Abstract 5640: Preclinical of assessment of oxidative stress and apoptotic mechanisms of garlic extract in the prevention of acute promyelocytic leukemia

Abstract

Abstract INTRODUCTION: Garlic supplementation in diet has been shown to benefit patients with cancer. Recently, the pharmacological role of garlic in the prevention and treatment of cancer has received increasing attention. However, the mechanisms by which garlic extract (GE)-induced cytotoxicity, oxidative stress, and apoptosis in cancer cell remain largely unknown. OBJECTIVE: The present study was designed to use HL-60 cells as test model to evaluate whether or not GE-induced cytotoxicty and apoptosis in human leukemia (HL-60) cells is mediated through oxidative stress. METHODS: Human leukemia (HL-60) cells were treated with increasing concentrations of GE for 12 h. Cell survival was determined by MTT assay. The extent of oxidative cell/tissue damage was determined by measuring lipid peroxidation (malondialdehyde) concentrations by spectrophotometry. Cell apoptosis was measured by flow cytometry assessment (Annexin-V and caspase-3 assays) and DNA laddering analysis, respectively. RESULTS: Data obtained from the MTT assay indicated that GE significantly (p < 0.05) reduced the viability of HL-60 cells in a dose-dependent manner. We detected a significant (p < 0.05) increase in malondialdehyde (MDA) concentrations in GE-treated HL-60 cells compared to the control. Flow cytometry data showed a strong concentration-response relationship between GE exposure and Annexin-V positive HL-60 cells. Similarly, a statistically significant and dose-dependent increase (p <0.05) was recorded with regard to caspase-3 activity in HL-60 cells undergoing late apoptosis. These results were confirmed by data of DNA laddering assay showing a clear evidence of nucleosomal DNA fragmentation in GE-treated cells. CONCLUSION: Our finding indicates that GE-induced cytotoxicity and apoptosis in HL-60 cells are executed by cell death, phosphatidylserine externalization, activation of caspase-3, and nucleosomal DNA fragmentation under the overproduction of MDA, a by-product of lipid peroxidation and biomarker of oxidative stress. We conclude that GE at therapeutic concentrations induces cytotoxic effect and apoptosis in human leukemia (HL-60) cells through oxidative stress. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5640. doi:1538-7445.AM2012-5640