Cannabinoid-mediated neuroprotection, not immunosuppression, may be more relevant to multiple sclerosis

Cannabinoids may exhibit symptom control in multiple sclerosis (MS). We show here that cannabinoid receptor (CBR) agonists can also be immunosuppressive and neuroprotective in models of MS. Immunosuppression was associated with reduced: myelin-specific T cell responses; central nervous system infiltration and reduced clinical disease. This was found to be largely CB1R-dependent and only occurred at doses that induced significant cannabimimetic effects that would not be achieved clinically. Lower, non-immunosuppressive doses of cannabinoids however, slowed the accumulation of nerve loss and disability, despite failing to inhibit relapses. This further highlights the neuroprotective potential of cannabinoids to slow the progression of MS. (C) 2007 Elsevier B.V. All rights reserved.