Oxidative stress in neonatology: Role of reactive oxygen species

Abstract

Oxygen is one of the most abundant elements on Earth and plays a central role in the evolution of complex life by maintaining a homeostasis within our planet biosphere. However, oxygen can also produce toxic molecules such as reactive oxygen species (ROS). ROS is a collective term that includes both free oxygen radicals and certain oxidizing agents that are easily converted into free radicals. ROS can be produced from both endogenous and exogenous substances and play a dual role in different biological systems, either harmful or beneficial to living organisms. On one hand, oxygen-dependent reactions and aerobic respiration have significant advantages but, on the other, overproduction of ROS has the potential to cause tissue damage. Living organisms have developed different ways of counteracting the harmful effects of ROS: by preventive mechanisms; repair; and physical and antioxidant defenses. The study of the interplay of the generation of ROS and their counteracting antioxidant defense systems during fetal and neonatal life is constantly changing and still not understood fully. New studies are being carried out to define the biological roles of these highly reactive species and in-vivo maintenance of optimal oxidant/antioxidant balance in neonates. It is now known that preterm birth, itself, is associated with an increased oxidant burden, which places these infants at much higher risk of tissue injury. In this article, we discuss the biochemical and physiological aspects of ROS-mediated injury in neonates.

Keywords

Neonate - oxygen - oxidative stress - reactive oxygen species