2.4. Measurement of cytotoxic activity
2.4.1. MTT reduction assay on human cervix cancer (HeLa) cells
Cytotoxic activity was assessed using the MTT assay (Mosmann,
1983). HeLa cells were seeded in 96-well plates at the density
of 10,000 cells/well. Starting concentrations of the extracts were
added to the cells and serial dilutions were made. After incubation
for 24 h, the MTT solution was added and the plates were incubated
again for 2 h. The MTT solution was removed and the formazan
product was solubilized using 10% DMSO plus 90% isopropanol.
Absorbance was measured at 570nm using a plate reader (Lucy-
1, Anthos). The viability was determined based on a comparison
with untreated cells. Doxorubicin hydrochloride (Sigma) was used
as a positive (cytotoxic) control.