Antiproliferative and apoptotic effects of garlic on chronic myeloid leukemia cell line

INTRODUCTION: Garlic is a plant commonly used for seasoning food in many different cultures of the world, and its medicinal properties have been known since ancient times. Epidemiological studies have shown that enhanced garlic consumption is closely related with reduced cancer incidence. In vitro studies indicate that garlic has antiproliferative and apoptotic effects on different cancer cell lines including HL-60 (human acute myeloid leukemia cell line). However, there are no reports on whether or not it affects CML (chronic myeloid leukemia) cell lines in vitro.

CML is a myeloproliferative disorder that is characterized by Philedelphia (Ph) chromosome. This chromosome is caused by resiprocal translocation t(9;22)(q34;q11.2) which results in BCR-ABL fusion gene produces a fusion tyrosine kinase (FTKs). The fusion tyrosine kinases create bipartite proteins in which the kinase is hyperactivated by an adjoining oligomerization domain. Oncogenic tyrosine kinases are thought to induce either directly or indirectly a critical repertoire of transforming events, namely uncontrolled cell growth, genomic instability and protection of DNA–damaged cells from apoptosis.

We hypothesized that garlic could cause apoptosis in CML cells. Therefore, in this study, it is aimed to investigate possible antiproliferative and apoptotic effects of garlic on 32Dp210 (BCR-ABL fusion gene (+) mouse CML cell line) and 32D (wild type mouse myeloid cell line) cell lines.

MATERIALS and METHODS: Cells were grown at 37⁰C under a humidified, 5% CO₂ atmosphere in RPMI 1640 medium supplemented with 20% fetal calf serum. Cells were incubated with garlic extract at final concentrations of 1% (w/v) and 0.4% (w/v) for 0, 24, 48 and 72 hours. Cell viability was detected by MTT assay and apoptosis was determined morphologically.

RESULTS: It is demonstrated that garlic has antiproliferative and apoptotic effects on both of the cell lines. All of the concentrations were found to be statistically different (p<0.001) in respect to their antiproliferative and apoptotic effects. The most effective apoptotic and antiproliferative concentration was found 0.4% (w/v). It has been calculated that at this concentration the death risk of 32Dp210 was 2.08 times higher than 32D. Our results indicate that garlic could be used as a potential chemopreventive agent in CML.