title: Hexane extracts of garlic cloves induce apoptosis through the generation             of reactive oxygen species in Hep3B human hepatocarcinoma cells.
abstract: Garlic (Allium sativum) compounds have recently received increasing attention due to their cancer chemopreventive properties, and their anticancer activities are extensively reported in many cancer cell lines. However, the anticancer activity and the signaling pathway associated with the induction of apoptosis by extracts of garlic cloves have not been elucidated. In this study, we examined the effects of hexane extracts of garlic cloves (HEGCs) on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death, using a Hep3B human hepatocarcinoma cell line in vitro. The results demonstrated that HEGCs mediate ROS production, and that this mediation is followed by a collapse of mitochondrial membrane potential (MMP, ΔΨm), the downregulation of anti-apoptotic Bcl-2 and Bcl-xL and the activation of caspase-9 and -3. HEGCs also promoted the activation of caspase-8 and the downregulation of Bid, a BH3-only pro-apoptotic member of the Bcl-2. However, the apoptotic phenomena displayed by HEGCs were significantly diminished by the presence of z-VAD-fmk (non-selective caspase inhibitor). Moreover, N-acetyl-L-cysteine (NAC), a widely used ROS scavenger, effectively blocked the HEGC-induced apoptotic effects via the inhibition of ROS production and MMP collapse. These observations clearly indicate that HEGC-induced ROS are key mediators of MMP collapse, which leads to the induction of apoptosis, followed by caspase activation.
authors.affiliation: Department of Biochemistry, Dongeui University College of Oriental                     Medicine, Busan 614-052, Republic of Korea.
authors.forename: Hye Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Han
authors.forename: Gi Young
authors.initials: GY
authors.lastname: Kim
authors.forename: Young-Whan
authors.initials: YW
authors.lastname: Choi
authors.forename: Yung Hyun
authors.initials: YH
authors.lastname: Choi
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D051023:BH3 Interacting Domain Death Agonist Protein / Q000096:biosynthesis; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D045744:Cell Line, Tumor; D015853:Cysteine Proteinase Inhibitors; D015536:Down-Regulation; D004789:Enzyme Activation; D016166:Free Radical Scavengers / Q000494:pharmacology; D005737:Garlic / Q000737:chemistry*; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000096:biosynthesis; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D016166:Free Radical Scavengers; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D000111:Acetylcysteine