Superoxide dismutase: its role in xenobiotic detoxification

Since the discovery of superoxide dismutase in 1969, the role of this enzyme in modulating cellular toxicity of superoxide has been well established. Experimentally, cellular damage from compounds or exposures which produce superoxide extracellularly can be prevented or modified by pretreating a cell or organ system with SOD. Likewise, induction of intracellular SOD by exposing the cell system to various types of nonlethal stress will impart resistance or tolerance to further exposures to oxidant and nonoxidant stresses which would normally be toxic. The differences in intracellular SOD activity based on species, age, and organ variability can have a major impact on the interpretation of toxicology data, particularly extrapolation to human toxicology. An awareness of the importance of SOD to the toxicity of xenobiotics which produce superoxide, either directly or indirectly, will enable those conducting toxicology studies to better understand and interpret their results.