The endocannabinoid system is implicated in a variety of physiological and pathological conditions (inflammation, immunomodulation, analgesia, cancer and others). The main active ingredient of cannabis, D9 -tetrahydrocannabinol (D9 -THC), produces its effects through activation of CB1 and CB2 receptors. CB1 receptors are expressed at high levels in the central nervous system (CNS), whereas CB2 receptors are concentrated predominantly, although not exclusively, in cells of the immune system. Endocannabinoids are endogenous lipid-signalling molecules that are generated in the cell membrane from phospholipid precursors. The two best characterized endocannabinoids identified to date are anandamide (AEA) and 2-arachidonoylglycerol (2-AG). Here we review the relationship between the endocannabinoid...

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...

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,...

The recently discovered endocannabinoid system (ECS), which includes endocannabinoids and the proteins that metabolize and bind them, has been implicated in multiple regulatory functions both in health and disease. Several studies have suggested that ECS is centrally and peripherally involved in the processing of pain signals. This finding is corroborated by the evidence that endocannabinoids inhibit, through a cannabinoid type-1 receptor (CB1R)-dependent retrograde mechanism, the release of neurotransmitters controlling nociceptive inputs and that the levels of these lipids are high in those regions (such as sensory terminals, skin, dorsal root ganglia) known to be involved in transmission and modulation of pain signals. In this...

Abstract Chemotherapy-induced nausea is one of the most distressing symptoms reported by patients undergoing treatment, and even with the introduction of newer antiemetics such as ondansetron and aprepitant, nausea remains problematic in the clinic. Indeed, when acute nausea is not properly managed, the cues of the clinic can become associated with this distressing symptom resulting in anticipatory nausea for which no effective treatments are available. Clinical trials exploring the potential of exogenous or endogenous cannabinoids to reduce chemotherapy-induced nausea are sparse; therefore, we must rely on the data from pre-clinical rat models of nausea. In this review, we explore the human and pre-clinical animal...

A nascent literature has postulated endocannabinoids (eCBs) as strong sleep-inducing lipids, particularly rapid-eye-movement sleep (REMs), nevertheless the exact mechanisms behind this effect remain to be determined. Anandamide and 2-arachidonyl glycerol, two of the most important eCBS, are synthesized in the hippocampus. This structure also expresses a high concentration of cannabinoid receptor 1 (CB1). Recent extensive literature supports eCBs as important regulators of hippocampal activity. It has also been shown that these molecules vary their expression on the hippocampus depending on the light–dark cycle. In this context we decided to analyze the effect of intrahippocampal administration of the eCB anandamide (ANA) on the sleep–waking cycle...

The Cannabis sativa plant has been exploited for medicinal, agricultural and spiritual purposes in diverse cultures over thousands of years. Cannabis has been used recreationally for its psychotropic properties, while effects such as stimulation of appetite, analgesia and anti-emesis have lead to the medicinal application of cannabis. Indeed, reports of medicinal efficacy of cannabis can been traced back as far as 2700 BC, and even at that time reports also suggested a neuroprotective effect of the cultivar. The discovery of the psychoactive component of cannabis resin, D9 -tetrahydrocannabinol (D9 -THC) occurred long before the serendipitous identification of a G-protein coupled receptor at which D9...

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.

Although adverse effects of cannabinoids on pregnancy have been indicated for many years, the mechanisms by which they exert their actions were not clearly understood. Only recently, molecular and biochemical approaches have led to the identification of two types of cannabinoid receptors, brain-type receptors (CB1-R) and spleen-type receptors (CB2-R), which mediate cannabinoid effects. These findings were followed by the discovery of endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG). The natural cannabinoids and endocannabinoids exert their effects via cannabinoid receptors and share similar pharmacological and physiological properties. Recent demonstration of expression of functional CB1-R in the preimplantation embryo and synthesis of anandamide in the pregnant uterus of...

Endocannabinoids (ECs) are defined as endogenous agonists of cannabinoid receptors type 1 and 2 (CB1 and CB2). ECs, EC anabolic and catabolic enzymes and cannabinoid receptors constitute the EC signalling system. This system participates in the control of lipid and glucose metabolism at several levels, with the possible endpoint of the accumulation of energy as fat. Following unbalanced energy intake, however, the EC system becomes dysregulated, and in most cases overactive, in several organs participating in energy homeostasis, particularly, in intraabdominal adipose tissue. This dysregulation might contribute to excessive visceral fat accumulation and reduced adiponectin release from this tissue, and to the onset of...