摘要
[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD( Alzheimer's Disease) model rat. [Methods]The AD model rat was replicated by injection of Aβ_(25-35) in the left lateral ventricles of SD rats. The low dose( 25 mg/kg),middle dose( 50 mg/kg) and high dose( 100 mg/kg) notoginsenoside Rg1 was used for intragastric administration,respectively,two times every day. After 4 weeks,the Morris water maze test was done to detect the learning and memory capacity,and the immunoblotting,immunohistochemical methods were used to detect the changes in the phosphorylation level and distribution of tau protein in hippocampus of the rats. [Results] After the intracerebroventricular injection of Aβ_(25-35),the learning and memory capacity of the model rats was significantly lower than the learning and memory capacity of the normal control rats. The immunoblotting test results showed that the phosphorylation level of tau protein threonine 231 site( Thr231) in hippocampus was significantly increased,and the nonphosphorylation level was significantly decreased. The morphological testing results showed that the phosphorylation level of tau protein Thr231 of AD model rats was increased markedly in region of DG,CA1 and CA3 of the hippocampus. The intervention of the middle dose notoginsenoside Rg1 could significantly improve the learning and memory capacity of the model rats in Morris water maze. The notoginsenoside Rg1 in three different doses could all reduce the phosphorylation level of tau protein Thr231 in the hippocampal DG,CA1,CA3 regions,and there were no significant differences among the three doses. [Conclusions]The notoginsenoside Rg1 could improve Aβ_(25-35)-induced spatial learning and memory impairment of the AD model rats,and decreased the phosphorylation level of tau protein in hippocampus.
[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD（ Alzheimer’s Disease） model rat. [Methods]The AD model rat was replicated by injection of Aβ25-35 in the left lateral ventricles of SD rats. The low dose（ 25 mg/kg）,middle dose（ 50 mg/kg） and high dose（ 100 mg/kg） notoginsenoside Rg1 was used for intragastric administration,respectively,two times every day. After 4 weeks,the Morris water maze test was done to detect the learning and memory capacity,and the immunoblotting,immunohistochemical methods were used to detect the changes in the phosphorylation level and distribution of tau protein in hippocampus of the rats. [Results] After the intracerebroventricular injection of Aβ25-35,the learning and memory capacity of the model rats was significantly lower than the learning and memory capacity of the normal control rats. The immunoblotting test results showed that the phosphorylation level of tau protein threonine 231 site（ Thr231） in hippocampus was significantly increased,and the nonphosphorylation level was significantly decreased. The morphological testing results showed that the phosphorylation level of tau protein Thr231 of AD model rats was increased markedly in region of DG,CA1 and CA3 of the hippocampus. The intervention of the middle dose notoginsenoside Rg1 could significantly improve the learning and memory capacity of the model rats in Morris water maze. The notoginsenoside Rg1 in three different doses could all reduce the phosphorylation level of tau protein Thr231 in the hippocampal DG,CA1,CA3 regions,and there were no significant differences among the three doses. [Conclusions]The notoginsenoside Rg1 could improve Aβ25-35-induced spatial learning and memory impairment of the AD model rats,and decreased the phosphorylation level of tau protein in hippocampus.
基金
Supported by National Natural Science Foundation of China(81673856,81573865)
China Postdoctoral Science Foundation(2016M592319,2017T100542)
Youth Project of Hubei University of Traditional Chinese Medicine(Zhong Yi Xiao Zi2015182)
PhD Research Foundation of Hubei University of Traditional Chinese Medicine(Zhong Yi Dang Zi201425)
