Abstract
PURPOSE: Based on the poor prognosis of drug resistance in pediatric acute lymphoblastic leukemia (ALL) and adverse effects of chemotherapy, this study was aimed to evaluate the effect of several herbal extracts on leukemic cells. METHODS: Two subtypes of T- and B-ALL cell lines, followed by ALL primary cells were treated with cinnamon, ginger, and green tea extracts, alone or in combination with methotrexate (MTX). Possible apoptosis was investigated using Annexin-V/PI double staining. Real-time PCR was applied to evaluate the expression levels of related ABC transporters upon combination therapy. RESULTS: The IC(50)s for cinnamon, ginger and green tea extracts on ALL cell lines were 300 μg/ml, 167 μg/ml and 70 μg/ml, respectively. Surprisingly, the methotrexate (MTX)-resistant sub-line showed more sensitivity to ginger. Combined treatment with ginger and MTX showed synergistic effects on CCRF-CEM, Nalm-6 and ALL primary cells. It was shown that ginger does not impair the high expression levels of ABCA2 or ABCA3 transporter genes in the ALL malignant cells, suggesting other molecular pathways involved in its anticancer potential. CONCLUSION: To the best of our knowledge, this is the first study that reveals the antileukemic effect of ginger extract on both, pediatric ALL cell lines and primary cells.