Cannabis sativa has been used as an anti-inflammatory plant for millennia. However until the elucidation of the chemistry of its constituents and the discovery of the endogenous cannabinoid system only a limited amount of research had been done on the effects of the plant or its constituents on inflammation. In the present overview we summarize our work on the effects of the non-psychotropic cannabidiol (CBD) and of a synthetic cannabidiol-derived acid (HU-320) in animal models of arthritis. Both compounds block progression of the disease, when administered after its onset. Cannabidiol was equally effective was administered i.p. or orally. Significant protection of the joints against...