Antiepileptic Effects of Cicadae Periostracum on Mice and Its Antiapoptotic Effects in H2O2-Stimulated PC12 Cells via Regulation of PI3K/Akt/Nrf2 Signaling Pathways

Abstract

Cicadae Periostracum (CPM), a commonly used animal traditional Chinese medicine (TCM), possesses antifebrile, spasmolytic, antiasthmatic, and antiphlogistic effects. In our present paper, we aimed to systemically investigate the antiepileptic effects of CPM in epileptic mice and explore the related molecular mechanism. Pentylenetetrazole- (PTZ) and strychnine-induced convulsion mice were established, and the results showed CPM could prolong the latency of convulsion and death and improve the neuronal damage in the hippocampus of PTZ-induced mice. Furthermore, the H2O2-treated PC12 cells were prepared to explore the possible mechanisms for the antiepileptic effects of CPM. CCK-8 results showed that CPM significantly improved the cell viability of H2O2-treated PC12 cells. Results of the acridine orange- (AO-) ethidium bromide (EB) staining, cell mitochondrial membrane potential (MOMP) analysis, and flow cytometry analysis showed that CPM significantly suppressed the H2O2-induced apoptosis in PC12 cells. In addition, CPM also downregulated the proapoptosis proteins, including Bax, cleaved- (C-) caspase-3, and C-caspase-9, and upregulated Bcl-2. Furthermore, CPM reduced the reactive oxygen species (ROS) levels via increasing antioxidative enzyme activities, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). Importantly, CPM could increase the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) in H2O2-induced PC12 cells and can promote the nuclear transfer of the nuclear factor E2-related factor 2 (Nrf2) and increase the expression of heme oxygenase-1 (HO-1) in the cytoplasm. In conclusion, our present study suggested CPM possessed antiepileptic effects through antiapoptosis of neuron cells via regulation of the PI3K/Akt/Nrf2 signaling pathway.