Unlocking Therapeutic Potential of Novel Thieno-Oxazepine Hybrids as Multi-Target Inhibitors of AChE/BChE and Evaluation Against Alzheimer’s Disease: In Vivo, In Vitro, Histopathological, and Docking Studies

<b>Background:</b> Alzheimer's disease (AD) is largely linked with oxidative stress, the accumulation of amyloid-<i>β</i> plaques, and hyperphosphorylated <i>τ</i>-protein aggregation. Alterations in dopaminergic and serotonergic neurotransmission have also been implicated in various AD-related symptoms. <b>Methods</b>: To explore new therapeutic agents, a series of bicyclic and tricyclic thieno-oxazepine derivatives were synthesized as potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The resultant compounds were purified via HPLC and characterized using spectral analysis techniques. Histopathological examinations, other antioxidants, and anti-inflammatory biomarkers were evaluated, and in silico ADMET calculations were performed for synthetic hybrids. Molecular docking was utilized to validate the new drugs' binding mechanisms. <b>Results</b>: The most powerful AChE inhibitors were <b>14</b> and <b>16</b>, with respective values of IC₅₀ equal to 0.39 and 0.76 µM. Derivative <b>15</b> demonstrated remarkable BChE-inhibitory efficacy, on par with tacrine, with IC₅₀ values of 0.70 µM. Hybrids <b>13</b> and <b>15</b> showed greater selectivity towards BChE, despite substantial inhibition of AChE. Compounds <b>13</b> and <b>15</b> reduced escape latency and raised residence time, with almost equal activity to donepezil. <b>Conclusions:</b> According to these findings, the designed hybrids constitute multipotent lead compounds that could be used in the creation of novel anti-AD medications.