Oxidative stress in chemical toxicity

Area of Science:

• Biochemistry
• Toxicology
• Molecular Biology

Background:

• Many compounds undergo redox cycling through enzymatic one-electron reduction, generating reactive oxygen species.
• These reactive oxygen species, including superoxide anion radicals, hydrogen peroxide, singlet oxygen, and hydroxyl radicals, play a significant role in cellular toxicity.
• The review critically evaluates the role of these oxygen metabolites in the toxicity of various compounds.

Purpose of the Study:

• To review the toxic effects of compounds that undergo redox cycling.
• To discuss the role of oxygen metabolites in toxicity.
• To evaluate the relationship between lipid peroxidation, DNA damage, and the toxicity of redox cycling compounds.

Main Methods:

• Literature review of studies on redox cycling compounds and their toxic effects.
• Analysis of the mechanisms of reactive oxygen species formation and their targets.
• Critical evaluation of the role of iron ions and metal chelates in induced toxicity.

Main Results:

• Enzymatic reduction of redox cycling compounds generates reactive intermediates that form superoxide anion radicals upon reaction with oxygen.
• Lipid peroxidation is induced by redox cycling quinonoid compounds, with iron ions playing a crucial role.
• DNA damage, particularly in cell nuclei, is linked to hydroxyl radicals generated during the redox cycling of compounds like bleomycin-iron complexes.

Conclusions:

• Oxygen radical formation via redox cycling is a critical factor in the toxicity of numerous compounds.
• Cellular protective mechanisms are crucial in mitigating the toxic effects of redox cycling compounds.
• Understanding these mechanisms is vital for assessing the risks associated with exposure to such compounds.