Therapeutic Potentials and uses of Cannabinoid Agonists in Health and Disease Conditions

Cannabis and its derivatives have great therapeutic potential and have been used for centuries for medicinal purposes. The side effects of cannabinoids include euphoric mood changes, acute psychotic episodes, initiation and exacerbation of schizophrenic psychosis in predisposed persons, impaired cognitive and psychomotor performance, tachycardia and hypotension. The production of complex behavioural effects by cannabinoids are mediated by cannabinoid receptors (CB1 and CB2) and by interactions with other neurochemical systems. It has been shown that the therapeutic and physiological effects of cannabinoids are dependent upon whether the administration is acute or chronic and on the route of administration. The physiological effects of cannabis and its derivatives include: reduction in psychomotor coordination and performance, alterations in thermoregulation, endocrine and reproductive functions and gut motility. There is also evidence of agonist selectivity for CB1 receptors coupled to different subtypes of Gi proteins or to Gi versus Go proteins. Cannabinoid-activated receptors distinct from CB1 or CB2 exist in the central nervous system. Cannabinoids are known to inhibit GABA-mediated inhibitory postsynaptic currents in the hippocampus via a presynaptic action at CB1 receptors located on GABAergic terminals. CB1 receptors have also been implicated in the inhibition of glutamatergic excitatory postsynaptic currents. The synthetic cannabinoid, Win 55,212-2, a mixed CB1-CB2 cannabinoid receptor agonist, was found to attenuate hyperalgesia in a rat model of neuropathic pain and suppress opioid-induced emesis in ferrets.