A method of treating neurological condition in a subject by administration of an extract, or fraction or sub-fraction thereof, of Nerium species or Thevetia species is provided, wherein the extract, or fraction or sub-fraction thereof, excludes oleandrin and neriifolin. Alzheimer's disease, Huntington's disease or stroke are treated by administering a therapeutically effective amount of the extract, or a fraction or sub-fraction thereof, to a subject. The extract can be present in a pharmaceutical composition.
