Based on Bioinformatics to Explore the Mechanism of "Tangzhiqing" Decoction Alleviating Type 2 Diabetes-associated Cognitive Dysfunction in Mice by Regulating Hippocampal Neuron Apoptosis and Autophagy.

Background: Diabetic cognitive dysfunction (DCD) is emerging as a chronic complication of diabetes that is gaining increasing international recognition. The traditional Chinese medicine (TCM) formulation, Tangzhiqing decoction (TZQ), has shown the capacity to modulate the memory function of mice with DCD by ameliorating insulin resistance. Nevertheless, the precise mechanism underlying the effects of TZQ remains elusive.

Methods: The chemical constituents of TZQ were screened using TCMSP databases, and DCDassociated disease targets were retrieved from various databases. Subsequently, core targets were identified through network topology analysis. The core targets underwent analysis using Gene Ontology (GO) functional annotations and enrichment in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Models were established through high-fat and high-glucose diet feeding along with intraperitoneal injection of streptozotocin (STZ). TZQ and metformin were administered at varying doses over 8 weeks. The Morris water maze was employed to evaluate the cognitive capabilities of each rat group, while indicators of oxidative stress and insulin were assessed in mice. Neuronal apoptosis in distinct groups of mice's hippocampi was detected using TdT-mediated dUTP Nick-End Labeling (TUNEL), and western blot (WB) analysis was conducted to assess the expression of apoptosis- and autophagy-related proteins, including Bax, Bcl2, Caspase3, Caspase8, Beclin1, ATG7, LC3, p62, and Lamp2, within the hippocampus.

Results: TZQ exhibited the capacity to modulate neuronal autophagy, ameliorate endoplasmic reticulum stress, apoptosis, inflammation, and oxidative stress, as well as to regulate synaptic plasticity and conduction. TZQ mitigated cognitive dysfunction in mice, while also regulating hippocampal inflammation and apoptosis. Additionally, it influenced the protein expression of autophagy-related factors such as Bax, Bcl2, Caspase3, Caspase8, Beclin1, ATG7, and LC3. Notably, this modulation significantly reduced neuronal apoptosis in the hippocampus and curbed excessive autophagy.

Conclusion: TZQ demonstrated a substantial reduction in neuronal apoptosis within the hippocampus and effectively suppressed excessive autophagy.