effects of phototheRapy on seRum paRaoxonase actIvIty and total antIoxIdant capacIty In newBoRn jaundIce

Objective: Phototherapy is an efficient and commonly used form of therapy for the treatment of neonatal hyperbilirubinemia. Paraoxonase 1 (PON1) is an antioxidative enzyme, which eliminates lipid peroxides. The aim of our study was to investigate the effect of phototherapy on serum PON1 activity and total antioxidant capacity (TAC) in hyperbilirubinemic full-term newborns. Material and Method: The study was performed on 40 full-term newborns between 3 to 15 days of age exposed to phototherapy. Serum PON1 activity and TAC levels of the babies were determined before and after phototherapy by spectrophotometric assays. Results: We have found that PON1 activity was not significantly affected by phototherapy whereas TAC levels were decreased significantly after phototherapy (p<0.001). Conclusion: Our findings demonstrated that phototherapy has no direct effect on PON1 activity. Also, decreased TAC levels might have resulted from increased oxidative stress which may lead to consumption of antioxidant molecules.