Participation of reactive oxygen species in the toxicity of cobalt, nickel, cadmium and mercury

VERSTRAETEN SV

Reactive Oxygen Species, Lipid Peroxidation and Protein Oxidation

Nova Publishers

Lugar: New York; Año: 2015; p. 95 - 126

Upon the industrial revolution in the XVIII century, the mobilization of metals from their natural reservoirs as well as their use increased exponentially. As a result, many heavy metals were mobilized towards the Earth?s surface, contaminated the soils, water and air, and became available for living organisms. Among others, Co, Ni, Cd and Hg are highly toxic metals for humans, and their mechanisms of toxicity are still under elucidation. However, they share with other metals a common mechanism of toxicity that involves the alteration of the intracellular redox status. This may be caused by increased generation of oxidant species, the impairment of the antioxidant defense system, or both. Among the oxidant species, the generation of reactive oxygen species (ROS) seems to be a common feature in the toxicity of most heavy metals, regardless of their redox-active or redox-inactive condition. The excessive production of ROS, together with the inhibition of certain components of the antioxidant defense system leads to the oxidative damage of key intracellular components, such as lipids, proteins and DNA. Moreover, by promoting oxidative stress these metals induce cell death via apoptosis or necrosis. In the present work, the current knowledge regarding the mechanisms involved in Co, Ni, Cd, and Hg mediated oxidative stress will be discussed.