In this work, the treatment of a tumor cell line (95-D cells)
with GA-T resulted in the inhibition of the cell growth in a dosedependent
manner. Our further experiments revealed that
apoptosis induction and cell cycle progression block were
simultaneously responsible for the inhibition of the tumor cell
growth. The percentage of cells in G1 cell cycle phase was
increased in 95-D cells under the GA-T treatment. For the effect
of ganoderma extracts, the cell cycle blocked at the transition
from G1 to S phase (Zhu et al., 2000) and G2/M phase (Lin et al.,
2003) were observed. The different effect may be caused by the
variety of triterpenes in extracts, because the activities of
triterpenes are dependent on their structures (Gan et al., 1998).
Caspase cascade plays a key role in apoptosis procedure
(Oubrahim et al., 2001). Caspase-3 typically functions at the
downstream of other caspases and directly activates enzymes
that are responsible for DNA fragmentation in intrinsic
apoptosis pathway. Caspase-8 is considered as a signaling and
key caspase in extrinsic pathway. Our data suggest that
activation of caspase-3 but not caspase-8 was involved in the