Cytotoxic and apoptotic effects of different extracts of Artemisia turanica Krasch. on K562 and HL-60 cell lines

Abstract

Artemisia is an important genus of Iranian flora. Cytotoxic activities for some species of the genus have already been reported. In this study, we have investigated the cytotoxic effects of n-hexane, CH2Cl2, EtOAc, EtOH, and EtOH/H2O (1:1) extracts of A. turanica Krasch. on two human leukemic cancer cell lines (K562 and HL-60) and J774 as normal cells using alamarBlue (resazurin) assay. PI staining of the fragmented DNA and western blot analysis were used to evaluate the possible apoptotic effect of the extract. The CH2Cl2 extract of A. turanica showed the most antiproliferative effect on cancer cells among all tested extracts with IC50 values of 69 and 104 μ g/mL on K562 and HL-60 cells, respectively, whereas the normal cells were not affected significantly by this extract. Sub-G1 peak in the flow cytometry histogram of the cells treated with CH2Cl2 extract of A. turanica and cleavage of PARP protein confirmed the induction of apoptosis with CH2Cl2 extract. Taken together, the findings of the present work suggest the anticancer potential of CH2Cl2 extract of A. turanica on human leukemic cancer cell lines.

Figure 1

Extraction scheme of n-hexane, CH₂Cl₂, EtOAc, EtOH, and EtOH/H2O (1 : 1) extracts of A. turanica.

Figure 2

The dose-dependent effects of n-hexane, CH₂Cl₂, EtOAc, EtOH, and EtOH/H2O (1 : 1) extracts on the growth of K562 and HL-60 cells and normal J774 cells. All extracts exhibited cytotoxic activity against apoptosis-proficient HL-60 and apoptosis-resistant K562 cells, with IC₅₀ values ranging from 68.83 to >450 μg/mL and with much less cytotoxic effects on normal J774 cells. Values were mean ± SEM of at least three independent experiments, each in triplicates.

Figure 3

PI staining and flow cytometry analysis of CH₂Cl₂ extract (0, 25, 50, and 100 μg/mL) induced apoptosis in K562 and HL-60 cells.

Figure 4

Proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) in HL-60 cells and level of Bax protein in HL-60 and K562 cells after 48 h exposure to CH₂Cl₂ extract of A. turanica (25, 50 and 100 μg/mL). β-Actin was used as a loading control. All Western blots were representative of 3 independent experiments.