CBD & D9-THC - the two faces of cannabis

Cannabidiol (CBD) and D9-tetrahydrocannabinol (D9-THC) are phytocannabinoids produced by the plant Cannabis sativa which have both shown promising therapeutic value as anti-inflammatory and neuroprotective agents in a variety of neurological disorders. However, the molecular mechanisms involved in their protective function are thought to be distinctly different probably due to their divergent receptor pharmacology. D9-THC is a potent agonist at the cannabinoid receptors 1 and 2 through which it is thought to modulate synaptic plasticity and inflammatory responses respectively. CBD on the other hand exhibits negligible affinity for both receptors prompting research into cannabinoid receptor independent mechanisms of action such as modulation of endogenous cannabinoid tone and calcium signalling. This review aims to give an introduction into the pharmacological and biological effects of D9-THC and CBD with particular reference to neurological disease