Methylene Blue Exerts Anticonvulsant and Neuroprotective Effects on Self-Sustaining Status Epilepticus (SSSE) Induced by Prolonged Basolateral Amygdala Stimulation in Wistar Rats

BACKGROUND: This study was designed to investigate the potential anticonvulsant and neuroprotective effects of methylene blue (MB) on self-sustaining status epilepticus (SSSE) induced by prolonged basolateral amygdala stimulation (BLA) in Wistar rats. MATERIAL/METHODS: The rats were randomly divided into 4 groups: (1) the Control group (rats without any treatment); (2) the Sham group (rats received electrode implantation but without electrical stimulation); (3) the SSSE group (rats received electrode implantation and additional electrical stimulation); and (4) the SSSE+MB group (rats received 1 mg/kg MB intraperitoneal injection 5 min after SSSE). SSSE models were established by prolonged BLA stimulation. The severities of SSSE were assessed by the number of separate seizures and the accumulated time of seizures. The variations of malondialdehyde/glutathione (MDA/GSH) were assessed 24 h after the establishment of SSSE. Nissl staining was performed to detect the surviving neurons in hippocampal CA1 and CA3 regions, and Western blotting assays were used to detect Caspase-3 (CASP3), B cell lymphoma 2 (BCL2), and BCL2-associated X protein (BAX). RESULTS: Compared with the SSSE group, treatment with MB (1) markedly reduced the number and accumulated time of seizure activities; (2) significantly attenuated the increase of MDA and the decrease of GSH hippocampal levels; (3) markedly improved the cell morphology and alleviated the neuronal loss in hippocampal CA1 and CA3 regions; (4) significantly attenuated the increase of CASP3 and BAX and the decrease of BCL2 hippocampal levels. CONCLUSIONS: MB has a protective effect in the SSSE model and may be useful as an adjuvant for preventing or treating epilepsy in humans.