Dual Inhibitors of p38α Mitogen-Activated Protein Kinase and Butyrylcholinesterase for the Modulation of Neuroinflammation and Cognitive Dysfunction.

Chronic neuroinflammation and cholinergic dysfunction are major contributors to cognitive decline in Alzheimer's disease. Here, we report a series of pyridazine-based multitarget-directed ligands that simultaneously inhibit human butyrylcholinesterase (hBChE) and p38α mitogen-activated protein kinase (p38α MAPK). Pyridazines 8 and 21 were identified as potent dual inhibitors with submicromolar inhibitory potencies against target enzymes and high selectivity over acetylcholinesterase. X-ray crystallographic analyses revealed the experimental binding modes of 8 and 21 in hBChE and p38α MAPK, and identified conserved π-π, π-cation, and hinge region interactions that rationalize dual-target engagement. Both compounds were blood-brain barrier permeable, exhibited low cytotoxicity, and significantly attenuated lipopolysaccharide-induced proinflammatory responses and apoptosis in BV2 microglia. In vivo, compound 21 enhanced cognitive performance in mouse models of scopolamine-induced amnesia and LPS-stimulated neuroinflammatory cognitive impairment. Collectively, these results document the potential of structure-assisted design to achieve selective dual-target pharmacology within a single molecular entity.