Cannabidiol (CBD) combined with delta-9 tetrahydrocannabinol (THC) was better at reducing seizures than either compound alone in an animal model, according to a new study.
Published in the peer-reviewed journal Cells, the study was conducted by researchers at the University of Toronto and the University Health Network in Toronto, The study was also published online by the US National Library of Medicine with the title Cannabidiol Exerts Anticonvulsant Effects Alone and in Combination with Δ9-THC through the 5-HT1A Receptor in the Neocortex of Mice.
“Cannabinoids have shown potential in drug-resistant epilepsy treatment; however, we lack knowledge on which cannabinoid(s) to use, dosing, and their pharmacological targets”, states the study’s abstract. “This study investigated (i) the anticonvulsant effect of Cannabidiol (CBD) alone and (ii) in combination with Delta-9 Tetrahydrocannabinol (Δ9-THC), as well as (iii) the serotonin (5-HT)1A receptor’s role in CBD’s mechanism of action.”
For the study, “Seizure activity, induced by 4-aminopyridine, was measured by extracellular field recordings in cortex layer 2/3 of mouse brain slices. The anticonvulsant effect of 10, 30, and 100 µM CBD alone and combined with Δ9-THC was evaluated.”
Researchers found that “An amount of ≥30 µM CBD alone exerted significant anticonvulsant effects while 10 µM CBD did not. However, 10 µM CBD combined with low-dose Δ9-THC (20:3 ratio) displayed significantly greater anticonvulsant effects than either phytocannabinoid alone.”
Furthermore, “blocking 5-HT1A receptors before CBD application significantly abolished CBD’s effects. Thus, our results demonstrate the efficacy of low-dose CBD and Δ9-THC combined and that CBD exerts its effects, at least in part, through 5-HT1A receptors. These results could address drug-resistance while providing insight into CBD’s mechanism of action, laying the groundwork for further testing of cannabinoids as anticonvulsants.”
Researchers conclude:
This study shows that CBD, especially at higher doses, displays anticonvulsant effects on mouse brain neocortical slices after seizure induction with 4-AP. The anticonvulsant effects of lower doses of CBD can be potentiated with the addition of low-dose Δ9-THC, suggesting that the combination of these phytocannabinoids, specifically at a 20:3 CBD: Δ9-THC ratio, can have greater anticonvulsant effects than either phytocannabinoid alone. Additionally, CBD’s anticonvulsant effects were abolished when slices were pre-treated with a 5-HT1A receptor antagonist. Thus, CBD exerts its anticonvulsant effects, at least in part, through the 5-HT1A receptor. In conclusion, these results help address the barrier of drug-resistance while providing insight into CBD’s mechanism of action, laying the groundwork for further testing of cannabinoids as anticonvulsants.
You can find the full text of the study by clicking here.
