Dexanabinol (HU-211) effect on experimental autoimmune encephalomyelitis: implications for the treatment of acute relapses of multiple sclerosis.

Dexanabinol (HU-211) is a synthetic non-psychotropic cannabinoid which suppresses TNF-alpha production in the brain and peripheral blood. The effects of dexanabinol in rat experimental autoimmune encephalomyelitis (EAE) were studied using different doses, modes of administration and time regimes. Dexanabinol, 5 mg/kg i.v. given once after disease onset (day 10), significantly reduced maximal EAE score. Increasing the dose or treatment duration resulted in further suppression of EAE. Drug administration at earlier phases during disease induction was not effective. Histological studies supported the clinical findings demonstrating reduction in the inflammatory response in the brain and spinal cord in animals treated with dexanabinol. The results suggest that dexanabinol may provide an alternative mode of treatment for acute exacerbations of multiple sclerosis (MS).