Emerging Roles of Rivastigmine Derivatives Bearing Antioxidant Motifs as Multi-Target Agents for the Management of...

Neurodegenerative disorders (NDs), such as Alzheimer's and Parkinson's diseases (AD and PD), despite having different main neuropathological hallmarks, share several interconnected aetiologic mechanisms and lack effective disease-modifying treatments. The multifactorial nature of these diseases has encouraged the development of new drugs such as multi-target-directed ligands (MTDLs). In this work, an anti-AD drug (rivastigmine, RIV) was fused and conjugated with a series of antioxidant scaffolds to obtain a small library of RIV-antiox hybrids. In addition to inhibitory activity towards both cholinesterases, these hybrids exhibited radical scavenging activity, inhibition of Aβ aggregation, and neuroprotection against cell death induced in AD models. The relevant anti-AD properties already found for these hybrids challenged us to also assess their capacity to modulate and interfere with ROS-associated harmful dysfunctions, namely in the dysregulation of biometal ions (Fe³⁺, Cu²⁺, and Zn²⁺) and upregulation of monoamine oxidases (MAOs). In particular, the capacity of the hybrids for metal chelation and inhibition of Cu-induced Aβ aggregation and MAO isoforms was evaluated, as well as their neuroprotection capacity in cell models of PD. Overall, some of these RIV hybrids appear as lead compounds for the development of novel multifunctional agents against NDs.