Inhibitory effects of constituents from Anemarrhena asphodeloides on the growth of human cancer cells
In this study, we evaluated the inhibitory effects of constituents derived from Anemarrhena asphodeloides BUNGE (Liliaceae) on the growth of human cancer cells. As a result, timosaponin A-III and nyasol effectively inhibited the growth of several human cancer cell lines. In HCT-15 colon cancer cells, timosaponin A-III arrested cell cycle progression in G0/G1 and G2/M phase and increased the accumulation of cells in sub-G1 phase, an indicator of inducing cell death, in a concentration-dependent manner. The increase of cell population in sub-G1 phase by timosaponin A-III was closely related to the induction of apoptosis, which was revealed by increase of DNA fragmentation, decrease of bcl-2 expression, activation of caspase-3 and -9, and cleavage of poly-(ADP-ribose) polymerase. In addition, in K562 human leukemia cells, another active constituent nyasol induced cell cycle arrest in G2/M phase, which was further manifested by modulation of the expression of cyclin B1, cyclin A and CDC25C. The increase of DNA fragmentation by nyasol in a dose-dependent manner also supports the proapoptotic potential of nyasol in K562 cells. These findings suggest the potential of constituents from A. asphodeloides on the inhibition of cancer cell growth by regulating cell cycle progression and inducing apoptosis.
Acknowledgements: This work was supported by a grant on Studies on the Identification of the Efficacy of Biologically Active Components from Oriental Herbal Medicines from the Korea Food and Drug Administration (2007).