Reactive Oxygen Species Generation in Human Cells by a Novel Magnetic Resonance Imaging Contrast Agent

Figure 1

Changes in intracellular reactive oxygen species (ROS) levels over time in response to various treatment conditions. Human prostate cancer cells (PC3, (a)), human normal tongue cells (Hs-680Tg, (b)), and human head and neck cancer cells (HN5, (c)) were treated with components of the novel MRI positive-contrast marker C4 as follows: 1% [w/v] CoCl₂⋅6H2O, 2% [w/v] N-acetylcysteine (NAC), or the combined Co : NAC solutions (1% : 2% [w/v]), in the presence or absence of 1000 μM H₂O₂. At 5, 30, 60, or 90 minutes after treatment, intracellular ROS levels were evaluated. Controls (Con) are cells not treated and not exposed to H₂O₂. The ROS levels were measured in terms of relative fluorescence units (RFUs) at excitation and emission wavelengths of 485 nm and 535 nm. Values shown are means ± SEM from at least 3 independent experiments. Student’s -tests (unpaired, unequal variance) were used for comparisons.

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