Abstract: The present invention provides compositions and methods for treating and preventing Alzheimer's disease by administering to a subject an effective amount of a dammarane or ginsenoside compound. The invention also provides compositions and methods for modulating beta-amyloid protein production, including A?42 in a cell. The invention further provides compositions and methods for treating and preventing neurodegeneration by administering to a subject an effective amount of a dammarane or ginsenoside compound. Additionally, the invention provides kits for use in treating and/or preventing Alzheimer's disease and neurodegeneration, as well as for reducing the production of beta-amyloid protein.