The cytotoxicity of eutigosides fromEurya emarginata against HL-60 promyelocytic leukemia cells
Two phenolic glucosides, eutigoside B and eutigoside C were isolated from the fresh leaves ofEurya emarginata. These two phenolic glucosides exerted a significant inhibitory effect on the growth of HL-60 promyelocytic leukemia cells. Furthermore, when the HL-60 cells were treated with eutigoside C, several apoptotic characteristics such as DNA fragmentation, morphologic changes, and increase of the population of sub-G1 hypodiploid cells were observed. In order to understand the mechanism of apoptosis induction by eutigoside C, we examined the changes of Bcl-2 and Bax expression levels. The eutigoside C reduced Bcl-2 protein and mRNA levels, but slightly increased Bax protein and mRNA levels in a time-dependent manner. When we examined the activation of caspase-3, an effector of apoptosis, the eutigoside C increased the expression of active form (19-kDa) of caspase-3 and the increase of their activities was demonstrated by the cleavage of poly (ADP-ribose) polymerase, a substrate of caspase-3, to 85-kDa. The results suggest that the inhibitory effect of eutigoside C fromE. emarginata on the growth of HL-60 appears to arise from the induction of apoptosisvia the down-regulation of Bcl-2 and the activation of caspase.
Key wordsEurya emarginata HL-60 Eutigosides B Eutigoside C Apoptosis. Bcl-2 Bax Caspase-3
Unable to display preview. Download preview PDF.
- Baff, G., Miyashita, T., Williamson, J. R., and Reed, J. C., Apoptosis induced by withdrawal of interleukin-3 (IL-3) from an IL-3-dependent hematopoietic cell line is associated with repartitioning of intracellular calcium and is blocked by enforced Bcl-2 oncoprotein production.J. Biol. Chem., 268, 6511–6519 (1993).Google Scholar
- Oberhammer, F., Wilson, J. W., Dive, C., Morris, I. D., Hickman, J. A., Wakeling, A. E., Walker, P. R., and Sikorska, M., Apoptosis death in epithelial cell: cleavage of DNA to 300 and/or 50 kb fragments prior to in the absence of internucleasomal fragmentation.EMBO J., 12, 3679–3684 (1993).PubMedGoogle Scholar
- Park, S. Y. and Kang, H. K., Effect of exptracts of plants growing in Jeju on the growth of HL-60 cells.Cheju J. Life Sci., 3, 85–94 (2000).Google Scholar
- Sambrook, J., Fritsch, E. F., and Maniatis, T., In: Molecular Cloning Laboratory Manual (2nd ed.), Cold Spring Harbor Laboratory Press, New York, 7–8 (1989).Google Scholar
- Sporn, M. B., Chemoprevention of cancer.Comment In Lancet, 15, 176–177 (1994).Google Scholar
- Wattenberg, L. W., Inhibition of carcinogenesis by minor dietary constituents.Cancer Res., 1, 2085–2091 (1992).Google Scholar