Neuroprotective effects of ginsenoside Rb1 on hippocampal neuronal injury and neurite outgrowth

Abstract

Ginsenoside Rb1 has been reported to exert anti-aging and anti-neurodegenerative effects. In the present study, we investigate whether ginsenoside Rb1 is involved in neurite outgrowth and neuroprotection against damage induced by amyloid beta (25–35) in cultured hippocampal neurons, and explore the underlying mechanisms. Ginsenoside Rb1 significantly increased neurite outgrowth in hippocampal neurons, and increased the expression of phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2. These effects were abrogated by API-2 and PD98059, inhibitors of the signaling proteins Akt and MEK. Additionally, cultured hippocampal neurons were exposed to amyloid beta (25–35) for 30 minutes; ginsenoside Rb1 prevented apoptosis induced by amyloid beta (25–35), and this effect was blocked by API-2 and PD98059. Furthermore, ginsenoside Rb1 significantly reversed the reduction in phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2 levels induced by amyloid beta (25–35), and API-2 neutralized the effect of ginsenoside Rb1. The present results indicate that ginsenoside Rb1 enhances neurite outgrowth and protects against neurotoxicity induced by amyloid beta (25–35) via a mechanism involving Akt and extracellular signal-regulated kinase 1/2 signaling.

Platycodon grandiflorus Root Extract Improves Learning and Memory by Enhancing Synaptogenesis in Mice Hippocampus

“…A large number of previous studies have shown the stimulating effects of ERK1/2 and natural products from plants on neurite outgrowth [ 56 , 57 , 58 , 59 , 60 ]. It has been reported that ginsenoside Rg1 and Rb1, and triterpenoid saponins, enhance the neurite outgrowth of hippocampal neurons by activating the ERK1/2 and PI3K/Akt pathways [ 56 , 57 ]. Ginsenoside Rd treatment also promotes the neurite outgrowth of PC12 cells by activating the MAPK/ERK and PI3K/Akt signaling proteins [ 60 ].…”

Chemical structures and biological activities of anti-AD natural products

“…. 人参皂苷Rb1属于20(S)-原人参二醇型皂苷, 具有 促进神经系统的生长、增加生长促进激酶(Akt和ki-nase1/2)的表达、抵抗Aβ诱导的细胞凋亡等神经保护 活性 [72,73] . Rb1可用于治疗包括AD在内的与Tau蛋白相…”

Plants‐Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

“…It can reduce neuronal death induced by hypoxic–ischemic insults, an effect probably mediated by the activation of glucocorticoid receptors, and by the inhibition of calcium influx through NMDA receptors and L-type voltage-dependent Ca 2+ channels and the resultant reduction of intracellular free Ca 2+ [ 279 ]. It also enhances neurite outgrowth and protects against neurotoxicity induced by A β through a mechanism involving Akt and ERK 1/2 signaling [ 280 ]. This compound ( 41 ) is also shown to be capable of helping Schwann cells recover from the oxidative insult induced by H 2 O 2 .…”

“…Furthermore, it increases the mRNA levels, protein levels, and secretion of nerve growth factor and brain-derived neurotrophic factor in Schwann cells after incubation with H 2 O 2 [ 281 ]. Ginsenoside Rg1 ( 41 ) as well as 38 and others have been shown to reduce the amount of A β detected in the brains of animals after single oral doses [ 280 ]. Review articles on the effects of ginseng extracts and isolated ginsenosides along with the aglycones relevant to cognition in humans are also available [ 282 , 283 ].…”