Abstract: Objective To investigate the effect and mechanism of salidroside delaying natural aging of primary hippocampal neurons. Methods Rat hippocampal neurons were isolated and then cultured into aging neurons, which were randomly divided into short-term (ST) group, long-term (LT) group, salidroside low- and high-concentration (10 µM and 20 µM) groups, positive drug cycloastragenol group (5 µM). Cell count method (CCK-8) was used to detect hippocampal neurons survival rate, senescence-associated β-galactosidase (SA-β-gal) staining kit was used to detect the hippocampus neuron aging, the apoptotic rate of hippocampal neurons was detected by flow cytometry, the expression of telomerase reverse transcriptase (TERT) was detected by western blot, PCR-ELISA method was used to detect telomerase activity of hippocampal neurons. Results Compared with the ST group, the hippocampal neurons appeared neuron degeneration, cell body contraction, and the cell survival rate decreased significantly (P<0.01), while SA-β-gal positive rate increased significantly in LT group (P<0.01). The apoptotic rate of neurons was significantly increased (P<0.01), while telomerase activities and TERT expression of neurons decreased obviously (P<0.01). Compared with LT group, the neuronal survival rate treated with salidroside and cycloastragenol were significantly increased (P<0.05), while SA-β-gal positive rate and apoptotic rate of neurons was significantly decreased (P<0.05), and the telomerase activities and TERT expression were significantly increased (P<0.01). Conclusion Salidroside could reduce the neuronal apoptosis and increase the telomerase activity to delay the senescence of hippocampal neurons.

Key words: salidroside, primary culture, hippocampal neurons, apoptosis, telomerase