Effects of α-mangostin on apoptosis induction of human colon cancer

AIM:To investigate the effect of α-mangostin on the growth and apoptosis induction of human colon cancer cells.METHODS:The three colorectal adenocarcinoma cell lines tested (COLO 205,MIP-101 and SW 620) were treated with α-mangostin to determine the effect on cell proliferation by MTT assay,cell morphology,chromatin condensation,cell cycle analysis,DNA fragmentation,phosphatidylserine exposure and changing of mitochondrial membrane potential.The molecular mechanisms of α-mangostin mediated apoptosis were further investigated by Western blotting analysis including activation of caspase cascade,cytochrome c release,Bax,Bid,p53 and Bcl-2 modifying factor.RESULTS:The highest inhibitory effect of α-mangostin on cell proliferation of COLO 205,MIP-101 and SW 620 were 9.74 ± 0.85 μg/mL,11.35 ± 1.12 μg/mL and 19.6 ± 1.53 μg/mL,respectively.Further study showed that α-mangostin induced apoptotic cell death in COLO 205 cells as indicated by membrane blebbing,chromatin condensation,DNA fragmentation,cell cycle analysis,sub-G1 peak (P < 0.05) and phosphatidylserine exposure.The executioner caspase,caspase-3,the initiator caspase,caspase-8,and caspase-9 were expressed upon treatment with α-mangostin.Further studies of apoptotic proteins were determined by Western blotting analysis showing increased mitochondrial cytochrome c release,Bax,p53 and Bmf as well as reduced mitochondrial membrane potential (P < 0.05).In addition,up-regulation of tBid and Fas were evident upon treatment with α-mangostin (P < 0.01).CONCLUSION:α-Mangostin may be effective as an anti-cancer agent that induced apoptotic cell death in COLO 205 via a link between extrinsic and intrinsic pathways.