The antitumour activity of Ixora coccinea L. (Rubiaceae) flowers was s
tudied in comparison to intraperitoneally transplanted Dalton's lympho
ma (ascitic and solid rumours) and Ehrlich ascites carcinoma (EAC) tum
ours in mice. Intraperitoneal administration of 200 mg/kg of the activ
e fraction (AF) of the I. coccinea flower increased the life-span of D
LA and EAC ascitic tumour-bearing mice by 113 and 68%, respectively. T
he AF showed less activity against solid rumours (DLA) as compared to
ascitic rumours. The same active fraction showed 50% cytotoxicity to D
LA, EAC and Sarcoma-180 (S-180) cells in vitro at concentrations of 18
, 60 and 25 mu g/ml, respectively. It was not toxic to normal lymphocy
tes, whereas it was toxic to transformed lymphocytes from leukaemic pa
tients, acute lymphoblastic leukaemia (ALL) and chronic myelogenous le
ukaemia (CML) and K-562 suspension cell cultures. The AF inhibited tri
tiated thymidine incorporation in cellular DNA. (C) 1998 Elsevier Scie
nce Ireland Ltd. All rights reserved.