Inhibitory Effects of Eleutherococcus senticosus Extracts on Amyloid β(25-35)–Induced Neuritic Atrophy and Synaptic Loss

Abstract

Abstract. Neurons with atrophic neurites may remain alive and therefore may have the potential to regenerate even when neuronal death has occurred in some parts of the brain. This study aimed to explore effects of drugs that can facilitate the regeneration of neurites and the reconstruction of synapses even in severely damaged neurons. We investigated the effects of Eleutherococcus senticosus extracts on the regeneration of neurites and the reconstruction of synapses in rat cultured cortical neurons damaged by amyloid β (Aβ) (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). Treatment with Aβ(25-35) (10 μM) induced axonal and dendritic atrophies and synaptic loss in cortical neurons. Subsequent treatment with the methanol extract and the water extract of E. senticosus (10 -1000 ng/ ml) resulted in significant axonal and dendritic regenerations and reconstruction of neuronal synapses. Co-application of the extract and Aβ(25-35) attenuated Aβ(25-35)-induced neuronal death. We investigated neurite outgrowth activities of eleutherosides B and E and isoflaxidin, which are known as major compounds in E. senticosus. Although eleutheroside B protected against Aβ(25-35)-induced dendritic and axonal atrophies, the activities of eleutheroside E and isofraxidin were less than that of eleutheroside B. Although the contents of these three compounds in the water extract were less than in the methanol extract, restoring activities against neuronal damages were not different between the two extracts. In conclusion, extracts of E. senticosus protect against neuritic atrophy and cell death under Aβ treatment, and one of active constituents may be eleutheroside B.

Active components from Siberian ginseng (Eleutherococcus senticosus) for protection of amyloid β(25–35)-induced neuritic atrophy in cultured rat cortical neurons

“…In AD, neuritic atrophy and synaptic loss occur prior to the neuronal death event and may be the first trigger of the memory impairment [21]. Therefore, our group mainly focuses on herbal drugs, such as E. senticosus [4], Panax ginseng [22] and Astragalus mongholicus [23], with potential in targeting aging-related disease in the early stage [7].…”

“…Isolation of compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) The EtOAc fraction (12.0 g) was separated into seven fractions (E1-E7) by silica gel column chromatography eluted with CHCl 3 -MeOH (20:1). Fraction E3 was purified using a Sephadex LH-20 column (GE Healthcare, Sweden) eluted with MeOH to give five fractions (E3.1-E3.5).…”

“…In the latest decade, attention has increasingly focused on the effects of Siberian ginseng, as a classical adaptogenic agent, on the nervous system [3]. Our research group has already revealed that the methanol and water extracts of the rhizome of E. senticosus had trophic and beneficial effects on neurite outgrowth, synapse formation and neuronal protection in an in vitro assay system for Alzheimer's disease (AD) [4].…”

“…Therefore, one supposed important approach for recovery from memory impairment in AD is to restore the neuritic atrophy. The extracts of E. senticosus rhizome could protect against neuritic atrophy and cell death under Ab treatment, and one of the active constituents might be eleutheroside B [4]. However, lots of other components in this herbal drug still need to be further investigated.…”

Anti‑tumour effects of polysaccharide extracted from Acanthopanax�senticosus and cell‑mediated immunity

“…In China, A. senticosus is used as a nutritional supplement and a sedative (18). A number of studies have demonstrated that A. senticosus has significant therapeutic effects on severe neurosis, fatigue, cardiovascular disease (19,20). A. senticosus can also improve the immune function (21).…”