Characterization of a new molecule capable of inhibiting several steps of the amyloid cascade in Alzheimer's disease.

Introduction: Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in elderly people. Existent therapies are directed at alleviating some symptoms, but are not effective in altering the course of the disease.

Methods: Based on our previous study that showed that an Aβ-interacting small peptide protected against the toxic effects of amyloid-beta peptide (Aβ), we carried out an array of in silico, in vitro, and in vivo assays to identify a molecule having neuroprotective properties.

Results: In silico studies showed that the molecule, referred to as M30 (2-Octahydroisoquinolin-2(1H)-ylethanamine), was able to interact with the Aβ peptide. Additionally, in vitro assays showed that M30 blocked Aβ aggregation, association to the plasma membrane, synaptotoxicity, intracellular calcium, and cellular toxicity, while in vivo experiments demonstrated that M30 induced a neuroprotective effect by decreasing the toxicity of Aβ in the dentate gyrus of the hippocampus and improving the alteration in spatial memory in behavior assays.

Discussion: Therefore, we propose that this new small molecule could be a useful candidate for the additional development of a treatment against AD since it appears to block multiple steps in the amyloid cascade. Overall, since there are no drugs that effectively block the progression of AD, this approach represents an innovative strategy.

Significance: Currently, there is no effective treatment for AD and the expectations to develop an effective therapy are low. Using in silico, in vitro, and in vivo experiments, we identified a new compound that is able to inhibit Aβ-induced neurotoxicity, specifically aggregation, association to neurons, synaptic toxicity, calcium dyshomeostasis and memory impairment induced by Aβ. Because Aβ toxicity is central to AD progression, the inhibition mediated by this new molecule might be useful as a therapeutic tool.