银杏叶提取物EGb761抑制高同型半胱氨酸血症诱导的AD大鼠Tau蛋白高磷酸化及认知功能障碍

Title:Ginkgo biloba Extract EGb761 Attenuates Hyperhomocysteinemia-induced AD Like Tau Hyperphosphorylation and Cognitive Impairment in Rats

Volume: 15 Issue: 1

关键词: 银杏提取物EGb761，阿尔茨海默病（AD），高同型半胱氨酸血症（HHcy），tau过度磷酸化，认知障碍，氧化损伤。

摘要: 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.

Cite this article as:

Ginkgo biloba Extract EGb761 Attenuates Hyperhomocysteinemia-induced AD Like Tau Hyperphosphorylation and Cognitive Impairment in Rats, Current Alzheimer Research 2018; 15 (1) . https://dx.doi.org/10.2174/1567205014666170829102135