Hippocampus protection from apoptosis by Baicalin in a LiClpilocarpine-induced rat status epilepticus model through autophagy activation

BACKGROUND Autophagy is associated with hippocampal injury following status epilepticus(SE)and is considered a potential therapeutic mechanism.Baicalin,an emerging multitherapeutic drug,has shown neuroprotective effects in patients with nervous system diseases due to its antioxidant properties.AIM To investigate the potential role of autophagy in LiCl-pilocarpine-induced SE.METHODS The drugs were administered 30 min before SE.Nissl staining showed that Baicalin attenuated hippocampal injury and reduced neuronal death in the hippocampus.Western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling assay confirmed that Baicalin reversed the expression intensity of cleaved caspase-3 and apoptosis in hippocampal CA1 following SE.Furthermore,western blotting and immunofluorescence staining were used to measure the expression of autophagy markers(p62/SQSTM1,Beclin 1,and LC3)and apoptotic pathway markers(cleaved caspase-3 and Bcl-2).RESULTS Baicalin significantly upregulated autophagic activity and downregulated mitochondrial apoptotic pathway markers.Conversely,3-methyladenine,a commonly used autophagy inhibitor,was simultaneously administered to inhibit the Baicalin-induced autophagy,abrogating the protective effect of Baicalin on the mitochondrial apoptotic level.CONCLUSION We illustrated that Baicalin-induced activation of autophagy alleviates apoptotic death and protects the hippocampus of SE rats.

Optimal concentration of necrostatin-1 for protecting against hippocampal neuronal damage in mice with status epilepticus

Hippocampal neurons undergo various forms of cell death after status epilepticus.Necrostatin-1 specifically inhibits necroptosis mediated by receptor interacting protein kinase 1 (RIP1) and RIP3 receptors.However,there are no reports of necroptosis in mouse models of status epilepticus.Therefore,in this study,we investigated the effects of necrostatin-1 on hippocampal neurons in mice with status epilepticus,and,furthermore,we tested different amounts of the compound to identify the optimal concentration for inhibiting necroptosis and apoptosis.A mouse model of status epilepticus was produced by intraperitoneal injection of kainic acid,12 mg/kg.Different concentrations of necrostatin- 1 (10,20,40,and 80 μM) were administered into the lateral ventricle 15 minutes before kainic acid injection.Hippocampal damage was assessed by hematoxylin-eosin staining 24 hours after the model was successfully produced.Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining,western blot assay and immunohistochemistry were used to evaluate the expression of apoptosis-related and necroptosis-related proteins.Necrostatin-1 alleviated damage to hippocampal tissue in the mouse model of epilepsy.The 40 μM concentration of necrostatin-1 significantly decreased the number of apoptotic cells in the hippocampal CA1 region.Furthermore,necrostatin-1 significantly downregulated necroptosis-related proteins (MLKL,RIP1,and RIP3) and apoptosis-related proteins (cleaved-Caspase-3,Bax),and it upregulated the expression of anti-apoptotic protein Bcl-2.Taken together,our findings show that necrostatin-1 effectively inhibits necroptosis and apoptosis in mice with status epilepticus,with the 40 μM concentration of the compound having an optimal effect.The experiments were approved by the Animal Ethics Committee of Fujian Medical University,China (approval No.2016-032) on November 9,2016.