Expression of Concern: Potent anti‐amyloidogenic and fibril‐destabilizing effects of polyphenols in vitro: implications for the prevention and therapeutics of Alzheimer's disease

• DOI: 10.1046/j.1471-4159.2003.01976.x
• Publication Date: 2003-09-12T11:55:21Z
• Authors: Kenjiro Ono; Yuji Yoshiike; Akihiko Takashima; Kazuhiro Hasegawa; Hironobu Naiki; Masahito Yamada
• Keywords: Myricetin; Morin; Amyloid beta

Abstract Cerebral deposition of amyloid β‐peptide (Aβ) in the brain is an invariant feature Alzheimer's disease (AD). A consistent protective effect wine consumption on AD has been documented by epidemiological studies. In present study, we used fluorescence spectroscopy with thioflavin T and electron microscopy to examine effects wine‐related polyphenols (myricetin, morin, quercetin, kaempferol (+)‐catechin (–)‐epicatechin) formation, extension, destabilization β‐amyloid fibrils (fAβ) at pH 7.5 37°C vitro . All examined dose‐dependently inhibited formation fAβ from fresh Aβ(1–40) Aβ(1–42), as well their extension. Moreover, these destabilized preformed fAβs. The overall activity molecules was order of: myricetin = morin quercetin > (–)‐epicatechin. effective concentrations (EC 50 ) myricetin, for extension fAβs were 0.1–1 µ m cell culture experiments, myricetin‐treated suggested be less toxic than intact fAβ, demonstrated 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay. Although mechanisms which inhibit Aβ, destabilize pre‐formed are still unclear, could a key molecule development preventives therapeutics AD.