The good face of Cannabis sativa: Cannabidiol

Abstract

Cannabidiol (CBD) is a phytocannabinoid derived from the Cannabis sativa plant, just l ike tetrahydrocannabinol (THC), but in contrast with the latter it shows no psychoactive effect. Unlike THC, CBD does not activate the reward system; however, it effects the opioid, serotonin, and cannabinoid receptor systems. Therefore, it is thought to be promising for the treatment of drug addiction. In particular, it acts as a non-competitive antagonist of CB1 receptor within the cannabinoid system (1). However, CBD has been shown not to be acting directly on the CB1 receptor. Most studies reported that it has no effect on the CB1 receptor at all, while some studies showed weak agonistic or weak antagonistic effects. CBD also has a low affinity for another cannabinoid receptor, the CB2 receptor (2). CBD can be converted into THC in some animal species and in laboratory settings, but this conversion does not happen in the human body (2,3). Because of its action on various receptors, cannabidiol’s effect is being investigated in many physical or psychiatric diseases. Clinical studies for the treatment of epilepsy are ongoing and positive results have been reported. In some preclinical studies, although not mainly in epilepsy, CBD has been shown to have neuroprotective, anxiolytic, antipsychotic, analgesic, anti-inflammatory, anti-asthmatic, and antitumor features (2). The therapeutic use of CBD has also been investigated in substance use disorders. Several preclinical studies have reported that CBD may have a therapeutic effect on opioid, cocaine, and psychostimulant addiction. Some studies have also obtained data suggesting that CBD may be beneficial in cannabis and tobacco addiction in humans (4). Substance use causes dysregulation in the mesolimbic circuit. CBD alleviates this dysregulation when administered regularly. Because of this feature, CBD was considered to be beneficial in substance use disorder. It is considered that its efficacy may depend on the dose and on whether it is administered before or in combination with the substance used (1). CBD is also thought to blunt the reward-facilitating effect of substance use through 5HT1A receptor agonism, which is effective in reducing stress and anxiety in the mesolimbic system. This suggestion is based on selective serotonin reuptake inhibitors and other antidepressants reducing substance use by alleviating mood symptoms. ABSTRACT