Delta(9)-tetrahydrocannabinol binds cannabinoid (CB(1) and CB(2)) receptors, which
are activated by endogenous compounds (endocannabinoids) and are involved in a wide
range of physiopathological processes (e.g. modulation of neurotransmitter release,
regulation of pain perception, and of cardiovascular, gastrointestinal and liver functions).
The well-known psychotropic effects of Delta(9)-tetrahydrocannabinol, which are mediated
by activation of brain CB(1) receptors, have greatly limited its clinical use. However,
the plant Cannabis contains many cannabinoids with weak or no psychoactivity that,
therapeutically, might be more promising than Delta(9)-tetrahydrocannabinol. Here,
we provide an overview of the recent pharmacological advances, novel mechanisms of
action, and potential therapeutic applications of such non-psychotropic plant-derived
cannabinoids. Special emphasis is given to cannabidiol, the possible applications
of which have recently emerged in inflammation, diabetes, cancer, affective and neurodegenerative
diseases, and to Delta(9)-tetrahydrocannabivarin, a novel CB(1) antagonist which exerts
potentially useful actions in the treatment of epilepsy and obesity.