Multi-target inhibition ability of neohesperidin dictates its neuroprotective activity: Implication in Alzheimer's disease therapeutics

The polygenic nature of Alzheimer's disease (AD) and cross-talk between several signaling cascades make it harder to decode the disease pathogenesis. beta-secretase (BACE1) works upstream in the amyloidogenic processing of amyloid precursor protein (APP) to generate A beta that rapidly aggregates to form fibrils, the most abundant component of plaques observed in AD brains. Here, we report dual inhibition of BACE1 and A beta aggregation by neohesperidin, a flavonoid glycoconjugate, using multi-spectroscopic approaches, force microscopy, molecular modeling, and validated the potency in SH-SY5Y neuroblastoma cell lines. Steady-state and time-resolved fluorescence reveal that neohesperidin binds close to the catalytic aspartate dyad. This binding conformationally restricts the protein in closed form which possibly precludes APP recognition and thereby inhibits BACE1 activity. Neohesperidin also dose-dependently inhibits the amyloid fibril formation, as evident from ANS, ThT assay, and AFM. Neohesperidin ameliorates aggregated A beta(25-35) induced ROS generation and mitochondrial dysfunction in the SH-SY5Y cell line. As a result, the amyloid induced apoptosis is significantly prohibited and normal neuronal morphology is rescued. These findings suggest neohesperidin as an inhibitor of the pathogenic conversion of A beta to fibrillar amyloid assembly. Neohesperidin thus emerges as a non-toxic multi-potent scaffold for the development of AD therapeutics. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Through multiple approaches, neohesperidin is found to inhibit both BACE1 and Aβ aggregation, presenting as a potential non-toxic multi-potent scaffold for the development of Alzheimer's disease therapeutics.