Anti-amyloidogenic effects of soybean isoflavones in vitro: Fluorescence spectroscopy demonstrating direct binding to Aβ monomers, oligomers and fibrils

► Isoflavones inhibited the fibrillization and oligomerization of amyloid β-proteins (Aβs). ► Isoflavones destabilized preformed amyloid β-protein (Aβ) fibrils. ► Glycitein bound to Aβ monomers, oligomers and fibrils, leading the anti-amyloidogenic effects. ► Glycitein bound to Aβ1-42, Aβ1-40, Aβ1-16 and Aβ25-35, having the most potent affinity for Aβ25-35.