Evaluation of the possible effect of oleuropein and relationship with the nitrergic system at penicillin-induced epileptiform activity model

Epilepsy is a very common neurological disease characterized by unprovoked and spontaneously recurrent seizures. Along with many different factors underlying the epileptic seizure formation mechanism, neurotransmitters are also thought to play a role. There are many studies examining the effect of nitric oxide, which functions as a neurotransmitter in the brain and as a secondary Messenger molecule in target cells, on epileptic activity. Experimental epilepsy models help to understand the mechanism of epileptogenesis and seizure formation. 88 male Wistar albino rats were divided into 11 groups. The effective dose was determined by administering oleuropein intraperitoneally in 3 different doses (20, 40, 80 mg/kg) 30 minutes after epileptic activity was created by administering 500 units of penicillin intracortically to rats under urethane anesthesia. In the second stage, nitrergic system agonist (L-Arginine) and antagonist (7-NI, L-NAME) agents were administered intraperitoneally alone and together with the effective dose of oleuropein. After 120 minutes of recording of interictal spike activity, the rats were decapitated and cerebral tissues were extracted. For statistical analysis, Kruskal Wallis test was used to compare the means of variables with three or more groups. Mann Whitney U was used to compare the means of variables with two groups. Compared to the Pen G group, it was determined that the percentage changes in the spike frequency of the group given 80 mg/kg oleuropein were significantly reduced and the effective dose of 80 mg/kg oleuropein was determined. When the effective dose group was compared with the combination groups, no evidence was found to indicate that the anticonvulsant effect of oleuropein was related to the nitrergic system. In pathological analyses, no significant difference was found between the experimental groups in terms of inflammation and congestion. In biochemical analyses, when the OLE effective dose group (80 mg/kg) was compared with the Pen G group, MDA values were significantly lower in the effective dose OLE group (p=0.001), while SOD, CAT and GPx values were significantly higher (p=0.035, p=0.002, p=0.035, respectively). As a result of this study, it was determined that oleuropein had an anticonvulsant effect in the epileptic activity model created by penicillin. More comprehensive studies are needed for the use of oleuropein in the treatment of epilepsy. Keywords: Epilepsy, Nitric oxide, Oleuropein