Induction of apoptosis by a hexane extract of aged black garlic in the human leukemic U937 cells

Abstract

BACKGROUND/OBJECTIVESIn this study, the apoptogenic activity and mechanisms of cell death induced by hexane extract of aged black garlic (HEABG) were investigated in human leukemic U937 cells.MATERIALS/METHODSCytotoxicity was evaluated by MTT (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide) assay. Apoptosis was detected using 4,6-diamidino-2-phenyllindile (DAPI) staining, agarose gel electrophoresis and flow cytometry. The protein levels were determined by Western blot analysis. Caspase activity was measured using a colorimetric assay.RESULTSExposure to HEABG was found to result in a concentration- and time-dependent growth inhibition by induction of apoptosis, which was associated with an up-regulation of death receptor 4 and Fas legend, and an increase in the ratio of Bax/Bcl-2 protein expression. Apoptosis-inducing concentrations of HEABG induced the activation of caspase-9, an initiator caspase of the mitochodrial mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase. HEABG also induced apoptosis via a death receptor mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid, and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. However, pre-treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, significantly blocked the HEABG-induced apoptosis of these cells, and increased the survival rate of HEABG-treated cells, confirming that HEABG-induced apoptosis is mediated through activation of caspase cascade.CONCLUSIONSBased on the overall results, we suggest that HEABG reduces leukemic cell growth by inducing caspase-dependent apoptosis through both intrinsic and extrinsic pathways, implying its potential therapeutic value in the treatment of leukemia.

Akacid Medical Formulation Induces Apoptosis in Myeloid and Lymphatic Leukemic Cell Lines In Vitro and In Vivo

“…4A . Hence, we conclude that AMF induces apoptosis via both the extrinsic and the intrinsic pathway, which has been found to be the case also with various naturally occurring and synthetic molecules [ 14 , 15 , 16 ].…”

Anticancer activity of Helicia nilagirica bedd in mice transplanted with Dalton’s lymphoma

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Physicochemical Properties, Biological Activity, Health Benefits, and General Limitations of Aged Black Garlic: A Review

“…ABG reduces cell motility, invasiveness, and activities of matrix metalloproteinase-2 (MMP-2) and MMP-9 in AGS human gastric cancer cells [ 60 ]. The hexane extract of ABG induces caspase-dependent apoptosis through both intrinsic and extrinsic pathways in U937 leukemic cells [ 61 ]. ABG inhibits HT29 colon cancer cell growth via the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway [ 62 ].…”