Convolidine as potent BACE1 inhibitor for Alzheimer's disease; in-silico coupled with in-vitro assessment

Alzheimer's Disease is a chronic progressive neurodegenerative disorder characterized by impaired intellect and cognitive functions. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) plays a pivotal role in the pathogenesis of Alzheimer's disease (AD) by initiating the amyloid cascade. Despite significant clinical efforts, most BACE1 inhibitors have failed to yield potent pharmacological effects. Our previous study, identified a group of natural compounds with satisfying pharmacological profiles with high affinity to BACE1, out of which the compound, 'convolidine' emerged as the most promising candidate based on the in-silico parameters such as docking score, interacting residues, binding energy, drug-likeness, ADMET, and biological activity prediction. The present study focused on the inhibitory potential of convolidine against BACE1 using dynamics simulation followed by protein-protein docking and in-vitro validation. Molecular dynamics simulation demonstrated that the BACE1-convolidine complex remained stable throughout the entire 200 ns simulation period. Also, the results of the post-dynamic docking study showed a reduced substrate affinity of BACE1 to its substrate, APP (Amyloid precursor protein), when BACE1 is bound to convolidine, suggesting compounds inhibitory potential. This in-silico assessment was validated in-vitro using a FRET-based BACE1 activity assay, where the result well aligned with the computational predictions. The findings revealed that convolidine could effectively inhibit BACE1, with an IC50 value of 0.49 µM, providing a solid foundation for its development as a promising therapeutic agent for AD management.