[Protective effects of Suanzaoren Decoction on hippocampal neuron and its influence on PI3K/Akt signaling pathway in...

This study explored the mechanism by which Suanzaoren Decoction(SZRD) ameliorates hippocampal neuronal damage in APP/PS1 mice by inhibiting Bax/Bcl-2/caspase-3-mediated apoptosis through the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt) signaling pathway. Differentially expressed genes(DEGs) in Alzheimer's disease(AD) were screened using the GEO database, and KEGG and GO enrichment analyses were performed using R software. Thirty 6-month-old APP/PS1 transgenic mice were randomly assigned to three groups: APP/PS1 group, low-dose SZRD group(12.96 g·kg~(-1)), and high-dose SZRD group(25.92 g·kg~(-1)), while ten age-matched male C57BL/6J mice served as the blank control group. The treatment groups received SZRD by gavage for 28 consecutive days. Following treatment, spatial learning and memory were assessed using the Morris water maze test. Neuronal numbers were evaluated by Nissl staining. Immunohistochemistry(IHC) was used to detect neuron-specific nuclear protein(NeuN) and assess amyloid-β(Aβ) deposition in hippocampal neurons. Western blot was performed to measure the expression levels of PI3K/Akt pathway proteins and apoptosis-related markers, including Bcl-2, Bax, caspase-3, and cleaved-caspase-3 in hippocampal tissues. Bioinformatics analysis identified 686 DEGs, with GO enrichment linked to synaptic function and neurotransmitter transport, and KEGG pathways including neuroactive ligand-receptor interaction and PI3K/Akt signaling. In vivo experiments showed that, compared with APP/PS1 mice, both low-and high-dose SZRD groups exhibited improved learning and memory, increased neuronal numbers, and decreased Aβ deposition. Furthermore, hippocampal levels of p-PI3K/PI3K, p-Akt/Akt, and Bcl-2 were upregulated, while Bax and cleaved-caspase-3/caspase-3 levels were downregulated. In conclusion, SZRD may improve hippocampal neuronal damage and cognitive function in APP/PS1 mice by regulating Bax/Bcl-2/caspase-3-mediated apoptosis through the PI3K/Akt signaling pathway.