Background: Prunusarmeniaca is a member of the Rosacea family. The most important ingredient of this family is amygdalin that is believed to have anti-tumor and analgesic properties. The aim of this study was to evaluate the anti-proliferative effects of Armeniacae semen extract on the acute leukemia, NALM-6, and KG-1 cell lines, and investigate the effect of the extract on apoptosis of these cell lines and caspase-3 gene expression.

Materials and Methods: We prepared aqueous, ethyl acetate, and hydro alcoholic extracts of the Armeniacae semen. The NALM-6 and KG-1 cell lines and mononuclear cells (PBMCs) of healthy controls were treated with different doses of the extracts for 48 hours, and then cell viability was investigated with the MTT test. High-Performance Liquid Chromatography was done for amygdalin identification. The percentage of apoptotic cells was determined using the Annexin V-FITC/PI flow cytometric kit, and caspase-3 gene expression was evaluated.

Results: MTT test revealed that the strongest Inhibition Concentration (IC50) in KG-1 and NALM-6 cell lines was related to the ethyl acetate extract. This extract did not have toxic effects on PBMCs. Flow cytometric analysis showed that the ethyl acetate extract at its IC50 concentration led to almost 50% apoptosis in both cell lines after 48 hours. In the molecular examination, after treatment, a significant increase was seen in caspase-3 gene expression in NALM6 and KG1 cells compared to the control (P<0.001 and P <0.05, respectively).

Conclusion: Our data confirmed that the ethyl acetate extract of Prunusarmeniaca could reduce the proliferation of KG-1 and NALM-6 cell lines probably by activating the apoptotic pathway.