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The kinetic signature of toxicity of four heavy metals and their mixtures on MCF7 breast cancer cell line.

Egiebor E, Tulu A, Abou-Zeid N, Aighewi IT, Ishaque A - Int J Environ Res Public Health (2013)

Bottom Line: The study was carried out using real time cell electronic sensing (RT-CES).Cells were seeded for 24 h before exposure to the metals and their mixtures.The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined--particularly for mercury--and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

View Article: PubMed Central - PubMed

Affiliation: Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA. abishaque@mail.umes.edu.

ABSTRACT
This study evaluated the kinetic signature of toxicity of four heavy metals known to cause severe health and environmental issues--cadmium (Cd), mercury (Hg) lead (Pb) arsenic (As)--and the mixture of all four metals (Mix) on MCF7 cancer cells, in the presence and absence of the antioxidant glutathione (GSH). The study was carried out using real time cell electronic sensing (RT-CES). RT-CES monitors in real time the electrical impedance changes at the electrode/culture medium interface due to the number of adhered cells, which is used as an index of cell viability. Cells were seeded for 24 h before exposure to the metals and their mixtures. The results showed that in the presence and absence of cellular glutathione, arsenic was the most cytotoxic of all five treatments, inducing cell death after 5 h of exposure. Lead was the least cytotoxic in both scenarios. In the presence of cellular GSH, the cytotoxic trend was As > Cd > MIX > Hg > Pb, while in the absence of GSH, the cytotoxic trend was As > Hg > MIX > Cd > Pb. The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined--particularly for mercury--and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

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Related in: MedlinePlus

Kinetics of cytotoxic responses for arsenic in LBSO-treated MCF7 cells as described in Figure 6 legend.
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ijerph-10-05209-f007: Kinetics of cytotoxic responses for arsenic in LBSO-treated MCF7 cells as described in Figure 6 legend.

Mentions: Following the method that was described previously, the individual chemicals and their mixture (except lead) were found to be cytotoxic within the concentration range that was tested. The kinetics response of LBSO treated MCF7 cells was different for each chemical. Cadmium (Figure 6), arsenic (Figure 7), mercury (Figure 8) and the mixture of all four chemicals (mix) (Figure 10) induced severe cytotoxic effects on MCF7 cells, while lead (Figure 9) showed a visible decrease in cell number 40 h after exposure to the highest concentration. The result shows that mercury and arsenic had severe cytotoxicity after only 4 h of exposure. All concentrations (0.34 ppm–21.7 ppm) of arsenic were fully cytotoxic after 32 h of exposure. After 32 h of exposure, the four higher concentrations (2.7 µg/mL–21.7 µg/mL) of mercury induced cytotoxic effects while the lower three concentrations (0.034 µg/mL–1.3 µg/mL) did not have any effects on the cells. The higher two concentrations (10.8 ppm–21.7 ppm) of cadmium induced cytotoxic effect after 6 h of exposure, while the lower concentration did not reveal any visible effects on MCF-7 cells. In the case of the mixture of all four chemicals (mix), the higher three concentrations induced cell death after 32 h of exposure, while the lower concentration showed neither a decrease in cell number nor an increase in cell proliferation. The highest concentration (21.7 ppm) of lead showed a little decrease in cell number after 40 h of exposure, but all other concentrations did not show any visible effect on MCF-7 cells.


The kinetic signature of toxicity of four heavy metals and their mixtures on MCF7 breast cancer cell line.

Egiebor E, Tulu A, Abou-Zeid N, Aighewi IT, Ishaque A - Int J Environ Res Public Health (2013)

Kinetics of cytotoxic responses for arsenic in LBSO-treated MCF7 cells as described in Figure 6 legend.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3822392&req=5

ijerph-10-05209-f007: Kinetics of cytotoxic responses for arsenic in LBSO-treated MCF7 cells as described in Figure 6 legend.
Mentions: Following the method that was described previously, the individual chemicals and their mixture (except lead) were found to be cytotoxic within the concentration range that was tested. The kinetics response of LBSO treated MCF7 cells was different for each chemical. Cadmium (Figure 6), arsenic (Figure 7), mercury (Figure 8) and the mixture of all four chemicals (mix) (Figure 10) induced severe cytotoxic effects on MCF7 cells, while lead (Figure 9) showed a visible decrease in cell number 40 h after exposure to the highest concentration. The result shows that mercury and arsenic had severe cytotoxicity after only 4 h of exposure. All concentrations (0.34 ppm–21.7 ppm) of arsenic were fully cytotoxic after 32 h of exposure. After 32 h of exposure, the four higher concentrations (2.7 µg/mL–21.7 µg/mL) of mercury induced cytotoxic effects while the lower three concentrations (0.034 µg/mL–1.3 µg/mL) did not have any effects on the cells. The higher two concentrations (10.8 ppm–21.7 ppm) of cadmium induced cytotoxic effect after 6 h of exposure, while the lower concentration did not reveal any visible effects on MCF-7 cells. In the case of the mixture of all four chemicals (mix), the higher three concentrations induced cell death after 32 h of exposure, while the lower concentration showed neither a decrease in cell number nor an increase in cell proliferation. The highest concentration (21.7 ppm) of lead showed a little decrease in cell number after 40 h of exposure, but all other concentrations did not show any visible effect on MCF-7 cells.

Bottom Line: The study was carried out using real time cell electronic sensing (RT-CES).Cells were seeded for 24 h before exposure to the metals and their mixtures.The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined--particularly for mercury--and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

View Article: PubMed Central - PubMed

Affiliation: Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA. abishaque@mail.umes.edu.

ABSTRACT
This study evaluated the kinetic signature of toxicity of four heavy metals known to cause severe health and environmental issues--cadmium (Cd), mercury (Hg) lead (Pb) arsenic (As)--and the mixture of all four metals (Mix) on MCF7 cancer cells, in the presence and absence of the antioxidant glutathione (GSH). The study was carried out using real time cell electronic sensing (RT-CES). RT-CES monitors in real time the electrical impedance changes at the electrode/culture medium interface due to the number of adhered cells, which is used as an index of cell viability. Cells were seeded for 24 h before exposure to the metals and their mixtures. The results showed that in the presence and absence of cellular glutathione, arsenic was the most cytotoxic of all five treatments, inducing cell death after 5 h of exposure. Lead was the least cytotoxic in both scenarios. In the presence of cellular GSH, the cytotoxic trend was As > Cd > MIX > Hg > Pb, while in the absence of GSH, the cytotoxic trend was As > Hg > MIX > Cd > Pb. The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined--particularly for mercury--and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

Show MeSH
Related in: MedlinePlus