Introduction: Multi-target anti-Alzheimer's disease (AD) compounds are promising leads for the development of AD modifying agents. Ionic compounds containing quaternary ammonium moiety were synthesized, and their multi-targeted anti-AD effects were examined. Methods: Imidazole derivatives containing a quaternary ammonium moiety were synthesized and evaluated for their potential anti-Alzheimer properties using computational (in silico), cellular (in vitro), and animal (in vivo) models. The inhibition kinetics of both human acetylcholinesterase (hAChE) and butyrylcholinesterase (hBuChE) were assessed. Neuroprotective effects in amyloid-beta (Aβ)-exposed PC12 cells were also examined. Furthermore, the compounds' impact on Aβ-induced memory impairment in Wistar rats was evaluated, with a detailed analysis of the underlying mechanisms. Results: Compound 5g demonstrated acceptable cytotoxicity against human cells. This compound exhibited non-competitive dual inhibition of both hAChE and hBuChE. Additionally, compound 5g mitigated the morphological changes induced by amyloid-beta (Aβ) in PC12 cells and decreased cell mortality. It exhibited anti-oxidative stress properties, evident by reduction in reactive oxygen species (ROS) production, and inhibition of lipid peroxidation. The compound also down regulated the expression of pro-inflammatory genes IL-1β and TNF-α. In vitro studies validated compound 5g's ability to inhibit lactate dehydrogenase (LDH), attenuate neuroinflammation, and prevent the autophagy-apoptosis cascade. When administered to rats with Aβ-induced memory dysfunction, compound 5g enhanced cognitive function and improved spatial memory. In the hippocampi of treated rats, there was a noted downregulation of TNF-α and NF-kB. Furthermore, compound 5g counteracted the elevated activity of AChE. Molecular modeling validated the binding of compound 5g to both steric and catalytic sites of cholinesterase enzymes. Conclusion: The novel quaternary ammonium derivative, compound 5g, demonstrated multi-target anti-AD properties, as evidenced by in silico, in vitro and in vivo studies. Behavioral assessments and molecular analyses further confirmed its therapeutic efficacy in amyloid-beta (Aβ)-challenged rats.
