Ionizing radiation is widely used in radiotherapy, in order to promote an apoptotic response in cancerous cells. Since the need of finding new substances that would enhance the radiation-induced apoptosis in cancerous cells is great, we studied the effect of epigallocatechin-gallate (EGCG, a tea component), resveratrol (a wine component) and curcuma on cell proliferation and radiation-induced apoptosis in the human leukaemic cell line, EOL-1, derived from a patient with eosinophilic leukaemia. Cells were X-irradiated with 0, 2, 4, 6 or 8 Gy and cultured in the presence of EGCG, resveratrol or curcuma (concentrations ranging from 0 to 200 µM) for 1, 2 or 3 days of culture. Cell proliferation was measured using trypan blue exclusion. Apoptosis was evaluated using light microscopy (morphology study after May-Grünwald Giemsa staining) and flow cytometry (annexin-V staining). Irradiation alone induced a dose-related reduction in cell proliferation and the appearance of polyploid cells in EOL-1 cells. Additionally, EOL-1 cells underwent a dose-related increase of apoptosis which, from the second day on, was accompanied by a dose-related increase of necrosis. When cells were exposed to EGCG, resveratrol or curcuma alone, a decrease in cell proliferation was observed, beginning from 25 µM EGCG and 50 µM resveratrol and curcuma , while an increase in the percentage of apoptotic cells was noticed from 50 µM EGCG, 100 µM resveratrol and curcuma in EOL-1 cells, after only one day of culture. Simultaneous exposure to X-irradiation and, EGCG, resveratrol or curcuma resulted in a synergistic decrease of cell proliferation as well as in a synergistic increase of apoptosis and necrosis.
|Journal||International Journal of Molecular Medicine|
|State||Published - 15 Jan 2005|