Control of cell cycle progression of cancer cells is an effective
strategy for cancer therapy because cell cycle deregulation is one
of the hallmarks of many common malignancies (Grana and Reddy,
1995; Molinari, 2000; Pavletich, 1999; Senderowicz, 2003). Cell cycle
phase distribution of treated SK-MEL-28 cells was analyzed to
determine if the proliferation inhibition by xanthones involved cell
cycle arrest. Treatment of SK-MEL-28 cells with c-mangostin and
8-deoxygartanin did induce G1-phase arrest. Treatment with amangostin
significantly increased the sub G1 peak (hypodiploid
debris) (P < 0.05) with a concomitant decrease in G1 phase, indicating
induction of apoptosis. The current results are not in agreement
with the study by Matsumoto et al. (2005), who reported that Sphase
cell cycle arrest was induced by c-mangostin, and G1-phase
arrest by a-mangostin and b-mangostin in human colon cancer