Ginsenoside Rg1 protects against neurodegeneration by inducing neurite outgrowth in cultured hippocampal neurons

作     者：Liang Huang Li-feng Liu Juan Liu Ling Dou Ge-ying Wang Xiao-qing Liu Qiong-lan Yuan 

作者机构：Department of Neurology Shanghai Tongji Hospital Tongji University School of Medicine 

出 版 物：《Neural Regeneration Research》 (中国神经再生研究（英文版）)

年 卷 期：2016年第11卷第2期

页      面：319-325页

核心收录：

学科分类：0710[理学-生物学] 1006[医学-中西医结合] 1002[医学-临床医学] 1001[医学-基础医学(可授医学、理学学位)] 10[医学] 100602[医学-中西医结合临床] 

基　　金：financially supported by the National Program on Key Basic Research Project of China(973 Program),No.2010CB945600,2011CB965100 the National Natural Science Foundation of China,No.81070987,30971531,81371213 a grant from the International Science & Technology Collaboration Program,No.2011DF30010 

主　　题：nerve regeneration ginsenoside Rgl neurite outgrowth Aft25 35 hippocampal neurons Akt MAPK apoptosis growth associatedprotein-43 Hoechst 33258 staining PD98059 API-2 neural regeneration 

摘      要：Ginsenoside Rg1（Rg1） has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal survival and neurite outgrowth in vitro after exposure to amyloid-beta peptide fragment 25–35（Aβ_（25–35））, and to explore whether the extracellular signal-regulated kinase（ERK） and Akt signaling pathways are involved in these biological processes. We cultured hippocampal neurons from newborn rats for 24 hours, then added Rg1 to the medium for another 24 hours, with or without pharmacological inhibitors of the mitogen-activated protein kinase（MAPK） family or Akt signaling pathways for a further 24 hours. We then immunostained the neurons for growth associated protein-43, and measured neurite length. In a separate experiment, we exposed cultured hippocampal neurons to Aβ_（25–35） for 30 minutes, before adding Rg1 for 48 hours, with or without Akt or MAPK inhibitors, and assessed neuronal survival using Hoechst 33258 staining, and phosphorylation of ERK1/2 and Akt by western blot analysis. Rg1 induced neurite outgrowth, and this effect was blocked by API-2（Akt inhibitor） and PD98059（MAPK/ERK kinase inhibitor）, but not by SP600125 or SB203580（inhibitors of c-Jun N-terminal kinase and p38 MAPK, respectively）. Consistent with this effect, Rg1 upregulated the phosphorylation of Akt and ERK1/2; these effects were reversed by API-2 and PD98059, respectively. In addition, Rg1 significantly reversed Aβ_（25–35）-induced apoptosis; this effect was blocked by API-2 and PD98059, but not by SP600125 or SB203580. Finally, Rg1 significantly reversed the Aβ_（25–35）-induced decrease in Akt and ERK1/2 phosphorylation, but API-2 prevented this reversal. Our results indicate that Rg1 enhances neurite outgrowth and protects against Aβ_（25–35）-induced damage, and that its mechanism may involve the activation of Akt and ERK1/2 signaling.