Ginsenoside Rb1 Improves Cognitive Impairment Induced by Insulin Resistance through Cdk5/p35-NMDAR-IDE Pathway.

Ranyao Yang,Guangyan Zhou,Xue Jiang,Donglou Liang,Xiqian He,Shusen Sun

doi:10.1155/2020/3905719

Abstract

The relationship between diabetes mellitus (DM) and Alzheimer's disease (AD) has attracted wide attention. Studies have reported that ginsenoside Rb1 can improve human cognitive ability and glucose tolerance during the development of diabetes. The mechanism behind the improvement in cognitive ability and glucose tolerance still remains unclear. In this study, streptozotocin- (STZ-) injected mice were used as models to explore the mechanisms behind the cognitive improvement of ginsenoside Rb1. According to the results of behavioral tests, ginsenoside Rb1 improved memory and cognitive ability of STZ-lesioned mice. In addition to that, ginsenoside Rb1 also relieved glucose intolerance induced by STZ injection by enhancing insulin sensitivity. These beneficial effects of ginsenoside Rb1 is most likely mediated by upregulating the expression of NMDAR1 and IDE in the hippocampus through inhibiting the activity of Cdk5/p35. This work will be of great importance in illustrating the mechanisms of ginsenoside Rb1 for improving cognitive ability, as well as revealing the relationship between diabetes and AD.

Highlights

Alzheimer’s disease (AD) is a complex neurodegenerative disorder with insidious onset and slow progression
Both AD and diabetes mellitus (DM) are connected with impaired insulin signalling, amyloid beta (Aβ) formation, neurofibrillary tangle formation, neuroinflammation, glycogen synthase kinase 3β (GSK3β) signalling, neuronal apoptosis, acetylcholine esterase activity regulation, and oxidative stress injury [4,5,6,7]
Ginsenoside Rb1 was dissolved in distilled water into the following concentrations: 0.01 nM, 0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM, 10 μM, and 100 μM

Summary

Introduction

Alzheimer’s disease (AD) is a complex neurodegenerative disorder with insidious onset and slow progression. Due to similar molecular and cellular mechanisms among type 1 diabetes (T1DM), type 2 diabetes (T2DM), and AD, AD has been referred to as ‘type 3 diabetes’ by researchers [8, 9]

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Results

Conclusion