Salidroside protects PC12 cells from Aβ1‑40‑induced cytotoxicity by regulating the nicotinamide phosphoribosyltransferase signaling pathway.

Alzheimer's disease (AD) is the most common type of senile dementia, which often develops in elderly or presenile individuals. As one of the pathological features of AD, amyloid β‑protein (Aβ) causes energy dysmetabolism, thereby inducing cellular damage and apoptosis. Salidroside is the main active component of the traditional Chinese medicine Rhodiola. Previous studies have demonstrated that salidroside exerts a regulatory role in energy metabolism. However, the role and the mechanism of action of salidroside in AD remain unclear. Therefore, the present study used Aβ1‑40 to induce damage in PC12 cells, thereby establishing a cell model of AD. In addition, salidroside treatment was performed to investigate the protective effect of salidroside and the underlying mechanisms. Aβ1‑40‑induced neuronal toxicity reduced cell viability and caused cellular damage. As a result, the expression level of nicotinamide phosphoribosyltransferase (NAMPT) decreased, the synthesis of nicotinamide adenine dinucleotide (NAD+; an energy metabolism‑associated coenzyme) became insufficient, and the NAD+/nicotinamide adenine dinucleotide hydride ratio was reduced. Administration of salidroside alleviated Aβ‑induced cell damage and increased the expression level of the key protein NAMPT and the synthesis of NAD+. The results of the present study demonstrate that salidroside exerts a protective effect on Aβ1‑40‑damaged PC12 cells. The underlying mechanism may be associated with the regulation of energy metabolism that relies predominantly on the NAMPT signaling pathway.