Abstract The cannabinoid system is now recognized as a regulator of both the nervous and immune systems. Although marijuana has been used for centuries for the treatment of a variety of disorders, its therapeutic mechanisms are only now being understood. The best-studied plant cannabinoid, delta9-tetrahydrocannabinol (THC), produced by Cannabis sativa and found in marijuana, has shown evidence of being immunosuppressive in both in vivo and in vitro. Since THC binds to at least two receptors that are differentially expressed by the immune and nervous systems, it has not been possible to clearly discriminate the biological effects it exerts in the two systems. In addition,...

Cannabinoids are a group of compounds that mediate their effects through cannabinoid receptors. The discovery of Δ9 -tetrahydrocannabinol (THC) as the major psychoactive principle in marijuana, as well as the identification of cannabinoid receptors and their endogenous ligands, has led to a significant growth in research aimed at understanding the physiological functions of cannabinoids. Cannabinoid receptors include CB1, which is predominantly expressed in the brain, and CB2, which is primarily found on the cells of the immune system. The fact that both CB1 and CB2 receptors have been found on immune cells suggests that cannabinoids play an important role in the regulation of the...

Multiple sclerosis is increasingly being recognized as a neurodegenerative disease that is triggered by in¯ammatory attack of the CNS. As yet there is no satisfactory treatment. Using experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis, we demonstrate that the cannabinoid system is neuroprotective during EAE. Mice de®cient in the cannabinoid receptor CB1 tolerate in¯ammatory and excitotoxic insults poorly and develop substantial neurodegeneration following immune attack in EAE. In addition, exogenous CB1 agonists can provide signi®cant neuroprotection from the consequences of in¯ammatory CNS disease in an experimental allergic uveitis model. Therefore, in addition to symptom management, cannabis may also slow the neurodegenerative processes...

Amongst the various demyelinating diseases that affect the central nervous system, those induced by an inflammatory response stand out because of their epidemiological relevance. The best known inflammatory-induced demyelinating disease is multiple sclerosis, but the immune response is a common pathogenic mechanism in many other less common pathologies (e.g., acute disseminated encephalomyelitis and acute necrotizing haemorrhagic encephalomyelitis). In all such cases, modulation of the immune response seems to be a logical therapeutic approach. Cannabinoids are well known immunomodulatory molecules that act through CB1 and CB2 receptors. While activation of CB1 receptors has a psychotropic effect, activation of CB2 receptors alone does not. Therefore, to...

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...

The ability of cannabinoids to modulate both inflammatory and degenerative neuronal damage prompted investigations on the potential benefits of such compounds in multiple sclerosis (MS)and in animal models of this disorder. Here we measured endocannabinoid levels, metabolism and binding, and physiological activities in 26 patients with MS (17 females, aged 19­43 years),25 healthy controls and in mice with experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS. Our results show that MS and EAE are associated with significant alterations of the endocannabinoid system. We found that anandamide (AEA),but not 2­arachidonoylglycerol (2­AG), was increased in the CSF of relapsing MS patients. AEA concentrations were also...

Theiler’s virus infection of the CNS induces an immune-mediated demyelinating disease in susceptible mouse strains and serves as a relevant infection model for human multiple sclerosis (MS). Cannabinoids may act as immunosuppressive compounds that have shown therapeutic potential in chronic inflammatory disorders. Using the Theiler’s murine encephalomyelitis virus model, we report here that treatment with the synthetic cannabinoids WIN 55,212–2, ACEA, and JWH-015 during established disease significantly improved the neurological deficits in a long-lasting way. At a histological level, cannabinoids reduced microglial activation, abrogated major histocompatibility complex class II antigen expression, and decreased the number of CD4infiltrating T cells in the spinal cord. Both...