Anticancer effects of Alpinia pricei Hayata roots

The leaves and roots of Alpinia pricei Hayata are used as a traditional wrapping for food and as a cooking substitute for fresh ginger. Our previous study showed that ethanol extracts from the roots of A. pricei Hayata (EEAP) and its phenolic compounds have anti-inflammatory effects. The aims of this work were to further study the in vitro anticancer activity of EEAP and its active compounds with respect to various cancer cells. The results from an MTT assay demonstrated that EEAP decreased the cell population growth of CH27, HL-60, and A549 cells. Flow cytometric analysis of HL-60 cells exposed to EEAP showed that the number of apoptotic cells increased in a time- and dose-dependent manner. Western blot data revealed that EEAP stimulated an increase in the level of protein expression of Fas, FasL, caspase-8, and tBid. Moreover, the ratio of the expression levels of pro- and anti-apoptotic Bcl-2 family members was changed after treatment with EEAP. EEAP-induced apoptosis involved the release of mitochondrial cytochrome c and subsequently induced the activation of caspase-9 and caspase-3, which were followed by the cleavage of poly(ADP-ribose) polymerase (PARP). The results also demonstrated that phenolic compounds (caffeic acid, apigenin, curcumin, and pinocembrin) from EEAP decreased the rate of population growth of HL-60 cells. Treatment of HL-60 cells with these phenolic compounds caused the loss of mitochondrial membrane potential. Our finding could provide critical information regarding the chemopreventive potential of ethanol extracts from A. pricei Hayata. These results also demonstrate that the EEAP-induced apoptotic ability in HL-60 cells might be related to the phenolic compounds.