Dual regulatory effects of neferine on amyloid- and tau aggregation studied by in silico, in vitro, and lab-on-a-chip technology

Alzheimer's disease (AD) is characterized by the presence of two critical pathogenic factors: amyloid-beta (A beta) and tau. A beta and tau become neurotoxic aggregates via self -assembly, and these aggregates contribute to the pathogenesis of AD. Therefore, there has been growing interest in therapeutic strategies that simultaneously target A beta and tau aggregates. Although neferine has attracted attention as a suitable candidate agent for alleviating AD pathology, there has been no study investigating whether neferine affects the modulation of A beta or tau aggregation/dissociation. Herein, we investigated the dual regulatory effects of neferine on A beta and tau aggregation/dissociation. We predicted the binding characteristics of neferine to A beta and tau using molecular docking simulations. Next, thioflavin T and atomic force microscope analyses were used to evaluate the effects of neferine on the aggregation or dissociation of A beta(42) and tau K18. We verified the effect of neferine on A beta fibril degradation using a microfluidic device. In addition, molecular dynamics simulation was used to predict a conformational change in the A beta(42)-neferine complex. Moreover, we examined the neuroprotective effect of neferine against neurotoxicity induced by A beta and tau and their fibrils in HT22 cells. Finally, we foresaw the pharmacokinetic properties of neferine. These results demonstrated that neferine, which has attracted attention as a potential treatment for AD, can directly affect A beta and tau pathology.