Alzheimer’s disease (AD) is the most common neurodegenerative disease. Deposition of amyloid β plaques (Aβ) and neurofibrillary tangles (NFTs) is the key pathological hallmark of AD. Accumulating evidence suggest that impairment of autophagy-lysosomal pathway (ALP) plays key roles in AD pathology.
The present study aims to assess the neuroprotective effects of Qingyangshen (QYS), a Chinese herbal medicine, in AD cellular and animal models and to determine its underlying mechanisms involving ALP regulation.
QYS extract was prepared and its chemical components were characterized by LC/MS. Then the pharmacokinetics and acute toxicity of QYS extract were evaluated. The neuroprotective effects of QYS extract were determined in 3XTg AD mice, by using a series of behavioral tests and biochemical assays, and the mechanisms were examined in vitro.
Oral administration of QYS extract improved learning and spatial memory, reduced carboxy-terminal fragments (CTFs), amyloid precursor protein (APP), Aβ and Tau aggregates, and inhibited microgliosis and astrocytosis in the brains of 3XTg mice. Mechanistically, QYS extract increased the expression of PPARα and TFEB, and promoted ALP both in vivo and in vitro.
QYS attenuates AD pathology, and improves cognitive function in 3XTg mice, which may be mediated by activation of PPARα-TFEB pathway and the subsequent ALP enhancement. Therefore, QYS may be a promising herbal material for further anti-AD drug discovery.

Copyright © 2021. Published by Elsevier GmbH.