title: Selenium (sodium selenite) causes cytotoxicity and apoptotic mediated cell death in PLHC-1 fish cell line through DNA and mitochondrial membrane potential damage.
abstract: Elevated concentration of selenium poses a toxic threat to organisms inhabiting aquatic ecosystems influenced by excessive inputs from anthropogenic sources. Selenium is also an essential micronutrient in living things, particularly in fish, and provides antioxidant properties to tissues. Whole fish and hepatocytes in primary culture show selenite toxicity above threshold levels. The present study was designed to investigate the process by which selenite exposure causes cellular toxicity and apoptotic and necrotic cell death in fish hepatoma cell line PLHC-1. PLHC-1 cells were exposed to various selenite concentrations (1, 10, 50 and 100 μM) for 10, 20 and 40 h intervals. The 24h inhibitory concentration 50 (IC₅₀) of selenite in PLHC-1 cell line was found to be 237 μM. Flow cytometery data showed that selenite exposed cells promote apoptotic and necrotic mediated cell death when selenite concentrations were ≥10 μM compared to control. Selenite exposure was associated with a significant increase of caspase-3 activities suggesting the induction of apoptosis. Selenite exposure at high levels (≥10 μM) and longer exposure times (≥20 h) induces mitochondrial membrane potential damage (ΔΨ(m)), DNA damage and elevated production of ROS which could be associated with cell death.
authors.affiliation: Department of Integrated Science and Technology, Marshall University, Huntington, WV 25755, USA.
authors.forename: Vellaisamy
authors.initials: V
authors.lastname: Selvaraj
authors.forename: Justin
authors.initials: J
authors.lastname: Tomblin
authors.forename: Mindy
authors.initials: M
authors.lastname: Yeager Armistead
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Murray
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018038:Sodium Selenite / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D004247:DNA; D053148:Caspase 3; D018038:Sodium Selenite