Cholinesterase, β-site
amyloid precursor protein cleaving
enzyme 1 (BACE1), and glycogen synthase kinase-3β (GSK-3β)
are the three main enzymes responsible for the early onset of Alzheimer’s
disease (AD). The main aim of the present study was to delineate and
accentuate the triple-inhibitory potential of arylbenzofurans from
Morus alba
against these enzymes. Overall, the enzyme
inhibition assays demonstrated the prominence of mulberrofuran D2
as an inhibitor of AChE, BChE, BACE1, and GSK-3β enzymes with
IC
50
values of 4.61, 1.51, 0.73, and 6.36 μM, respectively.
Enzyme kinetics revealed different modes of inhibition, and in silico
modeling suggested that mulberrofuran D2 inhibited these enzymes with
low binding energy through hydrophilic, hydrophobic, and π–cation
interactions in the active site cavities. Similarly, in Aβ-aggregation
assays, mulberrofuran D2 inhibited self-induced and AChE-induced Aβ
aggregation in a concentration-dependent manner that was superior
to reference drugs. These results suggest that arylbenzofurans from
M. alba
, especially mulberrofuran D2, are triple
inhibitors of cholinesterase, BACE1, and GSK-3β and may represent
a novel class of anti-AD drugs.