Abstract Introduction: Cannabis-based medicines have a number of therapeutic indications, including anti-inflammatory and analgesic effects. The endocannabinoid receptor system, including the cannabinoid receptor 1 (CB1) and receptor 2 (CB2) and the endocannabinoids, are implicated in a wide range of physiological and pathophysiological processes. Pre-clinical and clinical studies have demonstrated that cannabis-based drugs have therapeutic potential in inflammatory diseases, including rheumatoid arthritis (RA) and multiple sclerosis. The aim of this study was to determine whether the key elements of the endocannabinoid signalling system, which produces immunosuppression and analgesia, are expressed in the synovia of patients with osteoarthritis (OA) or RA. Methods: Thirty-two OA and 13 RA patients...

Many constituents of cannabis exhibit beneficial anti-inflammatory properties, such as 9-tetrahydrocannabinol (THC) in marijuana and gamma-linolenic acid (GLA) in hemp seed oil. The effects of these cannabis constituents on eicosanoid metabolism is reviewed. THC and GLA modulate the arachidonic acid cascade, inhibiting the production of series 2 prostaglandins and series 4 leukotrienes. Cannabinoid receptor- as well as non-receptor-mediated signal transduction pathways appear to be involved. It is proposed that THC acts as a selective cyclooxygenase-2 (COX-2) inhibitor.

Endocannabinoids including anandamide and 2-arachidonoylglycerol are involved in cancer pathophysiology in several ways, including tumor growth and progression, peritumoral inflammation, nausea and cancer pain. Recently we showed that the endocannabinoid profiles are deranged during cancer to an extent that this manifests in alterations of plasma endocannabinoids in cancer patients, which was mimicked by similar changes in rodent models of local and metastatic cancer. The present topical review summarizes the complexity of endocannabinoid signaling in the context of tumor growth and metastasis.

Research into the pharmacology of individual cannabinoids that began in the 1940s, several decades after the presence of a cannabinoid was first detected in cannabis, is concisely reviewed. Also described is how this pharmacological research led to the discovery of cannabinoid CB1 and CB2 receptors and of endogenous ligands for these receptors, to the development of CB1- and CB2-selective agonists and antagonists and to the realization that the endogenous cannabinoid system has significant roles in both health and disease, and that drugs which mimic, augment or block the actions of endogenously released cannabinoids must have important therapeutic applications. Some goals for future research are...

Cannabidiol is a component of marijuana that does not activate cannabinoid receptors, but moderately inhibits the degradation of the endocannabinoid anandamide. We previously reported that an elevation of anandamide levels in  cerebrospinal fluid inversely correlated to psychotic symptoms. Furthermore, enhanced anandamide signaling let to a lower transition rate from initial prodromal states into frank psychosis as well as postponed transition. In our translational approach, we performed a double-blind, randomized clinical trial of cannabidiol vs amisulpride, a potent antipsychotic, in acute schizophrenia to evaluate the clinical relevance of our initial findings. Either treatment was safe and led to significant clinical improvement, but cannabidiol displayed a...

In our previous study, we reported that the cannabinoid receptors CB1 and CB2 are overexpressed in human hepatocellular carcinoma (HCC) tissues. Recently, the antitumor potential of the endogenous cannabinoid anandamide (AEA) has also been addressed. The present study was conducted to investigate the anti-proliferative effects of AEA in HCC cells. The human HCC cell line Huh7 was used. Cell proliferation was measured by MTT assay and flow cytometry. Apoptotic analysis was investigated by TUNEL assay. Real-time PCR and western blot analysis were used to analyze the expression of relevant molecules. The results of this study demonstrated that AEA inhibited the proliferation of Huh7 cells,...

The endocannabinoid anandamide (AEA) is shown to induce apoptotic bodies formation and DNA fragmentation, hallmarks of programmed cell death, in human neuroblastoma CHP100 and lymphoma U937 cells. RNA and protein synthesis inhibitors like actinomycin D and cycloheximide reduced to one-fifth the number of apoptotic bodies induced by AEA, whereas the AEA transporter inhibitor AM404 or the AEA hydrolase inhibitor ATFMK significantly increased the number of dying cells. Furthermore, specific antagonists of cannabinoid or vanilloid receptors potentiated or inhibited cell death induced by AEA, respectively. Other endocannabinoids such as 2-arachidonoylglycerol, linoleoylethanolamide, oleoylethanolamide, and palmitoylethanolamide did not promote cell death under the same experimental conditions. The...

Since the discovery of endocannabinoids and their receptors, two major members of the endocannabinoid family, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), have been regarded almost as twin brothers. Pharmacological properties were initially considered to be similar, as these molecules were believed mutually exchangeable and almost indistinguishable in the regulation of synaptic functions, such as long- and short-term synaptic plasticity, and in behavioral aspects, such as learning and memory, reward and addiction, antinociception, and anxiety. In recent years, however, endocannabinoid signaling specificity began to emerge, in particular, due to the production of genetically engineered mice lacking key enzymes in endocannabinoid synthesis or degradation, together with the...

2-Arachidonoyl-glycerol 2-Ara-Gl has been isolated from various tissues and identified as an endogenous ligand for both cannabinoid receptors, CB and CB . Here we report that in spleen, as in brain and gut, 2-Ara-Gl is accompanied by several 1 2 2-acyl-glycerol esters, two major ones being 2-linoleoyl-glycerol 2-Lino-Gl and 2-palmitoyl-glycerol 2-Palm-Gl . These two esters do not bind to the cannabinoid receptors, nor do they inhibit adenylyl cyclase via either CB or CB ; however, they significantly potentiate 1 2 the apparent binding of 2-Ara-Gl and its apparent capacity to inhibit adenylyl cyclase. Together these esters also significantly potentiate 2-Ara-Gl inhibition of motor behavior,...

The endocannabinoid systemplays a crucial role in regulating emotionality and social behaviour, however it is unknown whether this system plays a role in symptoms associated with autism spectrum disorders. The current study evaluated if alterations in the endocannabinoid system accompany behavioural changes in the valproic acid (VPA) rat model of autism. Adolescent rats prenatally exposed to VPA exhibited impaired social investigatory behaviour, hypoalgesia and reduced lococmotor activity on exposure to a novel aversive arena. Levels of the endocananbinoids, anandamide (AEA) and 2-arachidonylglycerol (2-AG) in the hippocampus, frontal cortex or cerebellum were not altered in VPA- versus saline-exposed animals. However, the expression of mRNA for...