* β-Naphthoflavone induces oxidative stress in the intertidal copepod, Tigriopus japonicus.
- 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.
Overview of noun level
The noun level has 8 senses (first 6 from tagged texts)
1. (69) degree, grade, level -- (a position on a scale of intensity or amount or quality; "a
moderate grade of intelligence"; "a high level of care is required"; "it is all a matter of degree")
2. (22) grade, level, tier -- (a relative position or degree of value in a graded group; "lumber of
the highest grade")
3. (15) degree, level, stage, point -- (a specific identifiable position in a continuum or series or
especially in a process; "a remarkable degree of frankness"; "at what stage are the social
sciences?")
4. (5) level -- (height above ground; "the water reached ankle level"; "the pictures were at the
same level")
5. (1) level, spirit level -- (indicator that establishes the horizontal when a bubble is centered
in a tube of liquid)
6. (1) horizontal surface, level -- (a flat surface at right angles to a plumb line; "park the car
on the level")
7. level, layer, stratum -- (an abstract place usually conceived as having depth; "a good actor
communicates on several levels"; "a simile has at least two layers of meaning"; "the mind functions
on many strata simultaneously")
8. floor, level, storey, story -- (a structure consisting of a room or set of rooms at a single
position along a vertical scale; "what level is the office on?")
Overview of verb level
The verb level has 6 senses (first 3 from tagged texts)
1. (4) level -- (aim at; "level criticism or charges at somebody")
2. (1) level, raze, rase, dismantle, tear down, take down, pull down -- (tear down so as to make
flat with the ground; "The building was levelled")
3. (1) flush, level, even out, even -- (make level or straight; "level the ground")
4. charge, level, point -- (direct into a position for use; "point a gun"; "He charged his weapon at
me")
5. level -- (talk frankly with; lay it on the line; "I have to level with you")
6. level, level off -- (become level or even; "The ground levelled off")
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