Disclosed are combinations of natural and synthetic turmeric, ginger, ginko biloba, sage, and rosemary compounds suitable for treatment of beta-amyloid-disease induced disease that have synergistic anti-.beta.A peptide effects when members of the five groups of compounds are combined. Suitable members of the compounds include both natural compounds derived from extracts of each of Curcuma sp., Zingiber sp., Ginkgo biloba, Salvia sp., or Rosmarinus sp. as well as synthetic homologues and analogues of such natural compounds. Sage and rosemary derived compounds suitable alone for treatment of beta-amyloid induced disease is also described.