially processed in divergent efferent pathways.

Parkinson's disease related alterations in cannabinoid transmission

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic (DAergic) neurons of the substantia nigra pars compacta (SNc) by neurodegeneration. Recent findings in animal models of PD propose tonic inhibition of the remaining DA neurons through GABA release from reactive glial cells. Movement dysfunctions could be ameliorated by promotion of activity in dormant DA cells. The endocannabinoid system (ECS) is extensively present in basal ganglia (BG) and is known as an indirect modulator of DAergic neurotransmission, thus drugs designed to target this system have shown promising therapeutic potential in PD patients. Interestingly, down/up-regulation of cannabinoid receptors (CBRs) varies across the different stages of PD, suggesting that some of the motor/ non-motor deficits may be related to changes in CBRs. Determination of the profile of changes of these receptors across the different stages of PD as well as their neural distribution within the BG could improve understanding of PD and identify pathways important in disease pathobiology. In this review, we focus on temporal and spatial alterations of CBRs during PD in the BG. At present, as inconclusive, but suggestive results have been obtained, future investigations should be conducted to extend preclinical studies examining CBRs changes within each stage in controlled clinical trials in order to determine the potential of targeting CBRs in management of PD.