Research Paper Volume 11, Issue 2 pp 536—548
Geniposide-mediated protection against amyloid deposition and behavioral impairment correlates with downregulation of mTOR signaling and enhanced autophagy in a mouse model of Alzheimer's disease
- 1 Key Laboratory of Cellular Physiology, Shanxi Medical University, Taiyuan, Shanxi, PR China
- 2 Shanxi Medical College for Continuing Education, Taiyuan, Shanxi, PR China
- 3 Shanxi Provincial People’s Hospital, Taiyuan, Shanxi, PR China
- 4 Chemistry Department, Shanxi Medical University, Taiyuan, Shanxi, PR China
- 5 Second Hospital, Shanxi Medical University, Taiyuan, Shanxi, PR China
Received: August 15, 2018 Accepted: January 5, 2019 Published: January 26, 2019https://doi.org/10.18632/aging.101759
How to Cite
Copyright: Zhang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Geniposide, an iridoid glycoside extract from the gardenia fruit, is used in traditional Chinese medicine to alleviate symptoms of liver and inflammatory diseases. Geniposide activates GLP-1 receptors, known to modulate the activity of mechanistic target of rapamycin (mTOR), a key kinase regulating energy balance, proliferation, and survival in cells. mTOR activation inhibits autophagy, which is often disrupted in age-related diseases. Modulation of mTOR function to increase autophagy and inhibit apoptosis is involved in the protective effects of pharmacologic agents targeting diabetes and Alzheimer’s disease (AD). We investigated whether such mechanism could mediate geniposide’s neuroprotective effects in the APP/PS1 mouse model of AD. Eight-week treatment with geniposide improved cognitive scores in behavioral tests, reduced amyloid-β 1-40 plaque deposition, and reduced soluble Aβ1-40 and Aβ1-42 levels in the APP/PS1 mouse brain.This also showed increased p-Akt/Akt, p-mTOR/mTOR and decreased p-4E-BP1/4E-BP1 expression, and these patterns were partially reversed by geniposide. Evidence for enhanced autophagy, denoted by increased expression of LC3-II and Beclin1, was also seen after treatment with geniposide. Our data suggests that down regulation of mTOR signaling, leading to enhanced autophagy and lysosomal clearance of Aβ fibrils, underlies the beneficial effects of geniposide against neuropathological damage and cognitive deficits characteristic of AD.