High-throughput screening for amyloid-β binding natural small-molecules based on the combinational use of biolayer interferometry and UHPLC−DAD-Q/TOF-MS/MS

Discovery of drugs rapidly and effectively is an important aspect for Alzheimer's disease(AD).In this study,a novel high-throughput screening(HTS)method aims at screening the small-molecules with amyloid-β(Aβ)binding affinity from natural medicines,based on the combinational use of biolayer interferometry(BLI)and ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time-of-flight tandem mass spectrometry(UHPLC−DAD-Q/TOF-MS/MS)has been firstly developed.Briefly,the components in natural medicines disassociated from biotinylated Aβwere collected to analyze their potential Aβbinding affinity by UHPLC−DAD-Q/TOF-MS/MS.Here,baicalein was confirmed to exhibit the highest binding affinity with Aβin Scutellaria baicalensis.Moreover,polyporenic acid C(PPAC),dehydrotumulosic acid(DTA),and tumulosic acid(TA)in Kai-Xin-San(KXS)were also identified as potent Aβinhibitors.Further bioactivity validations indicated that these compounds could inhibit Aβfibrillation,improve the viability in Aβ-induced PC-12 cells,and decrease the Aβcontent and improve the behavioral ability in Caenorhabditis elegans.The molecular docking results confirmed that PPAC,DTA,and TA possessed good binding properties with Aβ.Collectively,the present study has provided a novel and effective HTS method for the identification of natural inhibitors on Aβfibrillation,which may accelerate the process on anti-AD drugs discovery and development.