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11:56
A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
The ascorbic acid paradox.
Michael Osiecki1, Parisa Ghanavi, Kerry Atkinson
1Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland 4059, Australia. michael.osiecki@qut.edu.au
Biochemical and Biophysical Research Communications
|August 25, 2010
Summary
Ascorbic acid (AA) acts as both an antioxidant and pro-oxidant in cell cultures. Its behavior is time, dose, and location-dependent, impacting intracellular and extracellular environments differently.
Area of Science:
- Cell Biology
- Biochemistry
- Oxidative Stress Research
Background:
- Ascorbic acid (AA) is widely used as a culture supplement, primarily recognized for its antioxidant functions.
- However, AA can also exhibit pro-oxidant properties under specific conditions, complicating its predictable behavior in biological systems.
- The complex composition of cell culture media can obscure the true effects of AA supplementation.
Purpose of the Study:
- To investigate the dual antioxidant and pro-oxidant effects of ascorbic acid (AA) on KG1a myeloid leukaemia cells.
- To determine the time- and dose-dependent impact of AA on both intracellular and extracellular environments.
- To explore the simultaneous occurrence of intracellular pro-oxidant and extracellular antioxidant activities.
Main Methods:
- Supplementation of KG1a cells with varying concentrations of ascorbic acid (AA).
- Evaluation of AA's impact on intracellular and extracellular environments over a 24-hour period.
- Assessment of antioxidant and pro-oxidant activities at different time points (2h, 4h, 24h).
Main Results:
- Intracellular antioxidant behavior was observed at 24 hours across tested AA concentrations (up to 250μM).
- Pro-oxidant activity was detected intracellularly at 2h and 4h with higher AA concentrations, demonstrating time and dose dependency.
- Extracellular medium consistently showed antioxidant activity, with no pro-oxidant effects observed.
- Simultaneous intracellular pro-oxidant and extracellular antioxidant activity was paradoxically observed.
Conclusions:
- The biological activity of ascorbic acid (AA) is highly dependent on concentration, incubation time, and cellular location.
- AA can exert opposing effects (pro-oxidant intracellularly, antioxidant extracellularly) concurrently.
- Accurate characterization of cell culture conditions is crucial for understanding the true impact of AA supplementation.
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