Novel Donepezil-Chalcone Hybrids as Potential Multifunctional Anti-Alzheimer's Disease Agents: Design, Synthesis, Computational Simulation, and In Vitro/In Vivo Biological Evaluation.

Abstract

A novel series of donepezil-chalcone including pyridine, piperazine, phenylamide skeleton hybrids were designed, synthesized, and evaluated for their inhibitory activities against AChE and BChE. Subsequently, a subset of these derivatives was investigation to inhibit Aβ_1-42 aggregation and promote Aβ_1-42 disaggregation effects. Among them, compounds 8b, 8c, 8j, and 8ab possessing good activity were further assayed for their inhibitory effects on BACE-1 and GSK3β, as well as their PI displacement activity. 8b (AChE, IC₅₀: 0.11 μM; BChE, IC₅₀: 0.18 μM; Aβ_1-42 aggregation, IC₅₀: 3.40 μM; their ability to promote Aβ_1-42 disaggregation, IC₅₀: 4.53 μM; BACE-1, IC₅₀: 1.82 μM; GSK3β, IC₅₀: 0.98 μM) exhibited prominent bioactivities across the above assays. Meanwhile, the molecular docking and the molecular dynamics simulations were performed to analyze the interactions between 8b and the key amino acid residues of the target proteins, which verified the stability of the corresponding protein ligand complexes. Furthermore, 8b significantly attenuated the cytotoxicity induced by Fe³⁺ and Cu²⁺ in BV-2 microglial cells, L-Glu in HT-22 hippocampal neuronal cells, and Aβ_1-42 in both BV-2 and SH-SY5Y neuroblastoma cells. Additionally, 8b reduced the levels of intracellular ROS and NO in LPS-stimulated BV-2 cells, demonstrating potent anti-inflammatory and neuroprotective properties. Acute toxicity tests in mice confirmed the safety profile of 8b. In in vivo studies, compound 8b effectively protected against neuroinflammation 8b ameliorated cognitive deficits in mice induced by AlCl₃ combined with L-galactose, which was associated with the upregulation of p-GSK3β and the downregulation of p-Tau expression. In conclusion, 8b holds great potential as a promising multitarget-directed new lead compound for the treatment of AD.