ABSTRACT

Cannabinoids are chemical compounds including natural cannabinoids found in the Cannabis plant, their synthetic counterparts, and endocannabinoids. Cannabidiol, a phytocannabinoid derived from the Cannabis plant, exerts anticonvulsant, anxiolytic, anti-inflammatory, neuroprotective, analgesic effects. Although there are many similarities between the pathophysiological mechanisms of pain and itch, researches that investigate the effect of cannabinoids on itching are insufficient. Here, we aimed to examine the antipruritic effect of cannabidiol and the contribution of spinal cannabinoid receptors.

Male Balb/c mice, weighing 20-30 g, were used. Itching behavior was produced by intradermal injection of compound 48/80 (100 μg/50 μl); cannabidiol (1, 3, 10 mg/kg, ip) was administered 30 minutes before compound 48/80 injections. Then, scratching of the injected site by the hind paws was videotaped for 30 minutes. Locomotor performances were assessed using a rotarod apparatus.

Cannabidiol had no effect on compound 48/80-induced itching behavior at any dose given; moreover, cannabidiol did not produce any impairment on motor function. AM-251, a cannabinoid receptor type 1 antagonist, and AM-630, a cannabinoid receptor type 2 antagonist were administered intrathecally to observe the contribution of spinal cannabinoid receptors to the antipruritic action of cannabidiol. We observed that cannabidol did not possess any effect on itching behaviour.

Our results indicate that systemic administration of cannabidiol does not attenuate compound 48/80 induced itching behavior in mice.

Keywords: Cannabidiol, compound 48-80, pruritus