Dual Inhibitors of Amyloid-β and Tau Aggregation with Amyloid-β Disaggregating Properties: Extended <i>In Cellulo</i>, <i>In Silico</i>, and Kinetic Studies of Multifunctional Anti-Alzheimer’s Agents

Abstract

In Alzheimer's disease, neurons slowly degenerate due to the accumulation of misfolded amyloid β and tau proteins. In our research, we performed extended studies directed at amyloid β and tau aggregation inhibition using <i>in cellulo</i> (<i>Escherichia coli</i> model of protein aggregation), <i>in silico</i>, and <i>in vitro</i> kinetic studies. We tested our library of 1-benzylamino-2-hydroxyalkyl multifunctional anti-Alzheimer's agents and identified very potent dual aggregation inhibitors. Among the tested derivatives, we selected compound <b>18</b>, which exhibited a unique profile of biological activity. This compound was the most potent and balanced dual aggregation inhibitor (Aβ₄₂ inhibition (inh.) 80.0%, tau inh. 68.3% in 10 μM), with previously reported <i>in vitro</i> inhibitory activity against <i>h</i>BuChE, <i>h</i>BACE1, and Aβ (<i>h</i>BuChE IC₅₀ = 5.74 μM; <i>h</i>BACE1 IC₅₀ = 41.6 μM; Aβ aggregation (aggr.) inh. IC₅₀ = 3.09 μM). In docking studies for both proteins, we tried to explain the different structural requirements for the inhibition of Aβ vs tau. Moreover, docking and kinetic studies showed that compound <b>18</b> could inhibit the amyloid aggregation process at several steps and also displayed disaggregating properties. These results may help to design the next generations of dual or selective aggregation inhibitors.