The therapeutic effect and molecular mechanism

of astragalosides against -amyloid–induced

neurotoxicity in primary cortical neurons

SPEAKER: LI-SHENG CHANG

DATE: 104.02.13

COMMENTATOR: KAO-CHANG LIN, CHING-PING CHANG

Introduction

Alzheimer’s Disease (AD):

Dementia is a brain disorder that seriously affects a person’s

memory, thinking, and reasoning skills.

About 5 percent of men and women ages 65 to 74 have

Alzheimer’s disease, and nearly half of those age 85 and older

may have the disease.

Alzheimer’s & Dementia 2014; 10:e47-e92

The prevalence of Alzheimer’s disease

http://www.tada2002.org.tw/tada_know_02.html衛生福利部

hippocampus

Alzheimer’s Disease (AD)

Amyloid Plaques

Neurofibrillary Tangles

Alzheimer’s association (http://www.alz.org)Adv Med Sci. 2014; 60(1):76-82.

Hypothesis of the development of Alzheimer's disease

Neurosci Biobehav Rev. 2015; 49C:71-81.

The formation of -amyloid

Nature Reviews Neuroscience 2008; 9, 532-544

The aggregation of tau protein

Nature Reviews Neuroscience 2008; 9, 532-544

Reproducing plaques and neurofibrillary tangles in transgenic mice

Nature Reviews Neuroscience 2008; 9, 532-544

Behavioural tests used to assess memory functions in AD mouse models

Nature Reviews Neuroscience 2008; 9, 532-544

The therapy of Alzheimer’s disease

• 乙醯膽鹼抑制劑（ Cholinesterase inhibitors):

目前改善阿茲海默氏症患者知能藥物的主流。目前有 donepezil (愛憶欣 ) 及 Exelon(憶思能 ) 與 Riminyl三種。

• 乙醯膽鹼的前身 (Acetylcholine precursors):有幾個小規模的 lecithin及 choline的臨床試驗，顯示無效。

• 尼古丁接受體促效劑（ Nicotinic cholinergic receptor

agonists):

兩個臨床試驗，其中一個發現尼古丁對學習能力有幫助，但記憶則沒有改善。• Muscarinic cholinergic agonists:

因為乙醯膽鹼的腸胃及暈厥的副作用，所以臨床試驗沒再繼續。

To investigate a possible therapeutic candidate

of drug for the treatment of Alzheimer's disease

黃耆總皂苷（ Astragalus membranaceus）

• 多年生草本，豆科植物莢膜黃耆或蒙古黃耆之乾燥根

• 產於中國華北、東北、內蒙古和西北，主產於山西、黑龍

江、遼寧、河北等省

• 有益氣固表、斂汗固脫、托瘡生肌、利水消腫之功效

• 用于治療氣虛乏力，中氣下陷，表虛自汗，血虛萎黃，內

熱消渴，慢性腎炎，蛋白尿，糖尿病等。炙黃耆益氣補中，

生用固表托瘡。

有效成分

•以現代科學分析技術已知具有：

1.多醣類（ astragalan，黃耆多醣）

2.三萜皂苷類（ astragalosides，黃耆總皂苷）

3.黃酮類、胺基酸、酚酸、蔗糖、微量元素等成分

J. Agric. Food Chem., 50:4861-4866, 2002.

Pharmacological activities of Astragalus

• Astragaloside IV can protect the myocardial cells of rats from damage caused by lack of oxygen, and increase the content and activity of superoxide dismutase (SOD) in the cytoplasm.

• Astragaloside IV can improve fructopyranose-induced metabolic syndrome in rats by increasing levels of nitric metabolite and cyclic guanosine monophosphate, which manifested as reduction in blood pressure and improvement in insulin resistance.

• Astragaloside IV acted on HepG2 cells transfected with hepatitis-B virus, and secretion of hepatitis-B surface antigen, hepatitis-Be antigen as well as serum HBV DNA levels were reduced.

Clin Exp Pharmacol Physiol 2009;36(4):351-357.

Molecules 2011;16(5):3896-3907

Biol PharmBull 2009;32(1):132-135

Astragaloside IV Alleviates Early Brain Injury Following Experimental Subarachnoid Hemorrhage in Rats

subarachnoid hemorrhage (SAH)

Int J Med Sci. 2014; 11(10):1073-81.

grade 1, no subarachnoid blood (scores=0);grade 2, minimal subarachnoid clots (scores=1);grade 3, moderate subarachnoid clots with recognizable arteries (scores=2) grade 4, blood clots covering all arteries (scores=3).

Astragaloside in Alzheimer’s disease

SK-N-SH cells

PLoS One. 2014; 9(6):e98866.

Aim

To investigate the protective effects of

astragalosides on A-induced primary

cortical neuron death

Astragalosides reverse A-induced neuron cell death

A25-35

Control 0 50 100 200 400

Cell

via

bil

ity (

% )

0

20

40

60

80

100

120

ug/ml AST

##

##

#

****

# :P<0.05 VS.Control.

:P<0.05 VS.A 25-35.

Cell morphology after AST treatment against on Ab-induced injury

Control Aβ 25-35 Aβ+50 ug/ml AST

Aβ+100 g/ml AST Aβ+200 g/ml AST Aβ+400 g/ml AST

200x

Astragalosides reverse A-induced DNA fragmentation

100 bp marker

C 0 50 100 200 400

Aβ25-35

ug/ml AST

Astragalosides reverses A-induced caspase 3 activation

Caspase-3

β-actin

Control 0 50 100 200 400ug/ml AST

Aβ 25-35

1 25.6 6.6 3 1.6 2.4

Summary (1)

Astragalosides exerts an inhibitory effect on A-

Induced apoptosis in primary cortical neuron

Astragalosides inhibits A-induced tau hyper-phosphorylation

Total-Tau

β-actin

C 0 50 100 200 400

Aβ 25-35

ug/ml AST

p-Tau ( S199/202 )

1 17.5 3.86.3 3.2 3.8

1 1.14.9 0.80.7 1.2

p-Tau ( T231 )

Synaptophysin

0.21 0.7 0.6 0.8 0.9

Astragalosides restores A-induced synapse loss

Control

MAP2 Synaptophysin DAPI Meraged

Aβ

Aβ+ 50 ug/ml AST

Aβ+ 200 ug/ml AST

Aβ+ 100 ug/ml AST

Aβ+ 400 ug/ml AST

Summary (2)

AST inhibits A-induced tau hyperphosphorylation

and maintains neuronal synapse

Future work

PI3K/Akt

β-amyloid deposition

Apoptosis

AST

β -cateninMitochondrial

dysfunctionNeurofibrillary

tangles

Tau hyperphosphorylationERK

ActivationInhibition

??

Thank you for your attention