The role of cannabinoids in regulation of nausea and vomiting, and visceral pain

Prenatal tetrahydrocannabinol and cannabidiol exposure produce sex-specific pathophysiological phenotypes in the adolescent prefrontal cortex and hippocampus

Clinical and preclinical evidence has demonstrated an increased risk for neuropsychiatric disorders following prenatal cannabinoid exposure. However, given the phytochemical complexity of cannabis, there is a need to understand how specific components of cannabis may contribute to these neurodevelopmental risks later in life. To investigate this, a rat model of prenatal cannabinoid exposure was utilized to examine the impacts of specific cannabis constituents (Δ9-tetrahydrocannabinol [THC]; cannabidiol [CBD]) alone and in combination on future neuropsychiatric liability in male and female offspring. Prenatal THC and CBD exposure were associated with low birth weight. At adolescence, offspring displayed sex-specific behavioural changes in anxiety, temporal order and social cognition, and sensorimotor gating. These phenotypes were associated with sex and treatment-specific neuronal and gene transcriptional alterations in the prefrontal cortex, and ventral hippocampus, regions where the endocannabinoid system is implicated in affective and cognitive development. Electrophysiology and RT-qPCR analysis in these regions implicated dysregulation of the endocannabinoid system and balance of excitatory and inhibitory signalling in the developmental consequences of prenatal cannabinoids. These findings reveal critical insights into how specific cannabinoids can differentially impact the developing fetal brains of males and females to enhance subsequent neuropsychiatric risk.

The Impact of the CB2 Cannabinoid Receptor in Inflammatory Diseases: An Update

The emergence of inflammatory diseases is a heavy burden on modern societies. Cannabis has been used for several millennia to treat inflammatory disorders such as rheumatism or gout. Since the characterization of cannabinoid receptors, CB1 and CB2, the potential of cannabinoid pharmacotherapy in inflammatory conditions has received great interest. Several studies have identified the importance of these receptors in immune cell migration and in the production of inflammatory mediators. As the presence of the CB2 receptor was documented to be more predominant in immune cells, several pharmacological agonists and antagonists have been designed to treat inflammation. To better define the potential of the CB2 receptor, three online databases, PubMed, Google Scholar and clinicaltrial.gov, were searched without language restriction. The full texts of articles presenting data on the endocannabinoid system, the CB2 receptor and its role in modulating inflammation in vitro, in animal models and in the context of clinical trials were reviewed. Finally, we discuss the clinical potential of the latest cannabinoid-based therapies in inflammatory diseases.

Exploration of Multiverse Activities of Endocannabinoids in Biological Systems

Over the last 25 years, the human endocannabinoid system (ECS) has come into the limelight as an imperative neuro-modulatory system. It is mainly comprised of endogenous cannabinoid (endocannabinoid), cannabinoid receptors and the associated enzymes accountable for its synthesis and deterioration. The ECS plays a proven role in the management of several neurological, cardiovascular, immunological, and other relevant chronic conditions. Endocannabinoid or endogenous cannabinoid are endogenous lipid molecules which connect with cannabinoid receptors and impose a fashionable impact on the behavior and physiological processes of the individual. Arachidonoyl ethanolamide or Anandamide and 2-arachidonoyl glycerol or 2-AG were the endocannabinoid molecules that were first characterized and discovered. The presence of lipid membranes in the precursor molecules is the characteristic feature of endocannabinoids. The endocannabinoids are released upon rapid enzymatic reactions into the extracellular space via activation through G-protein coupled receptors, which is contradictory to other neurotransmitter that are synthesized beforehand, and stock up into the synaptic vesicles. The current review highlights the functioning, synthesis, and degradation of endocannabinoid, and explains its functioning in biological systems.

Fatty Acid Amide Hydrolase (FAAH) Inhibition Plays a Key Role in Counteracting Acute Lung Injury

Acute lung injury (ALI) is a group of lung illnesses characterized by severe inflammation, with no treatment. The fatty acid amide hydrolase (FAAH) enzyme is an integral membrane protein responsible for the hydrolysis of the main endocannabinoids, such as anandamide (AEA). In pre-clinical pain and inflammation models, increasing the endogenous levels of AEA and other bioactive fatty acid amides (FAAs) via genetic deletion or the pharmacological inhibition of FAAH produces many analgesic benefits in several different experimental models. To date, nobody has investigated the role of FAAH inhibition on an ALI mouse model. Mice were subjected to a carrageenan injection and treated orally 1 h after with the FAAH inhibitor URB878 dissolved in a vehicle consisting of 10% PEG-400, 10% Tween-80 and 80% saline at different doses: The inhibition of FAAH activity was able to counteract not only the CAR-induced histological alteration, but also the cascade of related inflammatory events. URB878 clears the way for further studies based on FAAH inhibition in acute lung pathologies.

Cannabis and Cannabis Derivatives for Abdominal Pain Management in Inflammatory Bowel Disease

For centuries, cannabis and its components have been used to manage a wide variety of symptoms associated with many illnesses. Gastrointestinal (GI) diseases are no exception in this regard. Individuals suffering from inflammatory bowel disease (IBD) are among those who have sought out the ameliorating properties of this plant. As legal limitations of its use have eased, interest has grown from both patients and their providers regarding the potential of cannabis to be used in the clinical setting. Similarly, a growing number of animal and human studies have been undertaken to evaluate the impact of cannabis and cannabinoid signaling elements on the natural history of IBD and its associated complications. There is little clinical evidence supporting the ability of cannabis or related products to treat the GI inflammation underlying these disorders. However, 1 recurring theme from both animal and human studies is that these agents have a significant impact on several IBD-related symptoms, including abdominal pain. In this review, we discuss the role of cannabis and cannabinoid signaling in visceral pain perception, what is currently known regarding the efficacy of cannabis and its derivatives for managing pain, related symptoms and inflammation in IBD, and what work remains to effectively utilize cannabis and its derivatives in the clinical setting.

Cannabis Use is Associated With Reduced 30-Day All-cause Readmission Among Hospitalized Patients With Irritable Bowel Syndrome: A Nationwide Analysis

BACKGROUND

Cannabinoid receptors are potential therapeutic targets in a variety of gastrointestinal tract disorders. The authors hypothesize that the use of cannabis use is associated with better control of symptoms associated with irritable bowel syndrome (IBS). This study aimed to examine the utilization of inpatient services by patients with IBS who did and did not report the use of cannabis.

METHODS

This is a retrospective cohort study that utilized the 2016 Nationwide Readmissions Database. Inclusion criteria included a principal diagnosis of IBS. The primary outcome was 30-day hospital readmission rates for IBS-specific causes. Secondary outcomes included the 30-day hospital readmission rates for all causes, resource utilization, and the 5 most common principal diagnoses and independent risk factors associated with readmission.

RESULTS

Of the 7163 patients with IBS identified in the National Readmission Database, 357 reported the use of cannabis. The 30-day IBS-specific readmission rates were 1.5% in patients who reported cannabis use and 1.1% in those who did not report cannabis use (P=0.53). Among the cannabis users, none of the variables evaluated served as a significant predictor of IBS-specific readmission; median income was a predictor for readmission among those who did not report cannabis use (odds ratio, 2.77; 95% confidence interval, 1.15-6.67; P=0.02). The 30-day readmission rates for all causes were 8.1% and 12.7% for patients who did and did not report cannabis use, respectively. After adjusting for confounders, the odds of 30-day readmission for all causes were lower among patients who reported cannabis use compared with those who did not (adjusted odds ratio, 0.53; 95% confidence interval, 0.28-0.99; P=0.04). The 5 most frequent diagnoses at readmission among patients who did not report cannabis use were enterocolitis because of Clostridioides difficile, IBS without diarrhea, sepsis, noninfective gastroenteritis and colitis, and acute kidney failure. By contrast, the 5 most frequent readmission diagnoses for cannabis users were cyclical vomiting, IBS with diarrhea, endometriosis, right upper quadrant abdominal pain, and nausea with vomiting. A discharge disposition of "against medical advice" was identified as an independent risk factor for 30-day hospital readmission for all causes among patients who reported cannabis use. By contrast, higher comorbidity scores and discharges with home health care were independent predictors of 30-day hospital readmission for all causes among patients who did not report cannabis use. Private insurance was an independent factor associated with lower rates of readmission for all causes among those who did not report cannabis use.

CONCLUSION

Our review of the National Readmission Database revealed no statistically significant differences in 30-day readmission rates for IBS-specific causes when comparing patients who reported cannabis use with those who did not. However, the authors found that cannabis use was associated with reduced 30-day hospital readmission rates for all causes.

Management of Pediatric Cannabinoid Hyperemesis Syndrome: A Review

With significant increases noted in adolescent marijuana use across the United States, perhaps as a result of legislative changes over the past half-decade, clinicians must be increasingly aware of the potential negative health effects. One such effect that warrants concern is cannabinoid hyperemesis syndrome (CHS) in the pediatric population. A systematic review of the literature was performed to determine the safety and efficacy of management strategies for CHS using PubMed, Scopus, the Cumulative Index of Nursing and Allied Health (CINAHL), Web of Science, and Cochrane Library databases. Search terms used in each database were "pediatric OR child OR children OR adolescent" AND "cannabinoid OR marijuana" AND "hyperemesis OR cyclic vomiting OR vomiting" NOT "seizure OR chemotherapy OR pregnancy OR cancer OR AIDS OR HIV." Fourteen pieces of literature that described either effective, ineffective, or supportive management strategies for pediatric CHS were included in this review. Benzodiazepines were the most reported efficacious agents, followed by topical capsaicin cream and haloperidol. A total of 9 of the 14 studies described intravenous fluid resuscitation and hot bathing rituals as supportive measures, and 7 cases reported traditional antiemetics were ineffective for CHS. The heterogenicity of reported data, combined with the limited number of encounters, make it difficult to ascertain whether a definitive treatment strategy exists. Clinicians should be cognizant of pharmacotherapy agents that are efficacious, and perhaps more importantly, avoid using traditional antiemetic therapies that do not provide benefit.

Central regulatory mechanisms of visceral sensation in response to colonic distension with special reference to brain orexin

Visceral hypersensitivity is a major pathophysiology in irritable bowel syndrome (IBS). Although brain-gut interaction is considered to be involved in the regulation of visceral sensation, little had been known how brain controls visceral sensation. To improve therapeutic strategy in IBS, we should develop a novel approach to control visceral hypersensitivity. Here, we summarized recent data on central control of visceral sensation by neuropeptides in rats. Orexin, ghrelin or oxytocin in the brain is capable of inducing visceral antinociception. Dopamine, cannabinoid, adenosine, serotonin or opioid in the central nervous system (CNS) plays a role in the visceral hyposensitivity. Central ghrelin, levodopa or morphine could induce visceral antinociception via the orexinergic signaling. Orexin induces visceral antinociception through dopamine, cannabinoid, adenosine or oxytocin. Orexin nerve fibers are identified widely throughout the CNS and orexins are implicated in a number of functions. With regard to gastrointestinal functions, in addition to its visceral antinociception, orexin acts centrally to stimulate gastrointestinal motility and improve intestinal barrier function. Brain orexin is also involved in regulation of sleep/awake cycle and anti-depressive action. From these evidence, we would like to make a hypothesis that decreased orexin signaling in the brain may play a role in the pathophysiology in a part of patients with IBS who are frequently accompanied with sleep disturbance, depressive state and disturbed gut functions such as gut motility disturbance, leaky gut and visceral hypersensitivity.

A narrative review of the ethnomedicinal usage of Cannabis sativa Linnaeus as traditional phytomedicine by folk medicine practitioners of Bangladesh

BACKGROUND

There is a worldwide interest in the use of Cannabis sativa for biomedicine purposes. Cannabis has ethnomedicinal usage as a natural medicine in Bangladesh and cultivated during the British Empire period for revenues.

OBJECTIVE

Folk medicine practitioners (FMPs) from different districts of Bangladesh have been using Cannabis sativa, but until now there have not been any compiled studies particularly regarding this practice. Hence, this review is an effort to retrieve the traditional usage of Cannabis sativa as a phytomedicine from published ethnomedicinal studies.

METHODS AND MATERIALS

Information was searched by using the search terms "ethnomedicinal Cannabis sativa and Bangladesh"; "Bangladesh cannabaceae and ethnomedicinal survey"; "ganja, bhang and folk medicine Bangladesh"; "tetrahydrocannabinol (THC), cannabinoid and therapeutic, clinical trial"; and "cannabis and pharmacological/biological" and retrieved from ethnobotanical articles available on PubMed, Scopus, Science Direct, and Google Scholar databases. A search of the relevant scientific literature also was conducted to assess the efficacy of the ethnomedicinal usage of Cannabis sativa.

RESULTS

While reviewing over 200 ethnomedicinal plants' survey articles, we found that FMPs of Bangladesh from 12 different districts used Cannabis sativa to treat cited ailments like sleep-associated problems (n=5), neuropsychiatric and CNS problems (n=5), and infections and respiratory problems (n=5) followed by rheumatism, gastrointestinal, gynecological (n=4 each), cancer, sexual, and other ailments including hypertension, headache, itch, increases bile secretion, abortifacient, dandruff, fever, and urinary problems (n=1 each). There are a total of 15 formulations identified from the 11 out of 18 ethnomedicinal plant survey reports. The leaf was the main plant part used (53.8%), followed by root (23%), seed (7.7%) and flower, inflorescence, resin, and all parts 3.8% respectively.

CONCLUSIONS

Sales and cultivation of Cannabis are illegal at present in Bangladesh, but the use of Cannabis sativa as a natural phytomedicine has been practiced traditionally by folk medicine practitioners of Bangladesh for many years and validated through relevant pharmacological justification. Although Cannabis sativa possesses ethnomedicinal properties in the folk medicine of Bangladesh, it is, furthermore, needed to conduct biological research to consolidate pharmacological justification about the prospects and challenges of Cannabis and cannabinoids' use in Bangladesh as safer biomedicine in the future.

Serotonin 2A receptors and cannabinoids

Accumulating evidence has proven that both exogenous cannabinoids as well as imbalances in the endocannabinoid system are involved in the onset and development of mental disorders such as anxiety, depression, or schizophrenia. Extensive recent research in this topic has mainly focused on the molecular mechanisms by which cannabinoid agonists may contribute to the pathophysiology of these disorders. Initially, serotonin neurotransmitter garnered most attention due to its relationship to mood disorders and mental diseases, with little attention to specific receptors. To date, the focus has redirected toward the understanding of different serotonin receptors, through a demonstration of its versatile pharmacology and synergy with different modulators. Serotonin 2A receptors are a good example of this phenomenon, and the complex signaling that they trigger appears of high relevance in the context of mental disorders, especially in schizophrenia. This chapter will analyze most relevant attributes of serotonin 2A receptors and the endocannabinoid system, and will highlight the evidence toward the functional bidirectional interaction between these elements in the brain as well as the impact of the endocannabinoid system dysregulation on serotonin 2A receptors functionality.

Plasma endocannabinoids and cannabimimetic fatty acid derivatives are altered in gastroparesis: A sex- and subtype-dependent observation

BACKGROUND

Gastroparesis (GP) is a motility disorder of the stomach presenting with upper gastrointestinal symptoms in the setting of delayed gastric emptying. Endocannabinoids are involved in the regulation of GI function including motility. However, their role in the pathophysiology of GP has not been sufficiently investigated. Our goal was to compare the circulating levels of endocannabinoids and cannabimimetic fatty acid derivatives in GP versus control subjects.

METHODS

The study compared plasma concentrations of endocannabinoids and their lipoamine and 2-acyl glycerol congeners, measured by high-pressure liquid chromatography/tandem mass spectrometry (HPLC-MS-MS), in adult patients with diabetic gastroparesis (DM-GP; n = 24; n = 16 female), idiopathic gastroparesis (ID-GP; n = 19; n = 11 female), diabetic patients without GP (DM; n = 19; n = 10 female), and healthy controls (HC; n = 18; n = 10 female). Data, presented as mean ± SEM, were analyzed with ANOVA (Sidak post hoc).

KEY RESULTS

Endocannabinoids anandamide (AEA: 0.5 ± 0.1 nMol/L) and 2-arachidonoyl glycerol (2-AG: 2.6 ± 0.7 nMol/L) were significantly lower in female DM-GP patients vs. DM females (AEA: 2.5 ± 0.7 nMol/L and 2-AG: 9.4 ± 3.3 nMol/L). Other monoacylglycerols including 2-palmitoyl glycerol and 2-oleoyl glycerol were also lower in female DM-GP patients compared to DM females. No changes were observed in men.

CONCLUSIONS & INFERENCES

Endocannabinoids and other fatty acid derivatives with cannabimimetic properties are reduced in female DM-GP patients. Since GP, particularly with diabetic etiology, is more prevalent among women and since cannabinoids are antiemetic, this decrease in levels may contribute to symptom development in these subjects. Targeting the endocannabinoid system may be a future therapeutic option in DM-GP patients.

Marijuana Use in Patients with Symptoms of Gastroparesis: Prevalence, Patient Characteristics, and Perceived Benefit

BACKGROUND

Marijuana may be used by some patients with gastroparesis (Gp) for its potential antiemetic, orexigenic, and pain-relieving effects.

AIMS

The aim of this study was to describe the use of marijuana by patients for symptoms of Gp, assessing prevalence of use, patient characteristics, and patients' perceived benefit on their symptoms of Gp.

METHODS

Patients with symptoms of Gp underwent history and physical examination, gastric emptying scintigraphy, and questionnaires assessing symptoms. Patients were asked about the current use of medications and alternative medications including marijuana.

RESULTS

Fifty-nine of 506 (11.7%) patients with symptoms of Gp reported current marijuana use, being similar among patients with delayed and normal gastric emptying and similar in idiopathic and diabetic patients. Patients using marijuana were younger, more often current tobacco smokers, less likely to be a college graduate, married or have income > $50,000. Patients using marijuana had higher nausea/vomiting subscore (2.7 vs 2.1; p = 0.002), higher upper abdominal pain subscore (3.5 vs 2.9; p = 0.003), more likely to be using promethazine (37 vs 25%; p = 0.05) and dronabinol (17 vs 3%; p < 0.0001). Of patients using marijuana, 51% had been using it for more than 2 years, 47% were using this once or more per day, and 81% of marijuana users rated their benefit from marijuana as better or much better.

CONCLUSIONS

A subset of patients (12%) with symptoms of Gp use marijuana. Patients with severe nausea and abdominal pain were more likely to use marijuana and perceive it to be beneficial for their symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01696747.

Role of the stress response and the endocannabinoid system in Δ9-tetrahydrocannabinol (THC)-induced nausea

RATIONALE

Dysregulation of the endocannabinoid (eCB) system by high doses of Δ⁹-tetrahydrocannabinol (THC) is hypothesized to generate a dysfunctional hypothalamic-pituitary-adrenal (HPA) axis contributing to cannabinoid hyperemesis syndrome (CHS).

OBJECTIVES AND METHODS

Using the conditioned gaping model of nausea, we aimed to determine if pre-treatments that interfere with stress, or an anti-emetic drug, interfere with THC-induced nausea in male rats. The corticotropin-releasing hormone (CRH) antagonist, antalarmin, was given to inhibit the HPA axis during conditioning. Since eCBs inhibit stress, MJN110 (which elevates 2-arachidonylglycerol (2-AG)) and URB597 (which elevates anandamide (AEA)) were also tested. Propranolol (β-adrenergic antagonist) and WAY-100635 (5-HT_1A antagonist) attenuate HPA activation by cannabinoids and, therefore, were assessed. In humans, CHS symptoms are not alleviated by anti-emetic drugs, such as ondansetron (5-HT₃ antagonist); however, benzodiazepines are effective. Therefore, ondansetron and chlordiazepoxide were tested. To determine if HPA activation by THC is dose-dependent, corticosterone (CORT) was analyzed from serum of rats treated with 0.0, 0.5, or 10 mg/kg THC.

RESULTS

Antalarmin (10 and 20 mg/kg), MJN110 (10 mg/kg), URB597 (0.3 mg/kg), propranolol (2.5 and 5 mg/kg), WAY-100635 (0.5 mg/kg), and chlordiazepoxide (5 mg/kg) interfered with THC-induced conditioned gaping, but the anti-emetic ondansetron (0.1 and 0.01 mg/kg) did not. THC produced significantly higher CORT levels at 10 mg/kg than at 0.0 and 0.5 mg/kg THC.

CONCLUSIONS

Treatments that interfere with the stress response also inhibit THC-induced conditioned gaping, but a typical anti-emetic drug does not, supporting the hypothesis that THC-induced nausea, and CHS, is a result of a dysregulated stress response.

Cannabidiol and Other Non-Psychoactive Cannabinoids for Prevention and Treatment of Gastrointestinal Disorders: Useful Nutraceuticals?

Cannabis sativa is an aromatic annual flowering plant with several botanical varieties, used for different purposes, like the production of fibers, the production of oil from the seeds, and especially for recreational or medical purposes. Phytocannabinoids (terpenophenolic compounds derived from the plant), include the well-known psychoactive cannabinoid Δ9-tetrahydrocannabinol, and many non-psychoactive cannabinoids, like cannabidiol. The endocannabinoid system (ECS) comprises of endocannabinoid ligands, enzymes for synthesis and degradation of such ligands, and receptors. This system is widely distributed in the gastrointestinal tract, where phytocannabinoids exert potent effects, particularly under pathological (i.e., inflammatory) conditions. Herein, we will first look at the hemp plant as a possible source of new functional food ingredients and nutraceuticals that might be eventually useful to treat or even prevent gastrointestinal conditions. Subsequently, we will briefly describe the ECS and the general pharmacology of phytocannabinoids. Finally, we will revise the available data showing that non-psychoactive phytocannabinoids, particularly cannabidiol, may be useful to treat different disorders and diseases of the gastrointestinal tract. With the increasing interest in the development of functional foods for a healthy life, the non-psychoactive phytocannabinoids are hoped to find a place as nutraceuticals and food ingredients also for a healthy gastrointestinal tract function.

Patterns of Marijuana Use Among Patients With Celiac Disease in the United States: A Population-based Analysis of the NHANES Survey

BACKGROUND

Marijuana use has been assessed in patients with chronic gastrointestinal disorders and may contribute to either symptoms or palliation. Use in those with celiac disease (CD) has not been assessed. Our aim was to evaluate patterns of marijuana use in a large population-based survey among patients with CD, people who avoid gluten (PWAG), and controls.

STUDY

We analyzed data from the National Health and Nutrition Examination Survey from 2009 to 2014. χ tests and multivariable logistic regression were used to compare participants with CD and PWAG to controls regarding the use of marijuana.

RESULTS

Among respondents who reported ever using marijuana (overall 59.1%), routine (at-least monthly) marijuana use was reported by 46% of controls versus 6% of participants with diagnosed CD (P=0.005) and 66% undiagnosed CD as identified on serology (P=0.098) and 51% of PWAG (P=0.536). Subjects with diagnosed CD had lower odds of routine marijuana use compared with controls (odds ratio, 0.08; 95% confidence interval, 0.01-0.73), whereas participants with undiagnosed CD had increased odds of routine use (odds ratio, 2.26; 95% confidence interval, 0.83-6.13), which remained elevated even after adjusting for age, sex, race/ethnicity, health insurance status, alcohol, tobacco use, educational level, and poverty/income ratio.

CONCLUSIONS

In all groups, marijuana use was high. Although there were no differences among subjects with CD, PWAG, and controls who ever used marijuana, subjects with diagnosed CD appear to have decreased routine use of marijuana when compared with controls and PWAG. Those with undiagnosed CD have significantly higher rates of regular use. Future research should focus on the utilization of marijuana as it may contribute to further understanding of symptoms and treatments.

A Comprehensive Patient and Public Involvement Program Evaluating Perception of Cannabis-Derived Medicinal Products in the Treatment of Acute Postoperative Pain, Nausea, and Vomiting Using a Qualitative Thematic Framework

Introduction: Cannabis-derived medicinal products (CDMPs) have antiemetic properties and in combination with opioids have synergistic analgesic effects in part signaling through the delta and kappa opioid receptors. The objective of this patient and public involvement program was to determine perception of perioperative CDMPs in our local population to inform design of a clinical trial. Methods: A qualitative evaluation was conducted utilizing a focus group, semistructured interviews and a community event. Analysis was conducted through the framework methodology. Verbatim transcriptions were coded categorically into analytical frameworks for thematic analysis. Emergent themes and associated degree of consensus/dissent were determined. The participant cohort was composed of a group of patients and relatives representative of the target population (M:F=1:1, age range 33-85). Results: Most common coding categories in thematic analysis framework included side-effect profile, trial schedule of events, and safety. Consensus was that potential benefits of CDMPs were attractive compared with the known risk profile of opioid use. Decrease in opioid dependence was agreed to be an appropriate clinical end-point for a randomized controlled clinical trial and there was concurrence of positive opinion of a therapeutic schedule of 5 days. Negative CDMP perceptions included addiction, dysphoria, and adverse effects in psychiatric subpopulations. Sublingual or oral administration was the most acceptable route of administration, with some expressing that inhalation delegitimizes therapeutic properties. Conclusions: The perception of postoperative CDMP therapy was overwhelmingly positive in this West London population. The data from this thematic analysis will inform protocol development of clinical trials to determine analgesic and antiemetic efficacy of CDMPs.

Cachexia Anorexia Syndrome and Associated Metabolic Dysfunction in Peritoneal Metastasis

Patients with peritoneal metastasis (PM) of gastrointestinal and gynecological origin present with a nutritional deficit characterized by increased resting energy expenditure (REE), loss of muscle mass, and protein catabolism. Progression of peritoneal metastasis, as with other advanced malignancies, is associated with cancer cachexia anorexia syndrome (CAS), involving poor appetite (anorexia), involuntary weight loss, and chronic inflammation. Eventual causes of mortality include dysfunctional metabolism and energy store exhaustion. Etiology of CAS in PM patients is multifactorial including tumor growth, host response, cytokine release, systemic inflammation, proteolysis, lipolysis, malignant small bowel obstruction, ascites, and gastrointestinal side effects of drug therapy (chemotherapy, opioids). Metabolic changes of CAS in PM relate more to a systemic inflammatory response than an adaptation to starvation. Metabolic reprogramming is required for cancer cells shed into the peritoneal cavity to resist anoikis (i.e., programmed cell death). Profound changes in hexokinase metabolism are needed to compensate ineffective oxidative phosphorylation in mitochondria. During the development of PM, hypoxia inducible factor-1α (HIF-1α) plays a key role in activating both aerobic and anaerobic glycolysis, increasing the uptake of glucose, lipid, and glutamine into cancer cells. HIF-1α upregulates hexokinase II, phosphoglycerate kinase 1 (PGK1), pyruvate dehydrogenase kinase (PDK), pyruvate kinase muscle isoenzyme 2 (PKM2), lactate dehydrogenase (LDH) and glucose transporters (GLUT) and promotes cytoplasmic glycolysis. HIF-1α also stimulates the utilization of glutamine and fatty acids as alternative energy substrates. Cancer cells in the peritoneal cavity interact with cancer-associated fibroblasts and adipocytes to meet metabolic demands and incorporate autophagy products for growth. Therapy of CAS in PM is challenging. Optimal nutritional intake alone including total parenteral nutrition is unable to reverse CAS. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) stabilized nutritional status in a significant proportion of PM patients. Agents targeting the mechanisms of CAS are under development.

Opportunities for cannabis in supportive care in cancer

Cannabis has the potential to modulate some of the most common and debilitating symptoms of cancer and its treatments, including nausea and vomiting, loss of appetite, and pain. However, the dearth of scientific evidence for the effectiveness of cannabis in treating these symptoms in patients with cancer poses a challenge to clinicians in discussing this option with their patients. A review was performed using keywords related to cannabis and important symptoms of cancer and its treatments. Literature was qualitatively reviewed from preclinical models to clinical trials in the fields of cancer, human immunodeficiency virus (HIV), multiple sclerosis, inflammatory bowel disease, post-traumatic stress disorder (PTSD), and others, to prudently inform the use of cannabis in supportive and palliative care in cancer. There is a reasonable amount of evidence to consider cannabis for nausea and vomiting, loss of appetite, and pain as a supplement to first-line treatments. There is promising evidence to treat chemotherapy-induced peripheral neuropathy, gastrointestinal distress, and sleep disorders, but the literature is thus far too limited to recommend cannabis for these symptoms. Scant, yet more controversial, evidence exists in regard to cannabis for cancer- and treatment-related cognitive impairment, anxiety, depression, and fatigue. Adverse effects of cannabis are documented but tend to be mild. Cannabis has multifaceted potential bioactive benefits that appear to outweigh its risks in many situations. Further research is required to elucidate its mechanisms of action and efficacy and to optimize cannabis preparations and doses for specific populations affected by cancer.

Cannabinoid Use in Patients With Gastroparesis and Related Disorders: Prevalence and Benefit

OBJECTIVES

Gastroparesis (Gp) can be a challenging disorder to manage due to the paucity of treatment options. We do not know how frequently patients with Gp symptoms resort to cannabinoids to address their symptoms. This study (i) determines the prevalence of cannabinoid use in patients with Gp symptoms, (ii) describes the patients with Gp symptoms using cannabinoids, and (iii) assesses the patients' perceived benefit of cannabinoids for Gp symptoms.

METHODS

Consecutive outpatients with symptoms suggestive of Gp seen on follow-up at our academic center from June 2018 to September 2018 filled out questionnaires on their symptoms and the current treatments.

RESULTS

Of 197 patients, nearly half (n = 92, 46.7%) reported current (35.5%) or past (11.2%) use of cannabinoids, including tetrahydrocannabinol (n = 63), dronabinol (n = 36), and/or cannabidiol (n = 16). Of these, most perceived improvement in Gp symptoms from cannabinoids (93.5% with tetrahydrocannabinol, 81.3% with cannabidiol, and 47.2% with dronabinol). Cannabinoids were used most commonly via smoking (n = 46). Patients taking cannabinoids were younger (41.0 ± 15.4 vs 48.0 ± 15.9 years; P < 0.01) and had a higher Gastroparesis Cardinal Symptom Index total score (3.4 ± 1.0 vs 2.8 ± 1.3; P < 0.01) compared with patients with no history of cannabinoid use.

CONCLUSIONS

A third of patients with Gp symptoms actively use cannabinoids for their chronic symptoms. Most of these patients perceive improvement in their symptoms with cannabinoids. Patients taking cannabinoids were younger and more symptomatic than those not taking cannabinoids. Further studies on the efficacy and safety of cannabinoids in Gp will be useful.

Understanding the evidence for medical cannabis and cannabis-based medicines for the treatment of chronic non-cancer pain

The use of medical cannabis and cannabis-based medicines has received increasing interest in recent years; with a corresponding surge in the number of studies and reviews conducted in the field. Despite this growth in evidence, the findings and conclusions of these studies have been inconsistent. In this paper, we outline the current evidence for medical cannabis and cannabis-based medicines in the treatment and management of chronic non-cancer pain. We discuss limitations of the current evidence, including limitations of randomised control trials in the field, limits on generalisability of previous findings and common issues such as problems with measurements of dose and type of cannabinoids. We discuss future directions for medicinal cannabinoid research, including addressing limitations in trial design; developing frameworks to monitor for use disorder and other unintended outcomes; and considering endpoints other than 30% or 50% reductions in pain severity.

Cannabis and Turmeric as Complementary Treatments for IBD and Other Digestive Diseases

PURPOSE OF REVIEW

Complementary therapies for inflammatory bowel disease (IBD) have earned growing interest from patients and investigators alike, with a dynamic landscape of research in this area. In this article, we review results of the most recent studies evaluating the role of cannabis and turmeric for the treatment of IBD and other intestinal illnesses.

RECENT FINDINGS

Cannabinoids are well-established modulators of gut motility and visceral pain and have demonstrated anti-inflammatory properties. Clinical trials suggest that there may be a therapeutic role for cannabinoid therapy in the treatment of IBD, irritable bowel syndrome (IBS), nausea and vomiting, and GI motility disorders. Recent reports of serious adverse effects from synthetic cannabinoids highlight the need for additional investigation of cannabinoids to establish their efficacy and safety. Turmeric trials have demonstrated some promise as adjuvant treatment for IBD, though not in other GI disease processes. Evidence suggests that the use of cannabis and turmeric is potentially beneficial in IBD and IBS; however, neither has been compared to standard therapy in IBD, and thus should not be recommended as alternative treatment for IBD. For cannabis in particular, additional investigation regarding appropriate dosing and timing, given known adverse effects of its chronic use, and careful monitoring of potential bleeding complications with synthetic cannabinoids are imperative.

Assessment of rimonabant-like adverse effects of purported CB1R neutral antagonist / CB2R agonist aminoalkylindole derivatives in mice

BACKGROUND

Cannabinoids may be useful in the treatment of CNS disorders including drug abuse and addiction, where both CB1R antagonists / inverse agonists and CB2R agonists have shown preclinical efficacy. TV-5-249 and TV-6-41, two novel aminoalkylindoles with dual action as neutral CB1R antagonists and CB2R agonists, previously attenuated abuse-related effects of ethanol in mice.

PURPOSE

To further characterize these drugs, TV-5-249 and TV-6-41 were compared with the CB1R antagonist / inverse agonist rimonabant in assays relevant to adverse effects and cannabinoid withdrawal.

PROCEDURES AND FINDINGS

The cannabinoid tetrad confirmed that TV-5-249 and TV-6-41 were devoid of CB1R agonist effects at behaviorally-relevant doses, and neither of the novel drugs induced rimonabant-like scratching. Generalized aversive effects were assessed, and rimonabant and TV-5-249 induced taste aversion, but TV-6-41 did not. Schedule-controlled responding and observation of somatic signs were used to assess withdrawal-like effects precipitated by rimonabant or TV-6-41 in mice previously treated with the high-efficacy CB1R agonist JWH-018 or vehicle. Rimonabant and TV-6-41 dose-dependently suppressed response rates in all subjects, but TV-6-41 did so more potently in JWH-018-treated mice than in vehicle-treated mice, while rimonabant equally suppressed responding in both groups. Importantly, rimonabant elicited dramatic withdrawal signs, but TV-6-41 did not.

CONCLUSIONS

These findings suggest differences in both direct adverse effects and withdrawal-related effects elicited by rimonabant, TV-5-249, and TV-6-41, which could relate to neutral CB1R antagonism, CB2R agonism, or a combination of both. Both mechanisms should be explored and exploited in future drug design efforts to develop pharmacotherapies for drug dependence.

Emergency Department Burden of Nausea and Vomiting Associated With Cannabis Use Disorder: US Trends From 2006 to 2013

BACKGROUND AND AIMS

Chronic cannabis use is associated with nausea and vomiting that may lead to emergency department (ED) visits, multiple diagnostic tests, and procedures. The aim of this study was to analyze recent trends in ED visits for vomiting associated with cannabis use disorder between 2006 and 2013.

METHODS

Data were obtained from the National Emergency Department Sample records in which vomiting (ICD-9-CM codes 787.01, 787.03, and 536.2) was a primary diagnosis in combination with cannabis abuse or dependence (304.3, 304.30, 304.31, 304.32, 304.33, 305.2, 305.20, 305.21, 305.22, and 305.23) and were seen in the ED between 2006 and 2013. The National Emergency Department Sample collects data from more than 25 million visits in over 950 EDs and is weighted to provide national estimates.

RESULTS

The rate of ED visits for vomiting with cannabis use disorder from 2006 compared with 2013 increased from 2.3 to 13.3 per 100,000 ED visits, while the mean inflation-adjusted costs increased 68.5% from $2758.43 to $4647.62, respectively. Men between the ages of 20 and 29 were the most common group to present to the ED for vomiting with cannabis use disorder. The Midwest and West had the higher rates of ED visits for vomiting with cannabis use disorder compared with the Northeast and South.

CONCLUSIONS

ED visits for vomiting associated with cannabis use disorder is common and is associated with significant medical costs. Further research on the role of cannabis use in nausea and vomiting is warranted.

Cannabinoids and gastrointestinal motility: Pharmacology, clinical effects, and potential therapeutics in humans

BACKGROUND

Cannabinoid agents and cannabis are frequently used for relief of diverse gastrointestinal symptoms.

PURPOSE

The objective of this article is to increase the awareness of gastroenterologists to the effects of cannabinoids on gastrointestinal motility, as gastroenterologists are likely to encounter patients who are taking cannabinoids, or those with dysmotility that may be associated with cannabinoid mechanisms. The non-selective cannabinoid agonist, dronabinol, retards gastric emptying and inhibits colonic tone and phasic pressure activity. In addition to the well-recognized manifestations of cannabinoid hyperemesis, cannabinoid mechanisms result in human and animal models of gastrointestinal and colonic dysmotility. Decreased enteric FAAH activity is associated with colonic inertia in slow transit constipation and, conversely, the orphan G protein-coupled receptor, GPR55, is overexpressed in streptozotocin-induced gastroparesis, suggesting it is involved in inhibition of antral motility. Experimental therapies in gastrointestinal motility and functional disorders are focused predominantly on pain relief mediated through cannabinoid 2 receptors or inhibition of DAGLα to normalize colonic transit. In summary, cannabinoid mechanisms and pharmacology are relevant to the current and future practice of clinical gastroenterology.

Cannabinoid pharmacology and therapy in gut disorders

Cannabis sp. and their products (marijuana, hashish…), in addition to their recreational, industrial and other uses, have a long history for their use as a remedy for symptoms related with gastrointestinal diseases. After many reports suggesting these beneficial effects, it was not surprising to discover that the gastrointestinal tract expresses endogenous cannabinoids, their receptors, and enzymes for their synthesis and degradation, comprising the so-called endocannabinoid system. This system participates in the control of tissue homeostasis and important intestinal functions like motor and sensory activity, nausea, emesis, the maintenance of the epithelial barrier integrity, and the correct cellular microenvironment. Thus, different cannabinoid-related pharmacological agents may be useful to treat the main digestive pathologies. To name a few examples, in irritable bowel syndrome they may normalize dysmotility and reduce pain, in inflammatory bowel disease they may decrease inflammation, and in colorectal cancer, apart from alleviating some symptoms, they may play a role in the regulation of the cell niche. This review summarizes the main recent findings on the role of cannabinoid receptors, their synthetic or natural ligands and their metabolizing enzymes in normal gastrointestinal function and in disorders including irritable bowel syndrome, inflammatory bowel disease, colon cancer and gastrointestinal chemotherapy-induced adverse effects (nausea/vomiting, constipation, diarrhea).

The effect of history of severe mental illness on mortality in colorectal cancer cases: a register-based cohort study

BACKGROUND

While the link between mental illness and cancer survival is well established, few studies have focused on colorectal cancer. We examined outcomes of colorectal cancer among persons with a history of severe mental illness (SMI).

MATERIAL AND METHODS

We identified patients with their first colorectal cancer diagnosis in 1990-2013 (n = 41,708) from the Finnish Cancer Registry, hospital admissions due to SMI preceding cancer diagnosis (n = 2382) from the Hospital Discharge Register and deaths from the Causes of Death statistics. Cox regression models were used to study the impact on SMI to mortality differences.

RESULTS

We found excess colorectal cancer mortality among persons with a history of psychosis and with substance use disorder. When controlling for age, comorbidity, stage at presentation and treatment, excess mortality risk among men with a history of psychosis was 1.72 (1.46-2.04) and women 1.37 (1.20-1.57). Among men with substance use disorder, the excess risk was 1.22 (1.09-1.37).

CONCLUSION

Understanding factors contributing to excess mortality among persons with a history of psychosis or substance use requires more detailed clinical studies and studies of care processes among these vulnerable patient groups. Collaboration between patients, mental health care and oncological teams is needed to improve outcomes of care.

Cannabinoid receptor 2 as a novel target for promotion of renal cell carcinoma prognosis and progression

PURPOSE

Renal cell carcinoma (RCC) is the most common malignancy of urogenital system, and patients with RCC may face a poor prognosis. However, limited curable therapeutic options are currently available. The aim of this study is to investigate the role of Cannabinoid receptor 2 (CB2) in RCC progression.

METHODS

Immunohistochemistry was to investigate the expression pattern of CB2 in 418 RCC tissues and explore its prognostic function in RCC patients. Furthermore, the role of used CB2 si-RNA knockdown and inhibited by AM630, a CB2 inverse agonist, on cell proliferation, migration, and cell cycle of RCC cell lines in vitro was also investigated.

RESULTS

We observed that CB2 was up-regulated in RCC tissues, and presented as an independent prognostic factor for overall survival of RCC patients and higher CB2 expression tends to have poor clinical outcomes in survival analyses. Moreover, we also observed that CB2, incorporated with pN stage, pathological grade, and recurrence or distant metastasis after surgery, could obviously enhance their prognostic accuracy in a predictive nomogram analysis. In addition, knockdown or inhibition by AM630 for the expression of CB2 in vitro could significantly decreased cell proliferation and migration, and obviously induced cell cycle arrest in G2/M of RCC cells.

CONCLUSIONS

CB2 expression is functionally related to cellular proliferation, migration, and cell cycle of RCC cells. Our data suggest that CB2 might be a potential therapeutic target for RCC.

G protein-coupled receptor 55 (GPR55) expresses differently in patients with Crohn's disease and ulcerative colitis

AIM

To investigate the levels of G protein-coupled receptor 55 (GPR55) expression in colonic tissue of inflammatory bowel disease (IBD) patients and healthy controls, and its potential implication in IBD treatment.

METHODS

Fifty patients were enrolled in our prospective study: n = 21 with Crohn's disease (CD) and n = 16 with ulcerative colitis (UC); 19 women and 18 men. Control consisted of 13 non-IBD patients. In each subject, two biopsies were taken from different colonic locations. In IBD patients, biopsies both from endoscopically inflamed and non-inflamed areas were drawn and the development of inflammation confirmed in histopathological examination. GPR55 mRNA and protein expression were measured using real-time PCR and Western blot, respectively.

RESULTS

GPR55 expression at mRNA and protein level was detected in all samples tested. The level of GPR55 mRNA expression in non-inflamed colonic areas was comparable in all analyzed groups (p = .2438). However, in the inflamed tissues GPR55 mRNA expression was statistically significantly (p < .0001) higher (6.9 fold) in CD patients compared to UC. Moreover, CD patients manifested higher (12.5 fold) GPR55 mRNA expression in inflamed compared with non-inflamed colonic tissues (p < .0001). Although no significant differences were stated, GPR55 protein level tends to decrease in IBD as compared to control.

CONCLUSIONS

Different patterns of GPR55 expression at mRNA level were observed in IBD patients. We speculate that GPR55 is crucial for the mucosal inflammatory processes in IBD, particularly in CD and its expression may affect disease severity, and response to treatment. The GPR55 receptors may become an attractive target for novel therapeutic strategies in IBD.

Review: The Role of Cannabinoids on Esophageal Function-What We Know Thus Far

The endocannabinoid system (ECS) primarily consists of cannabinoid receptors (CBRs), endogenous ligands, and enzymes for endocannabinoid biosynthesis and inactivation. Although the presence of CBRs, both CB1 and CB2, as well as a third receptor (G-protein receptor 55 [GPR55]), has been established in the gastrointestinal (GI) tract, few studies have focused on the role of cannabinoids on esophageal function. To date, studies have shown their effect on GI motility, inflammation and immunity, intestinal and gastric acid secretion, nociception and emesis pathways, and appetite control. Given the varying and sometimes limited efficacy of current medical therapies for diseases of the esophagus, further understanding and investigation into the interplay of the ECS on esophageal health and disease may present new therapeutic modalities that may help advance current treatment options. In this brief review, the current understanding of the ECS role in various esophageal functions and disorders is presented.

Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment-a Systematic Review

Cannabinoid hyperemesis syndrome (CHS) is a syndrome of cyclic vomiting associated with cannabis use. Our objective is to summarize the available evidence on CHS diagnosis, pathophysiology, and treatment. We performed a systematic review using MEDLINE, Ovid MEDLINE, Embase, Web of Science, and the Cochrane Library from January 2000 through September 24, 2015. Articles eligible for inclusion were evaluated using the Grading and Recommendations Assessment, Development, and Evaluation (GRADE) criteria. Data were abstracted from the articles and case reports and were combined in a cumulative synthesis. The frequency of identified diagnostic characteristics was calculated from the cumulative synthesis and evidence for pathophysiologic hypothesis as well as treatment options were evaluated using the GRADE criteria. The systematic search returned 2178 articles. After duplicates were removed, 1253 abstracts were reviewed and 183 were included. Fourteen diagnostic characteristics were identified, and the frequency of major characteristics was as follows: history of regular cannabis for any duration of time (100%), cyclic nausea and vomiting (100%), resolution of symptoms after stopping cannabis (96.8%), compulsive hot baths with symptom relief (92.3%), male predominance (72.9%), abdominal pain (85.1%), and at least weekly cannabis use (97.4%). The pathophysiology of CHS remains unclear with a dearth of research dedicated to investigating its underlying mechanism. Supportive care with intravenous fluids, dopamine antagonists, topical capsaicin cream, and avoidance of narcotic medications has shown some benefit in the acute setting. Cannabis cessation appears to be the best treatment. CHS is a cyclic vomiting syndrome, preceded by daily to weekly cannabis use, usually accompanied by symptom improvement with hot bathing, and resolution with cessation of cannabis. The pathophysiology underlying CHS is unclear. Cannabis cessation appears to be the best treatment.

May cannabinoids prevent the development of chemotherapy-induced diarrhea and intestinal mucositis? Experimental study in the rat

BACKGROUND

The antineoplastic drug 5-fluoruracil (5-FU) is a pirimidine analog, which frequently induces potentially fatal diarrhea and mucositis. Cannabinoids reduce gastrointestinal motility and secretion and might prevent 5-FU-induced gut adverse effects. Here, we asked whether cannabinoids may prevent diarrhea and mucositis induced by 5-FU in the rat.

METHODS

Male Wistar rats received vehicle or the non-selective cannabinoid agonist WIN 55,212-2 (WIN; 0.5 mg kg^-1 injection^-1 , 1 injection day^-1 , 4 consecutive days) by intraperitoneal (ip) route; on the first 2 days, animals received also saline or 5-FU (150 mg kg^-1 injection^-1 , cumulative dose of 300 mg kg^-1 ). Gastrointestinal motor function was radiographically studied after barium contrast intragastric administration on experimental days 1 and 4. Structural alterations of the stomach, small intestine and colon were histologically studied on day 4. PAS staining and immunohistochemistry for Ki67, chromogranin A and CD163 were used to detect secretory, proliferating, and endocrine cells, and activated macrophages respectively.

KEY RESULTS

As shown radiographically, 5-FU induced significant gastric emptying delay (on days 1 and 4) and diarrhea (on day 4). WIN did not significantly alter the motility curves obtained for either control or 5-FU-treated animals but tended to reduce the severity of 5-FU-induced diarrhea and increased permanence of barium from day 1 to the beginning of day 4 in 5-FU-treated animals. 5-FU-induced mucositis was severe and not counteracted by WIN.

CONCLUSIONS AND INFERENCES

5-FU-induced diarrhea, but not mucositis, was partly prevented by WIN at a low dose. Cannabinoids might be useful to prevent chemotherapy-induced diarrhea.

Prevalence and Patterns of Marijuana Use in Young Adults With Inflammatory Bowel Disease

OBJECTIVES

Recent studies in adults report symptom relief with marijuana use in patients with inflammatory bowel disease (IBD). We assessed the prevalence, pattern, effects, and adverse effects of marijuana use in young adults with IBD.

METHODS

We conducted a prospective questionnaire survey study at a pediatric IBD clinic. All patients (18-21 years of age) answered anonymous questionnaires about demographics, IBD, medications, and marijuana use.

RESULTS

Fifty-three patients (mean age 18.7 years, 32 boys) were enrolled. Thirty-seven patients (70%) reported using marijuana currently or in the past. There was no statistically significant difference between the users and nonusers of marijuana regarding demographics, disease activity, or medications. Despite prolonged use of marijuana, 70% of patients did not discuss it with their gastroenterologists. Twenty-four patients used marijuana medicinally for IBD symptoms in addition to medical therapy. Although majority found marijuana to be moderately/very helpful, complete relief of symptoms such as abdominal pain, poor appetite, nausea, and diarrhea was seen in 29%, 37%, 14%, and 10% of patients, respectively. Only half of patients reported knowledge of possible adverse effects of marijuana and 19% of patients reported mild neuropsychiatric adverse effects. Overall, 98% of patients supported legalization of marijuana and 85% were interested in using medical marijuana if it became legally available.

CONCLUSIONS

We found a high rate of marijuana use in our cohort of young adults with IBD. Majority of users report symptom improvement but do not inform physicians. Future well-controlled studies are necessary to assess role of marijuana in IBD therapy.

Role of cannabis in digestive disorders

Cannabis sativa, a subspecies of the Cannabis plant, contains aromatic hydrocarbon compounds called cannabinoids. [INCREMENT]-Tetrahydrocannabinol is the most abundant cannabinoid and is the main psychotropic constituent. Cannabinoids activate two types of G-protein-coupled cannabinoid receptors: cannabinoid type 1 receptor and cannabinoid type 2 receptor. There has been ongoing interest and development in research to explore the therapeutic potential of cannabis. [INCREMENT]-Tetrahydrocannabinol exerts biological functions on the gastrointestinal (GI) tract. Cannabis has been used for the treatment of GI disorders such as abdominal pain and diarrhea. The endocannabinoid system (i.e. endogenous circulating cannabinoids) performs protective activities in the GI tract and presents a promising therapeutic target against various GI conditions such as inflammatory bowel disease (especially Crohn's disease), irritable bowel syndrome, and secretion and motility-related disorders. The present review sheds light on the role of cannabis in the gut, liver, and pancreas and also on other GI symptoms, such as nausea and vomiting, cannabinoid hyperemesis syndrome, anorexia, weight loss, and chronic abdominal pain. Although the current literature supports the use of marijuana for the treatment of digestive disorders, the clinical efficacy of cannabis and its constituents for various GI disorders remains unclear.

Clinical/Therapeutic Approaches for Cannabinoid Ligands in Central and Peripheral Nervous System Diseases: Mini Review

OBJECTIVE

Cannabinoids, the components of Cannabis sativa Linnaeus, interact with CB1 and CB2 receptors, which are located both in the central nervous system and in the periphery and thus may exert a widespread biological activity in the body. The main medicinal properties of cannabinoids include analgesic, anti-inflammatory, antitumor, appetite stimulation, antiemesis, and muscle relaxation effects. This mini review aims to explore existing clinical trials that investigated the use of cannabinoids in diseases affecting the nervous system.

METHODS

We reviewed recent studies of cannabinoid-based therapy for disorders affecting central and peripheral nervous system in human subjects.

RESULTS

There is evidence that cannabinoid-based drugs may effectively control some symptoms associated with nervous system dysfunction, especially various types of pain and neurologic disorders, although studies are limited.

CONCLUSIONS

The efficacy of cannabinoid drugs in the treatment of nervous system diseases should be verified in future large-scale randomized clinical trials.

Cannabinoids and GI Disorders: Endogenous and Exogenous

OPINION STATEMENT

Despite the political and social controversy affiliated with it, the medical community must come to the realization that cannabinoids exist as a ubiquitous signaling system in many organ systems. Our understanding of cannabinoids and how they relate not only to homeostasis but also in disease states must be furthered through research, both clinically and in the laboratory. The identification of the cannabinoid receptors in the early 1990s have provided us with the perfect target of translational research. Already, much has been done with cannabinoids and the nervous system. Here, we explore the implications it has for the gastrointestinal tract. Most therapeutics currently on the market presently target only one aspect of the cannabinoid system. Our main purpose here is to highlight areas of research and potential avenues of discovery that the cannabinoid system has yet to reveal.

THC (Δ9-Tetrahydrocannabinol) Exerts Neuroprotective Effect in Glutamate-affected Murine Primary Mesencephalic Cultures Through Restoring Mitochondrial Membrane Potential and Anti-apoptosis Involving CB1 Receptor-dependent Mechanism

Aging-related neurodegenerative diseases, such as Parkinson's disease (PD) or related disorders, are an increasing societal and economic burden worldwide. Δ9-Tetrahydrocannabinol (THC) is discussed as a neuroprotective agent in several in vitro and in vivo models of brain injury. However, the mechanisms by which THC exhibits neuroprotective properties are not completely understood. In the present study, we investigated neuroprotective mechanisms of THC in glutamate-induced neurotoxicity in primary murine mesencephalic cultures, as a culture model for PD. Glutamate was administered for 48 h with or without concomitant THC treatment. Immunocytochemistry staining and resazurin assay were used to evaluate cell viability. Furthermore, superoxide levels, caspase-3 activity, and mitochondrial membrane potential were determined to explore the mode of action of this compound. THC protected dopaminergic neurons and other cell types of primary dissociated cultures from glutamate-induced neurotoxicity. Moreover, THC significantly counteracted the glutamate-induced mitochondrial membrane depolarization and apoptosis. SR141716A, a CB₁ receptor antagonist, concentration-dependently blocked the protective effect of THC in primary mesencephalic cultures. In conclusion, THC exerts anti-apoptotic and restores mitochondrial membrane potential via a mechanism dependent on CB₁ receptor. It strengthens the fact that THC has a benefit on degenerative cellular processes occurring, among others, in PD and other neurodegenerative diseases by slowing down the progression of neuronal cell death. Copyright © 2016 John Wiley & Sons, Ltd.

The Role of the Endocannabinoid System in the Brain-Gut Axis

The actions of cannabis are mediated by receptors that are part of an endogenous cannabinoid system. The endocannabinoid system (ECS) consists of the naturally occurring ligands N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-AG), their biosynthetic and degradative enzymes, and the cannabinoid (CB) receptors CB1 and CB2. The ECS is a widely distributed transmitter system that controls gut functions peripherally and centrally. It is an important physiologic regulator of gastrointestinal motility. Polymorphisms in the gene encoding CB1 (CNR1) have been associated with some forms of irritable bowel syndrome. The ECS is involved in the control of nausea and vomiting and visceral sensation. The homeostatic role of the ECS also extends to the control of intestinal inflammation. We review the mechanisms by which the ECS links stress and visceral pain. CB1 in sensory ganglia controls visceral sensation, and transcription of CNR1 is modified through epigenetic processes under conditions of chronic stress. These processes might link stress with abdominal pain. The ECS is also involved centrally in the manifestation of stress, and endocannabinoid signaling reduces the activity of hypothalamic-pituitary-adrenal pathways via actions in specific brain regions, notably the prefrontal cortex, amygdala, and hypothalamus. Agents that modulate the ECS are in early stages of development for treatment of gastrointestinal diseases. Increasing our understanding of the ECS will greatly advance our knowledge of interactions between the brain and gut and could lead to new treatments for gastrointestinal disorders.

The Pharmacology of Visceral Pain

Visceral pain describes pain emanating from the internal thoracic, pelvic, or abdominal organs. Unlike somatic pain, visceral pain is generally vague, poorly localized, and characterized by hypersensitivity to a stimulus such as organ distension. While current therapeutics provides some relief from somatic pain, drugs used for treatment of chronic visceral pain are typically less efficacious and limited by multiple adverse side effects. Thus, the treatment of visceral pain represents a major unmet medical need. Further, more basic research into the physiology and pathophysiology of visceral pain is needed to provide novel targets for future drug development. In concert with chronic visceral pain, there is a high comorbidity with stress-related psychiatric disorders including anxiety and depression. The mechanisms linking visceral pain with these overlapping comorbidities remain to be elucidated. However, persistent stress facilitates pain perception and sensitizes pain pathways, leading to a feed-forward cycle promoting chronic visceral pain disorders. We will focus on stress-induced exacerbation of chronic visceral pain and provide supporting evidence that centrally acting drugs targeting the pain and stress-responsive brain regions may represent a valid target for the development of novel and effective therapeutics.