Induction of apoptosis in tumor cells by Licorice root flavonoids in vitro

摘要

Previously, we have shown that an experimental sample of licorice root flavonoids (LRF), inhibits proliferation of tumor cells in a dose dependent manner. The aim of this study was to evaluate the ability of LRF to induce apoptosis as a possible mechanism for its antiproliferative effect. The study was done by flow cytometry (Cytomics FC 500 Beckman Coulter, USA) and performed using a DNA-specific fluorochrome propidium iodide (Sigma, USA). The ability of LRF to induce apoptosis was studied against histologically different cell lines (U-937, A-431, GL-6). After 24 h of incubation of tumor cell lines with LRF (20 mkg/ml) there was a slight increase of apoptosis level for 10-15%. By 48 h incubation there were observed a statistically significant increase in the levels of apoptotic and tetraploid cells. Therefore we can conclude the following: evidently inhibition of proliferation of tumor cells is the result of G2/M cell cycle arrest, which causes their eventual apoptosis.