Cannabinoids and endocannabinoids as therapeutics for nervous system disorders:preclinical models and clinical studies

Cannabinoids are lipophilic substances derived from Cannabis sativa that can exert a variety of effects in the human body.They have been studied in cellular and animal models as well as in human clinical trials for their therapeutic benefits in several human diseases.Some of these include central nervous system(CNS)diseases and dysfunctions such as forms of epilepsy,multiple sclerosis,Parkinson’s disease,pain and neuropsychiatric disorders.In addition,the endogenously produced cannabinoid lipids,endocannabinoids,are critical for normal CNS function,and if controlled or modified,may represent an additional therapeutic avenue for CNS diseases.This review discusses in vitro cellular,ex vivo tissue and in vivo animal model studies on cannabinoids and their utility as therapeutics in multiple CNS pathologies.In addition,the review provides an overview on the use of cannabinoids in human clinical trials for a variety of CNS diseases.Cannabinoids and endocannabinoids hold promise for use as disease modifiers and therapeutic agents for the prevention or treatment of neurodegenerative diseases and neurological disorders.

SPME as a green sample-preparation technique for the monitoring of phytocannabinoids and endocannabinoids in complex matrices

The endocannabinoid system(ECS),particularly its signaling pathways and ligands,has garnered considerable interest in recent years.Along with clinical work investigating the ECS’functions,including its role in the development of neurological and inflammatory conditions,much research has focused on developing analytical protocols enabling the precise monitoring of the levels and metabolism of the most potent ECS ligands:exogenous phytocannabinoids(PCs)and endogenous cannabinoids(endocannabinoids,ECs).Solid-phase microextraction(SPME)is an advanced,non-exhaustive sample-preparation technique that facilitates the precise and efficient isolation of trace amounts of analytes,thus making it appealing for the analysis of PCs and ECs in complex matrices of plant and animal/human origin.In this paper,we review recent forensic medicine and toxicological studies wherein SPME has been applied to monitor levels of PCs and ECs in complex matrices,determine their effects on organism physiology,and assess their role in the development of several diseases.

Endocannabinoids are potential inhibitors of glioblastoma multiforme proliferation

Globally,it is evident that glioblastoma multiforme(GBM)is an aggressive malignant cancer with a high mortality rate and no effective treatment options.Glioblastoma is classified as the stage-four progression of a glioma tumor,and its diagnosis results in a shortened life expectancy.Treatment options for GBM include chemotherapy,immunotherapy,surgical intervention,and conventional pharmacotherapy;however,at best,they extend the patient’s life by a maximum of 5 years.GBMs are considered incurable due to their high recurrence rate,despite various aggressive therapeutic approaches which can have many serious adverse effects.Ceramides,classified as endocannabinoids,offer a promising novel therapeutic approach for GBM.Endocannabinoids may enhance the apoptosis of GBM cells but have no effect on normal healthy neural cells.Cannabinoids promote atypical protein kinase C,deactivate fatty acid amide hydrolase enzymes,and activate transient receptor potential vanilloid 1(TRPV1)and TRPV2 to induce pro-apoptotic signaling pathways without increasing endogenous cannabinoids.In previous in vivo studies,endocannabinoids,chemically classified as amide formations of oleic and palmitic acids,have been shown to increase the pro-apoptotic activity of human cancer cells and inhibit cell migration and angiogenesis.This review focuses on the biological synthesis and pharmacology of endogenous cannabinoids for the enhancement of cancer cell apoptosis,which have potential as a novel therapy for GBM.

Physical exercise and synaptic protection in human and pre-clinical models of multiple sclerosis

In multiple sclerosis,only immunomodulato ry and immunosuppressive drugs are recognized as disease-modifying therapies.Howeve r,in recent years,several data from pre-clinical and clinical studies suggested a possible role of physical exe rcise as disease-modifying therapy in multiple sclerosis.Current evidence is sparse and often conflicting,and the mechanisms underlying the neuroprotective and antinflammatory role of exercise in multiple sclerosis have not been fully elucidated.Data,mainly derived from pre-clinical studies,suggest that exe rcise could enhance longterm potentiation and thus neuroplasticity,could reduce neuroinflammation and synaptopathy,and dampen astrogliosis and microgliosis.In humans,most trials focused on direct clinical and MRI outcomes,as investigating synaptic,neuroinflammato ry,and pathological changes is not straightfo rward compared to animal models.The present review analyzed current evidence and limitations in research concerning the potential disease-modifying therapy effects of exercise in multiple sclerosis in animal models and human studies.

Maternal supplementation with n-3 fatty acids affects placental lipid metabolism, inflammation, oxidative stress, the endocannabinoid system, and the neonate cytokine concentrations in dairy cows

Background The placenta plays a crucial role in supporting and influencing fetal development.We compared the effects of prepartum supplementation with omega-3(n-3)fatty acid(FA)sources,flaxseed oil(FLX)and fish oil(FO),on the expression of genes and proteins related to lipid metabolism,inflammation,oxidative stress,and the endocannabinoid system(ECS)in the expelled placenta,as well as on FA profile and inflammatory response of neonates.Late-pregnant Holstein dairy cows were supplemented with saturated fat(CTL),FLX,or FO.Placental cotyledons(n=5)were collected immediately after expulsion,and extracted RNA and proteins were analyzed by RTPCR and proteomic analysis.Neonatal blood was assessed for FA composition and concentrations of inflammatory markers.Results FO increased the gene expression of fatty acid binding protein 4(FABP4),interleukin 10(IL-10),catalase(CAT),cannabinoid receptor 1(CNR1),and cannabinoid receptor 2(CNR2)compared with CTL placenta.Gene expression of ECS-enzyme FA-amide hydrolase(FAAH)was lower in FLX and FO than in CTL.Proteomic analysis identified 3,974 proteins;of these,51–59 were differentially abundant between treatments(P≤0.05,|fold change|≥1.5).Top canonical pathways enriched in FLX vs.CTL and in FO vs.CTL were triglyceride metabolism and inflammatory processes.Both n-3 FA increased the placental abundance of FA binding proteins(FABPs)3 and 7.The abundance of CNR1 cannabinoid-receptor-interacting-protein-1(CNRIP1)was reduced in FO vs.FLX.In silico modeling affirmed that bovine FABPs bind to endocannabinoids.The FLX increased the abundance of inflammatory CD44-antigen and secreted-phosphoprotein-1,whereas prostaglandin-endoperoxide synthase 2 was decreased in FO vs.CTL placenta.Maternal FO enriched neonatal plasma with n-3 FAs,and both FLX and FO reduced interleukin-6 concentrations compared with CTL.Conclusion Maternal n-3 FA from FLX and FO differentially affected the bovine placenta;both enhanced lipid metabolism and modulated oxidative stress,however,FO increased some transcriptional ECS components,possibly related to the increased FABPs.Maternal FO induced a unique balance of pro-and anti-inflammatory components in the placenta.Taken together,different sources of n-3 FA during late pregnancy enhanced placental immune and metabolic processes,which may affect the neonatal immune system.

The Modulating Role of Cannabis in Insomnia: A Review of the Literature

The objective of this study was to carry out a review of the literature covering the topic of the association between sleep, insomnia and the medicinal use of cannabis. The guiding question for carrying out this study was whether the medicinal use of cannabis could have a significant positive impact on reducing insomnia. To this end, a review of the literature on the topic was prepared, both in English and Portuguese, from 2005 to 2023, in the PubMed, Scielo and LILACS databases. To search the databases, the keywords “cannabis”, “cannabidiol”, “tetrahydrocannabinol”, “insomnia” and “endocannabinoid” were used. In total, the initial search resulted in 17 articles. After a more careful analysis, only 6 of these articles met the inclusion criteria established for this study. Thus, it was concluded that, although some studies link the use of medicinal cannabis with an improvement in sleep quality, the current literature still lacks more studies on the topic.

Effects of Chaiyuwendan decoction on endocannabinoids levels in adipose tissue of rats with chronic stress-induced depression

OBJECTIVE:To investigate how Chaiyuwendan decoction(CWD)affects endocannabinoid levels in the adipose tissue of depressed rats.METHODS:Twenty-four male Sprague-Dawley rats were randomly divided into four groups with six rats in each.One group was randomly selected as the control group.The remaining three groups were subjected to chronic stress to induce depression.Groups were randomly assigned as a model group,CWD group,and amitriptyline group.CWD was given to the CWD group once a day from the second day of modeling.The amitriptyline group was administered amitriptyline intragastrically(10 mg/kg)once a day.After treatment for 21 days,body weight and fat weight were measured and the levels of N-arachidonoylethanolamine(AEA),2-arachidonoylglycerol(2-AG),and N-palmitoylethanolamine(PEA)in adipose tissue were determined with liquid chromatography-mass spectrometry.RESULTS:Compared with the control group,body weight,fat weight,AEA,and PEA were significantly lower,and 2-AG was higher,in the model group(P<0.05,P<0.01).Compared with the model group,body weight,fat weight,the AEA,and PEA levels were significantly higher,and 2-AG level was significantly lower in the CWD group(P<0.05).However,the levels did not differ significantly between the CWD group and the amitriptyline group.CONCLUSION:CWD could regulate the levels of AEA,2-AG,and PEA in rats with depression induced by chronic stress.

Effects of omega-3 supplementation on components of the endocannabinoid system and metabolic and inflammatory responses in adipose and liver of peripartum dairy cows

Background:Dietary supplementation of omega-3 fatty acids can reduce the activation of the endocannabinoid system(ECS)by decreasing the availability of arachidonic acid,thus lowering endocannabinoids(e CBs)levels.The ECS is a modulator of energy metabolism,stress response and inflammation in mammals,yet there is little information on the roles of the ECS in transition dairy cows.During the periparturient period,the adipose tissue and liver are the main metabolic organs that participate in the adaptations of dairy cows to onset of lactation;however,exceeded adipose tissue lipolysis and accumulation of lipids in the liver have adverse effects on cows'physiology.Here we aimed to examine whether omega-3 supplementation during the transition period will modulate ECS activation and affect metabolic and inflammatory indices in postpartum dairy cows,by supplementing twenty-eight transition Holstein dairy cows with either saturated fat(CTL)or encapsulated flaxseed oil(FLX).Components of the ECS,metabolic and inflammatory markers were measured in blood,liver,and subcutaneous adipose tissue.Results:FLX supplementation reduced feed intake by 8.1%(P<0.01)and reduced plasma levels of arachidonic acid(by 44.2%;P=0.02)and anandamide(by 49.7%;P=0.03)postpartum compared to CTL.The m RNA transcription levels of the cannabinoid receptor 1(CNR1/CB1)tended to be lower(2.5 folds)in white blood cells of FLX than in CTL(P=0.10),and protein abundance of ECS enzyme monoacylglycerol lipase was higher in peripheral blood mononuclear cells of FLX than in CTL(P=0.04).In adipose tissue,palmitoylethanolamide levels were lower in FLX than in CTL(by 61.5%;P=0.02),relative m RNA transcription of lipogenic genes were higher,and the protein abundance of cannabinoid receptor 2(P=0.08)and monoacylglycerol lipase(P=0.10)tended to be higher in FLX compared to CTL.Hepatic 2-arachidonoylglycerol tended to be higher(by 73.1%;P=0.07),and interlukin-6 m RNA transcription level was 1.5 folds lower in liver of FLX than in CTL(P=0.03).Conclusions:Nutritional supplementation of omega-3 fatty acids seems to partly modulate ECS activation,which could be related to lower feed intake.The altered ECS components in blood,adipose tissue and liver are associated with moderate modulations in lipid metabolism in the adipose and inflammation in liver of peripartum dairy cows.

Medicinal cannabis products for the treatment of acute pain

For thousands of years,medicinal cannabis has been used for pain treatment,but its use for pain management is still controversial.Meta-analysis of the literature has shown contrasting results on the addition of cannabinoids to opioids compared with placebo/other active agents to reduce pain.Clinical studies are mainly focused on medicinal cannabis use in chronic pain management,for which the analgesic effect has been proven in many studies.This review focuses on the potential use of medical cannabis for acute pain management in preclinical studies,studies on healthy subjects and the few pioneering studies in the clinical setting.

Should gastroenterologists prescribe cannabis? The highs, the lows and the unknowns

Cannabis,commonly known as marijuana,is a drug extracted from the Cannabis plant known for its psychotropic and medicinal properties.It has been used for healing purposes during ancient times,although its psychoactive components led to its restricted use in medicine.Nonetheless,cannabis is found to have modulatory effects on the endocannabinoid system exhibiting its medicinal role in the gastrointestinal(GI)system.Emerging animal and human studies demonstrate the influential effects of cannabis on a variety of GI diseases including inflammatory bowel disease,motility disorders and GI malignancies.It also has a regulatory role in GI symptoms including nausea and vomiting,anorexia,weight gain,abdominal pain,among others.However,both its acute and chronic use can lead to undesirable side effects such as dependency and addiction,cognitive impairment and cannabinoid hyperemesis syndrome.We will discuss the role of cannabis in the GI system as well as dosing strategies to help guide gastroenterologists to assess its efficacy and provide patient counseling before prescription of medical marijuana.

Role of cannabinoids in chronic liver diseases

Cannabinoids are a group of compounds acting pri-marily via CB1 and CB2 receptors.The expression of cannabinoid receptors in normal liver is low or absent.However,many reports have proven up-regulation of the expression of CB1 and CB2 receptors in hepatic myofibroblasts and vascular endothelial cells,as well as increased concentration of endocannabinoids in liver in the course of chronic progressive liver diseases.It has been shown that CB1 receptor signalling exerts profibrogenic and proinflammatory effects in liver tis-sue,primarily due to the stimulation of hepatic stellate cells,whereas the activation of CB2 receptors inhibits or even reverses liver fibrogenesis.Similarly,CB1 re-ceptor stimulation contributes to progression of liver steatosis.In end-stage liver disease,the endocannabi-noid system has been shown to contribute to hepatic encephalopathy and vascular effects,such as portal hypertension,splanchnic vasodilatation,relative pe-ripheral hypotension and probably cirrhotic cardiomy-opathy.So far,available evidence is based on cellular cultures or animal models.Clinical data on the effects of cannabinoids in chronic liver diseases are limited.However,recent studies have shown the contribution of cannabis smoking to the progression of liver fibrosis and steatosis.Moreover,controlling CB1 or CB2 signal-ling appears to be an attractive target in managing liver diseases.

Genetic polymorphism in pathogenesis of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a complex symptom-based disorder without established biomarkers or putative pathophysiology. IBS is a common functional gastrointestinal disorder which is defined as recurrent abdominal pain or discomfort that has at least two of the following symptoms for 3 d per month in the past 3 mo according to ROME III: relief by defecation, onset associated with a change in stool frequency or onset with change in appearance or form of stool. Recent discoveries revealed genetic polymorphisms in specific cytokines and neuropeptides may possibly influence the frequencies and severity of symptoms, as well as the therapeutic responses in treating IBS patients. This review gives new insights on how genetic determinations influence in clinical manifestations, treatment responses and potential biomarkers of IBS.

A proposed modulatory role of the endocannabinoid system on adipose tissue metabolism and appetite in periparturient dairy cows

To sustain the nutrient demands of rapid fetal growth,parturition,and milk synthesis,periparturient dairy cows mobilize adipose tissue fatty acid stores through lipolysis.This process induces an inflammatory response within AT that is resolved as lactation progresses;however,excessive and protracted lipolysis compounds the risk for metabolic and inflammatory diseases.The suppression of lipolytic action and inflammation,along with amplification of adipogenesis and lipogenesis,serve as prospective therapeutic targets for improving the health of periparturient dairy cows.Generally,the activation of cannabinoid receptors by endocannabinoids enhances adipogenesis and lipogenesis,suppresses lipolysis,and increases appetite in mammals.These biological effects of activating the endocannabinoid system open the possibility of harnessing the endocannabinoid system through nutritional intervention in dairy herds as a potential tool to improve dairy cows’health,although much is still to be revealed in this context.This review summarizes the current knowledge surrounding the components of the endocannabinoid system,elaborates on the metabolic effects of its activation,and explores the potential to modulate its activity in periparturient dairy cows.

Cannabinoid CB_(2) receptors and spinal microglia are implicated in tingenone-mediated antinociception in mice

Objective:To investigate the antinociceptive effect of tingenone on inflammatory pain,as well as and the involvement of the cannabinoid receptors type 2(CB2)and spinal microglia in this process.Methods:Male Swiss mice were subjected to inflammatory pain induced by intraplantar injection of carrageenan.The nociceptive threshold was measured by von Frey filaments test.Tingenone was administered orally 60 min before carrageenan injection.To evaluate the involvement of CB2 receptor,endocannabinoids,and microglia,AM630(a CB2 receptor antagonist),MAFP(an inhibitor of an enzyme that hydrolyses endocannabinoids),and minocycline(a microglial inhibitor)were given intrathecally 20 min before tingenone administration.In addition,an immunofluorescence assay was used to evaluate CB2 receptor and CD11 B(a microglial marker)expression in the spinal cord dorsal horn.Results:Tingenone significantly reduced carrageenan-induced hyperalgesia,which was reversed by pretreatment with AM630.MAFP and minocycline potentiated and prolonged the tingenoneinduced antinociception.CD11 B expression was increased in the spinal cord dorsal horn of mice with inflammatory pain pretreated with tingenone,which was reduced by AM630,MAFP,and minocycline.Conclusions:CB2 receptors and endocannabinoids participate in the tingenone-induced antinociception which may involve the inhibition of microglia at spinal level.

Regulatory effects of anandamide on intracellular Ca^(2+) concentration increase in trigeminal ganglion neurons

Activation of cannabinoid receptor type 1 on presynaptic neurons is postulated to suppress neu- ~ ~ ~ 2＋ ~ ~ 2＋ rotransmlsslon by decreasing Ca reflux through high voltage-gated Ca channels. However, recent studies suggest that cannabinoids which activate cannabinoid receptor type 1 can increase neurotransmitter release by enhancing Ca2＋ influx in vitro. The aim of the present study was to investigate the modulation of intracellular Ca2＋ concentration by the cannabinoid receptor type 1 agonist anandamide, and its underlying mechanisms. Using whole cell voltage-damp and calcium imaging in cultured trigeminal ganglion neurons, we found that anandamide directly caused Ca2＋ influx in a dose-dependent manner, which then triggered an increase of intracellular Ca2＋ concentration. The cyclic adenosine and guanosine monophosphate-dependent protein kinase systems, but not the protein kinase C system, were involved in the increased intracellular Ca2＋concentration by anandamide. This result showed that anandamide increased intracellu- lar Ca2＋ concentration and inhibited high voltage-gated Ca2＋ channels through different signal transduction pathways.

Endocannabinoid system: A newer molecular target for the treatment of alcohol-related behaviors

The cannabinoid （CB） receptors, endocannabinoids （eCB） and their synthesizing and catabolizing enzymes and the proteins involved in their transport, constitute what is now recognized as the eCB system. The eCBs are a class of lipids that have been identifed as retro-grade messengers and produce their effects via presyn-aptic CB receptors. The major function of the eCBs has been suggested to be that of modulating the release of several neurotransmitters implicated in a number of biological functions that include reward and reinforce-ment. There is now significant evidence to suggest that the eCB system plays an important role in the development of alcohol tolerance, dependence and relapse. Recent studies suggest that the pharmacological manipulation of the eCB system has the potential not only to block the direct reinforcing properties of alcohol but also alleviate behavioral abnormalities associated with relapse. There is also accumulating evidence that points to the possible utility of the eCB system targeted drugs in the treatment of alcoholism-related behavioral disorders. The agents that block CB1 receptor function or inhibit the synthesis of eCBs are attractive candidate drugs that need to be explored. Further understanding of the role of the eCB system in molecular mechanism/s that underlies alcoholism-related behaviors should lead to a better treatment of this devastating disorder.

Cardiac and vascular changes in cirrhosis:Pathogenic mechanisms

Cardiovascular abnormalities accompany both portal hypertension and cirrhosis. These consist of hyperdynamic circulation, defined as reduced mean arterial pressure and systemic vascular resistance, and increased cardiac output. Despite the baseline increased cardiac output, ventricular inotropic and chronotropic responses to stimuli are blunted, a condition known as cirrhotic cardiomyopathy. Both conditions may play an initiating or aggravating pathogenic role in many of the complications of liver failure or portal hypertension including ascites, variceal bleeding, hepatorenal syndrome and increased postoperative mortality after major surgery or liver transplantation. This review briefly examines the major mechanisms that may underlie these cardiovascular abnormalities, concentrating on nitric oxide, endogenous cannabinoids, central neural activation and adrenergic receptor changes. Future work should address the complex interrelationships between these systems.

Hepatic stellate cells and innate immunity in alcoholic liver disease

Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

Hepatic non-parenchymal cells:Master regulators ofalcoholic liver disease?

Chronic alcohol consumption is one of the most common causes of the progression of alcoholic liver disease(ALD). In the past, alcohol-mediated hepatocyte injury was assumed to be a significantly major cause of ALD. However, a huge number of recent and brilliant studies have demonstrated that hepatic non-parenchymal cells including Kupffer cells, hepatic stellate cells, liver sinusoidal endothelial cells and diverse types of lymphocytes play crucial roles in the pathogenesis of ALD by producing inflammatory mediators such as cytokines, oxidative stress, micro RNA, and lipid-originated metabolites(retinoic acid and endocannabinoids) or by directly interacting with parenchymal cells(hepatocytes). Therefore, understanding the comprehensive roles of hepatic nonparenchymal cells during the development of ALD will provide new integrative directions for the treatment of ALD. This review will address the roles of nonparenchymal cells in alcoholic steatosis, inflammation, and liver fibrosis and might help us to discover possible therapeutic targets and treatments involving modulating the non-parenchymal cells in ALD.

Mechanisms of repetitive transcranial magnetic stimulation for antidepression: Evidence from preclinical studies

This review summarizes the anti-depressant mechanisms of repetitive transcranial magnetic stimulation in preclinical studies,including anti-inflammatory effects mediated by activation of nuclear factor-E2-related factor 2 signaling pathway,anti-oxidative stress effects,enhancement of synaptic plasticity and neurogenesis via activation of the endocannabinoid system and brain derived neurotrophic factor signaling pathway,increasing the content of monoamine neurotransmitters via inhibition of Sirtuin 1/monoamine oxidase A signaling pathway,and reducing the activity of the hypothalamic-pituitary-adrenocortical axis.We also discuss the shortcomings of transcranial magnetic stimulation in preclinical studies such as inaccurate positioning,shallow depth of stimulation,and difficulty in elucidating the neural circuit mechanism up-and down-stream of the stimulation target brain region.