Cannabis sativa has been associated with contradictory effects upon seizure states despite its medicinal
use by numerous people with epilepsy. We have recently shown that the phytocannabinoid cannabidiol
(CBD) reduces seizure severity and lethality in the well-established in vivo model of pentylenetetrazoleinduced generalised seizures, suggesting that earlier, small-scale clinical trials examining CBD effects in
people with epilepsy warrant renewed attention. Here, we reportthe effects of pure CBD (1, 10 and 100 mg/
kg) in two other established rodent seizure models, the acute pilocarpine model of temporal lobe seizure
and the penicillin model of partial seizure. Seizure activity was video recorded and scored offline using
model-specific seizure severity scales. In the pilocarpine model CBD (all doses) significantly reduced the
percentage of animals experiencing the most severe seizures. In the penicillin model, CBD (10 mg/kg)
significantly decreased the percentage mortality as a result of seizures; CBD (all doses) also decreased the
percentage of animals experiencing the most severe tonic–clonic seizures. These results extend the anticonvulsant profile of CBD; when combined with a reported absence of psychoactive effects, this evidence
strongly supports CBD as a therapeutic candidate for a diverse range of human epilepsies.
