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  2. Dendrobium nobile Lindl. alkaloid decreases Tau hyperphosphorylation via regulating PI3K/Akt/GSK-3β pathway in vitro and in vivo

Dendrobium nobile Lindl. alkaloid decreases Tau hyperphosphorylation via regulating PI3K/Akt/GSK-3β pathway in vitro and in vivo

  • J Ethnopharmacol. 2023 Dec 12:117592. doi: 10.1016/j.jep.2023.117592.
Juan Huang 1 Nanqu Huang 2 Yu Qiu 3 Jingshan Shi 4
Affiliations

Affiliations

  • 1 Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Key Laboratory of Basic Pharmacology and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Guizhou, China; School of Public Health, Zunyi Medical University, Guizhou, China.
  • 2 National Drug Clinical Trial Institution, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China.
  • 3 Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: qiuy@shsmu.edu.cn.
  • 4 Key Laboratory of Basic Pharmacology and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Guizhou, China. Electronic address: shijs@zmu.edu.cn.
Abstract

Ethnopharmacological relevant: Dendrobium is a traditional and precious Chinese medicinal herb. The Compendium of Materia Medica describes its effects as "benefiting intelligence and dispelling shock, lightning the body and extending life". Dendrobium nobile Lindl. is a precious variety of Dendrobium. Our previous data showed Dendrobium nobile Lindl. alkaloid (DNLA) has significant neuroprotective effects and can improve cognitive dysfunction. However, the specific effects and mechanisms of action of its main active component, DNLA, on cognitive dysfunction caused by Tau hyperphosphorylation, are still unclear.

Aim of the research: This study aimed to determine the effects of DNLA on phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase 3β (GSK-3β) pathway, thus to explore the mechanisms of DNLA to inhibit Tau hyperphosphorylation.

Materials and methods: We used wortmannin (WM) and GF-109203X (GFX)-induced hyperphosphorylation of Tau in N2a cells and rats to detect the protective mechanism of DNLA in vivo and in vitro. In vitro, the effect of modeling method on Tau hyperphosphorylation was screened and verified by Western Blotting (WB), and the regulation of Tau hyperphosphorylation and PI3K/Akt/GSK-3β pathway by different concentrations of DNLA was detected by WB. In vivo, MWM was used to detect the effect of DNLA on model rats, and then Nissl staining was used to detect the loss of neurons. Finally, WB was used to detect the regulation of Tau hyperphosphorylation and PI3K/Akt/GSK-3β pathway by different concentrations of DNLA.

Results: DNLA could rescue the abnormal PI3K/Akt/GSK-3β pathway and reverse the hyperphosphorylation of Tau induced by WM and GFX in N2a cells. Furthermore, DNLA improved the learning and memory of WM and GFX-induced model rats. Moreover, DNLA regulated PI3K/Akt/GSK-3β pathway and reduced the p-Tau and neuronal damage in the hippocampus of model rats.

Conclusion: DNLA may be a promising candidate for reducing hyperphosphorylation of Tau.

Keywords

Alzheimer's disease; Dendrobium nobile Lindl. alkaloid; Glycogen synthase kinase-3β; Tau hyperphosphorylation; Tau protein.

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