title: The involvement of mitochondrial apoptotic pathway in eugenol-induced cell death in human glioblastoma cells.
abstract: Eugenol, a natural phenolic constituent of clove oil, has a wide range of applications in medicine as a local antiseptic and anesthetic. However, the effect of eugenol on human glioblastoma is unclear. This study examined whether eugenol elevated intracellular free Ca(2+) levels ([Ca(2+)]i) and induced apoptosis in DBTRG-05MG human glioblastoma cells. Eugenol evoked [Ca(2+)]i rises which were reduced by removing extracellular Ca(2+). Eugenol-induced [Ca(2+)]i rises were not altered by store-operated Ca(2+) channel blockers but were inhibited by the PKC inhibitor GF109203X and the transient receptor potential channel melastatin 8 (TRPM8) antagonist capsazepine. In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished eugenol-induced [Ca(2+)]i rises. The phospholipase C (PLC) inhibitor U73122 significantly inhibited eugenol-induced [Ca(2+)]i rises. Eugenol killed cells which were not reversed by prechelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM). Eugenol induced apoptosis through increasing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, releasing cytochrome c and activating caspase-9/caspase-3. Together, in DBTRG-05MG cells, eugenol evoked [Ca(2+)]i rises by inducing PLC-dependent release of Ca(2+) from the endoplasmic reticulum and caused Ca(2+) influx possibly through TRPM8 or PKC-sensitive channels. Furthermore, eugenol induced the mitochondrial apoptotic pathway.
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, ROC.
authors.forename: Wei-Zhe
authors.initials: WZ
authors.lastname: Liang
authors.affiliation: Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi 613, Taiwan, ROC; Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chia-Yi 613, Taiwan, ROC.
authors.forename: Chiang-Ting
authors.initials: CT
authors.lastname: Chou
authors.affiliation: Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, ROC; Department of Surgery, National Defense Medical Center, Taipei 114, Taiwan, ROC.
authors.forename: Shu-Shong
authors.initials: SS
authors.lastname: Hsu
authors.affiliation: Department of Surgery, National Defense Medical Center, Taipei 114, Taiwan, ROC.
authors.forename: Wei-Chuan
authors.initials: WC
authors.lastname: Liao
authors.affiliation: Department of Pharmacy, Tajen University, Pingtung 907, Taiwan, ROC.
authors.forename: Pochuen
authors.initials: P
authors.lastname: Shieh
authors.affiliation: Department of Pharmacy, Tajen University, Pingtung 907, Taiwan, ROC.
authors.forename: Daih-Huang
authors.initials: DH
authors.lastname: Kuo
authors.affiliation: Department of Dermatology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, ROC.
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Tseng
authors.affiliation: Department of Nursing, Tzu Hui Institute of Technology, Pingtung 907, Taiwan, ROC.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Kuo
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, ROC. Electronic address: pseudoo67@gmail.com.
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Jan
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D020013:Calcium Signaling / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D005054:Eugenol / Q000494:pharmacology*; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D011493:Protein Kinase C / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D050053:TRPM Cation Channels / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D017382:Reactive Oxygen Species; D050053:TRPM Cation Channels; C425966:TRPM8 protein, human; D005054:Eugenol; D011493:Protein Kinase C; D010738:Type C Phospholipases
keywords: Apoptosis; Ca(2+); Eugenol; Human glioblastoma cells; TRPM8