a b s t r a c t
Mangosteen (Garcinia mangostana Linn.) is a tropical tree from South East Asia and its fruit pericarp is a
well-known traditional medicine. In this study, the cytotoxic effect of three xanthone compounds
(a-mangostin, c-mangostin, and 8-deoxygartanin) from mangosteen pericarp was investigated using
the human melanoma SK-MEL-28 cell line. Significant dose-dependent reduction in % cell viability was
induced. c-Mangostin and 8-deoxygartanine at 5 lg/ml increased the cell cycle arrest in G1 phase (90%
and 92%) compared with untreated cells (78%). All compounds induced apoptosis, of the highest being
a-mangostin at 7.5 lg/ml that induced 59.6% early apoptosis, compared to 1.7% in untreated cells. The
apoptotic effect of a-mangostin was via caspase activation and disruption of mitochondrial membrane
pathways as evidenced by 25-fold increased caspase-3 activity and 9-fold decreased mitochondrial
membrane potential when compared to untreated cells. In conclusion, these xanthones, especially amangostin,
are potential candidates as anti-melanoma agents.