title: Synergism and mechanism of Astragaloside IV combined with Ginsenoside Rg1 against autophagic injury of PC12 cells induced by oxygen glucose deprivation/reoxygenation.
abstract: The aim of this study was to explore the effect by which the combination of Astragaloside IV (AST IV) and Ginsenoside Rg1 (Rg1) resisted autophagic injury in PC12 cells induced by oxygen glucose deprivation/reoxygenation (OGD/R). We studied the nature of the interaction between AST IV and Rg1 that inhibited autophagy through the Isobologram method, and investigated the synergistic mechanism via the PI3K I/Akt/mTOR and PI3K III/Becline-1/Bcl-2 signaling pathways. Our results showed that, based on the 50% inhibiting concentration (IC50), AST IV combined with Rg1 at a 1:1 ratio resulted in a synergistic effect, whereas the combination of the two had an antagonistic effect on autophagy at ratios of 1:2 and 2:1. Meanwhile, AST IV and Rg1 alone increased cell survival and decreased lactate dehydrogenase (LDH) leakage induced by OGD/R, reduced autophagosomes and the LC3 II positive patch, down-regulated the LC3 II/LC3 I ratio and up-regulated the p62 protein; the 1:1 combination enhanced these effects. Mechanistic study showed that Rg1 and the 1:1 combination increased the phosphorylation of PI3K I, Akt and mTOR; the effects of the combination were greater than those of the drugs alone. AST IV and the 1:1 combination suppressed the expression of PI3K III and Becline-1, and the combination elevated Bcl-2 protein expression; the effects of the combination were better than those of the drugs alone. These results suggest that after 2 h-OGD followed by reoxygenation for 24h, PC12 cells suffer excessive autophagy and damage, which are blocked by AST IV or Rg1; moreover, the combination of AST IV and Rg1 at a 1:1 ratio of their IC50 concentrations has a synergistic inhibition on autophagic injury. The synergistic mechanism may be associated with the PI3K I/Akt/mTOR and PI3K III/Becline-1/Bcl-2 signaling pathways.
authors.affiliation: Molecular Pathology Laboratory, Hunan Provincial Key Laboratory for Prevention and Treatment of Integrated Traditional Chinese and Western Medicine on Cardio-Cerebral Diseases, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Huang
authors.affiliation: Molecular Pathology Laboratory, Hunan Provincial Key Laboratory for Prevention and Treatment of Integrated Traditional Chinese and Western Medicine on Cardio-Cerebral Diseases, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Huang
authors.initials: H
authors.lastname: Ding
authors.affiliation: Molecular Pathology Laboratory, Hunan Provincial Key Laboratory for Prevention and Treatment of Integrated Traditional Chinese and Western Medicine on Cardio-Cerebral Diseases, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Xiao-Qian
authors.initials: XQ
authors.lastname: Yang
authors.affiliation: Molecular Pathology Laboratory, Hunan Provincial Key Laboratory for Prevention and Treatment of Integrated Traditional Chinese and Western Medicine on Cardio-Cerebral Diseases, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Jing-Xian
authors.initials: JX
authors.lastname: Li
authors.affiliation: Hunan Education Department's Key Laboratory of Cell Biology and Molecular Technology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Biao
authors.initials: B
authors.lastname: Tang
authors.affiliation: Hunan Education Department's Key Laboratory of Cell Biology and Molecular Technology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Liu
authors.affiliation: Hunan Education Department's Key Laboratory of Cell Biology and Molecular Technology, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China.
authors.forename: Ying-Hong
authors.initials: YH
authors.lastname: Tang
authors.affiliation: Molecular Pathology Laboratory, Hunan Provincial Key Laboratory for Prevention and Treatment of Integrated Traditional Chinese and Western Medicine on Cardio-Cerebral Diseases, Hunan University of Chinese Medicine, Changsha, Hunan 410208, PR China. Electronic address: dchangq@sohu.com.
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Deng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D015687:Cell Hypoxia / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004357:Drug Synergism; D036145:Ginsenosides / Q000494:pharmacology*; D005947:Glucose / Q000172:deficiency*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology; D016716:PC12 Cells; D010588:Phagosomes / Q000187:drug effects; D051381:Rats; D012503:Saponins / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D014315:Triterpenes / Q000494:pharmacology*
chemical_list: D036145:Ginsenosides; D018696:Neuroprotective Agents; D012503:Saponins; D014315:Triterpenes; C052064:astragaloside A; D007770:L-Lactate Dehydrogenase; D005947:Glucose; C035054:ginsenoside Rg1
keywords: Astragaloside IV; Autophagic injury; Ginsenoside Rg1; PC12 cells OGD/R; PI3K I/Akt/mTOR; PI3K III/Beclin-1/Bcl-2; Synergism