Analysis of the Molecular Mechanism of Punicalagin in the Treatment of Alzheimer's Disease by Computer-Aided Drug Research Technology

The objective of this work is to explore the effect and potential mechanism of Punicalagin (Pun) in managing Alzheimer's disease (AD) based on computer-aided drug technology. The following methods were used: the intersection genes of Pun and AD were retrieved from the database and subjected to PPI analysis, GO, and KEGG enrichment analyses. Preliminary verification was performed by molecular docking, molecular dynamics (MD) simulation, and combined free energy calculation. The motor coordination and balance ability, anxiety degree, spatial learning, and memory ability of mice were measured by a rotating rod fatigue instrument, elevated cross maze, and Y maze, respectively. The amyloid beta protein (A beta) in the hippo-campus was examined by immunohistochemistry, and the phosphorylation of serine at position 404 of the tau protein (Tau-pS404) was examined by western blot in the mouse brain. The PPI network of Pun showed that the intersection genes were closely related and enriched in muscle cell proliferation and the response to lipopolysaccharide. Results of molecular docking, MD simulations, and MM-GBSA demonstrated that Pun was closely bound to the target protein. Pun could improve the cognitive function of AD mice, as well as reduce A beta(1-42) deposition and Tau phosphorylation in the brain (P < 0.05, P < 0.01). It can be concluded that Pun holds great promise in improving the cognitive function of AD mice. Mechanistically, Pun potentially acts on ALB, AKT1, SRC, EGFR, CASP3, and IGF-1 targets and mediates proteoglycan, lipid, and atherosclerosis in cancer, so as to reduce the accumulation of neurotoxic proteins in the brain.