Induction of apoptosis in leukemia cell lines by Linum persicum and Euphorbia cheiradenia

Purpose: In the present study two medicinal herbs Linum persicum and Euphorbia cheiradenia that are native to Iran were tested for their possible anticancer effect and induction of apoptosis on human tumor cell lines including leukemia cell lines. Methods: The effect of methanolic extracts of the herbs on the inhibition of cell proliferation was assessed by MTT colorimetric assay. K562 and Jurkat cell lines treated with the extracts were analyzed for the induction of apoptosis by flow cytometry using propidium iodide staining. DNA fragmentation analysis was performed. Results: Various concentrations of L. persicum and E. cheiradenia showed inhibitory effects on different cell lines. Two leukemic lines including K562 and Jurkat were the most sensitive cells for L. persicum with IC50 of 0.1 and 10 mu g/ml, respectively. In the cultures of tumor cell lines treated with E. cheiradenia, the main inhibitory effects was for Jurkat cells with IC50 of 12.5 mu g/ml. Results indicated a dose-dependent accumulation of cells in the sub-G1 phase. Study of internucleosomal DNA fragmentation showed a typical DNA laddering in agarose gels for both extracts. Conclusion: The present study showed cytotoxic activity of both herbs on tumor cell lines and suggests that this effect may in part be due to the induction of apoptosis in leukemic cells.