This invention concerns to a topical pharmaceutical composition comprising an water soluble Curcuma extract, and suitable excipients for said topical administration; the process for obtaining said pharmaceutical compositions; the use of different Curcuma extracts as photosensitizing agents for the treatment of proliferative diseases; and the use of Curcuma extract or curcuminoids in combination with a radiation for the treatment of proliferative diseases on eukaryote cells.