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Klein, T.W. Cannabinoid-based drugs as anti-inflammatory therapeutics. Nat. Rev. Immunol. 5, 400-411
Abstract
In the nineteenth century, marijuana was prescribed by physicians for maladies ranging from eating disorders to rabies. However, as newer, more effective drugs were discovered and as the potential for abuse of marijuana was recognized, its use as a therapeutic became restricted, and only recently has its therapeutic potential been re-evaluated. Recent studies in animal models and in humans have produced promising results for the treatment of various disorders - such as obesity, cancer, and spasticity and tremor due to neuropathology - with drugs based on marijuana-derived cannabinoids. Moreover, as I discuss here, a wealth of information also indicates that these drugs have immunosuppressive and anti-inflammatory properties; therefore, on the basis of this mode of action, the therapeutic usefulness of these drugs in chronic inflammatory diseases is now being reassessed.
... This upward pattern in lymphocyte counts, combined with the observation that IgG levels remained comparable across all groups (Table 2), raises the possibility that CBD supplementation may have influenced T-cell populations more than B-cell-mediated antibody production. This finding aligns with previous research showing that cannabinoids modulate immune function primarily through T-cell regulation and cytokine signaling, which may help maintain immune resilience under chronic stress conditions [31,32]. Additionally, these effects may be indirectly mediated by the stress-attenuating properties of CBD, which could help preserve lymphocyte homeostasis by mitigating cortisol-induced immunosuppression [33]. ...
... The accompanying PCA loadings plot (Figure 4) revealed that samples from the CON group were more closely associated with neutrophil counts, post-stress cortisol, and ∆Cortisol, indicating a heightened acute stress response accompanied by a stress leukogram [39,40]. In contrast, samples from the CBD oil group aligned more closely with albumin, ALP, and WBC counts, while the CBD gel group was associated with BUN, IgG, and lymphocytes, suggesting potential differences in immune modulation and renal-related responses between formulations [6,31,32,41,42]. The successful classification by Support Vector Machine (SVM) further confirms that these multivariate shifts were treatment-dependent, highlighting the value of combining multivariate analysis with machine learning classifiers to capture the comprehensive physiological footprint of CBD supplementation in stressed dogs. ...
Cannabidiol (CBD) has gained popularity in veterinary medicine for its potential to alleviate stress, pain, and inflammation in dogs. However, its oral administration is limited by hydrophobicity, variable absorption, and extensive first-pass metabolism, which requires optimized delivery methods to enhance efficacy. This study investigated the effects of daily oral supplementation of CBD oil and CBD gel (each at 4 mg/kg), compared to a placebo, over 14 days in shelter dogs subjected to solitary confinement-induced stress. Both CBD formulations appeared safe under the study conditions, with no adverse effects on hematological and biochemical parameters. Post-stress cortisol levels were significantly lower in CBD-treated groups compared to controls, with CBD-infused gel showing a pattern toward greater attenuation. Multivariate analysis revealed distinct blood profile shifts in CBD-treated dogs, with PCA loadings indicating associations between CBD supplementation and lymphocyte percentages and IgG levels. These findings support gel-based CBD as a promising strategy for stress modulation in dogs. Further studies should explore its pharmacokinetics and long-term immune effects to optimize veterinary applications.
... Cannabinoid receptors, particularly the CB2 receptor, are known for their immunomodulatory effects and have been investigated as potential therapeutic targets in various autoimmune and inflammatory diseases, including RA (Klein, 2005;Hua et al., 2020). Predominantly expressed on immune cells, CB2 plays a crucial role in modulating immune cell migration, cytokine production, and immune cell differentiation (Miller and Stella, 2008;Martinez-Aguilar et al., 2023). ...
... This mechanistic insight adds a new dimension to our understanding of how CB2 receptor activation impacts immune regulation beyond its known anti-inflammatory effects. While prior research has focused on the overall reduction of pro-inflammatory cytokines following CB2 activation, few studies have explored the specific intracellular signaling cascades that regulate T cell differentiation (Klein, 2005;Marcu et al., 2010). ...
Background
Adjuvant-induced arthritis (AIA) serves as a classic model for rheumatoid arthritis (RA), typified by inflammatory cell infiltration and joint damage. This study explores the therapeutic efficacy of HU-308, a CB2 receptor-specific agonist, on inflammation and immune balance in AIA.
Methods
AIA was induced in mice by CFA injection. AIA mice were treated with HU-308 or vehicle, and effects on paw swelling, spleen index, histopathology, and immune cell profiles were evaluated. Flow cytometry, in vitro differentiation assays, and Western blot analysis were performed to examine Th17 and Treg cells, as well as signaling pathways involved in their differentiation.
Results
HU-308 reduced paw swelling, lowered spleen index, and preserved joint integrity in AIA mice, mitigating inflammatory cell infiltration and bone erosion. Flow cytometry revealed that HU-308 restored the Th17/Treg imbalance in AIA, decreasing Th17 cell frequency and enhancing Treg cell infiltration. In vitro assays confirmed HU-308s role in promoting Treg differentiation and inhibiting Th17 polarization. Western blot analysis indicated that HU-308 modulated immune balance through the JAK/STAT5 and TGF-β/SMAD signaling pathways, increasing Foxp3 and TGF-β expression.
Conclusion
HU-308 demonstrates significant anti-inflammatory effects in AIA by restoring Th17/Treg balance and reducing joint damage. The findings indicate that HU-308 holds potential as an immunomodulatory agent for RA, providing valuable insights into CB2-mediated therapeutic strategies for autoimmune diseases.
... 18,19,21 CB2 agonists have been shown to reduce inflammation in several experimental models, including infectious diseases. [22][23][24][25][26][27][28][29] Our group demonstrated that treatment with the CB2 receptor agonist BCP modulated the acute inflammatory process induced by Mycobacterium bovis BCG-related pulmonary infection by inhibiting neutrophil migration, macrophage activation, and inflammatory mediator production. 30 GP1a is a synthetic selective CB2 agonist that has immunomodulatory effects. ...
... CB2 receptors are present in hematopoietic cells and predominantly mediate anti-inflammatory effects under some inflammatory conditions. 22,[24][25][26][27][28][29] Previously, we showed that the cannabinoid 2 receptor agonists GP1a (a synthetic CB2 receptor agonist) and β-caryophyllene (a sesquiterpene with cannabimimetic action) modulate the inflammatory reaction induced by M. bovis BCG. 30 Since a CB2 receptor agonist modulates the inflammatory response induced by Mycobacterium in vivo, we investigated the involvement of this receptor in murine macrophages stimulated by mycobacteria. Our findings are in agreement with those in the literature, which show that CB2 expression is increased in immune cells associated with pathological conditions, where it seems to have several immunosuppressive effects, including the inhibition of proinflammatory cytokine production. ...
Tuberculosis (TB) is one of the leading causes of death worldwide and a major public health problem. Immune evasion mechanisms and antibiotic resistance highlight the need to better understand this disease and explore alternative treatment approaches. Mycobacterial infection modulates the macrophage response and metabolism to persist and proliferate inside the cell. Cannabinoid receptor type 2 (CB2) is expressed mainly in leukocytes and modulates the course of inflammatory diseases. Therefore, our study aimed to evaluate the effects of the CB2-selective agonist GP1a on irradiated Mycobacterium bovis-BCG (iBCG)-induced J774A.1 macrophage activation. We observed increased expression of CB2 in macrophages after iBCG stimulation. The pretreatment with CB2-agonists, GP1a, JWH-133, and GW-833972A (10 µM), reduced iBCG-induced TNF-α and IL-6 release by these cells. Moreover, the CB2-antagonist AM630 (200 nM) treatment confirmed the activity of GP1a on CB2 by scale down its effect on cytokine production. GP1a pretreatment (10 µM) also inhibited the iBCG-induced production of inflammatory mediators as prostaglandin (PG)E2 and nitric oxide by macrophages. Additionally, GP1a pretreatment also reduced the transcription of proinflammatory genes (inos, il1b, and cox2) and genes related to lipid metabolism (dgat1, acat1, plin2, atgl, and cd36). Indeed, lipid droplet accumulation was reduced by GP1a treatment, which was partially blockade by AM630 pretreatment. Finally, GP1a pretreatment reduced the activation of the NF-κB signaling pathway. In conclusion, the activation of CB2 by GP1a modulated the macrophage response to iBCG by reducing inflammatory mediator levels and metabolic reprogramming.
... Additionally, cannabis use may alter the gut microbiome, indirectly affecting immune function through the gutimmune axis (44). Chronic cannabis use has been associated with decreased production of proinflammatory mediators and increased anti-inflammatory cytokines, potentially leading to an overall immunosuppressive effect (45). Furthermore, cannabis smoke contains similar harmful compounds to tobacco smoke, which may cause oxidative stress and DNA damage in immune cells (46). ...
... However, certain cannabinoids, such as CBD, have shown potential anti-inflammatory properties, suggesting a complex relationship between cannabis and immune function (47). The net effect of cannabis on immune function likely depends on factors such as dosage, frequency of use, and individual genetic variations in cannabinoid metabolism and receptor expression (43,45). ...
Introduction
Cannabinoids, both natural and synthetic, are a subject of scientific interest. Cannabis is widely used, and its impact on health and the immune system is being studied. The endocannabinoid system influences inflammation, including the Neutrophil-to-Lymphocyte Ratio (NLR), a potential diagnostic tool. Our study investigates the connection between cannabis use and NLR.
Methods
Our systematic review was registered in Prospero (#CRD42023463539). We searched six databases (PubMed, Scopus, Embase, PsycINFO, Web of Science, and CINAHL Complete) for records in English from inception to May 2024. We included observational studies that measured the Neutrophil-to-Lymphocyte Ratio (NLR) in cannabis users and control participants. We used the Newcastle–Ottawa Quality Assessment Scale to assess the quality of the included studies. We selected a random-effects model, and the statistical analysis was performed using Stata software version 17.
Results
Out of a total of 4,054 records, only five articles were selected for inclusion in the meta-analysis. All of these chosen studies utilized a retrospective design. Furthermore, it's worth noting that all of the studies included were of high quality. In five studies involving 3,359 cannabis users and 10,437 non-users, no significant difference in NLR was found (WMD: 0.12 [-0.16, 0.41], I2: 39.89%). Subgroup analysis on healthy and schizophrenia participants didn't show significant NLR differences (p=0.76). Secondary analysis revealed cannabis users had higher Platelet-to-Lymphocyte Ratio (PLR) (67.80 [44.54, 91.06]), neutrophil count (0.68 [0.25, 1.12]), white blood cell count (0.92 [0.43, 1.41]), monocyte count (0.11 [0.05, 0.16]), and Systemic Immune Inflammation Index (SII) (83.48 [5.92, 157.04]) compared to non-users
Conclusion
Our systematic review and meta-analysis reveal that cannabis use may affect NLR and hematologic parameters, suggesting a potential immune impact. Complex associations exist, requiring further research. Schizophrenia and pro-inflammatory factors are discussed, highlighting the need for ongoing investigation into cannabis-related immune changes and mental health.
Systematic review registration
https://www.crd.york.ac.uk/prospero/, identifier CRD42023463539.
... Cannabinoids have been shown to modulate the release of various digestive enzymes, potentially leading to increased enzyme levels [12]. The finding of significantly higher Amylase activity among male and female marijuana smokers compared to controls is consistent with the hypothesis that marijuana use can stimulate the pancreas, leading to increased secretion of digestive enzymes [14]. It was reported that chronic marijuana use may induce adaptive changes in the pancreas, resulting in altered enzyme secretion [14]. ...
... The finding of significantly higher Amylase activity among male and female marijuana smokers compared to controls is consistent with the hypothesis that marijuana use can stimulate the pancreas, leading to increased secretion of digestive enzymes [14]. It was reported that chronic marijuana use may induce adaptive changes in the pancreas, resulting in altered enzyme secretion [14]. Elevated amylase levels have also been observed in other studies involving substance use, suggesting a possible common pathway for enzyme elevation [15]. ...
Marijuana consumption is prevalent among young adults in Nigeria, and its effects on various physiological systems are of growing concern. This study investigates the impact of marijuana use on digestive enzymes, specifically serum amylase and lipase, to understand its potential implications on digestive health. This cross-sectional study was conducted in 120 participants comprising of 60 marijuana smokers and 60 non-smokers. Sociodemographic and lifestyle data were collected through structured questionnaires. Serum amylase and lipase activity levels were measured by spectrophotometric method and compared between the two groups. Statistical analysis was performed to assess differences and correlations. The study revealed that marijuana smokers had significantly higher serum amylase and lipase activities compared to non-smokers. Lipase activity correlated positively (r=0.425, p=0.019) with duration of marijuana use. Amylase activity was higher among males than females (r=-0.40, p=0.028). No significant correlation was found between the quantity of marijuana consumed and enzyme activities. Chronic marijuana consumption was associated with increased serum amylase and lipase activities, indicating potential alterations in pancreatic function. These findings suggest that marijuana use may have adverse effects on digestive health, warranting further investigation into the long-term implications. It is recommended that healthcare providers monitor digestive enzyme activities in marijuana users to detect early signs of pancreatic dysfunction.
... Cannabinoid receptors 1 and 2 (CB1R and CB2R) are major receptors that mediate the biological effects of phytocannabinoids, although other G protein-coupled receptors (GPCRs), such as GPR18, GPR55, and GPR119, may also play a role in mediating cannabinoid biology [18]. Growing evidence has demonstrated that cannabinoids can reduce the production of pro-inflammatory cytokines and inhibit tumor growth in humans and/or animal models [19,20]. However, the mechanism involved remains poorly understood. ...
... qRT-PCR was conducted using the Bio-Rad CFX96 Real-Time System, and the expression was standardized using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a control [18]. To analyse the data, the comparative Ct method was used [19], and all experiments were carried out in triplicate. The results indicate the fold induction of mRNA. ...
The incidence of chronic inflammatory disorders and autoimmune diseases is rapidly growing. To date, the COVID-19 pandemic caused by SARS-CoV-2 has killed over 6,209,000 people globally, while no drug has been proven effective for the disease. Screening natural anti-inflammatory compounds for clinical application has drawn much attention. In this study, we showed that high-CBD cannabis extracts #1, #5, #7, #169, and #317 suppressed the levels of expression of proinflammatory cyclooxygenase 2 (COX2) and increased the expression of the anti-inflammatory suppressor of cytokine signaling 3 (SOCS3) in human small intestinal epithelial cells (HSIEC) in TNFα/IFNγ-triggered inflammation. We revealed that these extracts, with the exception of extract #169, also profoundly attenuated induction of proinflammatory cytokines interleukin-6 (IL-6) and/or IL-8 proteins through miR-760-and miR-302c-3p-mediated silencing. The prevalent components in extracts #1 and #7 influenced the levels of IL-8 both individually as well as in combination with each other. However, the high-dose cannabis extracts displayed an inhibitory effect in the growth of HSIEC cells. These results show that our high-CBD cannabis extracts decrease the levels of proinflammatory molecules COX2, IL-6, and IL-8 via transcriptional suppression or miRNA-mediated silencing, highlighting their potential against COVID-19-associated cytokine storm syndrome.
... Indeed, cannabinoid receptors (CB1 and CB2) and their ligands are involved in the mechanisms of neuropathic pain [4]. At present, several studies strongly support the anti-inflammatory and immunomodulating properties of cannabinoids in different types of diseases such as inflammatory bowel disease, arthritis, vascular inflammation [5], and multiple sclerosis [6]. However, these studies were mainly conducted on animal models, while research in humans is still limited and fragmentary [6][7][8], as elegantly documented in a recent systematic review [9], despite the widespread use of cannabis and CBD-based products. ...
... The clinical use of drugs containing cannabis derivatives for the treatment of different CNS diseases is supported by several studies [2]; CBD, and cannabinoids in general, could exert analgesic and anti-inflammatory effects in several pain-related diseases [2][3][4]. The ability of CBD to trigger positive effects in several diseases was widely investigated and described [1,5,6,10,30], but, recently, it was also shown that cannabis smoking is able to induce changes in the expression of DNA-methyltransferase in lymphocytes, even if these results are not clearly related to specific clinical relevance [31]. ...
Cannabidiol (CBD), the main non-psychoactive component of Cannabis sativa L., is widely used in therapy for the treatment of different diseases and as an adjuvant drug. Our aim was to assess the effects of CBD on proinflammatory cytokine production and cell proliferation in human peripheral blood mononuclear cells (PBMCs) and on CD4+ T lymphocyte differentiation, and, furthermore, to test CBD’s ability to affect the functional properties of regulatory T cells (Treg). Experiments were performed on isolated PBMCs and purified CD4+ T lymphocytes obtained from the buffy coats of healthy subjects. Cytokines produced by CD4+ T cells were evaluated by flow cytometry and intracellular cytokine staining techniques. PBMC cytokine production was measured by an ELISA assay. Real-time PCR was used to assess the mRNA expression of cytokines and the key transcription factors (TFs) of CD4+ T cells. Finally, the proliferation of PBMC and CD4+ T effector cells (Teff), alone and in the presence of Treg, was assessed by flow cytometry. Results showed that CBD affects both the frequency of IL-4-producing CD4+ and of IFN-γ/IL-17-producing cells and dramatically decreases the mRNA levels of all TFs. Stimuli-induced cytokine mRNA expression was decreased while protein production was unaffected. CBD was unable to affect the ability of Treg to prevent Teff cell proliferation while it slightly increased PBMC proliferation. In conclusion, CBD may inhibit the expression of proinflammatory cytokines; however, the effect of CBD on cell proliferation suggests that this cannabinoid exerts a complex activity on human PBMCs and CD4+ T cells which deserves further investigation.
... Cannabinoid receptors 1 and 2 (CB1R and CB2R) are major receptors that mediate the biological effects of phytocannabinoids, although other G protein-coupled receptors (GPCRs), such as GPR18, GPR55, and GPR119, may also play a role in mediating cannabinoid biology [18]. Growing evidence has demonstrated that cannabinoids can reduce the production of pro-inflammatory cytokines and inhibit tumor growth in humans and/or animal models [19,20]. However, the mechanism involved remains poorly understood. ...
... qRT-PCR was conducted using the Bio-Rad CFX96 Real-Time System, and the expression was standardized using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a control [18]. To analyse the data, the comparative Ct method was used [19], and all experiments were carried out in triplicate. The results indicate the fold induction of mRNA. ...
The incidence of chronic inflammatory disorders and autoimmune diseases is rapidly growing. To date, the COVID-19 pandemic caused by SARS-CoV-2 has killed over 6,209,000 people globally, while no drug has been proven effective for the disease. Screening natural anti-inflammatory compounds for clinical application has drawn much attention. In this study, we showed that high-CBD cannabis extracts #1, #5, #7, #169, and #317 suppressed the levels of expression of proinflammatory cyclooxygenase 2 (COX2) and increased the expression of the anti-inflammatory suppressor of cytokine signaling 3 (SOCS3) in human small intestinal epithelial cells (HSIEC) in TNFα/IFNγ-triggered inflammation. We revealed that these extracts, with the exception of extract #169, also profoundly attenuated induction of proinflammatory cytokines interleukin-6 (IL-6) and/or IL-8 proteins through miR-760- and miR-302c-3p-mediated silencing. The prevalent components in extracts #1 and #7 influenced the levels of IL-8 both individually as well as in combination with each other. However, the high-dose cannabis extracts displayed an inhibitory effect in the growth of HSIEC cells. These results show that our high-CBD cannabis extracts decrease the levels of proinflammatory molecules COX2, IL-6, and IL-8 via transcriptional suppression or miRNA-mediated silencing, highlighting their potential against COVID-19-associated cytokine storm syndrome.
... The endocannabinoid system (ECS) predates the emergence of Cannabis sativa L., underscoring its importance in the physiological processes of various animal groups, including basal taxa (McPartland et al. 2006;Elphick 2012). ECS also plays a role in modulating inflammatory and analgesic processes (Lu et al. 2019;Ruhl et al. 2021;Kopustinskiene et al. 2022), as immune cells, such as macrophages and lymphocytes, release endocannabinoids and increase ECS receptor expression during inflammation (Klein 2005;Hryhorowicz et al. 2021). Endocannabinoids, such as 2-arachidonoylglycerol (2-AG) and anandamide (AEA), are synthesized on demand and rapidly degraded by the enzymes monoacylglycerol lipase and fatty acid amide hydrolase, respectively (Mechoulam et al. 1998). ...
Bryophytes, particularly liverworts, are known for producing bioactive compounds with therapeutic potential. In this review, we highlight the anti-inflammatory activities of liverworts, focusing on their ability to synthesize cannabinoids, compounds previously identified in only two genera. We explore the pharmacological parallels between liverwort cannabinoids and those from Cannabis sativa, emphasizing molecular similarities and interactions with the endocannabinoid system. Despite the promising nature of these compounds, there is a marked scarcity of studies exploring the pharmacological applications of liverwort-derived cannabinoids. This gap in research underscores the need for further investigation into their therapeutic potential. Additionally, we propose that cannabinoids or similar compounds may be more widespread in liverwort taxa than currently recognized, hypothesizing that other orders could also harbor these bioactive molecules. The potential discovery of new cannabinoids in liverworts could offer novel avenues for pharmacological exploitation. We conclude by calling for expanded chemical analyses to uncover more liverwort species with medicinally relevant compounds, which may reveal broader anti-inflammatory applications and therapeutic benefits.
... Thus, they are relevant to deciphering the effect of two potent synthetic cannabinoids, WIN 55,212-2, a non-selective cannabinoid receptor agonist, and HU-210, a highly potent classical cannabinoid, in cannabinoid signaling. The scientific literature strongly supports a relevant role for endocannabinoids in modulating the central inflammatory response both in neuronal and glial populations [24,25]. Our results show that both WIN 55,212-2 and HU-210 shared mechanisms of immune modulation during repeated administration and exerted immunosuppression during their withdrawal in the PFC and hippocampus. ...
Synthetic cannabinoid use raises concerns about its neuroinflammatory effects, including molecular adaptations of the endocannabinoid system (ECS) in the brain. This study investigates the pharmacological effects of 14-day repeated intraperitoneal administration, as well as 14-day administration followed by a 7-day withdrawal period of two synthetic cannabinoids: WIN55,212-2 and HU-210. The study assessed gene expression and protein markers related to the ECS, gliosis, and inflammation in two brain regions critical for cognitive processes and memory—key components of addiction pathways—the prefrontal cortex (PFC) and the hippocampus of rats. Our findings showed that repeated WIN55,212-2 administration induced adaptations in the ECS and reduced IBA1, a glial protein marker, along with inflammatory responses likely mediated through CB2 activity. Notably, regional differences emerged in the hippocampus, where repeated administration of WIN55,212-2 and HU-210 increased IBA1 and inflammatory markers, effects unrelated to CB2 activity. Withdrawal from WIN55,212-2 in the PFC, as well as from both compounds in the hippocampus, decreased IBA1 levels. This was associated with altered protein expression of cannabinoid-synthesizing and degrading enzymes, favoring acylethanolamide synthesis. These findings highlight region-specific effects of synthetic cannabinoids on cannabinoid signaling, gliosis, and inflammation. Further research is needed to elucidate the long-term neurobiological consequences of synthetic cannabinoid use and withdrawal.
... Several studies confirm the immune role of CB2R; the activation of this receptor by cannabinoids can, in fact, either suppress or enhance the production of pro-inflammatory agents, depending on the nature of the pro-inflammatory stimulus and the specific type of cannabinoid used [19]. The hepatic expression of these receptors is altered in different pathological situations, such as NAFLD [20], hepatic fibrosis [21], or hepatocellular carcinoma [22]. ...
The endocannabinoid system (ECS), composed of receptors, endocannabinoids, and enzymes that regulate biosynthesis and degradation, plays a fundamental role in the physiology and pathology of the gastrointestinal tract, particularly in the small and large intestine and liver. Specifically, cannabinoid receptor type 1 (CB1R) and cannabinoid receptor type 2 (CB2R), located principally in the nervous system and immune cells, orchestrate processes such as intestinal motility, intestinal and hepatic inflammation, and energy metabolism, respectively. The main endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), influence appetite, body weight regulation, and inflammatory states and thus have implications in obesity, non-alcoholic fatty liver disease (NAFLD) and irritable bowel syndrome (IBS). Recent studies have highlighted the therapeutic potential of targeting the ECS to modulate gastrointestinal and metabolic diseases. In particular, peripheral CB1R antagonists and CB2R agonists have shown efficacy in treating intestinal inflammation, reducing hepatic steatosis, and controlling IBS symptoms. Moreover, the ECS is emerging as a potential target for the treatment of colorectal cancer, acting on cell proliferation and apoptosis. This review highlights the opportunity to exploit the endocannabinoid system in the search for innovative therapeutic strategies, emphasizing the importance of a targeted approach to optimize treatment efficacy and minimize side effects.
... Cd toxicity typically triggers inflammation through the activation of pro-inflammatory cytokines such as TNF-α, IL-1β and IL-6, mainly via the NF-κB signalling pathway. CBD suppresses the expression of these cytokines by inhibiting NF-κB activation and TLR signalling, which play crucial roles in macrophage activation and inflammatory responses [47,48]. This modulation reduces systemic inflammation and contributes to tissue protection. ...
Current chelation treatments used for cadmium poisoning may cause some serious side effects. Thus, safer novel treatments could be promising for clinical use. This study evaluated the effects of cannabidiol on Cd toxicity. Four groups of 10 mice were formed: Groups I and III were cadmium‐free, while groups II and IV received 50 mg/L cadmium in drinking water. Groups III and IV received daily cannabidiol (25 mg/kg) via intragastric gavage. After 30 days, the animals were killed, and blood and tissue samples were collected. Oxidative stress and inflammation markers, including glutathione, catalase, myeloperoxidase, TNF‐α, IL‐1β and IL‐6, were analysed using ELISA. Additionally, histological evaluations of the liver, kidney and testis were performed. Cadmium exposure reduced glutathione and catalase levels in the blood, liver, kidney and testis, while increasing myeloperoxidase. Cannabidiol mitigated these effects on oxidative stress markers. Cannabidiol also reduced the increase in proinflammatory cytokines. Histopathological analysis revealed reduced liver and kidney damage in cannabidiol‐treated groups compared to cadmium‐only groups. In addition, histopathological evaluation showed CBD had no protective effect on the testicular tissue against Cd toxicity. Our results indicate that cannabidiol protects against some toxic effects of cadmium. If confirmed by future studies, cannabidiol may be proposed as a novel treatment for cadmium toxicity.
... Therefore, these data indicate an increase in pro-inflammatory cytokine production after LPS stimulation. Certain evidence suggests that LPS could modulate cannabinoid receptor expression in an inconsistent manner, both up-regulating and down-regulating receptor expression [33]. However, several factors with complex mechanisms are involved in cannabinoid receptor expression, which are not yet clearly elucidated. ...
Cannabidiol, the primary non-psychoactive phytocannabinoid found in cannabis, has generated significant research interest due to its potential for biological effects, such as anti-inflammatory, analgesic, immunomodulatory, and anticonvulsant properties. Several studies have demonstrated the potential of CBD to alter inflammatory cytokines; however, data on CBD’s effects on cell viability and pro-inflammatory cytokines in target animals, such as dogs, are limited. Therefore, in this study, we investigated the effects of CBD on the cell viability and modulation of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), in canine PBMCs stimulated with LPS. To evaluate the effect of CBD on neuroinflammation in epilepsy pathology, an independent study of five refractory epileptic dogs co-treated with CBD for 30 days was conducted. The current findings revealed that CBD concentrations of 16 µg/mL had a statistically significant effect on the viability of canine PBMCs with a calculated IC50 of 15.54 µg/mL. The effect of CBD on inflammatory cytokines in LPS-stimulated PBMCs tended to be dose-dependent, with CBD concentrations of 5–30 μg/mL resulting in decreased production of the tested pro-inflammatory cytokines. Considering the effect of CBD on cytokine production by PBMCs from epileptic dogs, CBD has the potential to modulate immune responses and provide benefits when used in combination with antiepileptic drugs. The findings provided evidence of CBD cytotoxicity and its effect on the alteration of pro-inflammatory cytokines in canine PBMCs.
... The possibility that agonists of cannabinoid receptors may favorably affect AD after systemic administration is also suggested by other data, e.g., the use of hempseed oil in the form of nutritional supplements, lessening skin dryness and pruritus (Callaway et al. 2005). We assume that the favorable clinical effect of the skin lesions is due to the decreased levels of pro-inflammatory mediators-TNF, IL-1 β, IL-6, IL-8, and IL-12 (Klein 2005) or others. Our results showed that the indicated beneficial effects were not observed in animals pretreated with a CB1 receptor antagonist, where the total score approached that of the positive controls. ...
Atopic dermatitis (AD) is a chronic inflammatory skin condition of significant health and social importance, which justifies the search for new means of treatment. Since the endogenous cannabinoid system appears to be involved in the pathogenesis of AD, the proposed article summarizes the clinical impact on skin inflammation in a rat model of 1-chloro-2,4-dinitrobenzene-induced atopic dermatitis-like condition after exogenous systemic administration of the cannabinoid receptor type 1 (CB1r) agonist anandamide, as well as after local treatment with a newly synthesized pyrrole moiety containing bioconjugate of FELL tetrapeptide with CB1r-dependent analgesic activity. The changes in skin lesions and ear thickness were estimated along with the CB1r expression immunohistochemically determined on skin punch biopsies. The results showed attenuation of skin lesions by anandamide and lack of positive effect after introduction of CB1r antagonist, accompanied by a change in CB1r expression, suggesting the involvement of the cannabinoid system in the defensive functions of the skin. The topically applied newly synthesized bioconjugate also favorably affected skin manifestations of inflammation, but without a change in CB1r expression, suggesting the involvement of other mechanisms in the reported effects.
... 14 Regarding the anti-inflammatory potential, animal studies have shown a decrease in pro-inflammatory molecules, such as tumor necrosis factor and interleukins (IL-8 and IL-6). 15 Regarding healing, it is likely that its complex process is influenced by phytocannabinoids, as they have a positive effect on the differentiation and proliferation of keratinocytes, on the action of fibroblasts, and on the control of inflammatory processes in general. 16 Studies have also shown that the use of Cannabis sativa extracts containing all phytocannabinoids has been superior to the use of isolated phytocannabinoids in several diseases. ...
Epidermolysis Bullosa (EB) is characterized by epithelial fragility with blistering and the presence of pain and chronic pruritus. Studies demonstrate the potential of cannabinoids in the treatment of dermatological disorders, presenting anti-inflammatory action, pruritus control, and analgesic effect. In addition, two case series of patients with EB demonstrated positive results with both topical and systemic use of cannabinoids. OBJECTIVES: to evaluate the therapeutic efficacy of the topical use of a tetrahydrocannabinol-rich (THC) Cannabis sativa ointment in a patient with EB. METHODS: this is the case report of a 4-year-old female patient with recessive dystrophic EB. Two similar chronic wounds were chosen, in which one was treated with the placebo and the other treated with the THC-rich Cannabis ointment. The influence on healing and on pain and pruritus symptoms was evaluated for 28 days. After this period, the blinding status was removed and, due to the results achieved, it was decided to continue the application of the THC-rich Cannabis ointment in both lesions. RESULTS: The THC-rich Cannabis sativa ointment improved the wound healing process and the control of pain and pruritus when compared to placebo. CONCLUSIONS: The use of the THC-rich Cannabis ointment was effective in the healing process of the chronic wounds presented by the patient. A positive effect was also observed in relation to pain, pruritus, and improvement in the overall quality of life.
... Since CNR1 is widely expressed in the central nervous system where it regulates pain perception, mood, and other neurological processes, the dysregulation of CNR1 signaling may impact the sensory innervation and pain responses associated with the EM (Rodríguez de Fonseca et al., 2005). Additionally, CNR1 has been shown to modulate immune cell function, including the production of pro-inflammatory cytokines Klein, 2005. The loss of CNR1 signaling in immune cells infiltrating the endometriotic lesions likely contributes to the altered immune profiles observed in our study. ...
Endometriosis (EM), characterized by the presence of endometrial-like tissue outside the uterus, is the leading cause of chronic pelvic pain and infertility in females of reproductive age. Despite its high prevalence, the molecular mechanisms underlying EM pathogenesis remain poorly understood. The endocannabinoid system (ECS) is known to influence several cardinal features of this complex disease including pain, vascularization, and overall lesion survival, but the exact mechanisms are not known. Utilizing CNR1 knockout (k/o), CNR2 k/o, and wild-type (WT) mouse models of EM, we reveal contributions of ECS and these receptors in disease initiation, progression, and immune modulation. Particularly, we identified EM-specific T cell dysfunction in the CNR2 k/o mouse model of EM. We also demonstrate the impact of decidualization-induced changes on ECS components, and the unique disease-associated transcriptional landscape of ECS components in EM. Imaging mass cytometry (IMC) analysis revealed distinct features of the microenvironment between CNR1, CNR2, and WT genotypes in the presence or absence of decidualization. This study, for the first time, provides an in-depth analysis of the involvement of the ECS in EM pathogenesis and lays the foundation for the development of novel therapeutic interventions to alleviate the burden of this debilitating condition.
... The seeds lowered TNF-α gene expression and IL-6 gene secretion. Moreover, cannabinoids demonstrated considerable anti-inflammatory action by inhibiting the synthesis of pro-inflammatory cytokines and chemokines and may be useful in treating inflammation-related illnesses [58,59]. Any procedure whose main goal is to lessen pain is referred to as an analgesic action. ...
Cannabis sativa, otherwise known as hemp, is discussed to highlight the various problems and prospects associated with its use as an herbal ingredient. The chemical composition of hemp, with classification based on cannabinoid contents, its biological activities, current global scenarios and legality issues, economic importance, and future prospects, are discussed.
... Consistent with the understanding that CBD possesses anti-inflammatory properties, most previous studies show that CBD has immunomodulatory properties that reduce neutrophil migration and mitigate excessive inflammation in mouse models. Accordingly, mice and human neutrophils have been shown to express both CBR1 and CBR2 receptors 34,35 . Subsequently, CBD was shown to inhibit cytokine production in animal and human cells of the innate and adaptive immune responses function to understand its full physiological impact on a particular cell. ...
Cannabidiol (CBD) is widely used as a natural alternative supplementary treatment for side effects and treatment symptoms relief in many diseases. Although the benefits or risks of using CBD are still largely unknown, there is a constant growth in its consumption. We show that CBD, via cannabinoid receptor 2, promotes N2-like neutrophil-polarization. Human primary neutrophils exposed to CBD gain N2-polarization features, exhibit reduced oxidative burst bacterial killing, and produce cytokine and chemokine arrays similar to N2-polarized cells. CBD-treated neutrophils also rapidly display a landscape of surface markers compatible with the described setup known for N2-polarized cells and can promote cancer cell proliferation, migration, and angiogenesis. Furthermore, CBD-stimulated neutrophils suppress T-cell proliferation, and their condition medium elevates the expression of PD-L1 in cancer cells, suggesting that this signaling pathway may be involved in regulating T-cell anti-tumor immunity. Our results underscore CBD's therapeutic potential and emphasize the need to understand its signaling.
... 28 It exhibits a broad spectrum of physiological effects, such as anti-inflammatory, analgesic, anti-convulsive, and immunosuppressive activities. 29,30 However, its clinical application is restricted due to the risk of abuse and the presence of psychomimetic side effects. Following the discovery of cannabinoid receptors and the ECS, considerable efforts have focused on unraveling the physiological roles of these receptors and exploring the potential for developing cannabinoid agonists and antagonists for therapeutic purposes. ...
Development of type 2 diabetes mellitus (T2DM) is associated with low-grade chronic type 2 inflammation and disturbance of glucose homeostasis. Group 2 innate lymphoid cells (ILC2s) play a critical role in maintaining adipose homeostasis via the production of type 2 cytokines. Here, we demonstrate that CB2, a G-protein-coupled receptor (GPCR) and member of the endocannabinoid system, is expressed on both visceral adipose tissue (VAT)-derived murine and human ILC2s. Moreover, we utilize a combination of ex vivo and in vivo approaches to explore the functional and therapeutic impacts of CB2 engagement on VAT ILC2s in a T2DM model. Our results show that CB2 stimulation of ILC2s protects against insulin-resistance onset, ameliorates glucose tolerance, and reverses established insulin resistance. Our mechanistic studies reveal that the therapeutic effects of CB2 are mediated through activation of the AKT, ERK1/2, and CREB pathways on ILC2s. The results reveal that the CB2 agonist can serve as a candidate for the prevention and treatment of T2DM.
... No entanto, deve-se reconhecer que as respostas a esses agentes ainda são parciais, com recorrência de tumores durante o acompanhamento. De fato, devido à heterogeneidade genética dos tumores, uma resposta completa em pacientes com neoplasia pulmonar é rara(Klein, ,2005)O desafio de prosseguir com o tratamento a tais pacientes está sendo considerada a possibilidade de utilização de fármacos alternativos, que, sozinhas ou em combinação, podem levar a uma resposta e sobrevivência aprimoradas em pacientes. O CBD é um possível exemplo, pois poderia ser uma droga potencial no tratamento do câncer. ...
O canabidiol (CBD) é a principal substância não psicoativa encontrada nas glândulas tricomas da planta de cânhamo, também conhecida como ‘canabinóides’ (CBs). Na investigação farmacológica, canabidiol está sendo amplamente estudado, devido às suas propriedades terapêuticas como agonista dos receptores canabinóides. Essas propriedades do CBD abrangem uma variedade de benefícios, como alívio da dor, relaxamento muscular, supressão do sistema imunológico, redução da inflamação e alergias, aumento do apetite, prevenção de náuseas, diminuição da pressão ocular, ampliação dos brônquios, proteção do sistema nervoso e possíveis efeitos contra o câncer. Apesar do conhecimento extenso sobre as propriedades terapêuticas dos CBs, sua aplicação clínica permanece limitada. No entanto, atualmente CBD, que compõe até 40% do extrato de Cannabis é considerado uma das opções mais promissoras na aplicação terapêutica devido à ausência de efeitos perceptuais e psicoativos. O CBD também é considerado um importante candidato para a ampliação de novas substâncias canabinomiméticas devido à sua excelente tolerabilidade em seres humanos.
... Tetrahydro cannabinoid (THC) cannabinoid receptor agonists, are reported to reduce chronic pain in diabetic animals [16,17]. Moreover, ∆-THC produce analgesic effect by inter acting with endogenous opioids because, naloxone, an opioid receptor antagonist, abolish the analgesic effect of cannabinoid [18].Furthermore, Cannabinoids and opioids produce synergistic effect and provide adequate pain reliefs in PDN [19]. In addition, recently, neurosteroids are reported to reduce neuropathic pain [20,21]. ...
... However, the findings regarding the comparative effects of CBD and THC on pain relief have been inconsistent [37]. While some studies suggest that THC may be more effective than CBD in alleviating inflammatory pain, others indicate synergistic effects when CBD is combined with morphine [38]. ...
Phytocannabinoids, a diverse group of naturally occurring compounds extracted from the Cannabis plant, have attracted interest due to their potential pharmacological effects and medicinal uses. This comprehensive review presents the intricate pharmacological profiles of phytocannabinoids while exploring the diverse impacts these substances have on biological systems. From the more than one hundred cannabinoids which were identified in the Cannabis plant so far, cannabidiol (CBD) and tetrahydrocannabinol (THC) are two of the most extensively studied phytocannabinoids. CBD is a non-psychoactive compound, which exhibits potential anti-inflammatory, neuroprotective, and anxiolytic properties, making it a promising candidate for a wide array of medical conditions. THC, known for its psychoactive effects, possesses analgesic and antiemetic properties, contributing to its therapeutic potential. In addition to THC and CBD, a wide range of additional phytocannabinoids have shown intriguing pharmacological effects, including cannabichromene (CBC), cannabigerol (CBG), and cannabinol (CBN). The endocannabinoid system, made up of the enzymes involved in the production and breakdown of endocannabinoids, cannabinoid receptors (CB1 and CB2), and endogenous ligands (endocannabinoids), is essential for preserving homeostasis in several physiological processes. Beyond their effects on the endocannabinoid system, phytocannabinoids are studied for their ability to modify ion channels, neurotransmitter receptors, and anti-oxidative pathways. The complex interaction between phytocannabinoids and biological systems offers hope for novel treatment approaches and lays the groundwork for further developments in the field of cannabinoid-based medicine. This review summarizes the state of the field, points out information gaps, and emphasizes the need for more studies to fully realize the therapeutic potential of phytocannabinoids.
... There are over 500 potentially active compounds within cannabis, with the two best studied compounds being cannabidiol (CBD) and ∆ 9 -tetrahydrocannibinol (THC) [13,14]. It is postulated that phyto-cannabinoids modulate inflammation via the endocannabinoid system, with CBD and THC interacting with endocannabinoid receptors in the brain, enteric nervous system, gastrointestinal epithelial cells, and both macrophages and plasma cells [15][16][17]. ...
We aimed to elucidate the effect of Medical Cannabis (MC) on appetite and nutritional status among patients with inflammatory bowel disease (IBD). A case series of patients with IBD were initiating treatment with MC for disease-related symptoms, at the IBD clinic of a tertiary referral medical center. Patients’ demographics, anthropometrics, medical history and treatment and MC use were systematically recorded. An appetite and food frequency questionnaire (SNAQ and FFQ) were filled before, and at 3 and 6 months of treatment. Patients with IBD initiating MC were enrolled (n = 149, age 39.0 ± 14.1 years, 42.3% female), and 33.6% (n = 50) were treated for improvement of nutritional status. A modest increase in appetite after 3 months was detected among all patients enrolled (Pv = 0.08), but there were no significant differences in energy or macronutrient intake, and in patients’ body mass index (BMI). A significant appetite improvement after 3 months was detected among 34.0% (n = 17) of patients, but this was not associated with increased caloric intake or BMI at 3 or 6 months. Among patients without increased appetite after 3 months of MC therapy, BMI decreased at 6 months (24.1 ± 3.7 vs. 23.4 ± 3.6, Pv = 0.010). MC may be a potential strategy to improve appetite among some patients with IBD, but not caloric intake or BMI.
... 6 Similarly, the key chemical components of cannabis, namely tetrahydrocannabinol (THC) and cannabidiol (CBD), act on the cannabinoid 1 and 2 receptors to produce antinociceptive effects. [6][7][8] Historically, cannabis-based products (CBPs) were considered effective for pain relief, but their use was limited because of a lack of clinical evidence. 9,10 However, evidence documenting modest improvement with use for certain conditions, such as chronic pain and rheumatoid arthritis, has rapidly increased, [11][12][13] but clinical evidence regarding its analgesic efficacy for various pain conditions remains conflicting. ...
Cannabinoids have recently gained a renewed interest due to their potential applicability to various medical conditions, specifically the management of chronic pain conditions. Unlike many other medications, medical cannabis is not associated with serious adverse events, and no overdose deaths have been reported. However, both safety and efficacy data for medical cannabis treatment of chronic, nonmalignant pain conditions are lacking. Therefore, representatives from the American Society of Pain and Neuroscience summarize the evidence, according to level and grade, for medical cannabis treatment of several different pain conditions. Treatment of cancer-related pain has prospective evidentiary support for the use of medical cannabis. Although 3 large and well-designed randomized controlled trials investigated cannabis treatment of cancer-related pain, the evidence yielded only a grade D recommendation. Neuropathic pain has been investigated in prospective studies, but a lack of high-quality evidence renders cannabis treatment for this indication a grade C recommendation. Both safety and efficacy data are lacking for use of medical cannabis to treat chronic nonmalignant pain conditions.
... Immune cells express both CB1 and CB2 receptors, with a predominance for CB2 [29,44]. The expression of these receptors depends on the immune cell's stimulation and activation state, with higher expression found in descending order on B and T lymphocytes, NK cells, monocytes, neutrophils, CD8 leukocytes, and CD4 leukocytes [45]. ...
Introduction: Cannabinoids are a well-documented treatment modality for various immune and inflammatory diseases, including asthma, chronic obstructive pulmonary disease, Crohn’s disease, arthritis, multiple sclerosis, and a range of neurodegenerative conditions. However, limited information is available regarding the therapeutic potential of cannabinoids in treating periodontal disease. Objective: The objective of this study is to analyze the current evidence on the antibacterial and immunomodulatory effects of cannabis and its role in the healing and regeneration processes within periodontal tissues. Results: This review discusses the potential role of cannabinoids in restoring periodontal tissue homeostasis. Conclusions: The examination of the endocannabinoid system and the physiological effects of cannabinoids in the periodontium suggests that they possess immunomodulatory and antibacterial properties, which could potentially promote proper tissue healing and regeneration.
... Trials have shown that the different compounds have a potential positive effect on a range of diseases such as multiple sclerosis, 8 cancer, 9 chronic pain, 8,10 and inflammation. 11 Furthermore, they possess the ability to reduce the side effects of traditional treatments such as chemotherapy because they can reduce pain, suppress nausea, and promote appetite. 10,12,13 The antimicrobial agents derived from C. sativa act as antibiotic adjuvants, and some possess antibiotic activity themselves and have been studied for their antiseptic properties since the 1950s. ...
Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen that causes a wide range of infections. Its resistance to β-lactam antibiotics complicates treatment due to the limited number of antibiotics with activity against MRSA. To investigate development of alternative therapeutics, the mechanisms that mediate antibiotic resistance in MRSA need to be fully understood. In this study, MRSA cells were subjected to antibiotic stress from methicillin in combination with three cannabinoid compounds and analyzed using proteomics to assess the changes in physiology. Subjecting MRSA to nonlethal levels of methicillin resulted in an increased production of penicillin-binding protein 2 (PBP2). Exposure to cannabinoids showed antibiotic activity against MRSA, and differential proteomics revealed reduced levels of proteins involved in the energy production as well as PBP2 when used in combination with methicillin.
The Endocannabinoid System (ECS) plays a critical role in maintaining physiological homeostasis, influencing a range of processes such as neuroprotection, inflammation, energy metabolism, and immune responses. Comprising cannabinoid receptors (CB1 and CB2), endogenous ligands (endocannabinoids), and the enzymes responsible for their synthesis and degradation, the ECS has attracted increasing attention in cancer research. Cannabinoid receptor activation has been associated with the regulation of cancer-related processes, including cell proliferation, apoptosis, and angiogenesis, suggesting that the ECS may have a role in tumor progression and cancer treatment. Preclinical studies have shown that cannabinoids, through their interaction with CB1 and CB2 receptors, can inhibit tumor cell growth, induce programmed cell death, and suppress the formation of new blood vessels in various cancer models. Despite these encouraging findings, the clinical translation of ECS-targeted therapies remains in its early stages. The complexity of tumor heterogeneity, the variability in patient responses, and the challenges associated with the pharmacokinetics of cannabinoids are significant obstacles to the broader application of these findings in clinical settings. This review provides an overview of the current understanding of the ECS’s involvement in cancer biology, focusing on key mechanisms by which it may influence carcinogenesis. Additionally, we discuss the therapeutic potential of targeting the ECS in cancer treatment, while highlighting the limitations and uncertainties that need to be addressed through ongoing research.
Cannabinoids are a class of natural products originally isolated from the plant Cannabis sativa , and the demand for cannabinoid-derived compounds has continuously grown. Recombinant microorganisms harboring metabolic pathways for synthesizing...
Unregulated, systemic inflammation negatively impacts health and production in dairy cows. Soluble mediators and platelets have been studied for their expansive role in mediating inflammation. Our objectives were to compare the plasma oxylipin and endocannabinoid profiles, and the platelet and plasma proteomic profiles of healthy cows to cows experiencing elevated systemic inflammation as indicated by plasma haptoglobin (Hp) concentrations. Postpartum cows at 3 DIM with plasma Hp concentrations 0.50 g/L and no clinical disease were enrolled into the high-inflammation group (n = 8). Cows with plasma Hp concentrations 0.1 g/L and no clinical disease were enrolled into the low-inflammation group (n = 8). Targeted lipidomic analysis revealed differences in the plasma oxylipin and endocannabinoid profile between high- and low-inflammation cows. Cows in the high-inflammation group had increased plasma concentrations of the oxylipins 9(S)-HpOTrE, 9(S)-HOTrE, 13(S)-HpOTrE, and 9,10-EpOME, and the endocannabinoid anandamide. In-depth proteomic analysis of platelets between the high- and low-inflammation groups revealed significant differences in protein categories related to platelet granule release and cellular iron uptake. Proteomic outputs from plasma revealed 24 proteins to be different between high and low-inflammation groups, including proteins involved in autophagy and immune mediation. Together, our results indicate that cows experiencing an exacerbated systemic inflammatory response in the postpartum may have impaired disease resistance, and platelets could be contributors to their inflammatory state.
Supplementary Information
The online version contains supplementary material available at 10.1038/s41598-024-82553-x.
An impact of legalization and decriminalization of marijuana is the gradual increase in the use of cannabis for recreational purposes, which poses a potential threat to society and healthcare systems worldwide. However, the discovery of receptor subtypes, endogenous endocannabinoids, and enzymes involved in synthesis and degradation, as well as pharmacological characterization of receptors, has led to exploration of the use of cannabis in multiple peripheral and central pathological conditions. The role of cannabis in the modulation of crucial events involving perturbed physiological functions and disease progression, including apoptosis, inflammation, oxidative stress, perturbed mitochondrial function, and the impaired immune system, indicates medicinal values. These events are involved in most neurological diseases and prompt the gradual progression of the disease. At present, several synthetic agonists and antagonists, in addition to more than 70 phytocannabinoids, are available with distinct efficacy as a therapeutic alternative in different pathological conditions. The present review aims to describe the use of cannabis in neurological diseases and psychiatric disorders.
This review discusses various sample pretreatment methods for the analytical assessment of endocannabinoids in biological fluids and tissues. Techniques like liquid-liquid extraction, protein precipitation, SALLE, SPME, and micro-solid phase extraction (µ-SPE) are investigated. The findings show that SALLE and SPME provide phase separation as a fast and environmentally friendly method and allow high sensitivity in the analyses. The analysis of endocannabinoids, particularly, 2-AG, is challenging due to its tendency to isomerize into 1-AG and its lack of stability. These challenges are highlighted, emphasizing the need for optimized analytical methods to ensure accurate and reliable results. In conclusion, this study demonstrates the applicability of effective extraction techniques as an alternative to traditional methods to obtain reliable results in endocannabinoid analyses and provides a new perspective to the literature.
Background and Aims: This investigation examined the association of pancreatitis and pancreatitis-related pain with serum levels of two endocannabinoid molecules such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and two paracannabinoid molecules such as oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). Methods: A case-control study was conducted within the Prospective Evaluation of Chronic Pancreatitis for Epidemiological and Translational Studies, including participants with no pancreas disease (N = 56), chronic abdominal pain of suspected pancreatic origin or indeterminate chronic pancreatitis (CP) (N = 22), acute pancreatitis (N = 33), recurrent acute pancreatitis (N = 57), and definite CP (N = 63). Results: Circulating AEA concentrations were higher in women than in men (p = 0.0499), and PEA concentrations were higher in obese participants than those who were underweight/normal or overweight (p = 0.003). Asymptomatic controls with no pancreatic disease had significantly (p = 0.03) lower concentrations of AEA compared with all disease groups combined. The highest concentrations of AEA were observed in participants with acute pancreatitis, followed by those with recurrent acute pancreatitis, chronic abdominal pain/indeterminant CP, and definite CP. Participants with pancreatitis reporting abdominal pain in the past year had significantly (p = 0.04) higher concentrations of AEA compared with asymptomatic controls. Levels of 2-AG were significantly lower (p = 0.02) among participants reporting abdominal pain in the past week, and pain intensity was inversely associated with concentrations of 2-AG and OEA. Conclusions: Endocannabinoid levels may be associated with stage of pancreatitis, perhaps through activation of the CB1 receptor. Validation of our findings would support the investigation of novel therapeutics, including cannabinoid receptor-1 antagonists, in this patient population.
Endometriosis (EM), characterized by the presence of endometrial-like tissue outside the uterus, is the leading cause of chronic pelvic pain and infertility in females of reproductive age. Despite its high prevalence, the molecular mechanisms underlying EM pathogenesis remain poorly understood. The endocannabinoid system (ECS) is known to influence several cardinal features of this complex disease including pain, vascularization, and overall lesion survival, but the exact mechanisms are not known. Utilizing CNR1 knockout (k/o), CNR2 k/o, and wild-type (WT) mouse models of EM, we reveal the contributions of ECS and these receptors in disease initiation, progression, and immune modulation. Particularly, we identified EM-specific T cell dysfunction in the CNR2 k/o mouse model of EM. We also demonstrate the impact of decidualization-induced changes on ECS components and the unique disease-associated transcriptional landscape of ECS components in EM. Imaging Mass Cytometry (IMC) analysis revealed distinct features of the microenvironment between CNR1, CNR2, and WT genotypes in the presence or absence of decidualization. This study, for the first time, provides an in-depth analysis of the involvement of the ECS in EM pathogenesis and lays the foundation for the development of novel therapeutic interventions to alleviate the burden of this debilitating condition.
Endometriosis (EM), characterized by the presence of endometrial-like tissue outside the uterus, is the leading cause of chronic pelvic pain and infertility in females of reproductive age. Despite its high prevalence, the molecular mechanisms underlying EM pathogenesis remain poorly understood. The endocannabinoid system (ECS) is known to influence several cardinal features of this complex disease including pain, vascularization, and overall lesion survival, but the exact mechanisms are not known. Utilizing CNR1 knockout (k/o), CNR2 k/o and wild type (WT) mouse models of EM, we reveal contributions of ECS and these receptors in disease initiation, progression, and immune modulation. Particularly, we identified EM-specific T cell dysfunction in the CNR2 k/o mouse model of EM. We also demonstrate the impact of decidualization-induced changes on ECS components, and the unique disease-associated transcriptional landscape of ECS components in EM. Imaging Mass Cytometry (IMC) analysis revealed distinct features of the microenvironment between CNR1, CNR2, and WT genotypes in the presence or absence of decidualization. This study, for the first time provides an in-depth analysis of the involvement of the ECS in EM pathogenesis and lays the foundation for the development of novel therapeutic interventions to alleviate the burden of this debilitating condition.
Alzheimer’s disease (AD) is a common neurodegenerative disease. In AD-associated neuroinflammation, astrocytes play a key role, finding glial activation both in patients and in animal models. The endocannabinoid system (ECS) is a neurolipid signaling system with anti-inflammatory and neuroprotective properties implicated in AD. Astrocytes respond to external cannabinoid signals and also have their own cannabinoid signaling. Our main objective is to describe the cannabinoid signaling machinery present in hippocampal astrocytes from 3×Tg-AD mice to determine if they are actively involved in the neurodegenerative process. Primary cultures of astrocytes from the hippocampus of 3×Tg-AD and non-Tg offspring were carried out. We analyzed the gene expression of astrogliosis markers, the main components of the ECS and Ca²⁺ signaling. 3×Tg-AD hippocampal astrocytes show low inflammatory activity (Il1b, Il6, and Gls) and Ca²⁺ flow (P2rx5 and Mcu), associated with low cannabinoid signaling (Cnr1 and Cnr2). These results were more evident in females. Our study corroborates glial involvement in AD pathology, in which cannabinoid signaling plays an important role. 3×Tg-AD mice born with hippocampal astrocytes with differential gene expression of the ECS associated with an innate attenuation of their activity. In addition, we show that there are sex differences from birth in this AD animal, which should be considered when investigating the pathogenesis of the disease.
Multiple sclerosis (MS) is a chronic demyelinating disease of the central and peripheral nervous systems. The symptoms, such as vision problems, muscle weakness, pain, balance problems, and paralysis, are due to the uncontrolled or inappropriate neural transmission that gradually worsens as the disease progresses. During the early stage of the disease, patients may experience long symptom-free periods, and the periods are interrupted by flare-ups that last days to weeks. It has been indicated that Cannabis, delta-9-tetrahydrocannabinol (THC), nabiximols, and oral Cannabis extract (OCE) may diminish spasticity associated with MS [19]. Nabiximols is a mucosal spray containing delta-9-THC and cannabidiol (CBD) in the 1:1 ratio and has been developed for treating MS. The US FDA has approved nabiximols and has also been approved in several European countries, Canada, and New Zealand for treating spasticity associated with MS.
Two types of endogenous cannabinoid-receptor agonists have been identified thus far. They are the ethanolamides of polyunsaturated fatty acids--arachidonoyl ethanolamide (anandamide) is the best known compound in the amide series--and 2-arachidonoyl glycerol, the only known endocannabinoid in the ester series. We report now an example of a third, ether-type endocannabinoid, 2-arachidonyl glyceryl ether (noladin ether), isolated from porcine brain. The structure of noladin ether was determined by mass spectrometry and nuclear magnetic resonance spectroscopy and was confirmed by comparison with a synthetic sample. It binds to the CB(1) cannabinoid receptor (K(i) = 21.2 +/- 0.5 nM) and causes sedation, hypothermia, intestinal immobility, and mild antinociception in mice. It binds weakly to the CB(2) receptor (K(i) > 3 microM).
The adaptive immune response is initiated by the interaction of T cell antigen receptors with major histocompatibility complex molecule-peptide complexes in the nanometer scale gap between a T cell and an antigen-presenting cell, referred to as an immunological synapse. In this review we focus on the concept of immunological synapse formation as it relates to membrane structure, T cell polarity, signaling pathways, and the antigen-presenting cell. Membrane domains provide an organizational principle for compartmentalization within the immunological synapse. T cell polarization by chemokines increases T cell sensitivity to antigen. The current model is that signaling and formation of the immunological synapse are tightly interwoven in mature T cells. We also extend this model to natural killer cell activation, where the inhibitory NK synapse provides a striking example in which inhibition of signaling leaves the synapse in its nascent, inverted state. The APC may also play an active role in immunological synapse formation, particularly for activation of naive T cells.
Many advances have been made in the last few years concerning our un- derstanding of the receptors and ligands composing the cannabinoid system. Like- wise, the science surrounding cytokine biology has advanced enabling us to measure these proteins more precisely as well as understand and interpret the meaning of changes in their levels. Scientists wishing to study the health consequences of smok- ing marijuana as well as understand the possible role of endogenous cannabimimetic ligands in immune regulation have continued to study the influence of these sub- stances on the regulation and development of the cytokine network. Research has shown that two major cannabinoid receptor subtypes exist and that subtype 1 (CB1) is expressed primarily in the brain whereas subtype 2 (CB2) is expressed primarily in the periphery. A variety of ligands for these receptors based on the cannabinoid structure have been synthesized and studied as well as low affinity compounds, non- cannabinoid ligands, and endogenous ligands derived from fatty acid eicosanoids. Highly selective receptor antagonists have also been introduced and studied. Syn- thetic, low affinity ligands such as (+)-HU-211 and DMH-11C have been shown to cause anti-inflammatory effects possibly through inhibiting the production and action of TNF-a and other acute phase cytokines. In addition, suppression of TNF and other cytokines such as GM-CSF, IL-6, IFNg, and IL-12 has also been seen following expo- sure to high affinity and psychoactive ligands such as marijuana and THC. However, some of these ligands have also been shown to increase rather than decrease inter- leukins such as IL-1, IL-4, IL-10, and IL-6, cytokines such as TNF-a, and chemokines such as IL-8, MIP-1, and RANTES. The endogenous ligand, anandamide, has been shown in culture to either suppress the proliferation response to prolactin or enhance the response to cytokines such as IL-3 and IL-6. This eicosanoid has also been shown to increase the production of interleukins and other cytokines. Cannabinoid receptors have been shown to be involved in some but not all of these effects. It is clear that psychoactive and nonpsychoactive compounds have demonstrated effects in vivo and in vitro on the production and function of a variety of cytokines. Depending upon the model system, these effects are often conflicting, and the involvement of canna- binoid receptors is unclear. However, enough evidence exists to suggest that the cannabinoid system significantly impacts the functioning of the cytokine network, and this association may provide clues to the mechanisms of certain immune diseases and form the basis for new immunotherapies.
Arachidonylethanolamide, an arachidonic acid derivative in porcine brain, was identified in a screen for endogenous ligands
for the cannabinoid receptor. The structure of this compound, which has been named "anandamide," was determined by mass spectrometry
and nuclear magnetic resonance spectroscopy and was confirmed by synthesis. Anandamide inhibited the specific binding of a
radiolabeled cannabinoid probe to synaptosomal membranes in a manner typical of competitive ligands and produced a concentration-dependent
inhibition of the electrically evoked twitch response to the mouse vas deferens, a characteristic effect of psychotropic cannabinoids.
These properties suggest that anandamide may function as a natural ligand for the cannabinoid receptor.
Marijuana and many of its constituent cannabinoids influence the central nervous system (CNS) in a complex and dose-dependent manner. Although CNS depression and analgesia are well documented effects of the cannabinoids, the mechanisms responsible for these and other cannabinoid-induced effects are not so far known. The hydrophobic nature of these substances has suggested that cannabinoids resemble anaesthetic agents in their action, that is, they nonspecifically disrupt cellular membranes. Recent evidence, however, has supported a mechanism involving a G protein-coupled receptor found in brain and neural cell lines, and which inhibits adenylate cyclase activity in a dose-dependent, stereoselective and pertussis toxin-sensitive manner. Also, the receptor is more responsive to psychoactive cannabinoids than to non-psychoactive cannabinoids. Here we report the cloning and expression of a complementary DNA that encodes a G protein-coupled receptor with all of these properties. Its messenger RNA is found in cell lines and regions of the brain that have cannabinoid receptors. These findings suggest that this protein is involved in cannabinoid-induced CNS effects (including alterations in mood and cognition) experienced by users of marijuana.
In this study, we report the isolation from canine intestines of 2-arachidonyl glycerol (2-Ara-Gl). Its structure was determined by mass spectrometry and by direct comparison with a synthetic sample. 2-Ara-Gl bound to membranes from cells transiently transfected with expression plasmids carrying DNA of either CB1 or CB2--the two cannabinoid receptors identified thus far--with Ki values of 472 +/- 55 and 1400 +/- 172 nM, respectively. In the presence of forskolin, 2-Ara-Gl inhibited adenylate cyclase in isolated mouse spleen cells, at the potency level of delta 9-tetrahydrocannabinol (delta 9-THC). Upon intravenous administration to mice, 2-Ara-Gl caused the typical tetrad of effects produced by THC: antinociception, immobility, reduction of spontaneous activity, and lowering of the rectal temperature. 2-Ara-Gl also shares the ability of delta 9-THC to inhibit electrically evoked contractions of mouse isolated vasa deferentia; however, it was less potent than delta 9-THC.
The major active ingredient of marijuana, delta 9-tetrahydrocannabinol (delta 9-THC), has been used as a psychoactive agent for thousands of years. Marijuana, and delta 9-THC, also exert a wide range of other effects including analgesia, anti-inflammation, immunosuppression, anticonvulsion, alleviation of intraocular pressure in glaucoma, and attenuation of vomiting. The clinical application of cannabinoids has, however, been limited by their psychoactive effects, and this has led to interest in the biochemical bases of their action. Progress stemmed initially from the synthesis of potent derivatives of delta 9-THC, and more recently from the cloning of a gene encoding a G-protein-coupled receptor for cannabinoids. This receptor is expressed in the brain but not in the periphery, except for a low level in testes. It has been proposed that the nonpsychoactive effects of cannabinoids are either mediated centrally or through direct interaction with other, non-receptor proteins. Here we report the cloning of a receptor for cannabinoids that is not expressed in the brain but rather in macrophages in the marginal zone of spleen.
Resistance to infection with Legionella pneumophila is primarily dependent upon cell-mediated immunity rather than humoral immunity. Recent evidence suggests that activation of cell-mediated immunity depends on Th1 cells and activation of humoral immunity depends on Th2 cells. In this report, delta 9-tetrahydrocannabinol (THC), the major psychoactive cannabinoid of marijuana and an immunomodulator, suppressed development of secondary immunity to L. pneumophila, which correlated with a reduction in Th1 activity. BALB/c mice, infected with a primary sublethal dose of L. pneumophila, developed resistance to a larger challenge infection 3 to 4 weeks later. However, intravenous injection of THC (4 mg/kg of body weight) 1 day prior to primary infection resulted in increased mortality after the challenge infection. The level of anti-L. pneumophila antibodies in serum increased in both THC-treated and control mice; however, in the THC group IgG1 antibodies which are stimulated by Th2 cells were elevated while Th1-regulated, IgG2a antibodies were depressed. Furthermore, cultured splenocytes from THC-treated mice had less L. pneumophila-specific lymphoproliferation, indicating a deficiency in cell-mediated immunity. Normal mouse splenocytes treated in vitro with THC and pokeweed mitogen showed suppressed production of gamma interferon, a cytokine associated with Th1 cells, but increased production of interleukin 4, a cytokine produced by Th2 cells. Splenocytes from THC-treated mice, stimulated in vitro with either pokeweed mitogen or anti-CD3 antibodies, also produced less gamma interferon, indicating less Th1 activity in these mice. These results suggest that THC decreases the development of anti-L. pneumophila immunity by causing a change in the balance of Th1 and Th2 activities.
Delta 9-tetrahydrocannabinol (delta 9-THC), the major psychoactive component of marijuana, has been shown to suppress macrophage soluble cytolytic activity. The purpose of this study was to determine whether delta 9-THC inhibited this function by affecting tumor necrosis factor-alpha (TNF-alpha). The RAW264.7 macrophage cell line was used as an in vitro bacterial lipopolysaccharide-inducible system for production of TNF-alpha. Macrophage-conditioned medium of RAW264.7 macrophages treated with delta 9-THC was shown to be deficient in tumoricidal activity. Immunoprecipitation experiments demonstrated that the macrophage-conditioned medium of cultures treated with drug contained lower levels of TNF-alpha. Northern analysis indicated that delta 9-THC had no effect on the levels of TNF-alpha messenger RNA. However, radiolabel pulsing and pulse-chase experiments revealed that the intracellular conversion of the 26-kD presecreted form of TNF-alpha to the 17-kD secreted form was inhibited by the drug. These results indicate that delta 9-THC suppresses soluble macrophage tumoricidal activity, at least in part, by decreasing the intracellular conversion of presecretory TNF-alpha to its 17-kD secretory form.
Macrophages are the primary cellular targets of bacterial lipopolysaccharide (LPS), but the role of macrophage-derived cytokines in LPS-induced septic shock is uncertain. Recent evidence indicates that activation of peripheral CB1 cannabinoid receptors contributes to hemorrhagic hypotension and that macrophage-derived anandamide as well as unidentified platelet-derived substances may be contributing factors. Here we demonstrate that rat platelets contain the endogenous cannabinoid 2-arachidonyl glyceride (2-AG), as identified by reverse phase high-performance liquid chromatography, gas chromatography, and mass spectrometry, and that in vitro exposure of platelets to LPS (200 microg/ml) markedly increases 2-AG levels. LPS-stimulated, but not control, macrophages contain anandamide, which is undetectable in either control or LPS-stimulated platelets. Prolonged hypotension and tachycardia are elicited in urethane-anesthetized rats treated 1) with LPS (15 mg/kg i.v.); 2) with macrophages plus platelets isolated from 3 ml of blood from an LPS-treated donor rat; or 3) with rat macrophages or 4) platelets preincubated in vitro with LPS (200 microg/ml). In all four cases, the hypotension but not the tachycardia is prevented by pretreatment of the recipient rat with the CB1 receptor antagonist SR141716A (3 mg/kg i.v.), which also inhibits the hypotensive response to anandamide or 2-AG. The hypotension elicited by LPS-treated macrophages or platelets remains unchanged in the absence of sympathetic tone or after blockade of nitric oxide synthase. These findings indicate that platelets and macrophages generate different endogenous cannabinoids, and that both 2-AG and anandamide may be paracrine mediators of endotoxin-induced hypotension via activation of vascular CB1 receptors.
Differentiated CD4 T cells can be divided into Th1 and Th2 types based on the cytokines they produce. Differential expression of chemokine receptors on either the Th1-type or the Th2-type cell suggests that Th1-type and Th2-type cells differ not only in cytokine production but also in their migratory capacity. Stimulation of endothelial cells with IFN-gamma selectively enhanced transmigration of Th1-type cells, but not Th2-type cells, in a transendothelial migration assay. Enhanced transmigration of Th1-type cells was dependent on the chemokine RANTES produced by endothelial cells, as indicated by the findings that Ab neutralizing RANTES, or Ab to its receptor CCR5, inhibited transmigration. Neutralizing Ab to chemokines macrophage-inflammatory protein-1alpha or monocyte chemotactic protein-1 did not inhibit Th1 selective migration. Whereas anti-CD18 and anti-CD54 blocked basal levels of Th1-type cell adherence to endothelial cells and also inhibited transmigration, anti-RANTES blocked only transmigration, indicating that RANTES appeared to induce transmigration of adherent T cells. RANTES seemed to promote diapedesis of adherent Th1-type cells by augmenting pseudopod formation in conjunction with actin rearrangement by a pathway that was sensitive to the phosphoinositol 3-kinase inhibitor wortmannin and to the Rho GTP-binding protein inhibitor, epidermal cell differentiation inhibitor. Thus, enhancement of Th1-type selective migration appeared to be responsible for the diapedesis induced by interaction between CCR5 on Th1-type cells and RANTES produced by endothelial cells. Further evidence that CCR5 and RANTES play a modulatory role in Th1-type selective migration derives from the abrogation of this migration by anti-RANTES and anti-CCR5 Abs.
Delta9-Tetrahydrocannabinol, the main active component of marijuana, induces apoptosis of transformed neural cells in culture. Here, we show that intratumoral administration of Delta9-tetrahydrocannabinol and the synthetic cannabinoid agonist WIN-55,212-2 induced a considerable regression of malignant gliomas in Wistar rats and in mice deficient in recombination activating gene 2. Cannabinoid treatment did not produce any substantial neurotoxic effect in the conditions used. Experiments with two subclones of C6 glioma cells in culture showed that cannabinoids signal apoptosis by a pathway involving cannabinoid receptors, sustained ceramide accumulation and Raf1/extracellular signal-regulated kinase activation. These results may provide the basis for a new therapeutic approach for the treatment of malignant gliomas.
The function of the peripheral cannabinoid receptor (CB2), which is mainly expressed on hematopoietic cells, remains an enigma. In an attempt to decipher its role, we used Affymetrix DNA chips to investigate the gene expression profile of the promyelocytic cells HL-60 transfected with the CB2 receptor and activated with the cannabinoid agonist CP 55,940. Agonist exposure of these cells led to an activation of a mitogen-activated protein kinase cascade and a receptor desensitization, indicating a functional coupling of the transfected receptors. At the genomic level, activation of the CB2 receptors induced an up-regulation of nine genes involved in cytokine synthesis, regulation of transcription, and cell differentiation. A majority of them are under the control of the transcription factor NF-kappaB, whose nuclear translocation was demonstrated. Many features of the transcriptional events, reported here for the first time, appeared to be related to an activation of a cell differentiation program, suggesting that CB2 receptors could play a role in the initialization of cell maturation. Moreover, we showed that CB2-activated wild-type HL-60 cells developed properties usually found in host defense effector cells such as an enhanced release of chemotactic cytokines and an increased motility, characteristic of more mature cells of the granulocytic-monocytic lineage.
The marijuana cannabinoid, delta 9-tetrahydrocannabinol (THC), suppresses immunity to Legionella pneumophila and development of Th1 activity and cell-mediated immunity. In the current study, THC effects on cytokines regulating the development of Th1 cells were examined. BALB/c mice showed significant increases in serum IL-12 and IFN-gamma within hours of infection; however, the levels of these Th1-promoting cytokines as well as resistance to a challenge infection were suppressed by THC (8 mg/kg) injected 18 h before priming. The Th2-promoting cytokine, IL-4, was increased within hours of a Legionella infection and was further increased by THC treatment. These results suggested that THC injection suppressed the cytokine environment promoting Th1 immunity. In additional experiments, THC pretreatment and infection of IL-4 knockout mice showed that serum IL-12 and IFN-gamma were suppressed equally in both knockout and normal mice. This suggested that the drug-induced increase in IL-4 was not responsible for the decreases in serum IL-12 and IFN-gamma. However, THC treatment was shown to suppress the expression of IL-12 receptor beta 2 mRNA, indicating that, in addition to suppression of IL-12, THC injection suppressed the expression of IL-12 receptors. Finally, the role of cannabinoid receptors in Th1-promoting cytokine suppression was examined, and results with receptor antagonists showed that both cannabinoid receptors 1 and 2 were involved. It is suggested that suppression of Th1 immunity to Legionella is not due to an increase in IL-4 production but to a decrease in IFN-gamma and IL-12. Furthermore, both types of cannabinoid receptors are involved.
2-Arachidonoylglycerol is an endogenous ligand for the cannabinoid receptors (CB1 and CB2). Previously, we provided evidence that 2-arachidonoylglycerol, but not anandamide (N-arachidonoylethanolamine), is the true natural ligand for the cannabinoid receptors. In the present study, we examined in detail the effects of 2-arachidonoylglycerol on the production of chemokines in human promyelocytic leukemia HL-60 cells. We found that 2-arachidonoylglycerol induced a marked acceleration in the production of interleukin 8. The effect of 2-arachidonoylglycerol was blocked by treatment of the cells with SR144528, a cannabinoid CB2 receptor antagonist, indicating that the effect of 2-arachidonoylglycerol is mediated through the CB2 receptor. Augmented production of interleukin 8 was also observed with CP55940, a synthetic cannabinoid, and an ether-linked analog of 2-arachidonoylglycerol. On the other hand, neither anandamide nor the free arachidonic acid induced the enhanced production of interleukin 8. A similar effect of 2-arachidonoylglycerol was observed in the case of the production of macrophage-chemotactic protein-1. The accelerated production of interleukin 8 by 2-arachidonoylglycerol was observed not only in undifferentiated HL-60 cells, but also in HL-60 cells differentiated into macrophage-like cells. Noticeably, 2-arachidonoylglycerol and lipopolysaccharide acted synergistically to induce the dramatically augmented production of interleukin 8. These results strongly suggest that the CB2 receptor and its physiological ligand, i.e., 2-arachidonoylglycerol, play important regulatory roles such as stimulation of the production of chemokines in inflammatory cells and immune-competent cells. Detailed studies on the cannabinoid receptor system are thus essential to gain a better understanding of the precise regulatory mechanisms of inflammatory reactions and immune responses.
The discovery of carboxylic acid metabolites of the cannabinoids (CBs) dates back more than three decades. Their lack of psychotropic activity was noted early on, and this resulted in a total absence of further research on their possible role in the actions of the CBs. More recent studies have revealed that the acids possess both analgesic and anti-inflammatory properties and may contribute to the actions of the parent drug. A synthetic analog showed similar actions at considerably lower doses. In this review, a brief survey of the extensive literature on metabolism of Δ9-tetrahydrocannabinol to the acids is presented, while more emphasis is given to the recent findings on the biological actions of this class of CBs. A possible mechanism involving effects on eicosanoids for some of these actions is also suggested. Finally, an analogy with a putative metabolite of anandamide, an endogenous CB, is discussed.
Δ9-Tetrahydrocannabinol from Cannabis sativa is mimicked by cannabimimetic analogs such as CP55940 and WIN55212-2, and antagonized by rimonabant and SR144528, through G-protein-coupled receptors, CB1 in the brain, and CB2 in the immune system. Eicosanoids anandamide and 2-arachidonoylglycerol are the “endocannabinoid” agonists for these receptors. CB1 receptors are abundant in basal ganglia, hippocampus and cerebellum, and their functional activity can be mapped during behaviors using cerebral metabolism as the neuroimaging tool. CB1 receptors couple to Gi/o to inhibit cAMP production, decrease Ca2+ conductance, increase K+ conductance, and increase mitogen-activated protein kinase activity. Functional activation of G-proteins can be imaged by [35S]GTPγS autoradiography. Post-synaptically generated endocannabinoids form the basis of a retrograde signaling mechanism referred to as depolarization-induced suppression of inhibition (DSI) or excitation (DSE). Under circumstances of sufficient intracellular Ca2+ (e.g., burst activity in seizures), synthesis of endocannabinoids releases a diffusible retrograde messenger to stimulate presynaptic CB1 receptors. This results in suppression of γ-aminobutyric acid (GABA) release, thereby relieving the post-synaptic inhibition. Tolerance develops as neurons adjust both receptor number and cellular signal transduction to the chronic administration of cannabinoid drugs. Future therapeutic drug design can progress based upon our current understanding of the physiology and pharmacology of CB1, CB2 and related receptors. One very important role for CB1 antagonists will be in the treatment of craving in the disease of substance abuse.
Cannabinoids - the active components of Cannabis sativa and their derivatives - exert palliative effects in cancer patients by preventing nausea, vomiting and pain and by stimulating appetite. In addition, these compounds have been shown to inhibit the growth of tumour cells in culture and animal models by modulating key cell-signalling pathways. Cannabinoids are usually well tolerated, and do not produce the generalized toxic effects of conventional chemotherapies. So, could cannabinoids be used to develop new anticancer therapies?
Several derivatives of cannabinol and the 1,1-dimethylheptyl homolog (DMH) of cannabinol were prepared and assayed for binding to the brain and the peripheral cannabinoid receptors (CB1 and CB2), as well as for activation of CB1- and CB2-mediated inhibition of adenylylcyclase. The DMH derivatives were much more potent than the pentyl (i.e., cannabinol) derivatives. 11-Hydroxycannabinol (4a) was found to bind potently to both CB1 and CB2 (Ki values of 38.0 ± 7.2 and 26.6 ± 5.5 nM, respectively) and to inhibit CB1-mediated adenylylcyclase with an EC50 of 58.1 ± 6.2 nM but to cause only 20% inhibition of CB2-mediated adenylylcyclase at 10 μM. It behaves as a specific, though not potent, CB2 antagonist. 11-Hydroxycannabinol-DMH (4b) is a very potent agonist for both CB1 and CB2 (Ki values of 100 ± 50 and 200 ± 40 pM; EC50 of adenylylcyclase inhibition 56.2 ± 4.2 and 207.5 ± 27.8 pM, respectively).
The stimulus-induced biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG) in intact mouse J774 macrophages and the inactivation of 2-AG by the same cells or by rat circulating macrophages was studied. By using gas chromatography-mass spectrometry, we found that ionomycin (5 µm) and lipopolysaccharide (LPS, 200 µg·mL−1) cause a 24-fold and 2.5-fold stimulation of 2-AG levels in J774 cells, respectively, thus providing unprecedented evidence that this cannabimimetic metabolite can be synthesized by macrophages. In J774 cells, LPS also induced a 7.8-fold increase of the levels of the other endocannabinoid, anandamide, and, in rat circulating macrophages, an almost twofold increase of 2-AG levels. Extracellular [3H]2-AG was cleared from the medium of intact J774 macrophages (t1/2 = 19–28 min) and esterified to phospholipids, diacylglycerols and triglycerides or hydrolyzed to [3H]arachidonic acid and glycerol. These catabolic processes were attenuated differentially by various enzyme inhibitors. Rat circulating macrophages were shown to contain enzymatic activities for the hydrolysis of 2-AG, including: (a) fatty acid amide hydrolase (FAAH), the enzyme responsible for anandamide breakdown and previously shown to catalyse also 2-AG hydrolysis, and (b) a 2-AG hydrolase activity different from FAAH and down-regulated by LPS. High levels of FAAH mRNA were found in circulating macrophages but not platelets, which, however, contain a 2-AG hydrolase. Both platelets and macrophages were shown to express the mRNA for the CB1 cannabinoid receptor. A macrophage 2-AG hydrolase with apparent Km = 110 µm and Vmax = 7.9 nmol·min−1·(mg protein)−1 was partially characterized in J774 cells and found to exhibit an optimal pH of 6–7 and little or no sensitivity to typical FAAH inhibitors. These findings demonstrate for the first time that macrophages participate in the homeostasis of the hypotensive and immunomodulatory endocannabinoid 2-AG through metabolic mechanisms that are subject to regulation.
We have studied the effect of cannabinoid agonists (CP 55,940 and cannabinol) on intestinal motility in a model of intestinal inflammation (induced by oral croton oil in mice) and measured cannabinoid receptor expression, endocannabinoids (anandamide and 2-arachidonylglycerol) and anandamide amidohydrolase activity both in physiological and pathophysiological states.
CP 55,940 (0.03 – 10 nmol mouse−1) and cannabinol (10 – 3000 nmol mouse−1) were more active in delaying intestinal motility in croton oil-treated mice than in control mice. These inhibitory effects were counteracted by the selective cannabinoid CB1 receptor antagonist SR141716A (16 nmol mouse−1). SR141716A (1 – 300 nmol mouse−1), administered alone, increased intestinal motility to the same extent in both control and croton oil-treated mice
Croton oil-induced intestinal inflammation was associated with an increased expression of CB1 receptor, an unprecedented example of up-regulation of cannabinoid receptors during inflammation.
High levels of anandamide and 2-arachidonylglycerol were detected in the small intestine, although no differences were observed between control and croton oil-treated mice; by contrast anandamide amidohydrolase activity increased 2 fold in the inflamed small intestine.
It is concluded that inflammation of the gut increases the potency of cannabinoid agonists possibly by ‘up-regulating’ CB1 receptor expression; in addition, endocannabinoids, whose turnover is increased in inflamed gut, might tonically inhibit intestinal motility.
British Journal of Pharmacology (2001) 134, 563–570; doi:10.1038/sj.bjp.0704293
Anandamide (ANA) and 2-arachidonoylglycerol (2-AG), two endogenous cannabinoids, can be generated by activated macrophages and platelets, respectively, in the context of endotoxic shock, and are proposed to play a crucial role in the induction of the shock-related hypotension. Taking advantage of our recently discovered function of polymyxin B (PMB) binding to ANA and 2-AG, we developed a new method for measuring ANA and 2-AG by applying PMB-immobilized beads to selectively adsorb them in biological fluids, instead of organic solvent extraction. The eluate from beads can be directly fractionated by reverse-phase high-performance liquid chromatography (HPLC), and the fractionations corresponding to authentic ANA and 2-AG are collected and derivatized with fluorogenic reagent and subsequently quantified by HPLC with fluorometric detection. The calibration graphs of ANA and 2-AG were linear over a range of 1 to 500 pmol/ml. The limits of detection for ANA and 2-AG were 20 and 50 fmol, respectively. Intraassay precision was 2.24–4.25 and 3.47–5.44%, and interassay was 4.05–6.14 and 4.92–7.28% for ANA and 2-AG, respectively. Using this method, we first determined a 4-fold and 3-fold higher level of ANA and 2-AG, respectively, in the sera of patients with endotoxic shock than in normal serum. This finding should help in elucidating the role of the endogenous cannabinoids in the hypotension of human endotoxic shock. This method is rapid, sensitive, and reliable for simultaneously quantifying ANA and 2-AG in biological fluids, and has potential for clinical usage.
The effect of Δ8-THC on experimental autoimmune encephalomyelitis (EAE) was examined. Δ8-THC is an analogue of Δ9-THC, the psychoactive component of marihuana. It is more stable and less psychotropic than Δ9-THC and like the latter it binds to the brain cannabinoid receptor. Two strains of rats were incolulated for EAE, and Δ8-THC (40 mg/kg) was administered for up to 21 days. Δ8-THC significantly reduced the incidence and severity of neurological deficit in both rat strains. The beneficial influence of Δ8-THC only occured on oral administration and not with parenteral injection. Serum corticosterone levels were twofold elevated in rats with EAE chronically treate with Δ8-THC. These results suggest that suppression of EAE cannabinoids may be related to their effect on corticosterone secretion.
Delta-9-tetrahydrocannabinol (THC), the major psychoactive component in marijuana, has been reported to be suppressive on some immune functions. Since interferons (IFNs) are important immunomodulatory proteins, the effect of in vivo or in vitro administration of THC on induction of IFN by various mitogens was examined. Splenocytes from normal mice in the presence of THC produced significantly less IFN when stimulated by phytohemagglutinin (PHA), concanavalin A (Con A), or Escherichia coli lipopolysaccharide (LPS). Induction of IFN by a bacterial antigen, Legionella pneumophila bacterial cells, was also suppressed by THC. Also, splenocytes which were incubated up to 24 h in the presence of THC partially recovered responses to mitogens when cells were washed before stimulation. This suggested that THC must be present in order to mitigate IFN induction. Splenocyte cultures from mice which were chronically injected with THC for 6 – 8 weeks were also less responsive to induction of IFN by the various mitogens. These results suggest that at least part of the immunosuppressive effects of THC may be related to depressed IFN production by stimulated lymphocytes. Since Con A and PHA are T cell mitogens and LPS is considered to be a macrophage and B cell stimulator, suppression of IFN production by these classes of cells indicate a wide range of effects of THC.
Marijuana cannabinoids are both psychoactive and immunoactive. Here, we will review evidence that cannabinoids modulate immunity and that cannabinoid receptors and endogenous ligands are expressed in immune tissues. Clues will also be presented concerning the role of the cannabinoid system in immune regulation and the possible molecular mechanisms involved.
In this study, we report the isolation from canine intestines of 2-arachidonyl glycerol (2-Ara-Gl). Its structure was determined by mass spectrometry and by direct comparison with a synthetic sample. 2-Ara-Gl bound to membranes from cells transiently transfected with expression plasmids carrying DNA of either CB1 or CB2—the two cannabinoid receptors identified thus far—with Ki values of 472 ± 55 and 1400 ± 172 nM, respectively. In the presence of forskolin, 2-Ara-Gl inhibited adenylate cyclase in isolated mouse spleen cells, at the potency level of Δ9-tetrahydrocannabinol (Δ9-THC). Upon intravenous administration to mice, 2-Ara-Gl caused the typical tetrad of effects produced by THC: antinociception, immobility, reduction of spontaneous activity, and lowering of the rectal temperature. 2-Ara-Gl also shares the ability of Δ9-THC to inhibit electrically evoked contractions of mouse isolated vasa deferentia; however, it was less potent than Δ9-THC.
The endogenous cannabinoid receptor agonist anandamide is a powerful vasodilator of isolated vascular preparations, but its mechanism of action is unclear. Here we show that the vasodilator response to anandamide in isolated arteries is capsaicin-sensitive and accompanied by release of calcitonin-gene-related peptide (CGRP). The selective CGRP-receptor antagonist 8-37 CGRP, but not the cannabinoid CB1 receptor blocker SR141716A, inhibited the vasodilator effect of anandamide. Other endogenous (2-arachidonylglycerol, palmitylethanolamide) and synthetic (HU 210, WIN 55,212-2, CP 55,940) CB1 and CB2 receptor agonists could not mimic the action of anandamide. The selective 'vanilloid receptor' antagonist capsazepine inhibited anandamide-induced vasodilation and release of CGRP. In patch-clamp experiments on cells expressing the cloned vanilloid receptor (VR1), anandamide induced a capsazepine-sensitive current in whole cells and isolated membrane patches. Our results indicate that anandamide induces vasodilation by activating vanilloid receptors on perivascular sensory nerves and causing release of CGRP. The vanilloid receptor may thus be another molecular target for endogenous anandamide, besides cannabinoid receptors, in the nervous and cardiovascular systems.
Anandamide was the first brain metabolite shown to act as a ligand of “central” CB1 cannabinoid receptors. Here we report that the endogenous cannabinoid potently and selectively inhibits the proliferation of human breast cancer cells in vitro. Anandamide dose-dependently inhibited the proliferation of MCF-7 and EFM-19 cells with IC50 values between 0.5 and 1.5 μM and 83–92% maximal inhibition at 5–10 μM. The proliferation of several other nonmammary tumoral cell lines was not affected by 10 μM anandamide. The anti-proliferative effect of anandamide was not due to toxicity or to apoptosis of cells but was accompanied by a reduction of cells in the S phase of the cell cycle. A stable analogue of anandamide (R)-methanandamide, another endogenous cannabinoid, 2-arachidonoylglycerol, and the synthetic cannabinoid HU-210 also inhibited EFM-19 cell proliferation, whereas arachidonic acid was much less effective. These cannabimimetic substances displaced the binding of the selective cannabinoid agonist [3H]CP 55,940 to EFM-19 membranes with an order of potency identical to that observed for the inhibition of EFM-19 cell proliferation. Moreover, anandamide cytostatic effect was inhibited by the selective CB1 receptor antagonist SR 141716A. Cell proliferation was arrested by a prolactin mAb and enhanced by exogenous human prolactin, whose mitogenic action was reverted by very low (0.1–0.5 μM) doses of anandamide. Anandamide suppressed the levels of the long form of the prolactin receptor in both EFM-19 and MCF-7 cells, as well as a typical prolactin-induced response, i.e., the expression of the breast cancer cell susceptibility gene brca1. These data suggest that anandamide blocks human breast cancer cell proliferation through CB1-like receptor-mediated inhibition of endogenous prolactin action at the level of prolactin receptor.
Since multiple sclerosis (MS) is believed to be an immune-mediated disease, it follows that its therapies should be directed towards modulating the immune system. Current MS treatments, which include the use of exogenous steroids that are immunosuppressive, do not meet therapeutic objectives. delta 9-Tetrahydrocannabinol (THC), an active component of marijuana, has been shown to be immunosuppressive. To test THC's ability to suppress an immune-mediated disease, experimental autoimmune encephalomyelitis (EAE), the laboratory model of MS, was used. Lewis rats and strain 13 guinea pigs were administered THC either before inoculation for EAE or treated with THC after injection. Control animals received placebo. The effect of dose, in addition to the timing of treatment, was also investigated. All animals treated with placebo developed severe clinical EAE 10-12 days post-injection (d.p.i.) and more than 98% died by 15 d.p.i. THC-treated animals had either no clinical signs or mild signs with delayed onset (13-15 d.p.i.) with survival greater than 95%. Examination of central nervous system tissue revealed a marked reduction of inflammation in the THC-treated animals. Therefore, as THC has been shown to inhibit both clinical and histologic EAE, it may prove to be a new and relatively innocuous agent for the treatment of immune-mediated diseases.
This study was undertaken to determine the effect of delta 9-tetrahydrocannabinol (delta 9-THC) on polyinosinic:polycytidylic acid [poly(I):poly(C)]-induced, and on herpes simplex virus type 2 (HSV-2)-induced, alpha/beta interferon in the B6C3F1 mouse. Animals were administered delta 9-THC, or the diluent, intraperitoneally for 4 consecutive days or at various time intervals prior to administration of the interferon inducer. Poly(I):poly(C) or HSV-2 was injected intravenously on Day 4. Animals receiving poly(I):poly(C) and treated with delta 9-THC at doses ranging from 5 to 100 mg/kg exhibited significantly lower titers of interferon than mice given poly(I):poly(C) and the diluent. Diminished interferon titers occurred in HSV-2-infected animals treated with delta 9-THC in doses exceeding 15 mg/kg when compared to virus-infected animals given the diluent. This suppression of early interferon persisted through 24 hr.
Delta 9-Tetrahydrocannabinol (THC) injection modulates immune cell function, but the significance of this in altering host resistance to infection is not understood. In addition, exposure to THC and other drugs of abuse during infection is associated with an acute mortality syndrome. We examined the effect of THC injection on the survival of mice infected with Legionella pneumophila (Lp). Mice given two injections of THC (8 mg/kg)-one 24 hr before and the second 24 hr after a sublethal Lp infection-experienced acute collapse and death. The drug injection after infection caused death; deaths occurred within 30 min after the injection, and neither one nor two drug injections before infection resulted in death. The THC-induced mortality resembled cytokine-mediated shock in both kinetics and symptoms; therefore, sera from drug-treated animals were measured for the acute-phase cytokines tumor necrosis factor (TNF) and interleukin 6 (IL6). The level of each cytokine was significantly elevated by THC treatment, suggesting a role in the observed mortality. To directly test this role, mice were administered a single injection of either anti-TNF alpha, anti-IL6, or a mixture of anti-IL1 alpha and -IL1 beta antibodies 1 hr before the second THC injection. Results showed that each antibody treatment protected the mice, with anti-IL6 being the most effective. Fluctuations in blood granulocytes levels also supported a role of acute-phase cytokines in THC-induced mortality. These results show that THC injection increases the blood levels of acute-phase cytokines in infected animal and that these elevated levels, at least in part, account for the mortality induced by THC injection.
The major psychoactive component of marijuana, delta 9-tetrahydrocannabinol (THC), has been shown to suppress the functions of various immune cells. However, the relationship of these findings to THC-induced suppression of host resistance to infection has not been firmly established. In this report, we review the literature concerning THC's effects on cytokine production and resistance to infection with Legionella pneumophila (Lp). Recent reports have linked THC-induced immunomodulation with drug-induced modulation of the cytokine network. Specifically, THC in vivo suppresses interferon (IFN) production while in vitro modulates the production of tumor necrosis factor (TNF), interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-2 receptor (IL-2R). These results suggested that THC treatment might alter host immunity by disrupting the cytokine network. Immunity and resistance to infection with Lp depends upon the activation of killer cells and the stimulation of the cytokine network. THC injection into rodents was observed to augment acute phase cytokine mobilization in response to a primary Lp infection; on the other hand, the drug suppressed the development of protective immunity and resistance to secondary Lp infection by causing a change in the profile of T helper cell cytokines produced by Th1 and Th2 cells. Thus, it appears that THC injection suppresses resistance to Lp infection by disrupting the cytokine network. Regarding the molecular mechanisms of these effects of THC, data is reviewed concerning the role of cannabinoid receptors (CR) in cells of the immune system. In summary, the literature to date supports the role of THC as an immunomodulator capable of suppressing resistance to infection through mechanisms involving alteration of the cytokine network. The role of CR receptors in these events has yet to be determined.
Interleukin (IL) 1 is a pleiotropic cytokine and an important mediator of various physiological responses including the acute phase response, inflammation, lymphocyte function and certain central nervous system responses. Because delta 9-tetrahydrocannabinol (THC) treatment also has been reported to affect these physiological responses, we tested the drug effect on IL1 production and secretion. Addition of THC to endotoxin (ETX)-treated murine, resident peritoneal macrophage cultures increased, in a dose-dependent manner, supernatant IL1 activity over ETX only treatment. Treatment with THC alone had no effect. Enzyme-linked immunosorbent assay studies and specific antibody neutralization studies demonstrated both IL1 alpha and IL1 beta were increased by drug treatment. The steady-state levels of cellular IL1 alpha and IL1 beta mRNAs, determined by Northern blotting and reverse transcription-polymerase chain reaction, were unchanged, suggesting the possibility THC was not increasing IL1 production. To examine this possibility further, ETX-activated macrophages, pulsed-labeled with 35S-methionine, were chased for 2, 4 and 6 hr in the presence of THC and the levels of the various IL1 bioforms determined by immunoprecipitation. These results showed THC treatment had no effect on the level of ETX-induced intracellular promature IL1 alpha and IL1 beta proteins; however, a THC-induced increase and prolongation of release of promature IL1 alpha and mature IL1 beta were observed. The immunoprecipitation results were confirmed by studies examining supernatant bioactivity. These results suggest THC augments the ETX-induced processing of IL1 beta and release of IL1 alpha rather than increasing the cellular production of IL1 protein.(ABSTRACT TRUNCATED AT 250 WORDS)
Brain-type cannabinoid receptor (CB1) mRNA has been demonstrated in several peripheral tissues; however, the function of this message is not clear. In the present study, we examined the levels of CB1 mRNA and receptor protein in stimulated immune cells to link message and protein expression with cell activation. Consistent with previous reports, immune cell lines from human and mouse were positive by reverse transcription-polymerase chain reaction for CB1 mRNA; however, one cell line, Jurkat, was only weakly positive. Mitogen activation of Jurkat cells, however, increased CB1 mRNA within 2 hr after stimulation and equilibrium binding studies, using Jurkat membranes, showed [3H]CP55,940 specific binding was negative early after mitogen stimulation but positive at 40 hr poststimulation. To investigate whether this observed increase in CB1 mRNA and specific binding activity was associated with expression of the CB1 protein, polyclonal antibodies were produced to a fusion protein consisting of glutathione S-transferase and a 342 amino acid portion (residues 33 through 374) of the CB1 protein. Western blotting analysis showed expression of several immunoreactive proteins on membranes from mitogen-activated Jurkat cells, but not on membranes from unstimulated cells. These results demonstrate a link between the level of CB1 mRNA and surface protein in activated immune cells, suggesting the possibility of a functional role of CB1 in immune cell activation.
Anandamide (arachidonoylethanolamide, AnNH) has been recently proposed as the endogenous ligand at the brain cannabinoid receptor CB1. Two alternative pathways have been suggested for the biosynthesis of this putative mediator in the central nervous system. Here we present data (1) substantiating further the mechanism by which AnNH is produced by phospholipase D (PLD)-catalysed hydrolysis of N-arachidonoylphosphatidylethanolamine in mouse neuroblastoma N18TG2 cells, and (2) suggesting for the first time that AnNH is biosynthesized via the same mechanism in a non-neuronal cell line, mouse J774 macrophages, together with other acylethanolamides and is possibly involved in the control of the immune/inflammatory response. Lipids from both neuroblastoma cells and J774 macrophages were shown to contain a family of N-acylphosphatidylethanolamines (N-aPEs), including the possible precursor of AnNH, N-arachidonoyl-PE. Treatment with exogenous PLD, but not with exogenous phospholipase A2 and ethanolamine, resulted in the production of a series of acylethanolamides (AEs), including AnNH, from both cell types. The formation of AEs was accompanied by a decrease in the levels of the corresponding N-aPEs. Enzymically active homogenates from either neuroblastoma cells or J774 macrophages were shown to convert synthetic N-[3H]arachidonoyl-PE into [3H]AnNH, thus suggesting that in both cells an enzyme is present which is capable of catalysing the hydrolysis of N-aPE(s) to the corresponding AE(s). Finally, as previously shown in central neurons, on stimulation with ionomycin, J774 macrophages also produced a mixture of AEs including AnNH and palmitoylethanolamide, which has been proposed as the preferential endogenous ligand at the peripheral cannabinoid receptor CB2 and, consequently, as a possible down-modulator of mast cells. On the basis of this as well as previous findings it is now possible to hypothesize for AnNH and palmitoylethanolamide, co-synthesized by macrophages, a role as peripheral mediators with multiple actions on blood cell function.
Traumatic brain injury triggers a cascade of events resulting in delayed edema, necrosis and impaired function. Harmful mediators are accumulating in the brain after injury and recently, the role of cytokines in the pathophysiology of brain injury has been suggested. We have developed an experimental model for closed head injury (CHI), in which edema, blood-brain-barrier disruption, motor and memory dysfunctions have been demonstrated. In this study, spatial and temporal induction of IL-1, IL-6 and TNF-alpha gene mRNA transcription and of TNF-alpha and IL-6 activity in rat brain after CHI are shown. Dexanabinol, HU-211, is a synthetic cannabinoid devoid of cannabimimetic effects; it exhibits pharmacological properties of N-methyl-D-aspartate (NMDA)-receptor antagonist and is an effective cerebroprotectant. We report here that HU-211 is a novel inhibitor of TNF-alpha production at a post-transcriptional stage. HU-211, pentoxyfilline and TNF-binding protein improved the outcome of CHI. We suggest that TNF-alpha is a primary mediator of neurotoxicity after CHI, as inhibition of TNF-alpha is associated with better clinical recovery. TNF-alpha modulating agents, if given within the early time window post-injury, may improve the final neurological outcome in victims of brain trauma.
Dexanabinol, HU-211, a synthetic cannabinoid devoid of psychotropic effects, improves neurological outcome in models of brain trauma, ischemia and meningitis. Recently, HU-211 was found to inhibit brain tumor necrosis factor (TNFalpha) production after head injury. In the present study, we demonstrate the ability of HU-211 to suppress TNFalpha production and to rescue mice and rats from endotoxic shock after LPS (Escherichia coli 055:B5) inoculation. In BALB/c mice, a dose of 10 mg/kg LPS, injected i.p., caused 57% and 100% mortality, at 24 and 48 hr, respectively. HU-211, administered i.p. 30 min before lipopolysaccharide (LPS), reduced lethality to 9 and 67% at these time points (P < .05). When coinjected with D-galactoseamine (i.p.), LPS was 100% lethal within 24 hr, whereas eight hourly injections of HU-211 caused mortality of C57BL/6 mice to drop to 10% (P < .001). Administration of LPS to Sprague-Dawley rats resulted in a 30% reduction in the mean arterial blood pressure within 30 min, which persisted for 3 hr. HU-211, given 2 to 3 min before LPS, completely abolished the typical hypotensive response. Furthermore, the drug also markedly suppressed in vitro TNFalpha production and nitric oxide generation (by >90%) by both murine peritoneal macrophages and rat alveolar macrophage cell line exposed to LPS. HU-211 may, therefore, have therapeutic implications in the treatment of TNFalpha-mediated pathologies.
Use of marijuana and cocaine is on the rise in the United States. Although pulmonary toxicity from these drugs has occasionally been reported, little is known about their effects on the lung microenvironment. We evaluated the function of alveolar macrophages (AMs) recovered from the lungs of nonsmokers and habitual smokers of either tobacco, marijuana, or crack cocaine. AMs recovered from marijuana smokers were deficient in their ability to phagocytose Staphylococcus aureus (p < 0.01). AMs from marijuana smokers and from cocaine users were also severely limited in their ability to kill both bacteria and tumor cells (p < 0.01). Studies using NG-monomethyl-L-arginine monoacetate, an inhibitor of nitric oxide synthase, suggest that AMs from nonsmokers and tobacco smokers were able to use nitric oxide as an antibacterial effector molecule, while AMs from smokers of marijuana and cocaine were not. Finally, AMs from marijuana smokers, but not from smokers of tobacco or cocaine, produced less than normal amounts of tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor, and interleukin-6 when stimulated in culture with lipopolysaccharide. In contrast, the production of transforming growth factor-beta, an immunosuppressive cytokine, was similar in all groups. These findings indicate that habitual exposure of the lung to either marijuana or cocaine impairs the function and/or cytokine production of AMs. The ultimate outcome of these effects may be an enhanced susceptibility to infectious disease, cancer, and AIDS.
The purpose of this review was to identify and analyze the controlled clinical trial data for peripheral neuropathic pain (PNP) and complex regional pain syndromes (CRPS). A total of 72 articles were found, which included 92 controlled drug trials using 48 different treatments. The methods of these studies were critically reviewed and the results summarized and compared. The PNP trial literature gave consistent support (two or more trials) for the analgesic effectiveness of tricyclic antidepressants, intravenous and topical lidocaine, intravenous ketamine, carbamazepine and topical aspirin. There was limited support (one trial) for the analgesic effectiveness of oral, topical and epidural clonidine and for subcutaneous ketamine. The trial data were contradictory for mexiletine, phenytoin, topical capsaicin, oral non-steroidal anti-inflammatory medication, and intravenous morphine. Analysis of the trial methods indicated that mexiletine and intravenous morphine were probably effective analgesics for PNP, while non-steroidals were probably ineffective. Codeine, magnesium chloride, propranolol, lorazepam, and intravenous phentolamine all failed to provide analgesia in single trials. There were no long-term data supporting the analgesic effectiveness of any drug and the etiology of the neuropathy did not predict treatment outcome. Review of the controlled trial literature for CRPS identified several potential problems with current clinical practices. The trial data only gave consistent support for analgesia with corticosteroids, which had long-term effectiveness. There was limited support for the analgesic effectiveness of topical dimethylsulfoxyde (DMSO), epidural clonidine and intravenous regional blocks (IVRBs) with bretylium and ketanserin. The trial data were contradictory for intranasal calcitonin and intravenous phentolamine and analysis of the trial methods indicated that both treatments were probably ineffective for most patients. There were consistent trial data indicating that guanethidine and reserpine IVRBs were ineffective, and limited trial data indicating that droperidol and atropine IVRBs were ineffective. No placebo controlled data were available to evaluated sympathetic ganglion blocks (SGBs) with local anesthetics, surgical sympathectomy, or physical therapy. Only the capsaicin trials presented data which allowed for meta-analysis. This meta-analysis demonstrated a significant capsaicin effect with a pooled odds ratio of 2.35 (95% confidence intervals 1.48, 3.22). The methods scores were higher (P < 0.01) for the PNP trials (66.2 +/- 1.5, n = 66) than the CRPS trials (57.6 +/- 2.9, n = 26). The CRPS trials tended to use less subjects and were less likely to use placebo controls, double-blinding, or perform statistical tests for differences in outcome measures between groups. There was almost no overlap in the controlled trial literature between treatments for PNP and CRPS, and treatments used in both conditions (intravenous phentolamine and epidural clonidine) had similar results.
To assess the antiinflammatory activity of dimethylheptyl-THC-11 oic acid (DMH-11C), a nonpsychoactive synthetic derivative of tetrahydrocannabinol.
Acute inflammation was induced by injection of interleukin-1beta and tumor necrosis factor alpha into subcutaneous air pouches formed on the backs of mice. Inflammation was quantified 6 hours later by pouch fluid leukocyte counts. Adjuvant-induced polyarthritis in rats was used as a model of chronic inflammation and joint tissue injury. Animals were either untreated, treated with safflower oil, or treated with DMH-11C in safflower oil. Arthritis was assessed by clinical observation and by histomorphologic evaluation of tibiotarsal joints.
Oral administration of DMH-11C reduced the accumulation of pouch fluid leukocytes and significantly reduced the severity of adjuvant-induced polyarthritis. Histopathologic studies of tibiotarsal joints showed that DMH-11C treatment attenuated pannus formation and joint tissue injury.
DMH-11C suppresses acute inflammation in the subcutaneous air pouch in mice and chronic joint inflammation characteristic of adjuvant disease in rats. These results demonstrate the potential use of this nonpsychoactive cannabinoid as an antiinflammatory agent.
Marijuana, Cannabis sativa, elicits a variety of effects in experimental animals and humans. Delta-9-tetrahydrocannabinol (THC) is the major psychoactive component in marijuana. This substance has been shown, also, to be immunosuppressive and to decrease host resistance to bacterial, protozoan, and viral infections. Macrophages, T lymphocytes, and natural killer cells appear to be major targets of the immunosuppressive effects of THC. Definitive data which directly link marijuana use to increased susceptibility to infection in humans currently is unavailable. However, cumulative reports indicating that THC alters resistance to infection in vitro and in a variety of experimental animals support the hypothesis that a similar effect occurs in humans.
The potent analgesic effects of cannabis-like drugs and the presence of CB1-type cannabinoid receptors in pain-processing areas of the brain and spinal cord indicate that endogenous cannabinoids such as anandamide may contribute to the control of pain transmission within the central nervous system (CNS). Here we show that anandamide attenuates the pain behaviour produced by chemical damage to cutaneous tissue by interacting with CB1-like cannabinoid receptors located outside the CNS. Palmitylethanolamide (PEA), which is released together with anandamide from a common phospholipid precursor, exerts a similar effect by activating peripheral CB2-like receptors. When administered together, the two compounds act synergistically, reducing pain responses 100-fold more potently than does each compound alone. Gas-chromatography/mass-spectrometry measurements indicate that the levels of anandamide and PEA in the skin are enough to cause a tonic activation of local cannabinoid receptors. In agreement with this possibility, the CB1 antagonist SR141716A and the CB2 antagonist SR144528 prolong and enhance the pain behaviour produced by tissue damage. These results indicate that peripheral CB1-like and CB2-like receptors participate in the intrinsic control of pain initiation and that locally generated anandamide and PEA may mediate this effect.
Glutamic acid is the principal excitatory neurotransmitter in the mammalian central nervous system. Glutamic acid binds to a variety of excitatory amino acid receptors, which are ligand-gated ion channels. It is activation of these receptors that leads to depolarisation and neuronal excitation. In normal synaptic functioning, activation of excitatory amino acid receptors is transitory. However, if, for any reason, receptor activation becomes excessive or prolonged, the target neurones become damaged and eventually die. This process of neuronal death is called excitotoxicity and appears to involve sustained elevations of intracellular calcium levels. Impairment of neuronal energy metabolism may sensitise neurones to excitotoxic cell death. The principle of excitotoxicity has been well-established experimentally, both in in vitro systems and in vivo, following administration of excitatory amino acids into the nervous system. A role for excitotoxicity in the aetiology or progression of several human neurodegenerative diseases has been proposed, which has stimulated much research recently. This has led to the hope that compounds that interfere with glutamatergic neurotransmission may be of clinical benefit in treating such diseases. However, except in the case of a few very rare conditions, direct evidence for a pathogenic role for excitotoxicity in neurological disease is missing. Much attention has been directed at obtaining evidence for a role for excitotoxicity in the neurological sequelae of stroke, and there now seems to be little doubt that such a process is indeed a determining factor in the extent of the lesions observed. Several clinical trials have evaluated the potential of antiglutamate drugs to improve outcome following acute ischaemic stroke, but to date, the results of these have been disappointing. In amyotrophic lateral sclerosis, neurolathyrism, and human immunodeficiency virus dementia complex, several lines of circumstantial evidence suggest that excitotoxicity may contribute to the pathogenic process. An antiglutamate drug, riluzole, recently has been shown to provide some therapeutic benefit in the treatment of amyotrophic lateral sclerosis. Parkinson's disease and Huntington's disease are examples of neurodegenerative diseases where mitochondrial dysfunction may sensitise specific populations of neurones to excitotoxicity from synaptic glutamic acid. The first clinical trials aimed at providing neuroprotection with antiglutamate drugs are currently in progress for these two diseases.
The discovery of carboxylic acid metabolites of the cannabinoids (CBs) dates back more than three decades. Their lack of psychotropic activity was noted early on, and this resulted in a total absence of further research on their possible role in the actions of the CBs. More recent studies have revealed that the acids possess both analgesic and anti-inflammatory properties and may contribute to the actions of the parent drug. A synthetic analog showed similar actions at considerably lower doses. In this review, a brief survey of the extensive literature on metabolism of delta 9-tetrahydrocannabinol to the acids is presented, while more emphasis is given to the recent findings on the biological actions of this class of CBs. A possible mechanism involving effects on eicosanoids for some of these actions is also suggested. Finally, an analogy with a putative metabolite of anandamide, an endogenous CB, is discussed.
1',1'-Dimethylheptyl-Delta-8-tetrahydrocannabinol-11-oic acid (CT-3) is a novel cannabinoid that is under development by Atlantic Pharmaceuticals as an anti-inflammatory and analgesic drug. The objective of the study was to investigate the effects of CT-3 on overt symptom complex (Irwin's test), nociception, gastrointestinal (GI) ulceration, and pharmacological availability after intragastric (i.g.) and intraperitoneal (i.p.) administration. Analgesic studies were assessed in the hot-plate (55 degrees C) and the tail clip tests in mice and in the tail clip test in rats. In addition, pharmacological interaction of CT-3 with the solvent dimethyl sulfoxide (DMSO) was investigated in rats. In mice, CT-3 decreased spontaneous motor activity and induced dose-dependent, analgesic activity in the tail clip and hot-plate tests, with potency similar to morphine sulfate after i.g. and i.p. administration. However CT-3 showed more prolonged duration of analgesic action than morphine. In rats, CT-3 showed marked analgesia in the tail clip test and had similar i.p. and i.g. median effective dose (ED(50) values; 5 mg/kg). CT-3 was devoid of GI ulceration when administered with DMSO either acutely at doses below 100 mg/kg or chronically at a dosage of 30 mg/kg/day for 5 days. In contrast, indomethacin induced GI ulceration and deaths. The concurrent use of DMSO with CT-3 decreased its analgesic action, increased its adverse central nervous system effects, and induced GI ulceration. The evidence indicates that CT-3 exhibits a large dissociation between its anti-inflammatory/analgesic effects and its ulcerogenic actions. CT-3 warrants clinical development as a novel anti-inflammatory and analgesic drug.
Cannabinol (CBN), an immunosuppressive cannabinoid and ligand for the peripheral cannabinoid receptor CB2, inhibits the cAMP signaling cascade in forskolin-stimulated thymocytes. The objective of the present studies was to further characterize the mechanism of CBN immune modulation by investigating its effects on interleukin-2 (IL-2) secretion, cAMP response element (CRE), and kappaB DNA binding activity in phorbol ester (phorbol-12-myristate-13-acetate, PMA) plus calcium ionophore (PMA/Io)-activated thymocytes. PMA/Io treatment induced CRE and kappaB DNA binding activity that was attenuated in the presence of CBN. A concomitant and concentration-related inhibition of IL-2 also was produced by CBN in PMA/Io-activated thymocytes. PMA/Io induced two CRE DNA binding complexes, a major complex consisting of a cAMP response element-binding protein (CREB)-1 homodimer, and a minor CREB-1/activating transcription factor (ATF)-2 complex. Both CRE complexes were inhibited by CBN. Conversely, two kappaB DNA binding complexes were observed, but only one was PMA/Io-inducible. However, the DNA binding activity of both complexes was diminished in the presence of CBN. The PMA/Io-inducible kappaB complex was a p65/c-Rel heterodimer. Analysis of up-stream regulation revealed a decrease in phosphorylated CREB/ATF nuclear proteins in PMA/Io-activated thymocytes after CBN treatment. Similarly, CBN prevented the phosphorylation-dependent degradation of the nuclear factor-kappaB inhibitory protein IkappaB-alpha. These results provide a potential link between the CBN-mediated inhibition of thymocyte function, including IL-2 production, and the inhibition of two critical transcription factor families, CREB/ATF and NF-kappaB/Rel.
Chronic relapsing experimental allergic encephalomyelitis (CREAE) is an autoimmune model of multiple sclerosis. Although both these diseases are typified by relapsing-remitting paralytic episodes, after CREAE induction by sensitization to myelin antigens Biozzi ABH mice also develop spasticity and tremor. These symptoms also occur during multiple sclerosis and are difficult to control. This has prompted some patients to find alternative medicines, and to perceive benefit from cannabis use. Although this benefit has been backed up by small clinical studies, mainly with non-quantifiable outcomes, the value of cannabis use in multiple sclerosis remains anecdotal. Here we show that cannabinoid (CB) receptor agonism using R(+)-WIN 55,212, delta9-tetrahydrocannabinol, methanandamide and JWH-133 (ref. 8) quantitatively ameliorated both tremor and spasticity in diseased mice. The exacerbation of these signs after antagonism of the CB1 and CB2 receptors, notably the CB1 receptor, using SR141716A and SR144528 (ref. 8) indicate that the endogenous cannabinoid system may be tonically active in the control of tremor and spasticity. This provides a rationale for patients' indications of the therapeutic potential of cannabis in the control of the symptoms of multiple sclerosis, and provides a means of evaluating more selective cannabinoids in the future.
Previous studies have shown that mice primed with Corynebacterium parvum produce higher levels of inflammatory cytokines than unprimed mice upon challenge with lipopolysaccharide (LPS). Herein, we describe experiments in which two cannabinoid (CB) agonists, WIN 55212-2 [(R)-(+)-[2, 3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]pyrrolo[1,2,3-de]1, 4-benzoxazin-6-yl](1-naphthyl)methanone) and HU-210 [(-)-11-hydroxy-delta(8) tetrahydrocannabinol-dimethylheptyl], were examined for their effects on LPS-induced cytokines in C. parvum-primed and unprimed mice. These agonists have been reported to bind selectively to the CB2 and CB1 receptor subtypes, respectively. WIN 55212-2 (3.1-50 mg/kg i.p.) and HU-210 (0.05-0.4 mg/kg i.p.) decreased serum tumor necrosis factor-alpha and interleukin-12 (IL-12) and increased IL-10 when administered to mice before LPS. The drugs also protected C. parvum mice (but not unprimed mice) against the lethal effects of LPS. The protection afforded to C. parvum mice could not be attributed to the higher levels of IL-10 present in these mice after agonist treatment. The WIN 55212-2- and HU-210-mediated changes in the responsiveness of mice to LPS were antagonized by SR141716A [N-(piperdin-1-yl)-5-(4-chloropheny)-1-(2, 4-dichloropheny)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride], a selective CB1 receptor antagonist, but not by SR144528 [N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2. 1]heptan-2-yl]5-(4-choro-3-methylphenyl)-1-(4-methylbenzyl)p yrazole-3 -carboxamide], a selective antagonist at the CB2 receptor. Therefore, both CB agonists modulated LPS responses through the CB1 receptor. Surprisingly, SR141716A itself modulated cytokine responses in a manner identical with that of WIN 55212-2 and HU-210 when administered alone to mice. The agonist-like effects of SR141716A, which were more striking in unprimed than in primed mice, suggested that the antagonist also could function as a partial agonist at the CB1 receptor. Our findings indicate a role for the CB1 receptor subtype in cytokine modulation by CB ligands.