Figure 5. Colorimetric assay of caspase-3 activity of cancer cells; U937, HeLa, HepG2 and MCF-7 and normal cells (bottom) treated with or without the microbial extracts at the concentration of 40 µg/ml Ys102; 125 μg/ml  B92; 100 µg/ml B151; and 40 µg/ml B100 extracts, respectively at 37ºC for 24 hrs. Z-VAD-fmk is a broad range caspase inhibitor. The results shown are the representatives of three independent experiments. The treated sample showed significantly increased (*) in caspase activity compared to those untreated and caspase inhibitor addition (P < 0.05).