title: The Mechanism of Safrole-Induced [Ca²⁺]i Rises and Non-Ca²⁺-Triggered Cell Death in SCM1 Human Gastric Cancer Cells.
abstract: Safrole is a carcinogen found in plants. The effect of safrole on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) and viability in SCM1 human gastric cancer cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺](i). Safrole at concentrations of 150-450 μM induced a [Ca²⁺](i) rise in a concentration-dependent manner. The response was reduced by 60% by removing extracellular Ca²⁺. Safrole-evoked Ca²⁺ entry was not altered by nifedipine, econazole, SKF96365, and protein kinase C activator or inhibitor. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished safrole-evoked [Ca²⁺](i) rises. Conversely, treatment with safrole abolished thapsigargin or BHQ-evoked [Ca²⁺](i) rises. Inhibition of phospholipase C (PLC) with U73122 abolished safrole-induced [Ca²⁺](i) rises. At 250-550 μM, safrole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/propidium iodide staining data suggest that safrole (350-550 μM) induced apoptosis concentration-dependently. These studies suggest that in SCM1 human gastric cancer cells, safrole induced [Ca²⁺](i) rises by inducing PLC-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via non-store-operated Ca²⁺ entry pathways. Safrole-induced cell death may involve apoptosis.
authors.affiliation: Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 81345, Taiwan, Republic of China.
authors.forename: Tzu-Yi
authors.initials: TY
authors.lastname: Hung
authors.affiliation: Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi 61363, Taiwan, Republic of China.|Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chia-Yi 61363, Taiwan, Republic of China.
authors.forename: Chiang-Ting
authors.initials: CT
authors.lastname: Chou
authors.affiliation: Department of Pediatrics, St. Joseph Hospital, Kaohsiung 80288, Taiwan, Republic of China.
authors.forename: Te-Kung
authors.initials: TK
authors.lastname: Sun
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan, Republic of China.
authors.forename: Wei-Zhe
authors.initials: WZ
authors.lastname: Liang
authors.affiliation: Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan, Republic of China.
authors.forename: Jin-Shiung
authors.initials: JS
authors.lastname: Cheng
authors.affiliation: Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 81345, Taiwan, Republic of China.
authors.forename: Yi-Chien
authors.initials: YC
authors.lastname: Fang
authors.affiliation: Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 81345, Taiwan, Republic of China.
authors.forename: Yih-Do
authors.initials: YD
authors.lastname: Li
authors.affiliation: Department of Pharmacy, Tajen University, Pingtung 90741, Taiwan, Republic of China.
authors.forename: Pochuen
authors.initials: P
authors.lastname: Shieh
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan, Republic of China.
authors.forename: Chin-Man
authors.initials: CM
authors.lastname: Ho
authors.affiliation: Department of Nursing, Tzu Hui Institute of Technology, Pingtung 92641, Taiwan, Republic of China.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Kuo
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan, Republic of China.
authors.forename: Jia-Rong
authors.initials: JR
authors.lastname: Lin
authors.affiliation: Department of Pharmacy, Tajen University, Pingtung 90741, Taiwan, Republic of China.
authors.forename: Daih-Huang
authors.initials: DH
authors.lastname: Kuo
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan, Republic of China.
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Jan
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D016923:Cell Death; D045744:Cell Line, Tumor; D016257:Fura-2; D006801:Humans; D012451:Safrole / Q000009:adverse effects*; D013270:Stomach / Q000187:drug effects*; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D010738:Type C Phospholipases; D012451:Safrole; D002118:Calcium; D016257:Fura-2