Isoliquiritigenin, which is possibly a principal anti-tumor constituent of
licorice, a traditional Chinese herb, was examined for apoptosis-Inducing a
ctivity in human gastric cancer MGC-803 cells. Typical morphological and bi
ochemical features of apoptosis including cell shrinkage, chromatin condens
ation, DNA ladder formation, and appearance of apoptotic peaks (subG(1)) we
re observed in MGC-803 cells with isoliquiritigenin treatment. Using Fluo-3
and Rh123 as fluorescent probes, respectively, it was found that the intra
cellular free calcium concentration increased and the mitochondrial transme
mbrane potential (Delta Psi (m)) decreased in a dose-dependent manner in ap
optotic cells. These results suggest that isoliquiritigenin induced apoptos
is of MGC-803 cells through calcium- and Delta Psi (m)-dependent pathways,
indicating that it is potentially useful as a natural anti-cancer agent.