Elucidating the inhibitory potential of Vitamin A against fibrillation and amyloid associated cytotoxicity

Protein aggregation and amyloid fibrillation are associated with many serious human pathophysiologies like Alzheimer's, Parkinson's diseases, type II diabetes etc. A powerful strategy for controlling and understanding amyloid protein aggregation is the modulation of protein self-assembly. In this study, anti-fibrillation activity of vitamin A (VA) and its effect on the kinetics of amyloid formation of A beta-42 peptide was investigated by employing various spectroscopic, imaging and computational approaches. The present data of Thioflavin T (ThT) fluorescence assay, circular dichroism (CD), dynamic light scattering assay, transmission electron microscopy and cell cytotoxicity assay demonstrated that vitamin A significantly inhibits fibril formation. Our experimental studies inferred that Vitamin A protects human neuroblastoma cell line (SH-SY5Y) and the neuroprotective effect against amyloid induced cytotoxicity is through modification of the amyloid formation towards formation of nontoxic aggregates. Molecular docking demonstrated that vitamin A interacts with A beta-42 through hydrophobic interactions as well as hydrogen bonding. Therefore, the study signifies the role of vitamin A as a potential molecule in preventing A beta-42 aggregation and associated pathophysiology. Hence, Vitamin A and related compounds can thus act as effective inhibitors in the therapeutic development to combat systemic amyloidosis. (C) 2019 Published by Elsevier B.V.