and Apoptosis Induction of Methanolic Extract of

Copyright © 2012 T-Johari S. A. Tajudin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Methanolic extract of Cynometra cauliflorawhole fruit was assayed for cytotoxicity against the human promyelocytic leukemia HL-60 and the normal mouse fibroblast NIH/3T3 cell lines by using theMTT assay. The CD50 of the extract for 72 hours was 0.9 µg/mL whereas the value for the cytotoxic drug vincristine was 0.2 µg/mL. The viability of the NIH/3T3 cells was at 80.0 % when treated at 15.0 µg/mL. The extract inhibited HL-60 cell proliferation with dose dependence. AO/PI staining of HL-60 cells treated with the extract revealed that majority of cells were in the apoptotic cell death mode. Flow cytometry analysis of HL-60 cells treated at CD50 of the extract showed that the early apoptotic cells were 31.0, 26.3 and 19.9 % at 24, 48, and 72 hours treatment, respectively. The percentage of late apoptotic cells was increased from 62.0 at 24 hours to 64.1 and 70.2 at 48 and 72 hours, respectively. Meanwhile, percent of necrotic cells were 4.9, 6.6, and 8.5 at 24, 48, and 72 hours, respectively. This study has shown that the methanoli