Effects of thymoquinone, the major constituent of Nigella sativa seeds, on penicillin-induced epileptiform activity in rats.

Objective: To investigate the effects of thymoquinone (TQ) in a penicillin-induced epilepsy model in rats.

Methods: This experimental study included 56 adult male Wistar rats. Experiments were performed in the Research Laboratory of the Department of Physiology, Medical School, Duzce University, Duzce, Turkey, between October 2013 and December 2014. Animals were divided into the following 7 groups: sham, control, only thymoquinone, vehicle (Dimethylsulfoxide), and doses of 10, 50, and 100 mg/kg of TQ. After rats were anesthetized, the left part of the skull was removed. A pair of silver/silver chloride electrodes was placed on the somatomotor area, and electrocorticographic recording was started. After 5 minutes basal activity was recorded, and TQ was applied intraperitoneally. At the thirtieth minute after TQ, epileptiform activity was induced by intracortical penicillin. The first spike latency, spike frequency, and the amplitude of epileptiform activity were analyzed statistically.

Results: The different doses of TQ significantly increased the latency time to onset of first spike wave, and decreased the frequency, and amplitude of epileptiform activity in the first 20 minutes compared with the control group.

Conclusion: Thymoquinone shows potential as an antiepileptic drug resulting from its effects of prolonged latency time, and reduced spike wave frequency and amplitude of epileptiform activity.