Aged garlic extract and its constituent, S‑allyl‑L‑cysteine, induce the apoptosis of neuroblastoma cancer cells due to mitochondrial membrane depolarization

Abstract

Aged garlic extract (AGE) has been demonstrated to have therapeutic properties in tumors; however its mechanisms of action have not yet been fully elucidated. A previous study revealed that AGE exerts an anti-proliferative effect on a panel of both sensitive [wild-type (WT)] and multidrug-resistant (MDR) human cancer cells. Following treatment of the cells with AGE, cytofluorimetric analysis revealed the occurrence of dose-dependent mitochondrial membrane depolarization (MMD). In this study, in order to further clarify the mechanisms of action of AGE, the effects of AGE on mitochondria isolated from rat liver mitochondria (RLM) were also examined. AGE induced an effect on the components of the electrochemical gradient (Δµ H +), mitochondrial membrane potential (ΔΨ m) and mitochondrial electrochemical gradient (ΔpH m). The mitochondrial membrane dysfunctions of RLM induced by AGE, namely the decrease in both membrane potential and chemical gradient were associated with a higher oxidation of both the endogenous glutathione and pyridine nucleotide content. To confirm the anti-proliferative effects of AGE, experiments were performed on the human neuroblastoma (NB) cancer cells, SJ-N-KP and the MYCN-amplified IMR5 cells, using its derivative S-allyl-L-cysteine (SAC), with the aim of providing evidence of the anticancer activity of this compound and its possible molecular mechanism as regards the induction of cytotoxicity. Following treatment of the cells with SAC at 20 mM, cell viability was determined by MTT assay and apoptosis was detected by flow cytometry, using Annexin V-FITC labeling. The percentages of cells undergoing apoptosis was found to be 48.0% in the SJ-N-KP and 50.1% in the IMR5 cells. By cytofluorimetric analysis, it was suggested that the target of SAC are the mitochondria. Mitochondrial activity was examined by labeling the cells with the probe, 5,5' ,6,6'-tetrachloro-1,1' ,3,3'-tetraethylimidacarbocyanine iodide (JC-1). Following treatment with SAC at 50 mM, both NB cell lines exhibited a marked increase in MMD. On the whole, the findings of this study indicate that both natural products, AGE and SAC, cause cytotoxicity to tumor cells via the induction of mitochondrial permeability transition (MPT).

Enzymatic Spermine Metabolites Induce Apoptosis Associated with Increase of p53, caspase-3 and miR-34a in Both Neuroblastoma Cells, SJNKP and the N-Myc-Amplified Form IMR5

“…After incubation, cells were washed with PBS-1% BSA twice, centrifuged, and resuspended in 1 mL PBS-1% BSA. Both SJNKP and IMR5 cells were subsequently seeded in a 96-multiwell plate and processed according to Kanamori et al [50].…”

Phytochemicals from Indian Ethnomedicines: Promising Prospects for the Management of Oxidative Stress and Cancer

“…Some garlic-based water-soluble phytochemicals such as S-allylmercaptocysteine (SAMC) and S-allyl cysteine (SAC) also exhibited potent anticancer activity [134]. SAC could also exhibit stronger antioxidant properties than fresh garlic, and has powerful anticancer activity not only at the early stage but also at the late stages of the ailment.…”

Garlic as a Potential Nominee in Functional Food Industry

“…Anticarcinogenic outcome of garlic has been characterized by diverse mechanisms including upsurge level of glutathione, collective enzymes actions such as S-transferase, catalase, and glutathione, hunting ability to minimize radicals, restoration mechanism of DNA, safety of chromosomal impairment and settlement of cytochrome p4502E1 [49]. Different studies have been proceed including anti-proliferative ability of garlic active compounds to stop the tumor growth in vitro and in vivo [50]. Protein extracted from garlic bulb has significant effect against tumor size.…”