Extracts from plant material, or semi-purified/purified molecules or compounds prepared from the extracts that demonstrate the ability to modulate one or more cellular activities are provided. The extracts are capable of slowing down, inhibiting or preventing cell migration, for example, the migration of endothelial cells or neoplastic cells and thus, the use of the extracts to slow down, inhibit or prevent abnormal cell migration in an animal is also provided. Methods of selecting and preparing the plant extracts and methods of screening the extracts to determine their ability to modulate one or more cellular activity are described. The purification or semi-purification of one or more molecules from the described extracts is also contemplated as well as the use of these molecules, alone or in combination with an extract, to slow down, inhibit or prevent abnormal cell migration in an animal.