Breadfruit (Artocarpus communis Moraceae) is cultivated in tropical and subtropical regions as a traditional
starch crop and also has potential medicinal properties. The aim of this work was to study the in vitro anticancer activity of compounds isolated from the leaves of Artocarpus communis. Three new geranyl
chalcone derivatives including
isolespeol (1), 5'-geranyl-2',4',4-trihydroxychalcone (2), and 3,4,2',4'-tetrahydroxy-3'-geranyldihydrochalcone (3), together with two known compounds lespeol (4) and
xanthoangelol (5), were isolated from the leaves of Artocarpus communis. The structures of 1- 5 were elucidated by spectroscopy and through comparison with data reported in the literature. The effects of geranyl
chalcone derivatives (1- 5) on the viability of human
cancer cells (including SW 872, HT-29, COLO 205, Hep3B, PLC5, Huh7, and HepG2 cells) were investigated. The results indicate that
isolespeol (1) showed the highest inhibitory activity with an IC 50 value of 3.8 muM in SW 872 human
liposarcoma cells. Treatment of SW 872 human
liposarcoma cells with
isolespeol (1) caused the loss of mitochondrial membrane potential (DeltaPsim). Western blotting revealed that
isolespeol (1) stimulated increased
protein expression of Fas, FasL, and p53. The expression ratios of pro- and antiapoptotic Bcl-2 family members were also changed by
isolespeol (1) treatment to subsequently induce the activation of
caspase-9 and
caspase-3, which was followed by cleavage of
poly (ADP-ribose) polymerase (PARP). These results demonstrate that
isolespeol (1) induces apoptosis in SW 872 cells through Fas- and mitochondria-mediated pathways.