"Screening of analgesic activity of industrial hemp isolates. Focusing on cannabidiol and cannabidiol acid"

Abstract

Cannabidiol (CBD) is a non-addictive ingredient of cannabis, which is synthesized through the decarboxylation of its precursor acid, cannabidiolic acid (CBDA). An amount of studies report that these two substances have a wide range of pharmacological properties, among them their analgesic effect, especially on neuropathic pain. However, few experimental studies have investigated the analgesic effect of low doses of CBD and CBDA. In the present study, the analgesic and motoric effects of both CBD (1, 3, 10, 30 mg/kg) and CBDA (0.03, 0.1, 0.3, 1, 3, 10 mg/kg) were investigated using the Open Field apparatus and the Hot Plate test. The analgesic properties of CBD were also studied in a rat model of neuropathic pain using the von Frey test. Present results showed that only the highest dose of CBD (30mg/kg) causes a decrease in spontaneous motor activity. Acute administration of CBD induced an analgesic effect at the dose of 1 mg/kg (i.p.), one hour following its administration. Additionally, chronic administration of CBD (1 and 3 mg/kg, i.p.) induced analgesic effect, using the Hot Plate test. On the other hand, acute CBD administration did not affect the analgesic action of codeine while it did not induce a statistically significant effect on neuropathic pain as deduced using the von Frey test. Finally, analgesic effect was also appeared following acute CBDA administration and this effect was prominent at the dose of 0.1 mg/kg (i.p.), using the Hot Plate test. The results of the present study show that the acute administration of CBD and CBDA induce analgesic effects at low doses. Moreover, analgesic effect was also observed following the chronic
administration of CBD. These findings confirm and extend information on phytocannabinoids-induced analgesia and contribute to the development of new therapeutic approaches for the treatment of pain.

ASPROGERAKAS Michalis