Fig. 4.

Comparison of anticancer effects between GRE and AGRE on protein levels in HCT116 cells. (A) Induction of apoptosis by GRE or AGRE in HCT116 cells. The cells were exposed to 50 μg/mL and 100 μg/mL of GRE or AGRE for 24 hours; protein levels were determined by Western blot analyses. The band intensity was calculated and compared with that of untreated cells using ImageJ after normalization relative to GAPDH expression. (B) Histogram represents the fold changes of activated caspase-3, caspase-8, and caspase-9 by AGRE compared with that of GRE. (C) Antiproliferative effects of GRE and AGRE on HCT116 cells. The cells were exposed to 50 μg/mL and 100 μg/mL of GRE or AGRE for 24 hours, and then subjected to Western blot analyses to determine the levels of phosphorylated forms of MAPK proteins, including ERK, p38, and JNK (or AKT). (D) Investigation of the antiproliferative effects of GRE and AGRE for 24 hours using the MAPK cascade inhibitors PD98059 (10 μM), SB203580 (5 μM), and SP600125 (10 μM), and the PI3K inhibitor LY294005 (10 μM). Cell viability was determined by MTT assay. The results show the means ± SD of three independent experiments. ^*p < 0.05 and ^**p < 0.01 versus GRE treated cells.