Cytotoxic and antitumour principles from Ixora coccinea flowers.

The antitumour activity of Ixora coccinea L. (Rubiaceae) flowers was studied in comparison to intraperitoneally transplanted Dalton's lymphoma (ascitic and solid tumours) and Ehrlich ascites carcinoma (EAC) tumours in mice. Intraperitoneal administration of 200 mg/kg of the active fraction (AF) of the I. coccinea flower increased the life-span of DLA and EAC ascitic tumour-bearing mice by 113 and 68%, respectively. The AF showed less activity against solid tumours (DLA) as compared to ascitic tumours. The same active fraction showed 50% cytotoxicity to DLA, EAC and Sarcoma-180 (S-180) cells in vitro at concentrations of 18, 60 and 25 microg/ml, respectively. It was not toxic to normal lymphocytes, whereas it was toxic to transformed lymphocytes from leukaemic patients, acute lymphoblastic leukaemia (ALL) and chronic myelogenous leukaemia (CML) and K-562 suspension cell cultures. The AF inhibited tritiated thymidine incorporation in cellular DNA.