Ginsenosides Decrease β-Amyloid Production via Potentiating Capacitative Calcium Entry

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Alzheimer's disease (AD) is characterized by amyloid-beta (Aβ) plaques and calcium (Ca2+) dysregulation.
• Decreased capacitative calcium entry (CCE) is linked to increased Aβ production, while its activation may reduce Aβ.
• Panax ginseng and its compounds (ginsenosides) are known for cognitive benefits, with some showing Aβ-lowering effects, but mechanisms are unclear.

Purpose of the Study:

• To investigate the relationship between CCE and Aβ production.
• To examine the effects of various ginsenosides on CCE levels and their impact on Aβ production.

Main Methods:

• Assessed the effects of different ginsenosides (Rk1, Rg5, Rg3, Re, Rb2) on CCE levels in relevant models.
• Utilized 2-aminoethoxydipherryl borate (2APB), a CCE inhibitor, to confirm the role of CCE.
• Measured Aβ42 production in the presence and absence of ginsenosides and 2APB.

Main Results:

• Aβ-lowering ginsenosides (Rk1, Rg5, Rg3) were found to potentiate CCE.
• Ginsenosides without Aβ-lowering effects (Re, Rb2) did not potentiate CCE.
• The CCE-potentiating effect of ginsenosides was blocked by 2APB, which alone increased Aβ42 production and prevented ginsenoside-induced Aβ reduction.

Conclusions:

• Ginsenosides decrease Aβ production by potentiating CCE levels, establishing a direct link between CCE and Aβ production.
• Modulating CCE represents a potential novel therapeutic strategy for Alzheimer's disease.