A method of making an antineoplastic extract, said extract prepared from Deschampsia antarctica plants, wherein the plants are grown in vitro and treated with a physical or chemical process which increases the polyphenol content of plant tissues, wherein the physical process includes UV irradiation provided to the plants for about 2 hours, and wherein the chemical process includes incubation in NaCl salt solution which involves soaking the plant in the solution for about 30 minutes.
