Effect of Pterostilbene, a Natural Analog of Resveratrol, on the Activity of some Antiepileptic Drugs in the Acute Seizure Tests in Mice.

Pterostilbene (PTE), a natural analog of resveratrol, is available both as a diet ingredient and a dietary supplement. The present study was undertaken to assess the effect of PTE on the activity of antiepileptic drugs in the acute seizure tests in mice, i.e., the intravenous pentetrazole (iv PTZ) seizure threshold, maximal electroshock (MES), and 6 Hz-induced psychomotor seizure tests. Our study revealed that PTE enhanced the anticonvulsant effect of clonazepam but did not change the activity of tiagabine in the iv PTZ test. In the MES test, PTE increased the effect of carbamazepine but did not affect the protective properties of topiramate, while in the 6-Hz test, we noted a significant enhancement of the activity of oxcarbazepine, but there were no changes in the activity of valproate. Interactions of PTE with carbamazepine and oxcarbazepine were pharmacokinetic, which was determined by the increase of concentration of these antiepileptic drugs both in the serum and brain. In contrast, interactions between PTE and clonazepam were pharmacodynamic since there were no changes in the concentration of clonazepam. Combined treatment with carbamazepine and PTE significantly attenuated muscular strength (estimated in the grip strength test) but did not change motor coordination (assessed in the chimney test) in mice. Other studied antiepileptic drugs and their combinations with PTE did not change these parameters. Further studies are required to evaluate the influence of PTE on the activity of anticonvulsant drugs to estimate the safety of using PTE by patients with epilepsy.