“Exogenous cannabinoids such as marijuana exert their influence through cannabinoid receptors. Endogenous cannabinoids such as anandamide (AEA) function through the same receptors, and their physiological roles are a subject of intense study. Here, we show that AEA plays a pivotal role in maintaining immunological health in the gut. The immune system in the gut actively tolerates the foreign antigens present in the gut through mechanisms that are only partially understood. We show that AEA contributes to this critical process by promoting the presence of CX3CR1hi macrophages, which are immunosuppressive. These results uncover a major conversation between the immune and nervous systems. In addition, with the increasing prevalence of ingestion of exogenous marijuana, our study has significant implications for public health.” http://www.pnas.org/content/early/2017/04/18/1612177114.full “Our study unveils a role for the endocannabinoid system in maintaining immune homeostasis in the gut/pancreas and reveals a conversation between the nervous and immune systems using distinct receptors.” https://www.ncbi.nlm.nih.gov/pubmed/28439004
Category Archives: Gastrointestinal Disorders
Cannabinoids as gastrointestinal anti-inflammatory drugs.
“In this mini-review, we focus on the potential of the endocannabinoid system as a target for novel therapies to treat gastrointestinal (GI) inflammation. We discuss the organization of the endocannabinoid signaling and present possible pharmacological sites in the endocannabinoid system. We also refer to recent clinical findings in the field. Finally, we point at the potential use of cannabinoids at low, non-psychoactive doses to counteract non-inflammatory pathological events in the GI tract, like chemotherapy-induced diarrhea, as evidenced by Abalo et al. in the rat model.” https://www.ncbi.nlm.nih.gov/pubmed/28239924]]>
The cannabinoid 1 receptor antagonist, AM251, prolongs the survival of rats with severe acute pancreatitis.
“It has recently been recognized that anandamide (arachidonylethanolamide), which is an endogeneous-cannabinoid (endocannabinoid), mediates septic shock.
Cannabinoid means a mind-active material in cannabis (marijuana).
Anandamide is mainly produced by macrophages. Cannabinoid 1 (CB1) receptor, which is one of the cannabiniod receptors, is also known to mediate hypotensive shock.
The role of endocannabinoids in the progression of acute pancreatitis is unclear. The aims of this study are to clarify their relationship and to find a new therapeutic strategy by regulating the endocannabinoid signaling in acute pancreatitis.
This is the first report to show that endocannabinoids are involved in the deterioration of acute pancreatitis and that the down-regulation of endocannabinoid signaling may be a new therapeutic strategy for severe acute pancreatitis.”
Cannabinoid receptor-1 blockade attenuates acute pancreatitis in obesity by an adiponectin mediated mechanism.
“Obesity is a risk factor for increased severity of acute pancreatitis.
Adipocytes produce adiponectin, an anti-inflammatory molecule that is paradoxically decreased in the setting of obesity. We have shown that adiponectin concentration inversely mirrors the severity of pancreatitis in obese mice.
Cannabinoid receptor CB-1 blockade increases circulating adiponectin concentration. We, therefore, hypothesize that blockade of CB-1 would increase adiponectin and attenuate pancreatitis severity.
“The endocannabinoid system has been shown to mediate beneficial effects on gastrointestinal inflammation via cannabinoid receptors 1 (CB(1)) and 2 (CB(2)).
These receptors have also been reported to activate the MAP kinases p38 and c-Jun NH(2)-terminal kinase (JNK), which are involved in early acinar events leading to acute pancreatitis and induction of proinflammatory cytokines.
Our aim was to examine the role of cannabinoid receptor activation in an experimental model of acute pancreatitis and the potential involvement of MAP kinases.
The unselective CB(1)/CB(2) agonist HU210 ameliorated pancreatitis in wild-type and CB(1)-/- mice, indicating that this effect is mediated by CB(2).
Furthermore, blockade of CB(2), not CB(1), with selective antagonists engraved pathology.
Stimulation with a selective CB(2) agonist attenuated acute pancreatitis and an increased activation of p38 was observed in the acini.
With use of MK2-/- mice, it could be demonstrated that this attenuation is dependent on MK2. Hence, using the MK2-/- mouse model we reveal a novel CB(2)-activated and MAP kinase-dependent pathway that modulates cytokine expression and reduces pancreatic injury and affiliated complications.”
“In different models of paralytic ileus, cannabinoid receptors are overexpressed and endogenous cannabinoids are massively released, contributing to gastrointestinal dysmotility. The antitumoral drug vincristine depresses gastrointestinal motility and a similar mechanism could participate in this effect. Therefore, our aim was to determine, using CB1 and CB2 antagonists, whether an increased endocannabinoid tone is involved in vincristine-induced gastrointestinal ileus.
Key results: Vincristine induced damage to the mucosa of ileum and colon and reduced gastrointestinal motor function at 0.5 mg/kg. The effect on motor function was particularly evident when the study started 24 h after administration. AM251, but not AM630, significantly prevented vincristine effect, particularly in the small intestine, when administered thrice. AM251 alone did not significantly alter gastrointestinal motility.
Conclusions: The fact that AM251, but not AM630, is capable of reducing the effect of vincristine suggests that, like in other experimental models of paralytic ileus, an increased cannabinoid tone develops and is at least partially responsible for the alterations induced by the antitumoral drug on gastrointestinal motor function. Thus, CB1 antagonists might be useful to prevent/treat ileus induced by vincristine.” 