EVALUATION OF THE EFFECTS OF ZAFIRLUKAST ON THE CENTRAL NERVOUS SYSTEM IN PENTYLENETETRAZOLE INDUCED KINDLING EPILEPSY MODEL

Project no. 22874 · Status: Kapanmış · 2021

Summary

Epilepsy affects around 50 million people worldwide. While 25% of patients do not respond to treatment, 25% of epilepsy patients have preventable causes. For this reason, treatments to prevent epileptogenesis are needed.In the literature, CysLTR antagonists have been shown to have ameliorative effects in experimental epilepsy conditions, but most of these studies are electrophysiological studies and their histopathological effects have not been sufficiently investigated. Whether they have protective effects on gliosis, tight junctions and cytokine association, which are important in pathogenesis, has not been shown. It has not been shown whether they have effects on BBB permeability in PTZ kindling model. Zafirlukast has not been tested in epilepsy conditions. For these reasons, we aimed to evaluate the effects of zafirlukast in PTZ kindling epilepsy model.In our study, 75 male C57BL6 mice between 20-30 g were used. Experimental groups were divided as Saline, DMSO, Zafir, PTZ, PTZ+Zafir with n=15. PTZ and PTZ+Zafir were performed with PTZ induction every other day and kindling model was developed. Seizure severity of the subjects were examined according to the modified Racine epilepsy severity scale and seizure latency, frequency and duration were also evaluated. In each group, n=3 subjects were examined for BBB permeability with Evans Blue. The remaining n=12 subjects were evaluated in open field test. From each group, n=6 subjects were included in histologic analysis and n=6 subjects were included in biochemical analysis.PTZ+Zafir group had more severe, shorter latency, more frequent and longer seizures than PTZ. In open field test, PTZ+Zafir group was more anxious compared to Saline group. In Evans Blue evaluation, PTZ+Zafir group had more severe BBB permeability in all regions except cerebellum compared to all groups, while the second highest permeability was in PTZ. There was no difference between the other groups. In BBB evaluation with albumin, PTZ+Zafir had the highest intensity in all regions, while in the cerebral cortex, the intensity in Zafir was more severe compared to Saline and DMSO. ZO-1 expression was decreased in PTZ+Zafir and PTZ. There was no difference between the other groups.In histologic examinations, PTZ had a higher number of degenerated neurons in all regions, while PTZ+Zafir improved the number of degenerated neurons in all regions. In CA1 region, the number of degenerated neurons in Zafir was higher than Saline. While Iba-1 expression was higher in PTZ in all regions, there was no difference between the other groups. GFAP expression was higher in PTZ and PTZ+Zafir in all regions. In CA3, CA1 and cerebellum, Zafir group had higher GFAP expression than Saline. There was loss of NeuN expression in DG, CA3, CA1 and cerebral cortex in PTZ+Zafir. In PTZ, there was loss of NeuN expression in CA1 and cerebral cortex regions. Zafir had higher NeuN expression in the DG region than Saline and in the CA3 region than both Saline and DMSO.In biochemical analysis, PTZ+Zafir had higher TGF-β1 levels in the cerebrum than Saline. There was no difference between the groups in terms of IL-1β, MMP-9, MDA and MPO levels.Zafirlukast treatment had dual effects in PTZ kindling model. Contrary to our hypothesis, epileptic activity worsened in PTZ+Zafir. There may be an excitability enhancing effect of zafirlukast by an unknown mechanism or drug interaction with PTZ. By increasing albumin exposure of brain tissue, it may have caused TGF-β1-mediated astrocyte activation and potentiated the mechanisms of epileptogenesis. However, zafirlukast increased NeuN expression in some regions. Since there was lower microglial activation in PTZ+Zafir, fewer degenerating neurons, and although the PTZ+Zafir group had more severe seizures, there was no expected increase in IL-1β, MMP-9, MDA and MPO levels compared to the literature, the possible positive effects of zafirlukast are inhibition of microglia-related inflammation pathways and neuroprotection by preventing oxidative stress. In order to better understand the effects of zafirlukast on epilepsy, it should be tested in different epilepsy models, at different doses and solvents, with different treatment timings.Keywords: Blood-Brain Barrier; Zafirlukast; Epilepsy, generalized

View details