To investigate the anti-proliferative, apoptotic and differentiating activities of Eurycoma
root extracts on HL-60 leukemic cells.
HL-60 cells were treated with different partially purified sub-fractions (F1 – F3) derived from
the resin chromatography of the crude methanol root extract of E. longifolia
roots, at different doses and
time points. The anti-proliferative activity of E. longifolia
was assessed via cell counting and trypan blue
exclusion. Apoptosis was evaluated via Annexin-V FITC/IP and Hoechst staining. Flow cytometry and
Wright staining were used to assess its differentiation activities.
F1 showed unremarkable growth inhibition rate while F2 and F3 showed growth inhibitory
effects with median inhibitory concentration (IC50
) values of 15.2 and 28.6 μg/ml, respectively.
Treatment with F2 and F3 (100 μg/ml) for 96 h increased cell death from 3.3 to 95.5 and 76.3 %,
respectively. Treatment with F2 (50 μg/ml) induced apoptosis by 14, 19.5 and 25 % after 24, 48 and
72 h, respectively. No differentiation activity was observed, as indicated by absence of myeloid
maturation and a non-significant CD14 positivity (p > 0.05).
Conclusion: E. longifolia
extract (F2) showed promising anti-leukemic activity and can be a candidate
for the development of a drug for the treatment of acute promyelocytic leukemia (APL).