Investigating the potential of novel thiazolidinone derivatives as anti-alzheimer agents: A comprehensive study through kinetics, <i>in silico</i>, and <i>in vitro</i> approaches

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by behavior, memory, and cognitive impairment. Acetylcholinesterase (AChE) is primarily responsible for acetylcholine (ACh) breakdown and is considered a leading cause of AD. The current study was designed to assess thiazolidinone compounds (1-12) as synthetic inhibitors of AChE as potential therapeutic options for AD. For this purpose, inhibitory activities, kinetics analysis, antispasmodic potential, and molecular dynamic (MD) simulations were conducted for 12 newly synthesized thiazolidinone compounds. The results demonstrate significant inhibition of AChE (IC50 ranging from 209.53 ± 1.01 µM to 1656.01 ± 1.60 µM) by all tested compounds. Kinetic analysis revealed that these compounds bind to the allosteric site and reduce AChE proficiency. The non-competitive nature of these compounds is an important finding that suggests that they could effectively reduce ACh hydrolysis even at high substrate concentrations. The obtained molecular docking results suggested that these compounds formed π-π stacking and hydrogen bonding interactions with the anionic sub-site and peripheral anionic site (PAS) of AChE. Their inhibitory efficacy is supported by this structural insight, which also helps in identifying important interactions for future optimization. MD simulation showed that the interaction of selected compounds 12 and 3 with AChE remains stable during simulations. This highlights their potential as effective therapeutic agents. Additionally, the whole series displayed calcium (Ca2+) antagonistic and antispasmodic potential, which could contribute to their therapeutic impacts beyond the inhibition of AChE. Among all tested compounds, compounds 12 and 3 demonstrated the highest proficiency in countering spontaneous and potassium (K+)-induced spasms. Therefore, the anti-AChE activity, Ca2⁺ antagonistic abilities, and safety profile of these compounds position them as potential multi-target drug candidates for AD and its related complications in the future.