DNA damage induced by a chromium(III) Schiff base complex is reversible under physiological condition

Area of Science:

• Bioinorganic Chemistry
• Coordination Chemistry
• Molecular Biology

Background:

• The development of metal complexes for DNA interaction is crucial for therapeutic applications.
• Chromium complexes, particularly those with salen-type ligands, show potential for DNA binding and cleavage activities.

Purpose of the Study:

• To structurally characterize the novel chromium(III) complex, [Cr(naphen)(H2O)(2)]+.
• To investigate the DNA binding and cleavage mechanisms of the complex.
• To assess the repairability of DNA damage induced by the complex.

Main Methods:

• X-ray crystallography for structural characterization.
• DNA binding studies using techniques like UV-Vis spectroscopy and fluorescence.
• DNA cleavage assays in the presence of biological reductants and oxidants.
• Electron Paramagnetic Resonance (EPR) spectroscopy to identify reactive oxygen species.
• Cell viability assays with Escherichia coli DNA repair enzymes.

Main Results:

• The chromium(III) complex [Cr(naphen)(H2O)(2)]+ was structurally characterized, revealing an extended aromatic system.
• The complex binds intercalatively to calf thymus DNA (CT DNA).
• It promotes DNA cleavage via hydroxyl radical generation in the presence of ascorbate and hydrogen peroxide.
• DNA damage induced by the complex is repairable by Escherichia coli DNA repair enzymes.

Conclusions:

• The [Cr(naphen)(H2O)(2)]+ complex exhibits DNA binding and cleavage properties.
• Hydroxyl radicals are implicated in the oxidative DNA cleavage mechanism.
• The study demonstrates the potential for DNA repair of the induced damage, suggesting therapeutic relevance.