Oxidative stress and neonatal jaundice: an etiological study

ABSTRACT

This study aimed at investigating the role of oxidative stress in the development of neonatal jaundice. The enzyme activities of erythrocyte glucose-6-phosphate dehydrogenase [G6PD], plasma glutathione peroxidase [GSHPx] and glutathione-S-transferase [GST] were measured by quantitative determination of enzyme activity in 40 jaundiced full term newborns with different peak bilirubin levels [12.5 - 20 mg/dl] [not attributable to any known etiology] and 20 control newborns. The level of plasma advanced oxidation protein products [AOPP], an index of oxidative stress was also measured in these newborns. None of the jaundiced newborns needed phototherapy or exchange blood transfusion before the study. Plasma GSHPx activity was significantly lower in infants with hyperbilirubinaemia compared to control group. However, the enzyme activities of both plasma GST and erythrocyte G6PD as well as plasma AOPP concentrations were significantly higher in jaundiced newborn infants than in the control group. Plasma GSHPx activity demonstrated a significant negative correlation with GST activity, bilirubin concentration and AOPP levels. A significant positive correlation was also evident between serum bilirubin and plasma AOPP concentrations. The results of this study suggest that low GSHPx activity in jaundiced newborn infants might predispose these infants to oxidative stress. This may result in the development of mild oxidative hemolysis and jaundice