In a study on mice with ovarian cancer, theanine (found in green tea) enhanced the inhibitory effect of the chemotherapy drug Doxorubicin on tumor growth and increased the Doxorubicin concentration in the tumor. Oral administration of theanine or green tea improved the anti-tumor activity of Doxorubicin. The combination of theanine with Doxorubicin decreased liver metastasis.
