Neuroprotective effect of astaxanthin (ATX) against cognitive impairment on PTZ-induced epileptic seizures in rats and against PTZ-induced neurotoxicity in SH-SY5Y human neuroblastoma cell culture

Objective: Epilepsy is a common brain disorder that seizures could cause neuronal loss in the hippocampus. Oxidative stress has an important role in the pathology of this way. The aim of this study was to investigate the neuroprotective effect of astaxanthin (ATX), on pentylenetetrazole (PTZ) induced epileptic seizures in rats and in SH-SY5Y human neuroblastoma cell culture. Method: In our study, we used 42 male 230-250 g Wistar Albino rats. Animals were divided into seven groups as control, saline (PTZ; 1 ml/kg serum physiologic), positive control (2,5 mg/kg diazepam), 10 mg/kg, 20 mg/kg, 40 mg/kg and 80 mg/kg ATX for seven days. Thirty min after the administration of the last drug at the indicated doses, PTZ was administered 45 mg/kg to induce an epileptic seizure. The animals were observed for 30 min. Seizure stages according to the Racine Scale (RC) and first myoclonic jerk times (FMJ). Twenty four hours after PTZ injection, passive avoidance test was performed, and then brain tissues were removed for biochemical and histopathological evaluation. The hippocampal Cornu Ammonis 1 (CA1), CA3 and dentate gyrus (DG) regions were evaluated histopathologically regarding neuronal damage. Besides, oxidative stress markers total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)) were measured in brain tissues. Furthermore, ATX was performed in vitro SH-SY5Y human neuroblastoma cell culture to evaluate PTZ-induced neurotoxicity. Results: When epileptic behaviors were evaluated, ATX did not affect RC and FMJ (p>0, 05). However, ATX reduced both cognitive impairment in passive avoidance test and neuronal damage in the hippocampus (p<0, 05). Moreover, ATX reduced both TOS levels and OSI in the brain (p<0, 05). Besides of these in vitro studies, ATX increased neuronal viability in vitro. Conclusions: Although ATX does not have antiepileptic properties directly, it has a protective effect on not only in vivo but also in vitro. These effects may occur by possible oxidative pathways