Abstract
Scope:
Alzheimer's Disease (AD) is a neurodegenerative condition marked by the formation and aggregation of amyloid-β (Aβ) peptides. There exists, to this day, no cure or effective prevention for the disease; however, there is evidence that a healthy diet and certain food products can slow down first occurrence and progression of peptide aggregates. To investigate if food ingredients can interact with peptide aggregates in membrane mimics, we prepared synthetic membranes that contained aggregates consisting of cross-β sheets of Aβ25-35 .
Methods and results:
We studied the impact of resveratrol, found in grapes, caffeine, ingredient in coffee, β-carotene, found in orange fruits and vegetables, and Epigallocatechin gallate (EGCG), a component of green tea, on the size and volume fraction of Aβ aggregates using optical and fluorescence microscopy, X-ray diffraction, UV-Visible spectroscopy, and Molecular Dynamics (MD) simulations. All compounds were found to be membrane active and spontaneously partitioned in the synthetic brain membranes. While resveratrol and caffeine led to membrane thickening and reduced membrane fluidity, β-carotene and EGCG preserved or increased fluidity.
Conclusion:
Resveratrol and caffeine did not reduce the volume fraction of peptide aggregates while β-carotene significantly reduced plaque size. Interestingly, EGCG dissolved peptide aggregates and significantly decreased the corresponding cross-β and β-sheet signals.
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