RT Journal Article SR Electronic T1 Induction of Apoptosis by Eurycoma longifolia Jack Extracts JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 2205 OP 2213 VO 25 IS 3B A1 TEE, THIAM TSUI A1 AZIMAHTOL, HAWARIAH LOPE PIHIE YR 2005 UL http://ar.iiarjournals.org/content/25/3B/2205.abstract AB Extracts of the plant Eurycoma longifolia have been shown to possess cytotoxic, antimalarial, anti-ulcer, antipyretic and plant growth inhibition activities. The present study investigated the effects of extracts and their chromatographic fractions from the root of E. longifolia on the growth of a human breast cancer cell line, MCF-7. Our data indicated that E. longifolia extracts and fractions exert a direct antiproliferative activity on MCF-7. The bioassay-guided root fractionation resulted in the isolation of three active fractions, F5, F6 and F7, which displayed IC50 values of (6.17±0.38) μg/ml, (4.40±0.42) μg/ml and (20.00±0.08) μg/ml, respectively. The resultant from F7 purification, F16, exhibited a higher cytotoxic activity towards MCF-7, (IC50=15.23± 0.66 μg/ml) and a certain degree of selectivity against a normal breast cell line, MCF-10A (IC50=66.31±0.47 μg/ml). F16 significantly increased apoptosis in MCF-7 cells, as evaluated by the Tdt-mediated dUTP nick end labelling assay and nuclear morphology. Western blotting revealed down-regulation of the anti-apoptotic Bcl-2 protein expression. F16, however, did not affect the expression of the pro-apoptotic protein, Bax. These results, therefore, suggest that F16 has antiproliferative effects on MCF-7 cells by inducing apoptosis through the modulation of Bcl-2 protein levels. Copyright© 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved