Kuan Zeng1, Mengzhu Li1, Jichang Hu1, Yacoubou Abdoul Razak Mahaman1, Jian Bao1, Fang Huang1, Yiyuan Xia1, Xinghua Liu1, Qun Wang1, Jian-Zhi Wang1, Yang Yang1, Rong Liu1, Xiaochuan Wang1.
Abstract
BACKGROUND: Ginkgo biloba extract EGb761 has shown the neuroprotective effects on Alzheimer's disease (AD) through the protection against the Aβ-induced neurotoxicity. However, it is not completedly clear whether EGb761 attenuates tau hyperphosphorylation, another of the most prominent mechanisms underlying the pathology of AD.
METHODS: we employed hyperhomocysteinemia (HHcy) to mimic AD like pathological alterations and memory deficits in rats as model, and injected EGb761 with or after HHcy injection as prevention and treatment, injected saline as control. We measured the status of oxidative damage and spatial and learning memory in rats. Then we detected the level of memory-related proteins, tau phosphorylation and the level and activity of tau kinase (GSK-3β) and phosphatase (PP2A) by Western blotting and Immunohistochemistry.
RESULTS: We found that EGb761 could significantly antagonize HHcy-induced oxidative damage, recover PP2Ac and GSK3β activities deregulated by HHcy. Furthermore, tau was hyperphosphorylated at Thr231, Ser262, Ser396, and Ser404, most common PP2Ac and GSK3β targeted sites in the hippocampus and prefrontal cortex of HHcy rats, whereas EGb761 recovered the tau phosphorylation at those sites. Behavioral tests revealed that EGb761 rescued HHcy-induced spatial reference memory deficit and upregulated the expression of synapse-associated protein PSD95 and synapsin-1.
CONCLUSION: EGb761 might be a promising drug to treat AD through its anti-oxidative activity and decreasing tau hyperphosphorylation besides the protection against the Aβ-induced neurotoxicity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
BACKGROUND: Ginkgo biloba extract EGb761 has shown the neuroprotective effects on Alzheimer's disease (AD) through the protection against the Aβ-induced neurotoxicity. However, it is not completedly clear whether EGb761 attenuates tau hyperphosphorylation, another of the most prominent mechanisms underlying the pathology of AD.
METHODS: we employed hyperhomocysteinemia (HHcy) to mimic AD like pathological alterations and memory deficits in rats as model, and injected EGb761 with or after HHcy injection as prevention and treatment, injected saline as control. We measured the status of oxidative damage and spatial and learning memory in rats. Then we detected the level of memory-related proteins, tau phosphorylation and the level and activity of tau kinase (GSK-3β) and phosphatase (PP2A) by Western blotting and Immunohistochemistry.
RESULTS: We found that EGb761 could significantly antagonize HHcy-induced oxidative damage, recover PP2Ac and GSK3β activities deregulated by HHcy. Furthermore, tau was hyperphosphorylated at Thr231, Ser262, Ser396, and Ser404, most common PP2Ac and GSK3β targeted sites in the hippocampus and prefrontal cortex of HHcy rats, whereas EGb761 recovered the tau phosphorylation at those sites. Behavioral tests revealed that EGb761 rescued HHcy-induced spatial reference memory deficit and upregulated the expression of synapse-associated protein PSD95 and synapsin-1.
CONCLUSION: EGb761 might be a promising drug to treat AD through its anti-oxidative activity and decreasing tau hyperphosphorylation besides the protection against the Aβ-induced neurotoxicity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Entities:
Keywords:
Alzheimer's disease (AD); Ginkgo biloba extract EGb761; cognitive impairment; hyperhomocysteinemia (HHcy); oxidative damage; tau hyperphosphorylation
Mesh：
Substances：
Year: 2018
PMID： 28847282 DOI： 10.2174/1567205014666170829102135
Source DB: PubMed Journal: Curr Alzheimer Res ISSN： 1567-2050 Impact factor: 3.498