The subject invention concerns materials and methods for treating or preventing a neurodegenerative condition or disease associated with β-amyloid peptide deposition in neural tissue in a person or animal by administering a therapeutically effective amount of a polyphenol, or an analog, isomer, metabolite, or prodrug thereof, that increases expression or activity of a protein that exhibits α-secretase activity. The subject invention also provides methods to increase α-secretase expression and/or activity in cells by administering polyphenol flavonoids like (−)-epigallocatechin-3-gallate (EGCG) and epicatechin (EC), two polyphenols derived from green tea and other plants and that can be produced synthetically. Furthermore, there are provided methods to decrease or inhibit the production of Aβ1-40 or Aβ1-42 by administering the EGCG and EC compounds, their analogs, metabolites, and prodrugs.
