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

Abstract

BACKGROUND/OBJECTIVES:In 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/METHODS: Cytotoxicity 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. RESULTS: Exposure 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. CONCLUSIONS: Based 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.

Formation, nutritional value, and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans

“…BG exhibits excellent in vitro and in vivo therapeutic effects on several cancers (lung cancer, liver cancer, gastric cancer, leukemia, breast cancer, and colon cancer). A hexane extract of ABG was reported to exhibit anticancer effects in human leukemic U937 cells, as the extract induces caspase‐dependent apoptosis via an extrinsic pathway involving the death receptor 4 and Fas legend, while raising the ratio of Bax/Bcl‐2 protein expression via increasing the protein levels of pro‐apoptotic Bax and reducing the anti‐apoptotic Bcl‐2 expression (Park et al., ). ABG was found able to inhibit the growth of HT29 colon cancer cells and induce apoptosis via inhibiting the phosphatidylinositol 3‐kinase protein kinase B signaling pathway, because of the upregulation of phosphatase and tensin homology deleted on chromosome 10, downregulation of serine/threonine kinase and phosphorylated‐serine/threonine kinase expression, and suppression of the 70‐kDa ribosomal protein S6 kinase 1 at the mRNA and protein levels (Dong et al., ).…”

A Review of Component and Pharmacology Activities of Black Garlic

“…That garlic organo-sulfur compounds test (5-100 µM) worked to protect against DNA damage (Belloir et al, 2006). Park et al, (2014) reported U937 cells were exposed to various concentrations of hexane extract aged black garlic (HEABG) for 24 h or 10 µg/mL of HEABG for the indicated times. The MTT assay was used to examine the effect of HEABG on cell viability.…”

Synthesis and Evaluation of 2,4-Disubstituted Quinazoline Derivatives with Potent Anti-Angiogenesis Activities

“…All filter discs had the same size, and any visual size differences are due to the various distances from which pictures were taken. H-NMR (400 MHz) and 13 C-NMR (101 MHz) spectra were recorded on a Bruker 400 NMR instrument with tetramethylsilane (TMS) as an internal standard. Only new compounds' NMR data is given.…”

“…56 (m, 4H), 2.41 (s, 6H), 1.97-1.85 (m, 2H), 1.05 (t, J = 7.1 Hz, 6H). 13 C-NMR (CDCl 3 ) δ = 171.05, 160.60, 159.10, 147.99, 141.19, 136.74, 132.56, 131.74, 127.35 -1-yl)propanemide (11d). Compound 8 was treated with excess N-methylpiperazine according to the general aminolysis procedure to afford 11d as a white solid in 44% yield after column chromatography with petroleum ether/EtOAc (10:1) elution; mp 167-168 °C.…”

“…After 48 h of treatment at 37 °C in a humidified atmosphere of 5% CO 2 , 5 mg/mL MTT solution (10 μL) was added to each well and further incubated for 4 h. Each well was then added dimethyl sulfoxide (DMSO, 100 μL), and the optical density (OD) was recorded at 490 nm. All measurements were done in triplicate, and the IC 50 values were derived from the mean OD values of the triplicate tests versus drug concentration curves [12,13].…”