Manipulation of the Endocannabinoid System in Colitis: A Comprehensive Review

Estrogen receptor α aggravates intestinal inflammation via promoting the activation of NLRP3 inflammasome

Activation of the NLRP3 inflammasome and estrogen receptor α (ERα) has been shown to increase the risk of inflammatory bowel diseases (IBD) or promote disease recurrence. In previous work, we demonstrated that ERα regulated the transcription of NLRP3. However, the precise mechanism by which ERα modulates NLRP3 in IBD models remains unclear. In this study, we induced IBD in wild-type mice using DSS or TNBS, followed by treatment with the ERα-specific agonist PPT. The results showed that IBD symptoms and intestinal inflammation responses were significantly exacerbated after PPT treatment. Furthermore, the activation of ERα by PPT led to a marked increase in the expression of NLRP3 and pro-inflammatory cytokines, including IL-1β and IL-18, suggesting that ERα activation exacerbated intestinal inflammation and impaired mucosal healing during the recovery phase of inflammation. In contrast, ERα-knockout mice exhibited only mild symptoms when exposed to DSS or TNBS, with a concurrent reduction in NLRP3 expression, indicating that ERα plays a role in inflammation susceptibility. Similar findings were observed in NCM-460 cells, where the inflammation response was attenuated in ERα-knockdown cells. Importantly, we demonstrated that ERα interacted with the NLRP3 inflammasome and promoted its assembly. Collectively, we propose an underlying pathogenesis of IBD, that is, ERα can interact with the NLRP3 inflammasome and promote its expression and assembly, thereby exacerbating intestinal inflammation in IBD models. Therefore, ERα could serve as a potential therapeutic target for NLRP3 inflammasome-associated intestinal inflammation.

Endocannabinoids regulate enteric neuron-glia networks and visceral hypersensitivity following inflammation through a glial-dependent mechanism

Acute gastrointestinal (GI) inflammation induces neuroplasticity that produces long-lasting changes in gut motor function and pain. The endocannabinoid system is an attractive target to correct pain and dysmotility, but how inflammation changes endocannabinoid control over cellular communication in enteric neurocircuits is not understood. Enteric glia modulate gut neurons that control motility and pain and express monoacylglycerol lipase (MAGL) which controls endocannabinoid availability. We used a combination of in situ calcium imaging, chemogenetics, and selective drugs to study how endocannabinoid mechanisms affect glial responses and subsequent enteric neuron activity in health and following colitis in Wnt1Cre;GCaMP5g-tdT;GFAP::hM3Dq mice. Trpv1Cre;GCaMP5gtdT mice were used to study nociceptor sensitivity and Sox10CreERT2;Mgllf/f mice were used to test the role of glial MAGL in visceral pain. The data show that endocannabinoid signaling regulates neuro-glial signaling in gut neurocircuits in a sexually dimorphic manner. Inhibiting MAGL in healthy samples decreased glial responsiveness but this effect was lost in females following colitis and converted to an excitatory effect in males. Manipulating CB1 and CB2 receptors revealed further sex differences amongst neuro-glia signaling that were impacted following inflammation. Inflammation increased gut nociceptor sensitivity in both sexes but only females exhibited visceral hypersensitivity in vivo. Blocking MAGL normalized nociceptor responses in vitro and deleting glial Mgll in vivo rescued visceral hypersensitivity in females. These results show that sex and inflammation impact endocannabinoid mechanisms that regulate intercellular enteric glia-neuron communication. Further, targeting glial MAGL could provide therapeutic benefits for visceral nociception in a sex-dependent manner.

Priming lymphocyte responsiveness and differential T cell signaling in pediatric IBD patients with Cannabis use

The prevalence of inflammatory bowel disease (IBD) has increased dramatically in recent years, particularly in pediatric populations. Successful remission with current therapies is limited and often transient, leading patients to seek alternative therapies for symptom relief, including the use of medical marijuana (Cannabis sativa). However, chronic cannabis use among IBD patients is associated with increased risk for surgical interventions. Therefore, determining the direct impact of cannabis use on immune modulation in IBD patients is of critical importance. Peripheral blood mononuclear cells of cannabis using and non-using pediatric IBD patients were phenotyped by flow cytometry and functionally assessed for their cytokine production profile. A phospho-kinase array was also performed to better understand changes in immune responses. Results were then compared with serum phytocannabinoid profiles of each patient to identify cannabinoid-correlated changes in immune responses. Results demonstrated elevated levels of a myriad of pro-inflammatory cytokines in users versus non-users. Differences in signaling cascades of activated T cells between users and non-users were also observed. A number of anti-inflammatory cytokines were inversely correlated with serum phytocannabinoids. These results suggest that cannabis exposure, which can desensitize cannabinoid receptors, may prime pro-inflammatory pathways in pediatric IBD patients.

Bergenin Alleviates Ulcerative Colitis By Decreasing Gut Commensal Bacteroides vulgatus-Mediated Elevated Branched-Chain Amino Acids

Ulcerative colitis is closely associated with the dysregulation of gut microbiota. There is growing evidence that natural products may improve ulcerative colitis by regulating the gut microbiota. In this research, we demonstrated that bergenin, a naturally occurring isocoumarin, significantly ameliorates colitis symptoms in dextran sulfate sodium (DSS)-induced mice. Transcriptomic analysis and Caco-2 cell assays revealed that bergenin could ameliorate ulcerative colitis by inhibiting TLR4 and regulating NF-κB and mTOR phosphorylation. 16S rRNA sequencing and metabolomics analyses revealed that bergenin could improve gut microbiota dysbiosis by decreasing branched-chain amino acid (BCAA) levels. BCAA intervention mediated the mTOR/p70S6K signaling pathway to exacerbate the symptoms of ulcerative colitis in mice. Notably, bergenin greatly decreased the symbiotic bacteria Bacteroides vulgatus (B. vulgatus), and the gavage of B. vulgatus increased BCAA concentrations and aggravated the symptoms of ulcerative colitis in mice. Our findings suggest that gut microbiota-mediated BCAA metabolism plays a vital role in the protective effect of bergenin on ulcerative colitis, providing novel insights for ulcerative colitis prevention through manipulation of the gut microbiota.

Gut-brain axis interacts with immunomodulation in inflammatory bowel disease

The brain and the gastrointestinal (GI) tract are important sensory organs in the body and the two-way interaction that exists between them regulates key physiological and homeostatic functions. A growing body of research suggests that this bidirectional communication influences the development and progression of functional GI disorders and plays an important role in the treatment of central nervous system (CNS) disorders. Inflammatory bowel disease (IBD) is a classic intestinal disorder with a high prevalence but still unclear pathogenesis that has been widely discussed in recent years. However, in the studies available to date, we find that many authors have chosen to discuss the influence of the brain on intestinal disorders from the top down, starting with physical and psychological disorders. Coming very naturally, based on these substantial research evidence, we focus on exploring the links between bidirectional communication in the gut-brain axis and IBD, and highlight the role of the gut microbiota, vagus nerve (VN), receptors and immune cells involved in regulating IBD through the gut-brain axis in this review.

Pharmacohistory of Cannabis Use-A New Possibility in Future Drug Development for Gastrointestinal Diseases

Humans have employed cannabis for multiple uses including medicine, recreation, food, and fibre. The various components such as roots, flowers, seeds, and leaves have been utilized to alleviate pain, inflammation, anxiety, and gastrointestinal disorders like nausea, vomiting, diarrhoea, and inflammatory bowel diseases (IBDs). It has occupied a significant space in ethnomedicines across cultures and religions. Despite multi-dimensional uses, the global prohibition of cannabis by the USA through the introduction of the Marijuana Tax Act in 1937 led to prejudice about the perceived risks of cannabis, overshadowing its medicinal potential. Nevertheless, the discovery of tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis, and the endocannabinoid system renewed scientific interest in understanding the role of cannabis in modulating different conditions, including gastrointestinal disorders. Preparations combining cannabidiol and THC have shown promise in mitigating gut symptoms through anti-inflammatory and motility-enhancing effects. This review revisits the ethnomedicinal use of cannabis in gastrointestinal diseases and emphasizes the need for further research to determine optimal dosages, formulations, and safety profiles of cannabis-based medicines. It also underscores the future potential of cannabinoid-based therapies by leveraging the role of the expanded endocannabinoid system, an endocannabinoidome, in the modulation of gastrointestinal ailments.

Alginate-based drug carrier systems to target inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is an inflammatory disorder that affects the gastrointestinal tract. IBD has become an increasingly common condition in both developed and developing nations over the last few decades, owing to a variety of factors like a rising population and diets packed with processed and junk foods. While the root pathophysiology of IBD is unknown, treatments are focused on medications aimed to mitigate symptoms. Alginate (AG), a marine-derived polysaccharide, is extensively studied for its biocompatibility, pH sensitivity, and crosslinking nature. This polymer is thoroughly researched in drug delivery systems for IBD treatment, as it is naturally available, non-toxic, cost effective, and can be easily and safely cross-linked with other polymers to form an interconnected network, which helps in controlling the release of drugs over an extended period. There are various types of drug delivery systems developed from AG to deliver therapeutic agents; among them, nanotechnology-based systems and hydrogels are popular due to their ability to facilitate targeted drug delivery, reduce dosage, and increase the therapeutic efficiency. AG-based carrier systems are not only used for the sustained release of drug, but also used in the delivery of siRNA, interleukins, and stem cells for site directed drug delivery and tissue regenerating ability respectively. This review is focussed on pathogenesis and currently studied medications for IBD, AG-based drug delivery systems and their properties for the alleviation of IBD. Moreover, future challenges are also be discoursed to improve the research of AG in the field of biopharmaceuticals and drug delivery.

Increased expression of CB2 receptor in the intestinal biopsies of children with inflammatory bowel disease

OBJECTIVES

The Cannabinoid Receptor type 2 (CB2) is involved in inflammation and immune cell modulation. In previous studies, we demonstrated the association between the CNR2 rs35761398 polymorphism and the risk for pediatric inflammatory bowel disease (IBD). In this study, we analyzed the intestinal biopsies from Crohn disease (CD) and ulcerative colitis (UC) pediatric patients at the diagnosis to evaluate the expression of CB2 and several factors associated with IBD inflammatory pathways.

METHODS

We enrolled five patients with CD, five with UC, and five controls (CTR). We analyzed ileum and rectum biopsies from patients of each group evaluating the expression of CB2, Toll-like receptor 4, interleukin-6, and interleukin-1β by western blot and immunofluorescence.

RESULTS

Western blot analysis showed a significant increase of CB2 in the CD ileum and in the UC rectum biopsies and an increase of TLR4 in the UC rectum. We also observed a significant over-expression of the IL-6 in UC rectum. The immunofluorescence analysis confirmed western blot data, showing also a T-lymphocytes infiltration colocalized with CB2 expression in the CD ileum and UC rectum.

CONCLUSIONS

Our results show an upregulation of CB2 in pediatric IBD, which might have implications for drug discovery.

IMPACT

The Cannabinoid Receptor type 2 (CB2) is involved in the inflammation and modulation of the immune response in pediatric inflammatory bowel disease (IBD). CB2 receptor is more expressed in the inflamed intestine of pediatric IBD patients. CB2 could be used as a potential therapeutic target to reduce IBD-related inflammatory state in childhood.

Therapeutic Effects of Medicinal Cannabinoids on the Gastrointestinal System in Pediatric Patients: A Systematic Review

Changes in cannabis legalization have generated interest in medicinal cannabinoids for therapeutic uses, including those that target the gastrointestinal (GI) tract. These effects are mediated through interactions with the endocannabinoid system. Given the increasing societal awareness of the therapeutic potential of cannabinoids, it is important to ensure pediatric representation in clinical studies investigating cannabinoid use. This systematic review aims to assess the efficacy of medicinal cannabinoids in treating GI symptoms in pediatric patients. A literature search of Medline, Embase, CINAHL, Web of Science, and the Cochrane Library was performed from inception until June 23, 2020. Study design, patient characteristics, type, dose and duration of medicinal cannabinoid therapy, and GI outcomes were extracted. From 7303 records identified, 5 studies met all inclusion criteria. Included studies focused on chemotherapy-induced nausea, inflammatory bowel disease, and GI symptoms associated with severe complex motor disorders. Results varied based on the symptom being treated, the type of cannabinoid, and the patient population. Medicinal cannabinoids may have a potential role in treating specific GI symptoms in specific patient populations. The limited number and heterogenicity of included studies highlight the demand for future research to distinguish effects among different cannabinoid types and patient populations and to examine drug interactions. As interest increases, higher quality studies are needed to understand the efficacy of cannabinoids as a pediatric GI treatment and whether these benefits outweigh the associated risks (Registration Number: PROSPERO CRD42020202486).

Symptoms and Extraintestinal Manifestations in Active Cannabis Users with Inflammatory Bowel Disease

Introduction: Cannabis use is common in the setting of inflammatory bowel disease (IBD). Patients frequently use cannabis to treat IBD-associated symptoms, and there is evidence that cannabis and its derivatives are helpful for this purpose. However, it is unclear how the symptom profiles of active IBD cannabis users and nonusers compare and how these symptoms may relate to their underlying disease state and/or complications. Materials and Methods: We performed a retrospective cohort study using a consented IBD natural history registry from a single tertiary care referral center between January 1, 2015 and August 31, 2020. We asked patients about current cannabis use and frequency. We also abstracted demographic and clinical characteristic information, including endoscopic severity, and totals and subscores of surveys assessing IBD characteristics, presence of anxiety/depression, and IBD-associated symptoms. We compared clinical and demographic factors of cannabis users and nonusers and developed a logistic regression model to evaluate for independent associations with cannabis use. Results: Three hundred eighty-three IBD patients met the inclusion criteria (206 females, 177 males; 258 Crohn's disease [CD], 118 ulcerative colitis, and 7 indeterminate colitis). Thirty patients (7.8%) were active cannabis users, consuming it for an average of 2.7 times per week. Cannabis users were more likely to report abdominal pain (83.3% vs. 61.7%), gas (66.7% vs. 45.6%), tenesmus (70.0% vs. 47.6%), and arthralgias (53.3% vs. 20.3%) compared to those that did not use cannabis (p<0.05 for each). Incidence of moderate-severe endoscopic inflammation was similar between cannabis users and nonusers, while CD-associated complications were more common in nonusers (39.1% vs. 69.7%, p<0.05). The only factor that demonstrated a significant association with cannabis use on multivariable analysis was arthralgia (p<0.01). Discussion: Active IBD cannabis users were more likely to report a variety of symptoms, including abdominal pain, gas, tenesmus, and arthralgias. However, they did not demonstrate more frequent active disease or IBD-associated complications, suggesting that other nonluminal factors influence their symptoms and/or decision to use cannabis. These findings demonstrate the importance of evaluating for extraintestinal contributors to symptom burden in IBD cannabis users, as well as the ongoing need to develop safer and more effective methods for recognizing and managing abdominal pain and other symptoms in this setting.

Medical marijuana for inflammatory bowel disease: the highs and lows

Increased interest in cannabis as a potential treatment and/or adjuvant therapy for inflammatory bowel disease (IBD) has been driven by patients with refractory disease seeking relief as well those who desire alternatives to conventional therapies. Available data have shown a potential role of cannabis as a supportive medication, particularly in pain reduction; however, it remains unknown whether cannabis has any impact on the underlying inflammatory process of IBD. The purpose of this review article is to summarize the available literature concerning the use of cannabis for the treatment of IBD and highlight potential areas for future study.

Endocannabinoid System as a Promising Therapeutic Target in Inflammatory Bowel Disease - A Systematic Review

Inflammatory bowel disease (IBD) is a general term used to describe a group of chronic inflammatory conditions of the gastrointestinal tract of unknown etiology, including two primary forms: Crohn's disease (CD) and ulcerative colitis (UC). The endocannabinoid system (ECS) plays an important role in modulating many physiological processes including intestinal homeostasis, modulation of gastrointestinal motility, visceral sensation, or immunomodulation of inflammation in IBD. It consists of cannabinoid receptors (CB1 and CB2), transporters for cellular uptake of endocannabinoid ligands, endogenous bioactive lipids (Anandamide and 2-arachidonoylglycerol), and the enzymes responsible for their synthesis and degradation (fatty acid amide hydrolase and monoacylglycerol lipase), the manipulation of which through agonists and antagonists of the system, shows a potential therapeutic role for ECS in inflammatory bowel disease. This review summarizes the role of ECS components on intestinal inflammation, suggesting the advantages of cannabinoid-based therapies in inflammatory bowel disease.

Carboxylesterase 2 proteins are efficient diglyceride and monoglyceride lipases possibly implicated in metabolic disease

Carboxylesterase 2 (CES2/Ces2) proteins exert established roles in (pro)drug metabolism. Recently, human and murine CES2/Ces2c have been discovered as triglyceride (TG) hydrolases implicated in the development of obesity and fatty liver disease. The murine Ces2 family consists of seven homologous genes as opposed to a single CES2 gene in humans. However, the mechanistic role of Ces2 protein family members is not completely understood. In this study, we examined activities of all Ces2 members toward TGs, diglycerides (DGs), and monoglycerides (MGs) as the substrate. Besides CES2/Ces2c, we measured significant TG hydrolytic activities for Ces2a, Ces2b, and Ces2e. Notably, these Ces2 members and CES2 efficiently hydrolyzed DGs and MGs, and their activities even surpassed those measured for TG hydrolysis. The localization of CES2/Ces2c proteins at the ER may implicate a role of these lipases in lipid signaling pathways. We found divergent expression of Ces2 genes in the liver and intestine of mice on a high-fat diet, which could relate to changes in lipid signaling. Finally, we demonstrate reduced CES2 expression in the colon of patients with inflammatory bowel disease and a similar decline in Ces2 expression in the colon of a murine colitis model. Together, these results demonstrate that CES2/Ces2 members are highly efficient DG and MG hydrolases that may play an important role in liver and gut lipid signaling.

Comorbid anxiety-like behavior in a rat model of colitis is mediated by an upregulation of corticolimbic fatty acid amide hydrolase

Peripheral inflammatory conditions, including those localized to the gastrointestinal tract, are highly comorbid with psychiatric disorders such as anxiety and depression. These behavioral symptoms are poorly managed by conventional treatments for inflammatory diseases and contribute to quality of life impairments. Peripheral inflammation is associated with sustained elevations in circulating glucocorticoid hormones, which can modulate central processes, including those involved in the regulation of emotional behavior. The endocannabinoid (eCB) system is exquisitely sensitive to these hormonal changes and is a significant regulator of emotional behavior. The impact of peripheral inflammation on central eCB function, and whether this is related to the development of these behavioral comorbidities remains to be determined. To examine this, we employed the trinitrobenzene sulfonic acid-induced model of colonic inflammation (colitis) in adult, male, Sprague Dawley rats to produce sustained peripheral inflammation. Colitis produced increases in behavioral measures of anxiety and elevations in circulating corticosterone. These alterations were accompanied by elevated hydrolytic activity of the enzyme fatty acid amide hydrolase (FAAH), which hydrolyzes the eCB anandamide (AEA), throughout multiple corticolimbic brain regions. This elevation of FAAH activity was associated with broad reductions in the content of AEA, whose decline was driven by central corticotropin releasing factor type 1 receptor signaling. Colitis-induced anxiety was reversed following acute central inhibition of FAAH, suggesting that the reductions in AEA produced by colitis contributed to the generation of anxiety. These data provide a novel perspective for the pharmacological management of psychiatric comorbidities of chronic inflammatory conditions through modulation of eCB signaling.

Targeting the endocannabinoid system with microbial interventions to improve gut integrity

The endocannabinoid system is a metabolic pathway involved in the communication between the gut microbiota and the host. In the gut, the endocannabinoid system regulates the integrity of the intestinal barrier. A compromised integrity of the intestinal barrier is associated with several disorders such as inflammatory bowel disorder, obesity and major depressive disorder. Decreasing the integrity of the intestinal barrier results in an increased translocation of bacterial metabolites, including lipopolysaccharides, across the epithelial layer of the gut, causing the subsequent inflammation. Targeting the endocannabinoid system in the gut can improve the integrity of the intestinal barrier. Currently, microbial interventions in the form of probiotics are under investigation for the treatment of diseases related to a compromised integrity of the intestinal barrier. However, the role of the endocannabinoid system in the gut is ambiguous since activity of the endocannabinoid system is increased in obesity and decreased in inflammatory bowel disease, emphasizing the need for development of personalized microbial interventions. This review discusses the role of the endocannabinoid system in regulating the gut barrier integrity and highlights current efforts to develop new endocannabinoid-targeted microbial interventions.

Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment

Cannabis sativa L. turned out to be a valuable source of chemical compounds of various structures, showing pharmacological activity. The most important groups of compounds include phytocannabinoids and terpenes. The pharmacological activity of Cannabis (in epilepsy, sclerosis multiplex (SM), vomiting and nausea, pain, appetite loss, inflammatory bowel diseases (IBDs), Parkinson's disease, Tourette's syndrome, schizophrenia, glaucoma, and coronavirus disease 2019 (COVID-19)), which has been proven so far, results from the affinity of these compounds predominantly for the receptors of the endocannabinoid system (the cannabinoid receptor type 1 (CB1), type two (CB2), and the G protein-coupled receptor 55 (GPR55)) but, also, for peroxisome proliferator-activated receptor (PPAR), glycine receptors, serotonin receptors (5-HT), transient receptor potential channels (TRP), and GPR, opioid receptors. The synergism of action of phytochemicals present in Cannabis sp. raw material is also expressed in their increased bioavailability and penetration through the blood-brain barrier. This review provides an overview of phytochemistry and pharmacology of compounds present in Cannabis extracts in the context of the current knowledge about their synergistic actions and the implications of clinical use in the treatment of selected diseases.

Bioactive lipids in inflammatory bowel diseases - From pathophysiological alterations to therapeutic opportunities

Inflammatory bowel diseases (IBDs), such as Crohn's disease and ulcerative colitis, are lifelong diseases that remain challenging to treat. IBDs are characterized by alterations in intestinal barrier function and dysregulation of the innate and adaptive immunity. An increasing number of lipids are found to be important regulators of inflammation and immunity as well as gut physiology. Therefore, the study of lipid mediators in IBDs is expected to improve our understanding of disease pathogenesis and lead to novel therapeutic opportunities. Here, through selected examples - such as fatty acids, specialized proresolving mediators, lysophospholipids, endocannabinoids, and oxysterols - we discuss how lipid signaling is involved in IBD physiopathology and how modulating lipid signaling pathways could affect IBDs.

Endocannabinoids Inhibit the Induction of Virulence in Enteric Pathogens

Endocannabinoids are host-derived lipid hormones that fundamentally impact gastrointestinal (GI) biology. The use of cannabis and other exocannabinoids as anecdotal treatments for various GI disorders inspired the search for mechanisms by which these compounds mediate their effects, which led to the discovery of the mammalian endocannabinoid system. Dysregulated endocannabinoid signaling was linked to inflammation and the gut microbiota. However, the effects of endocannabinoids on host susceptibility to infection has not been explored. Here, we show that mice with elevated levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG) are protected from enteric infection by Enterobacteriaceae pathogens. 2-AG directly modulates pathogen function by inhibiting virulence programs essential for successful infection. Furthermore, 2-AG antagonizes the bacterial receptor QseC, a histidine kinase encoded within the core Enterobacteriaceae genome that promotes the activation of pathogen-associated type three secretion systems. Taken together, our findings establish that endocannabinoids are directly sensed by bacteria and can modulate bacterial function.

Cannabinoids: A Guide for Use in the World of Gastrointestinal Disease

Cannabinoids have been known as the primary component of cannabis for decades, but the characterization of the endocannabinoid system (ECS) in the 1990s opened the doors for cannabis' use in modern medicine. The 2 main receptors of this system, cannabinoid receptors 1 and 2, are found on cells of various tissues, with significant expression in the gastrointestinal (GI) tract. The characterization of the ECS also heralded the understanding of endocannabinoids, naturally occurring compounds synthesized in the human body. Via secondary signaling pathways acting on vagal nerves, nociceptors, and immune cells, cannabinoids have been shown to have both palliative and detrimental effects on the pathophysiology of GI disorders. Although research on the effects of both endogenous and exogenous cannabinoids has been slow due to the complicated legal history of cannabis, discoveries of cannabinoids' treatment potential have been found in various fields of medicine, including the GI world. Medical cannabis has since been offered as a treatment for a myriad of conditions and malignancies, including cancer, human immunodeficiency virus/acquired immunodeficiency syndrome, multiple sclerosis, chronic pain, nausea, posttraumatic stress disorder, amyotrophic lateral sclerosis, cachexia, glaucoma, and epilepsy. This article hopes to create an overview of current research on cannabinoids and the ECS, detail the potential advantages and pitfalls of their use in GI diseases, and explore possible future developments in this field.

Cannabidiol primer for healthcare professionals

Emerging research and clinical data are demonstrating potential benefits of cannabidiol for multiple medical conditions. This article gives healthcare providers information on cannabidiol and the endocannabinoid system as a foundation on which to build their medical knowledge as the risks and benefits of CBD in various diseases are further evaluated over time.

Cannabis, the Endocannabinoid System and Immunity-the Journey from the Bedside to the Bench and Back

The Cannabis plant contains numerous components, including cannabinoids and other active molecules. The phyto-cannabinoid activity is mediated by the endocannabinoid system. Cannabinoids affect the nervous system and play significant roles in the regulation of the immune system. While Cannabis is not yet registered as a drug, the potential of cannabinoid-based medicines for the treatment of various conditions has led many countries to authorize their clinical use. However, the data from basic and medical research dedicated to medical Cannabis is currently limited. A variety of pathological conditions involve dysregulation of the immune system. For example, in cancer, immune surveillance and cancer immuno-editing result in immune tolerance. On the other hand, in autoimmune diseases increased immune activity causes tissue damage. Immuno-modulating therapies can regulate the immune system and therefore the immune-regulatory properties of cannabinoids, suggest their use in the therapy of immune related disorders. In this contemporary review, we discuss the roles of the endocannabinoid system in immunity and explore the emerging data about the effects of cannabinoids on the immune response in different pathologies. In addition, we discuss the complexities of using cannabinoid-based treatments in each of these conditions.

Alternative and Complementary Approaches for the Treatment of Inflammatory Bowel Disease: Evidence From Cochrane Reviews

The Cochrane IBD Group presented a symposium at Digestive Diseases Week 2018 entitled “Alternative and Complementary Approaches for the Treatment of IBD: Evidence from Cochrane Reviews.” This article summarizes the data presented at this symposium.

The potential of metabolic and lipid profiling in inflammatory bowel diseases: A pilot study

Inflammatory bowel diseases (IBDs) are conditions that still pose significant problems. A third of the patients are either misdiagnosed or a proper diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC) cannot be made. We need new biomarkers, so that we can offer patients the best treatment and keep the disease in an inactive state for as long as possible. Alterations in metabolic profiles have been incriminated in the pathophysiology of IBD. The aim of the present study was to identify molecules that could serve as biomarkers for a positive diagnosis of IBD as well as to discriminate UC from colonic CD. Twenty-two patients with active colonic IBD (UC = 17, CD = 5) and 24 age- and gender-matched healthy controls were enrolled. Plasma lipid and metabolic profiles were quantified using ultra-high-performance liquid chromatography combined with mass spectrometry. Univariate and multivariate statistical tests were employed. Six lipid species and 7 metabolites were significantly altered in IBD patients compared to healthy controls, with the majority belonging to glycerophospholipid, linoleic acid, and sphingolipid metabolisms. Five lipid species and only 1 metabolite were significantly increased in UC compared to CD. This preliminary study suggests that lipid and metabolic profiling of serum can become diagnostic tools for IBD. In addition, they can be used to differentiate between CD and UC.

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.

An overview of cannabis based treatment in Crohn's disease

Introduction: Cannabis use among inflammatory bowel disease (IBD) patients is common. There are many studies of various laboratory models demonstrating the anti-inflammatory effect of cannabis, but their translation to human disease is still lacking.Areas covered: The cannabis plant contains many cannabinoids, that activate the endocannabinoid system. The two most abundant phytocannabinoids are the psychoactive Tetrahydrocannabinol (THC), and the (mostly) anti-inflammatory cannabidiol (CBD). Approximately 15% of IBD patients use cannabis to ameliorate disease symptoms. Unfortunately, so far there are only three small placebo controlled study regarding the use of cannabis in active Crohns disease, combining altogether 93 subjects. Two of the studies showed significant clinical improvement but no improvement in markers of inflammation.Expert opinion: Cannabis seems to have a therapeutic potential in IBD. This potential must not be neglected; however, cannabis research is still at a very early stage. The complexity of the plant and the diversity of different cannabis chemovars create an inherent difficulty in cannabis research. We need more studies investigating the effect of the various cannabis compounds. These effects can then be investigated in randomized placebo controlled clinical trials to fully explore the potential of cannabis treatment in IBD.

Endocannabinoid system in irritable bowel syndrome and cannabis as a therapy

Irritable bowel syndrome (IBS) global burden is underestimated despite its high prevalence. It's a gastrointestinal disease having obscure pathophysiology with multiple therapies yet unsatisfactory remedies. The Endocannabinoid system (ECS) of our body plays a key role in maintaining normal physiology of the gastrointestinal tract as well as involves abnormalities including functional diseases like IBS. This review highlights the importance of the Endocannabinoid system, its connections with the normal gastrointestinal functions and abnormalities like IBS. It also discusses the role of cannabis as medical therapy in IBS patients. A literature search for articles related to endocannabinoids in IBS and medical cannabis in PubMed and Google Scholar was conducted. The studies highlighted the significant participation of ECS in IBS. However, the breach in obtaining the promising therapeutic model for IBS needed further investigation in ECS and uncover other treatments for IBS. This review summarizes ECS, highlights the relationship of ECS with IBS and explores cannabis as a potential therapy to treat IBS.

Medical cannabis for inflammatory bowel disease: real-life experience of mode of consumption and assessment of side-effects

OBJECTIVE

Use of medical cannabis for improving symptoms of inflammatory bowel disease is increasing. However, reports on long-term outcomes are lacking. This prospective, observational study assessed the effects of licensed cannabis use among patients with inflammatory bowel disease.

METHODS

Dose and mode of consumption, adverse events, use of other medications, and long-term effects were evaluated among 127 patients with inflammatory bowel disease using legalized medical cannabis. Blood count, albumin, and C-reactive protein were assessed before, 1 month, and at least 1 year after medical cannabis therapy was initiated. Questionnaires on disease activity, patient function, and signs of addiction were completed by patients and by a significant family member to assess its effects.

RESULTS

The average dose used was 31 ± 15 g/month. The average Harvey-Bradshaw index improved from 14 ± 6.7 to 7 ± 4.7 (P < 0.001) during a median follow-up of 44 months (interquartile range, 24-56 months). There was a slight, but statistically significant, average weight gain of 2 kg within 1 year of cannabis use. The need for other medications was significantly reduced. Employment among patients increased from 65 to 74% (P < 0.05). We conclude that the majority of inflammatory bowel disease patients using cannabis are satisfied with a dose of 30 g/month. We did not observe negative effects of cannabis use on the patients' social or occupational status.

CONCLUSIONS

Cannabis use by inflammatory bowel disease patients can induce clinical improvement and is associated with reduced use of medication and slight weight gain. Most patients respond well to a dose of 30 g/month, or 21 mg Δ9-tetra- hydrocannabinol (THC) and 170 mg Cannabidiol (CBD) per day.

[High-dose dronabinol treatment vs. medicinal cannabis flowers]

This article reports a case of pronounced, chronic lumboischialgia, which was not satisfactorily controlled by conventional analgesic treatment. The level of pain under high-dose dronabinol treatment with oral and inhalative administration as well as the way to reimburse the cost of medicinal cannabis flowers, the treatment success and criteria of the economic prescription procedure are presented.

Cannabis effects on lipoproteins

PURPOSE OF REVIEW

The endocannabinoid system affects several physiological functions. A family of endocannabinoid receptors is susceptible to cannabis constituents. Cannabis is widely used in our society and following its recent legalization in Canada, we focus on how exposure to cannabis and pharmacologic cannabinoid receptor type 1 (CB1) inhibition affect lipoprotein levels.

RECENT FINDINGS

Several groups have reported that exposure to cannabis does not increase weight despite the marked increase in caloric intake. In observational studies, the effect of smoked cannabis exposure on plasma lipids is variable. Some studies in specific patient populations with longer exposure to cannabis seemed to identify slightly more favorable lipoprotein profiles in the exposed group. Several larger controlled clinical trials using orally administered rimonabant, a CB1 receptor antagonist, have consistently shown relative improvements in weight and plasma levels of triglyceride and high-density lipoprotein cholesterol among patients receiving the treatment.

SUMMARY

The widely variable findings on the relationship of cannabis in various forms with plasma lipids preclude any definitive conclusions. Cannabis has complex effects on the cardiovascular system and its effects on lipid profile must be considered in this overall context. Further properly controlled research is required to better understand this topic.

Cannabis Oil Use by Adolescents and Young Adults With Inflammatory Bowel Disease

OBJECTIVES

The aim of the study was to describe use of oral or sublingual cannabis oil (CO) by adolescent and young adult patients with inflammatory bowel disease (IBD).

METHODS

A descriptive study of IBD patients 13 to 23 years of age seen between January 2015 through December 2017 at Children's Hospital Colorado. Information obtained included chart abstraction, electronic and interview self-report, and serum cannabinoid levels. We compared CO users and cannabis non-users for clinical characteristics and perceptions of risk. Users of CO provided information on routes, patterns, motivations, and perceived benefits and problems with use.

RESULTS

The 15 users and 67 non-users were similar for clinical characteristics and pain and appetite scores. 9 of 15 (60%) CO users had used in the past 30 days, an average of 22 ± 9 times; and 4 used daily. A variety of strengths and CBD:THC ratios were reported. Most common perceived effect of use was on sleep quality, nausea, and increase in appetite. Of the 15 users, 6 used only CO and no additional forms of cannabis. Of these 6 CO only users, 5 reported a medical reason for use, most commonly to relieve pain.

CONCLUSIONS

Adolescent and young adults with IBD used oral CO and many used other cannabis products as well. Users perceived some medical benefit. Care teams should strive for open communication about use until further information on safety and efficacy becomes available.

Cannabis, a potential treatment option in pediatric IBD? Still a long way to go

INTRODUCTION

The onset of inflammatory bowel disease (IBD) in children is rising. Current treatment options are based on immunomodulatory therapy. Alternative treatment options are upcoming since they appear to be effective in individual patients. Cannabis might relief IBD symptoms in these cases and improve quality of life. Recent evidence suggests a potential anti-inflammatory effect of cannabis. Areas covered: This review presents an overview of recent literature on the use of cannabis in IBD focussing on pediatric IBD patients. Background information on the role of the endocannabinoid system within the gastrointestinal tract is presented. Other modalities of cannabis and its purified ingredients will be discussed as well, with attention to its applicability in children with IBD. Expert opinion: More research is needed on the efficacy and safety of cannabis in pediatric IBD. Studies are well underway, but until then the use of cannabis in pediatric IBD cannot be recommended.

A Quantitative Analysis of Colonic Mucosal Oxylipins and Endocannabinoids in Treatment-Naïve and Deep Remission Ulcerative Colitis Patients and the Potential Link With Cytokine Gene Expression

BACKGROUND

The bioactive metabolites of omega 3 and omega 6 polyunsaturated fatty acids (ω-3 and ω-6) are known as oxylipins and endocannabinoids (eCBs). These lipid metabolites are involved in prompting and resolving the inflammatory response that leads to the onset of inflammatory bowel disease (IBD). This study aims to quantify these bioactive lipids in the colonic mucosa and to evaluate the potential link to cytokine gene expression during inflammatory events in ulcerative colitis (UC).

METHODS

Colon biopsies were taken from 15 treatment-naïve UC patients, 5 deep remission UC patients, and 10 healthy controls. Thirty-five oxylipins and 11 eCBs were quantified by means of ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Levels of mRNA for 10 cytokines were measured by reverse transcription polymerase chain reaction.

RESULTS

Levels of ω-6-related oxylipins were significantly elevated in treatment-naïve patients with respect to controls, whereas the levels of ω-3 eCBs were lower. 15S-Hydroxy-eicosatrienoic acid (15S-HETrE) was significantly upregulated in UC deep remission patients compared with controls. All investigated cytokines had significantly higher mRNA levels in the inflamed mucosa of treatment-naïve UC patients. Cytokine gene expression was positively correlated with several ω-6 arachidonic acid-related oxylipins, whereas negative correlation was found with lipoxin, prostacyclin, and the eCBs.

CONCLUSIONS

Increased levels of ω-6-related oxylipins and decreased levels of ω-3-related eCBs are associated with the debut of UC. This highlights the altered balance between pro- and anti-inflammatory lipid mediators in IBD and suggests potential targets for intervention.

Members of the endocannabinoid system are distinctly regulated in inflammatory bowel disease and colorectal cancer

Preclinical studies have demonstrated that the endocannabinoid system (ECS) plays an important role in the protection against intestinal inflammation and colorectal cancer (CRC); however, human data are scarce. We determined members of the ECS and related components of the ‘endocannabinoidome’ in patients with inflammatory bowel disease (IBD) and CRC, and compared them to control subjects. Anandamide (AEA) and oleoylethanolamide (OEA) were increased in plasma of ulcerative colitis (UC) and Crohn’s disease (CD) patients while 2-arachidonoylglycerol (2-AG) was elevated in patients with CD, but not UC. 2-AG, but not AEA, PEA and OEA, was elevated in CRC patients. Lysophosphatidylinositol (LPI) 18:0 showed higher levels in patients with IBD than in control subjects whereas LPI 20:4 was elevated in both CRC and IBD. Gene expression in intestinal mucosal biopsies revealed different profiles in CD and UC. CD, but not UC patients, showed increased gene expression for the 2-AG synthesizing enzyme diacylglycerol lipase alpha. Transcripts of CNR1 and GPR119 were predominantly decreased in CD. Our data show altered plasma levels of endocannabinoids and endocannabinoid-like lipids in IBD and CRC and distinct transcript profiles in UC and CD. We also report alterations for less known components in intestinal inflammation, such as GPR119, OEA and LPI.

Cannabis for the treatment of ulcerative colitis

BACKGROUND

Cannabis and cannabinoids are often promoted as treatment for many illnesses and are widely used among patients with ulcerative colitis (UC). Few studies have evaluated the use of these agents in UC. Further, cannabis has potential for adverse events and the long-term consequences of cannabis and cannabinoid use in UC are unknown.

OBJECTIVES

To assess the efficacy and safety of cannabis and cannabinoids for the treatment of patients with UC.

SEARCH METHODS

We searched MEDLINE, Embase, WHO ICTRP, AMED, PsychINFO, the Cochrane IBD Group Specialized Register, CENTRAL, ClinicalTrials.Gov and the European Clinical Trials Register from inception to 2 January 2018. Conference abstracts and references were searched to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any form or dose of cannabis or its cannabinoid derivatives (natural or synthetic) to placebo or an active therapy for adults (> 18 years) with UC were included.

DATA COLLECTION AND ANALYSIS

Two authors independently screened search results, extracted data and assessed bias using the Cochrane risk of bias tool. The primary outcomes were clinical remission and relapse (as defined by the primary studies). Secondary outcomes included clinical response, endoscopic remission, endoscopic response, histological response, quality of life, C-reactive protein (CRP) and fecal calprotectin measurements, symptom improvement, adverse events, serious adverse events, withdrawal due to adverse events, psychotropic adverse events, and cannabis dependence and withdrawal effects. We calculated the risk ratio (RR) and corresponding 95% confidence interval for dichotomous outcomes. For continuous outcomes, we calculated the mean difference (MD) and corresponding 95% CI. Data were pooled for analysis when the interventions, patient groups and outcomes were sufficiently similar (determined by consensus). Data were analyzed on an intention-to-treat basis. GRADE was used to evaluate the overall certainty of evidence.

MAIN RESULTS

Two RCTs (92 participants) met the inclusion criteria. One study (N = 60) compared 10 weeks of cannabidiol capsules with up to 4.7% D9-tetrahydrocannabinol (THC) with placebo capsules in participants with mild to moderate UC. The starting dose of cannabidiol was 50 mg twice daily increasing to 250 mg twice daily if tolerated. Another study (N = 32) compared 8 weeks of therapy with two cannabis cigarettes per day containing 0.5 g of cannabis, corresponding to 23 mg THC/day to placebo cigarettes in participants with UC who did not respond to conventional medical treatment. No studies were identified that assessed cannabis therapy in quiescent UC. The first study was rated as low risk of bias and the second study (published as an abstract) was rated as high risk of bias for blinding of participants and personnel. The studies were not pooled due to differences in the interventional drug.The effect of cannabidiol capsules (100 mg to 500 mg daily) compared to placebo on clinical remission and response is uncertain. Clinical remission at 10 weeks was achieved by 24% (7/29) of the cannabidiol group compared to 26% (8/31) in the placebo group (RR 0.94, 95% CI 0.39 to 2.25; low certainty evidence). Clinical response at 10 weeks was achieved in 31% (9/29) of cannabidiol participants compared to 22% (7/31) of placebo patients (RR 1.37, 95% CI 0.59 to 3.21; low certainty evidence). Serum CRP levels were similar in both groups after 10 weeks of therapy. The mean CRP in the cannabidiol group was 9.428 mg/L compared to 7.638 mg/L in the placebo group (MD 1.79, 95% CI -5.67 to 9.25; moderate certainty evidence). There may be a clinically meaningful improvement in quality of life at 10 weeks, measured with the IBDQ scale (MD 17.4, 95% CI -3.45 to 38.25; moderate certainty evidence). Adverse events were more frequent in cannabidiol participants compared to placebo. One hundred per cent (29/29) of cannabidiol participants had an adverse event, compared to 77% (24/31) of placebo participants (RR 1.28, 95% CI 1.05 to1.56; moderate certainty evidence). However, these adverse events were considered to be mild or moderate in severity. Common adverse events included dizziness, disturbance in attention, headache, nausea and fatigue. None (0/29) of the cannabidiol participants had a serious adverse event compared to 13% (4/31) of placebo participants (RR 0.12, 95% CI 0.01 to 2.11; low certainty evidence). Serious adverse events in the placebo group included worsening of UC and one complicated pregnancy. These serious adverse events were thought to be unrelated to the study drug. More participants in the cannabidiol group withdrew due to an adverse event than placebo participants. Thirty-four per cent (10/29) of cannabidiol participants withdrew due to an adverse event compared to 16% (5/31) of placebo participants (RR 2.14, 95% CI 0.83 to 5.51; low certainty evidence). Withdrawls in the cannabidiol group were mostly due to dizziness. Withdrawals in the placebo group were due to worsening UC.The effect of cannabis cigarettes (23 mg THC/day) compared to placebo on mean disease activity, CRP levels and mean fecal calprotectin levels is uncertain. After 8 weeks, the mean disease activity index score in cannabis participants was 4 compared with 8 in placebo participants (MD -4.00, 95% CI -5.98 to -2.02). After 8 weeks, the mean change in CRP levels was similar in both groups (MD -0.30, 95% CI -1.35 to 0.75; low certainty evidence). The mean fecal calprotectin level in cannabis participants was 115 mg/dl compared to 229 mg/dl in placebo participants (MD -114.00, 95% CI -246.01 to 18.01). No serious adverse events were observed. This study did not report on clinical remission, clinical response, quality of life, adverse events or withdrawal due to adverse events.

AUTHORS' CONCLUSIONS

The effects of cannabis and cannabidiol on UC are uncertain, thus no firm conclusions regarding the efficacy and safety of cannabis or cannabidiol in adults with active UC can be drawn.There is no evidence for cannabis or cannabinoid use for maintenance of remission in UC. Further studies with a larger number of patients are required to assess the effects of cannabis in UC patients with active and quiescent disease. Different doses of cannabis and routes of administration should be investigated. Lastly, follow-up is needed to assess the long term safety outcomes of frequent cannabis use.

Preventive effect of bergenin against the development of TNBS-induced acute colitis in rats is associated with inflammatory mediators inhibition and NLRP3/ASC inflammasome signaling pathways

Ulcerative colitis is an idiopathic inflammatory bowel disease characterized by intestinal inflammation; blocking this inflammatory process may be the key to the development of new naturally occurring anti-inflammatory drugs, with greater efficiency and lower side effects. The objective of this study is to explore the effects of bergenin (BG) in TNBS (2,4,6-trinitrobenzenesulfonic acid)-induced acute colitis model in rats in order to assist in the studies for the development of novel natural product therapies for inflammatory bowel disease. 48 Wistar rats were randomized into six groups: (i) Control and (ii) TNBS control; (iii) 5-ASA 100 mg/kg/day (iv) BG 12 mg/kg/day (v) BG 25 mg/kg/day and (vi) BG 50 mg/kg/day. Colitis was induced by instillation of TNBS. Colitis was evaluated by an independent observer who was blinded to the treatment. Our results revealed that bergenin decreased the macroscopic and microscopic damage signs of colitis, and reduced the degree of neutrophilic infiltration in the colon tissue; also, it was capable to down-regulate COX-2, iNOS, IkB-α, and pSTAT3 protein expression. Similarly, using a protocol for indirect ELISA quantification of cytokines, bergenin treatment reduced IL-1β, IFN-γ and IL-10 levels, and inhibited both canonical (IL-1) and non-canonical (IL-11) NLRP3/ASC inflammasome signaling pathways in TNBS-induced acute colitis. Conclusion: Our study has provided evidence that administration of bergenin reduced the damage caused by TNBS in an experimental model of acute colitis in rats, reduced levels of pro-inflammatory proteins and cytokines probably by modulation of pSTAT3 and NF-κB signaling and blocking canonical and non-canonical NLRP3/ASC inflammasome pathways.

Anandamide inhibits FcεRI-dependent degranulation and cytokine synthesis in mast cells through CB2 and GPR55 receptor activation. Possible involvement of CB2-GPR55 heteromers

Activation of high affinity receptor for IgE (FcεRI) by IgE/antigen complexes in mast cells (MCs) leads to the release of preformed pro-inflammatory mediators stored in granules by a Ca²⁺-dependent process known as anaphylactic degranulation. Degranulation inhibition has been proposed as a strategy to control allergies and chronic inflammation conditions. Cannabinoids are important inhibitors of inflammatory reactions but their effects on IgE/Ag-mediated MCs responses are not well described. In this study, we analyzed the effect of the endocannabinoid anandamide (AEA), the selective CB₂ receptor agonist HU308, and the GPR55 receptor agonist lysophosphatidylinositol (LPI) on FcεRI-induced activation in murine bone marrow-derived mast cells (BMMCs). Our results show that AEA, HU380 and LPI inhibited FcεRI-induced degranulation in a concentration-dependent manner. This effect was mediated by CB₂ and GPR55 receptor activation through a mechanism insensitive to pertussis toxin. Degranulation inhibition was prevented by CB₂ and GPR55 antagonism, but not by CB₁ receptor blockage. AEA also inhibited calcium-dependent cytokine mRNA synthesis induced by FcεRI crosslinking, without affecting early phosphorylation events. In addition, AEA, HU308 and LPI inhibited intracellular Ca²⁺ rise in response to IgE/Ag. CB₂ and GPR55 receptor antagonism could not prevent the inhibition produced by AEA and HU308, but partially blocked the one caused by LPI. These results indicate that AEA inhibits IgE/Ag-induced degranulation through a mechanism that includes the participation of CB₂ and GPR55 receptors acting in close crosstalk, and show that CB₂-GPR55 heteromers are important negative regulators of FcεRI-induced responses in MCs.

Endocannabinoids in the treatment of gasytrointestinal inflammation and symptoms

The evolving policies regarding the use of therapeutic Cannabis have steadily increased the public interest in its use as a complementary and alternative medicine in several disorders, including inflammatory bowel disease. Endocannabinoids represent both an appealing therapeutic strategy and a captivating scientific dilemma. Results from clinical trials have to be carefully interpreted owing to possible reporting-biases related to cannabinoids psychotropic effects. Moreover, discriminating between symptomatic improvement and the real gain on the underlying inflammatory process is often challenging. This review summarizes the advances and latest discovery in this ever-changing field of investigation, highlighting the main limitations in the current use of these drugs in clinical practice and the possible future perspectives to overcome these flaws.

The Use of Complementary and Alternative Medicine in Patients With Inflammatory Bowel Disease

Complementary and alternative medicine (CAM) includes products or medical practices that encompass herbal and dietary supplements, probiotics, traditional Chinese medicines, and a variety of mind-body techniques. The use of CAM in patients with inflammatory bowel disease (IBD) is increasing as patients seek ways beyond conventional therapy to treat their chronic illnesses. The literature behind CAM therapies and their application, efficacy, and safety is limited when compared to studies of conventional, allopathic therapies. Thus, gastroenterologists are often ill equipped to engage with their patients in informed and meaningful discussions about the role of CAM in IBD. The aims of this article are to provide a comprehensive summary and discussion of various CAM modalities and to appraise the evidence for their use.

Cannabinoid Receptor-2 Ameliorates Inflammation in Murine Model of Crohn's Disease

BACKGROUND AND AIMS

Cannabinoid receptor stimulation may have positive symptomatic effects on inflammatory bowel disease [IBD] patients through analgesic and anti-inflammatory effects. The cannabinoid 2 receptor [CB2R] is expressed primarily on immune cells, including CD4+ T cells, and is induced by active inflammation in both humans and mice. We therefore investigated the effect of targeting CB2R in a preclinical IBD model.

METHODS

Employing a chronic ileitis model [TNFΔARE/+ mice], we assessed expression of the CB2R receptor in ileal tissue and on CD4+ T cells and evaluated the effect of stimulation with CB2R-selective ligand GP-1a both in vitro and in vivo. Additionally, we compared cannabinoid receptor expression in the ilea and colons of healthy human controls with that of Crohn's disease patients.

RESULTS

Ileal expression of CB2R and the endocannabinoid anandamide [AEA] was increased in actively inflamed TNF∆ARE/+ mice compared with controls. CB2R mRNA was preferentially induced on regulatory T cells [Tregs] compared with T effector cells, approximately 2.4-fold in wild-type [WT] and 11-fold in TNF∆ARE/+ mice. Furthermore, GP-1a enhanced Treg suppressive function with a concomitant increase in IL-10 secretion. GP-1a attenuated murine ileitis, as demonstrated by improved histological scoring and decreased inflammatory cytokine expression. Lastly, CB2R is downregulated in both chronically inflamed TNF∆ARE/+ mice and in IBD patients.

CONCLUSIONS

In summary, the endocannabinoid system is induced in murine ileitis but is downregulated in chronic murine and human intestinal inflammation, and CB2R activation attenuates murine ileitis, establishing an anti-inflammatory role of the endocannabinoid system.

Cannabinoids for treating inflammatory bowel diseases: where are we and where do we go?

INTRODUCTION

Fifty years after the discovery of Δ9-tetrahydrocannabinol (THC) as the psychoactive component of Cannabis, we are assessing the possibility of translating this herb into clinical treatment of inflammatory bowel diseases (IBDs). Here, a discussion on the problems associated with a potential treatment is given. From first surveys and small clinical studies in patients with IBD we have learned that Cannabis is frequently used to alleviate diarrhea, abdominal pain, and loss of appetite. Single ingredients from Cannabis, such as THC and cannabidiol, commonly described as cannabinoids, are responsible for these effects. Synthetic cannabinoid receptor agonists are also termed cannabinoids, some of which, like dronabinol and nabilone, are already available with a narcotic prescription. Areas covered: Recent data on the effects of Cannabis/cannabinoids in experimental models of IBD and in clinical trials with IBD patients have been reviewed using a PubMed database search. A short background on the endocannabinoid system is also provided. Expert commentary: Cannabinoids could be helpful for certain symptoms of IBD, but there is still a lack of clinical studies to prove efficacy, tolerability and safety of cannabinoid-based medication for IBD patients, leaving medical professionals without evidence and guidelines.