Unveiling the potential of novel indol-3-yl-phenyl allylidene hydrazine carboximidamide derivatives as AChE/BACE 1 dual inhibitors: a combined in silico, synthesis and in vitro study

Abstract

Alzheimer's disease (AD) is a complex and debilitating neurological disorder that primarily affects the brain, leading to cognitive decline and memory loss. AD is a chronic and progressive disease that gradually impairs an individual's ability to function independently, affecting their daily activities and quality of life.1 Worldwide, as of 2023, the current estimate of 50 million people worldwide with dementia is expected to increase to 78 million by 2030 and a staggering 139 million by 2050.2 The disease is characterized by several neuro-pathological features such as reduced levels of acetylcholine (ACh), accumulation of amyloid-β, formation of neurofibrillary tangles made of hyperphosphorylated tau-protein, oxidative stress, and imbalanced biometal levels.3 The current approach to treating neurological disorders involves the use of medication that aims to enhance cognitive functions or alleviate symptoms by targeting the mechanisms of neurotransmitters in the brain using cholinesterase inhibitors (such as donepezil, galantamine, and rivastigmine see Fig. 1) and N-methyl-D-aspartate (NMDA) receptor antagonist i.e. memantine.4,5 Patients with declining cognitive functions who are prescribed cholinesterase inhibitors or similar medications have not shown any significant improvement in preventing the advancement of AD.6 Despite ongoing efforts to develop drugs that modify the course of AD and slow its progression, there are still potential obstacles that may impede success, such as unanticipated toxicity or inadequate effectiveness in human clinical trials.7 The complexity of AD and its multifaceted nature have rendered the existing single-targeted drugs ineffective in producing the desired therapeutic effect. It is widely believed that compounds with the ability to modulate multiple targets are more effective than those that only act on a single target, due to the inadequate results of the one drug one target (ODOT) strategy. Therefore, there is a need for the development of multi-targeted therapies to slow down the progression of the disease