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Detection of drug-induced, superoxide-mediated cell damage and its prevention by antioxidants

K Horáková1, A Sovcíková, Z Seemannová

  • 1Department of Biochemistry and Microbiology, Slovak University of Technology, Bratislava, Slovak Republic. horakova@chelin.chtf.stuba.sk

Free Radical Biology & Medicine
|April 11, 2001
PubMed

Insights

Cell growth tests effectively measure toxicity from benzo(c)fluorene derivatives. Antioxidants like quercetin protect cells by reducing superoxide levels, as confirmed by INT-reductase activity assays.

Area of Science:

  • Toxicology
  • Cell Biology
  • Biochemistry

Background:

  • Cytotoxic activity of benzo(c)fluorene derivatives was investigated.
  • Lysosomal and mitochondrial changes were observed as potential responses to oxidative stress.
  • Superoxide (O2*-) generation's role in cytotoxicity was explored.

Purpose of the Study:

  • To characterize the cytotoxic mechanism of benzo(c)fluorene derivatives.
  • To establish a relationship between superoxide production and cellular damage.
  • To evaluate the protective effects of antioxidants against superoxide-induced cytotoxicity.

Main Methods:

  • Utilized a system measuring 3-(4-iodophenyl)-2-(4-nitrophenyl)-5-phenyltetrazolium chloride (INT) reductase activity in the presence of superoxide dismutase (SOD).
  • Validated in vitro tests using known superoxide inducers (cyclosporin A, benzo(a)pyrene) and non-inducers (citrinin, cycloheximide).
  • Assessed antioxidant protection using quercetin (Qe) in simultaneous exposure assays with HeLa cells and cytotoxic agents.

Main Results:

  • Cell growth inhibition tests proved superior toxicity indicators compared to other assays.
  • Quercetin demonstrated a protective effect, completely abolishing inhibition of cell proliferation and clonogenic survival.
  • These protective effects correlated with reduced superoxide levels (INT-reductase assay with SOD) and increased intracellular SOD activity.

Conclusions:

  • Cell growth assays are reliable indicators for assessing cytotoxicity.
  • Antioxidants, such as quercetin, can mitigate superoxide-induced cellular damage.
  • The INT-reductase assay with SOD serves as a valid method for estimating superoxide levels and evaluating antioxidant capacity.

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