Effects of chronic administrati̇on of thymoquinone on penicillin induced epileptiform activity in rats

Thymoquinone (TQ) is derived from Nigella sativa (NS) which is a traditional medical plant and used as a food additive. Aim of this study is to investigate chronic effects of thymoquinone, which has been shown anticonvulsant, anticancer, antioxidant and neuroprotective effects, on experimental penicillin-induced epilepsy model in rats. In this study 49 adult male Wistar rats were used, and these rats were divided into 7 groups as control (saline), control (penicillin), control (diazepam), the doses of 10 mg/kg and 50 mg/kg of thymoquinone and 10 mg/kg TQ+ diazepam and 50 mg/kg TQ + diazepam. All of the substances were administered intraperitoneally during 21 days, except penicillin. After rats were anesthetized with administration of the 1.25 g/kg dose urethane intraperitoneally, the left part of the cortex was opened and the electrodes were placed on somatomotor area. Epileptiform activity was induced by intracortical (i.c.) administration of penicillin (500 IU, 2.5 μl). Obtained electrocorticographic (ECoG) data from recordings were analyzed by software. The first spike latency, spike wave frequency, and spike wave amplitude of epileptiform activity were analyzed statistically. When the groups were compared in terms of latency time to onset of the first epileptiform activity, it was determined that latency time to onset of the first epileptiform activity of all groups was longer than the control group (p = 0.007). There were no significant difference was found between the groups except for some time periods (p>0,05). In conclusion, it was observed that the application of chronic thymokinone on an experimental penicillin induced epileptiform activity model in rats did not detect any spike wave frequency and amplitude representing epileptic seizures, but prolonged the onset of initial epileptiform activity. However it was determined that TQ prolonged latency time to onset of the first epileptiform activity.