title: β-Naphthoflavone induces oxidative stress in the intertidal copepod, Tigriopus japonicus.
abstract: β-Naphtoflavone (β-NF) is a flavonoid and enhances oxidative stress in vertebrates with little information from aquatic invertebrates as yet. In this study, we investigated the effects of β-NF on the antioxidant defense systems of the intertidal copepod Tigriopus japonicus. To measure the β-NF-triggered changes in oxidative stress markers, such as intracellular reactive oxygen species (ROS), glutathione (GSH) concentration, residual glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD) activity, T. japonicus were exposed to β-NF (0.5 and 1 mg/L) for 72 h. Significant (P < 0.05) induction of the intracellular ROS content (%) was observed in 1 mg/L of β-NF exposed T. japonicus, compared to the negative control and H2O2-exposed group. The GSH levels were significantly increased in the 0.5 mg/L of β-NF-exposed group for 12 h and 1 mg/L of β-NF-exposed groups for 12-24 h. GPx, GST, and GR activities showed a significant increase in the 1 mg/L β-NF-exposed group, indicating that β-NF induces oxidative stress in T. japonicus. To understand the effects of β-NF at the level of transcript expression, a 6K microarray analysis was employed. Transcript profiles of selected antioxidant-related genes were modulated after 72 h exposure to 1 mg/L of β-NF. From microarray data, 10 GST isoforms, GR, GPx, PH-GPx, and Se-GPx were chosen for a time-course test by real-time RT-PCR. T. japonicus GST-S, GST-O, GST-M, and GST-D1 were significantly increased in a 1 mg/L β-NF-exposed group. T. japonicus GPx, GR, and Se-GPx mRNA levels were also significantly increased at both concentrations. Our results revealed that oxidative stress was induced by β-NF exposure in T. japonicus.
authors.affiliation: Research Institute for Natural Sciences, Hanyang University, Seoul, 133-791, South Korea.
authors.forename: Jae-Sung
authors.initials: JS
authors.lastname: Rhee
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Bo-Mi
authors.initials: BM
authors.lastname: Kim
authors.forename: Kenneth Mei Yee
authors.initials: KM
authors.lastname: Leung
authors.forename: Il-Chan
authors.initials: IC
authors.lastname: Kim
authors.forename: Joung Han
authors.initials: JH
authors.lastname: Yim
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D033342:Copepoda / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000633:toxicity; D046228:Microarray Analysis; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D019324:beta-Naphthoflavone / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D019324:beta-Naphthoflavone; D006861:Hydrogen Peroxide; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase
keywords: Tigriopus japonicus; biomarkers; oxidative stress; β-NF; β-naphthoflavone