Affiliations: Department of Pediatrics, Institute of Medical
Sciences, Banaras Hindu University, Varanasi, India
Note: [] Correspondence: Sriparna Basu, M.D., %Associate Professor in
Neonatology and Perinatology, Department of Pediatrics, Institute of Medical
Sciences, Banaras Hindu University, Varanasi – 221005, India. Tel.: +91
9935340260; Fax: +91 542 2367568; E-mail: [email protected]
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