Anti-convulsive Effect of Thiamine and Melatonin Combination in Mice: Involvement of Oxidative Stress.

Background: Epilepsy, the second most frequent neurological disease, is a chronic disorder with a high lifetime prevalence. Therefore, various studies are needed to find new effective therapeutic agents to treat seizures or prevent their complications. In this study, we investigated the effects of thiamine, melatonin and their combination on pentylenetetrazol (PTZ)-induced tonic-clonic seizures in mice.

Methods: Male mice were randomly divided into six groups, including control, seizure control, diazepam, melatonin, thiamine and melatonin, and thiamine combination groups. Drugs were given orally in drinking water for 14 days. On the 15th day, the seizure was induced (except the control group) by intraperitoneal injection of PTZ. In all groups, the time between the injection and the start of the seizure (latency), and also the length of the seizure attack (duration), were measured in a 30-minute period. After measuring the latency and duration in all groups, mice were killed by CO₂ Box and their brains were dissected to be analyzed for malondialdehyde (MDA) level as a marker of oxidative stress.

Results: The seizure duration was significantly lower in the groups of melatonin, thiamine and thiamine and melatonin combination compared to the seizure control group. The latency times in these groups were significantly greater than in the seizure control group. Moreover, MDA concentrations were lower in these groups compared to the seizure control group.

Conclusion: Thiamine, melatonin and their combination can decrease the duration time of seizure and increase the latency period, which may result from inhibition of oxidative stress in the brain.