Plant isoquinoline alkaloids as potential neurodrugs: A comparative study of the effects of benzo[c]phenanthridine and berberine-based compounds on ?-amyloid aggregation.

ABSTRACT: Herein we present a comparative study of the effects of isoquinoline alkaloids belonging to benzo[c]phenanthridine and berberine families on ?-amyloid aggregation. Results obtained using a Thioflavine T (ThT) fluorescence assay and circular dichroism (CD) spectroscopy suggested that the benzo[c]phenanthridine nucleus, present in both sanguinarine and chelerythrine molecules, was directly involved in an inhibitory effect of A?_1-42 aggregation. Conversely, coralyne, that contains the isomeric berberine nucleus, significantly increased propensity for A?_1-42 to aggregate. Surface Plasmon Resonance (SPR) experiments provided quantitative estimation of these interactions: coralyne bound to A?_1-42 with an affinity (K_D?=?11.6??M) higher than benzo[c]phenanthridines. Molecular docking studies confirmed that all three compounds are able to recognize A?_1-42 in different aggregation forms suggesting their effective capacity to modulate the A?_1-42 self-recognition mechanism. Molecular dynamics simulations indicated that coralyne increased the ?-content of A?_1-42, in early stages of aggregation, consistent with fluorescence-based promotion of the A?_1-42 self-recognition mechanism by this alkaloid. At the same time, sanguinarine induced A?_1-42 helical conformation corroborating its ability to delay aggregation as experimentally proved in vitro. The investigated compounds were shown to interfere with aggregation of A?_1-42 demonstrating their potential as starting leads for the development of therapeutic strategies in neurodegenerative diseases.

SUBMITTER: Marasco D 

PROVIDER: S-EPMC7577920 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature