The antinociceptive activity and mechanism of action of cannabigerol.

Cannabis has been used for centuries to treat pain. The antinociceptive activity of tetrahydrocannabinol (THC) or cannabidiol (CBD) has been widely studied. However, the antinociceptive effects of other cannabis components, such as cannabichromene (CBC) and cannabigerol (CBG), have rarely been revealed. The antinociceptive mechanism of CBG is not yet clear, so we investigated the antinociceptive effect of CBG on different pain models, and explored the mechanism of action of CBG to exert antinociceptive effects. In the current study, we compared the antinociceptive effects of CBC, CBD, and CBG on the carrageenan-induced inflammatory pain model in mice, and the results showed that CBG had a better antinociceptive effects through intraplantar administration. On this basis, we further investigated the antinociceptive effect of CBG on CIA-induced arthritis pain model and nerve pain model in mice, and found that CBG also relieved on both types of pain. Then, we explored the antinociceptive mechanism of CBG, which revealed that CBG can activate TRPV1 and desensitize it to block the transmission of pain signals. In addition, CBG can further activate CB2R, but not CB1R, to stimulate the release of β-endorphin, which greatly promotes the antinociceptive effect. Finally, the safety test results showed that CBG had no irritating effect on the rabbits' skin, and it did not induce significant biochemical and hematological changes in mice. Transdermal delivery results also indicated that CBG has certain transdermal properties. Overall, this study indicates that CBG is promising for developing a transdermal dosage for pain management.