Antioxidant status in neonatal jaundice before and after phototherapy

Bilirubinemia and retinopathy of prematurity in infants ≤ 29 weeks' gestational age

BACKGROUND

Bilirubin is a known antioxidant. We hypothesized that the degree of bilirubinemia is inversely associated with oxidative stress-mediated retinopathy of prematurity (ROP).

METHODS

A prospective study was performed to determine if bilirubinemia is associated with ROP in infants ≤ 29 wks' gestational age and birth weights ≤ 1000 g. Total serum bilirubin (TSB) levels were measured at least twice daily during the first week and at least daily during the second week to determine peak and mean TSB levels. The outcomes were the incidence and severity of ROP.

RESULTS

Of 193 infants studied, 110 developed ROP: 53 had mild (stage 1 in zone 2 or 3); 31 had moderate (stage 2 in zone 2 or 3); and 26 had severe ROP ( ≥ stage 3 in any zone or any stage in zone 1). Mean TSB levels were associated with the severity (adjusted odds ratio [AOR] 0.68, 95% confidence interval [CI]:0.47-0.98, p = 0.04), but not with the incidence of ROP (AOR 0.81, 95% CI:0.52-1.27, p = 0.3). Peak TSB levels were also associated with the severity (AOR 0.71, 95% CI:0.52-0.96, p = 0.02), but not with the incidence of ROP (AOR 0.71, 95% CI:0.48-1.01, p = 0.07).

CONCLUSIONS

Bilirubinemia may be protective against severity of ROP.

IMPACT

Retinopathy of prematurity (ROP) is a disease mediated by oxidative stress. Increasing antioxidant status may decrease the incidence and severity of ROP. Bilirubin is a known antioxidant; however, findings from observational studies evaluating the role of bilirubinemia against the incidence and/or severity of ROP in premature infants are conflicting. Our findings from this prospective study suggests that bilirubinemia may be protective against the severity of ROP.

The effect of solarium light therapy on selected biological and biochemical parameters of peripheral blood in young and old horses

The aim of the study was to assess the impact of solarium light therapy on selected biological and biochemical parameters of peripheral blood in recreational horses. The study involved 10 horses divided into two groups of young (aged 5 to 7 years) and old (aged 14 to 19 years) individuals. All animals participated in light therapy sessions every other day. Blood was sampled three times during the study: before the treatment, after five light sessions, and after ten light sessions. Morphological parameters, the activity of antioxidant enzymes, TAS values, and the levels of glutathione (GSH), vitamin D3, vitamin C, and malondialdehyde (MDA) were measured in the whole blood. Light therapy contributed to an increase in MCV, HDW, MCVr, CHr and MPV indices, and simultaneously a decrease in the basophil counts, MCHC, RDW and CHCMr indices in both groups of horses (p ≤ 0.05). At the same time reticulocytes fell in older whereas white blood cells and monocytes counts expanded in younger individuals. The treatment also increased the activity of glutathione reductase (GR) and glutathione peroxidase (GPx) in young but decreased the activity of mentioned enzymes in blood plasma of old horses. The total antioxidant status (TAS) of the blood plasma rose progressively, whereas GSH levels declined in all individuals. Moreover, vitamin D3 levels did not change, whereas vitamin C levels gradually decreased during the experiment. The therapy also helped to reduce levels of MDA in the blood plasma, especially of older horses (p ≤ 0.05). In turn, GPx and GR activities as well as MDA levels significantly declined, whereas GSH levels notably elevated in erythrocytes (p ≤ 0.05). Solarium light therapy appears to have a beneficial impact on the morphological parameters and antioxidant status of blood in recreational horses in the winter season. However, the observed results could in part be attributed to the natural physiological adaptation of each individual organism to the treatment.

Chloroacetonitrile reduces rat prenatal bone length and induces oxidative stress, apoptosis, and DNA damage in rat fetal liver

One of the disinfection byproducts of chlorinating drinking water is chloroacetonitrile (CAN). Thirty-six female rats were used and distributed equally into four groups. The low dose treated group received CAN at a dose of 5.5 mg/kg body weight/day (1/40 LD₅₀ ) orally from the 6th to 12th day of gestation. The high dose treated group received 11 mg/kg body weight/day (1/20 LD₅₀ ) of CAN orally for the same period, the vehicle control group received 1 mL of corn oil, and the water control group received 1 mL of distilled water orally for the same period. High dose exposure to CAN significantly reduced gravid uterine weight, fetal body weights, and length, and caused obvious skeletal deformities, weak mineralization. Fetal tibial growth plates displayed histopathologic changes. Induced oxidative stress and redox imbalance in fetal liver tissues was evidenced by significantly decreased in catalase and superoxide dismutase activity, and elevated malondialdehyde levels. Histopathological, glycogen content changes, and DNA damage were observed in the fetal liver of high dose treated group. Additionally, administration of high dose of CAN induced apoptosis, evidenced by increased caspase-3 concentration in fetal liver. Thus, extensive exposure to CAN induces poor pregnancy outcomes. CAN levels in water should be monitored regularly.

Evaluation of thiol-disulfide homeostasis and oxidative stress parameters in newborns receiving phototherapy

The aim of our study was to evaluate oxidative stress and thiol-disulfide homeostasis in term newborns receiving phototherapy. The study was planned as a single-blind, intervention study in a single center with level 3 neonatal intensive care unit to investigate the effect of phototherapy on the oxidative system in term newborns with hyperbilirubinemia. Neonates with hyperbilirubinemia were treated with total body exposure phototherapy technique for 18 h using a Novos^® device. Blood samples of 28 term newborns were taken before and after phototherapy. Total and native thiol, total antioxidant status (TAS) and total oxidant status (TOS), and oxidative stress index (OSI) levels were measured. The 28 newborn patients included 15 (54%) males and 13 (46%) females with a mean birthweight of 3080.1 ± 366.5 g. Native and total thiol levels were found to be decreased in patients receiving phototherapy (p = 0.021, p = 0.010). Besides, significantly lower TAS and TOS levels were found after phototherapy (p < 0.001, p < 0.001). We found that decreased thiol levels were related to increased oxidative stress. We also determined significantly the lower bilirubin levels after phototherapy (p < 0.001). In conclusion, we found that phototherapy treatment induced decreased oxidative stress associated with hyperbilirubinemia in neonates. Thiol-disulfide homeostasis can be used as a marker of oxidative stress due to hyperbilirubinemia in the early period.

Intensive phototherapy and oxidant-antioxidant status in infants with jaundice

OBJECTIVE

Conventional phototherapy converts unconjugated bilirubin to its oxidation products and consequently causes oxidative stress with lipid peroxidation products. New devices that deliver intensive phototherapy are efficacious in treating severe hyperbilirubinemia and minimizing the need for exchange transfusions. However, the oxidative stress status when using these devices has not been explored. Therefore, we aimed to study the impact of using intensive phototherapy on the oxidant-antioxidant status in severely jaundiced neonates.

STUDY DESIGN

This prospective case-control study included term newborns admitted with severe hyperbilirubinemia managed with intensive phototherapy. Baseline oxidant-antioxidant concentrations were compared to healthy controls and re-measured after 8 h of intensive phototherapy exposure.

RESULTS

The study included 40 cases with severe jaundice and 40 non-jaundiced apparently normal controls. Total serum bilirubin at enrollment was 23.4 ± 4.2 mg/dl that significantly decreased after 8 h of therapy to 15.4 ± 3.4 mg/dl (p < 0.001). The decline of total serum bilirubin was 1 mg/dl/h. Bilirubin: albumin ratio decreased from 3.45 ± 0.28 to 2.7 ± 0.21 (p < 0.001). Total antioxidant capacity (TAC), superoxide dismutase (SOD), malondialdehyde (MDA), and total oxidative stress (TOS) concentrations were lower in cases (p < 0.001, p < 0.001, p = 0.049, and p < 0.001 respectively) compared to controls. Following 8 h of intensive phototherapy, further decline of TAC (p = 0.016) with increased concentrations of TOS (p = 0.005) were noted. SOD and MDA did not change.

CONCLUSIONS

Although efficacious, intensive phototherapy was associated with increased oxidative stress. The clinical correlates for harms related to such oxidative stress need further studying.

Conventional intensive versus LED intensive phototherapy oxidative stress burden in neonatal hyperbilirubinaemia of haemolytic origin

Background: Phototherapy causes oxidative stress which is of particular importance in neonates because of the increased susceptibility of neonatal red blood cell membranes to oxidative damage.Aim: To evaluate the oxidant/antioxidant status in neonates with haemolytic hyperbilirubinaemia before and after exposure to two different intensive phototherapy light sources.Patients and Methods: A randomised controlled study was undertaken in 54 full-term neonates with indirect haemolytic hyperbilirubinaemia admitted to a neonatal intensive care unit in the first week of life. They were randomly divided into two equal groups. Group 1 infants were exposed to intensive conventional phototherapy (Bilisphere 360) and Group 2 were exposed to an intensive light-emitting diode (LED) phototherapy device (Bilitron bed 3600). Total serum bilirubin (TSB), total oxidative stress (TOS), total antioxidant capacity (TAC) and the oxidative stress index (OSI) were measured before and 48 hours after initiation of phototherapy.Results: There was a significant decrease in TSB after phototherapy in both groups (p < 0.001). The TOS and OSI were significantly increased after phototherapy in both groups (p < 0.001) but more so in Group 1 with conventional phototherapy (p = 0.05 and 0.01, respectively). TAC was significantly decreased after phototherapy in both groups (p < 0.00) but more so in Group 1 (p = 0.03).There were significant increases in the incidence of dehydration, hyperthermia and skin rash in the conventional compared with the LED phototherapy group (p = 0.02, 0.01 and 0.02, respectively). However, there was a significant increase in the incidence of hypothermia in the LED compared with the conventional phototherapy group (p = 0.001).Conclusion: Both intensive conventional and LED phototherapy are equally effective in decreasing TSB, but intensive LED phototherapy is safer than intensive conventional phototherapy with regard to oxidative stress and oxidant/antioxidant imbalance.Abbreviations: DSB: direct serum bilirubin; G6PD: glucose-6-phosphate dehydrogenase enzyme; LED: light-emitting diode; OSI: oxidative stress index; TAC: total antioxidant capacity; TOS: total oxidative stresses; TSB: total serum bilirubin.

Thiol-Disulfide Homeostasis, Serum Ferroxidase Activity, and Serum Ischemia Modified Albumin Levels in Neonatal Jaundice

AIM

Hyperbilirubinemia causes oxidative stress.

METHOD

We evaluated three oxidative stress markers in hyperbilirubinemic neonates (native/total thiol levels, serum ferroxidase activity and ischemia modified albumin (IMA), comparing these levels to levels in a control group to determine which indicators were the most sensitive.

RESULTS

Serum from 124 term infants (67 with pathologic jaundice and 57 controls) were evaluated. Native/total thiol ratio was significantly lower (p:0.021) while disulfide levels were significantly higher (p:0.001) in the jaundiced group. There was no significant difference in ferroxidase (p:0.603) or IMA (p:0.251) levels.

CONCLUSION

Altered thiol/disulfide homeostasis in the favor of disulfide indicates augmented oxidative stress in jaundiced term infants. The lack of alteration in ferroxidase or IMA levels suggests these latter alterations take more time or more severe oxidative stress to become altered or are not as sensitive as the thiol/disulfide ratio to detect oxidative stress states.

Effect of phototherapy on oxidant/antioxidant status: a randomized controlled trial

In order to evaluate the effect of different types of phototherapy on oxidant/antioxidant status in hyperbilirubinemic neonates, an interventional randomized control trial was conducted on 120 neonates ≥35 weeks' gestational age with indirect hyperbilirubinemia reaching phototherapy level. This study is registered with ClinicalTrials.gov as NCT03074292. Neonates were assigned to three groups; 40 neonates received conventional phototherapy, 40 received intensive phototherapy and 40 received blue light-emitting diodes (LED) phototherapy. Complete blood count (CBC), total serum bilirubin (TSB), total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), copper (Cu), zinc (Zn), and iron (Fe) levels were measured before and 24 hours after phototherapy. TSB decreased postphototherapy in all three groups (p < .05 for all), with significantly lower levels following intensive and LED phototherapy compared to conventional phototherapy (p < .05 for both). TAC decreased postphototherapy in the three groups (p < .05 for all). MDA and NO increased postphototherapy (p < .05 for all), with the intensive phototherapy group having the highest levels followed by the conventional while LED phototherapy group showed the lowest levels in comparison to the other groups (p < .05). Cu, Zn and Fe increased postphototherapy in all three groups (p < .05 for all). Positive correlations were found between postphototherapy TSB with TAC, Cu and Zn (p < .05) and negative correlations with MDA, NO and Fe (p < .05) among neonates of the 3 studied groups. In conclusion, different photo therapies have an impact on oxidant/antioxidant balance and are associated with increased oxidative stress markers with the LED phototherapy being the safest.

The consequence of phototherapy exposure on oxidative stress status of expressed human milk

OBJECTIVE

There exists evidence that phototherapy can disturb the oxidant/antioxidant balance in favor of oxidants. If phototherapy is continued during tube feeding in preterms, expressed human milk is subjected to phototherapy lights for about 20 min per feeding. We aimed to investigate the effects of phototherapy lights on oxidative/antioxidative status of expressed human milk.

STUDY DESIGN

Milk samples of 50 healthy mothers were grouped as control and phototherapy and exposed to 20 min of day-light and phototherapy light, respectively. Total antioxidant capacity (mmol-Trolox equiv/L) and total oxidant status (mmol-H₂O₂/L) in expressed human milk samples were measured.

RESULTS

Levels of antioxidant capacity of the expressed human milks in the phototherapy group were lower than those of the control group [mmol-Trolox equiv/L; median (interquartile-range): 1.30 (0.89-1.65) and 1.77 (1.51-2.06), p: < .001]. Levels of oxidant status were similar in both groups.

CONCLUSION

We demonstrated that phototherapy decreased antioxidant capacity of expressed human milk without any alteration in oxidative status. We think that this observation is important for the care of very low birth weighted infants who have limited antioxidant capacity and are vulnerable to oxidative stress. It may be advisable either to turn off the phototherapy or cover the tube and syringe to preserve antioxidant capacity of human milk during simultaneous tube feeding and phototherapy treatment.

Neonates with sickle cell disease are vulnerable to blue light phototherapy-induced oxidative stress and proinflammatory cytokine elevations

Sickle cell disease is a frequent genetic anomaly characterized by altered molecular structure of hemoglobin resulting into crescent-like deformation of the red blood corpuscles. Neonatal jaundice is a frequent co-morbidity in sickle cell disease. Phototherapy induces isomerization of bilirubin rendering it extractable through urine and hence it is used as a routine treatment of neonatal jaundice. An exposure to light phototherapy as a treatment of neonatal jaundice induces oxidative stress. It is hypothesized that such exposure of neonates with sickle cell disease to the blue light phototherapy as a treatment of neonatal jaundice induces severe oxidative stress and increases the levels of proinflammatory cytokines. This hypothesis is supported with two case studies of sickle cell disease suffering neonates who were exposed to blue light phototherapy to treat jaundice. In both these cases, exposure to phototherapy induced oxidative stress (increased lipid peroxidation and superoxide dismutase, slight change in activity of catalase and GSH) and elevated the levels of proinflammatory cytokine (TNFα, IL-1, and IL-6) in the sickle cell disease suffering neonates. These observations warrant further investigations to determine the consequences and clinical significance of the blue phototherapy-induced oxidative and proinflammatory stress in Sickle cell disease suffering neonates exposed to phototherapy as a treatment of jaundice.

Investigation on malondialdehyde, S100B, and advanced oxidation protein product levels in significant hyperbilirubinemia and the effect of intensive phototherapy on these parameters

BACKGROUND

The parameters of oxidative stress [advanced oxidation protein products (AOPPs), malondialdehyde (MDA), and S100B] and the effect of intensive phototherapy (PT) on these parameters have not been studied extensively in newborns with significant hyperbilirubinemia (SH). We aimed to measure the levels of MDA, S100B, and AOPPs in newborns with SH, and to compare newborns with healthy control newborns without hyperbilirubinemia on the basis of these parameters of oxidative stress. In addition, we investigated the effect of intensive PT on these parameters during the treatment of SH and report our findings for the first time in the literature.

METHODS

The study was performed in newborns (n = 62) who underwent intensive PT because of SH. Newborns without jaundice constituted the control group (n = 30). Both groups were compared with respect to demographic characteristics and biochemical (laboratory) parameters including MDA, AOPPs, and S100B. MDA, AOPPs, and S100B were also compared before and after intensive PT in the PT group. In the study group, a correlation analysis of demographic characteristics; MDA, AOPP, and S100B values; and changes occurring in MDA, AOPPs, and S100B values due to the effect of intensive PT was performed.

RESULTS

Serum total bilirubin, S100B, and MDA levels in the PT group before performing PT were significantly higher than those in the control group. In newborns receiving PT serum total bilirubin, MDA and AOPP levels decreased significantly after intensive PT. In correlation analysis, a statistically significant negative correlation was found only between the amount of bilirubin decrease with PT and AOPP levels after PT in the study group.

CONCLUSION

Whether the significant decrease in MDA levels, which was higher prior to PT, is due to the decrease in serum bilirubin levels or due to the effect of intensive PT itself remains to be determined in further studies. The decrease in AOPP levels after PT implies that intensive PT has protective effects on oxidative stress.

Correlation between oxidative stress and G6PD activity in neonatal jaundice

Fetal distress represents a pathophysiological condition in which oxygen is not available to the fetus in sufficient quantities. In cases of glucose 6-phosphate dehydrogenase (G6PD) deficiency, under conditions of oxidative stress, the residual G6PD and complimentary antioxidant mechanisms may become insufficient to neutralize the large amounts of ROS and to prevent severe hemolysis. Alteration in the oxidant-antioxidant profile is also known to occur in neonatal jaundice. The study group included 22 neonates presented with fetal distress during labor and 24 neonates with no evidence of fetal distress (control group). Umbilical cord blood samples were taken immediately after delivery, and the following blood tests were carried out after birth and at discharge from the hospital: erythrocyte count, total bilirubin, G6PD activity, and parameters presenting oxidative status [thiobarbituric acid reactive substances (TBARS), NO, O2 (-), H2O2, SOD, CAT, O2 (-)/SOD, and H2O2/CAT]. There were no significant differences in TBARS and NO values among neonates with or without fetal distress. However, the values of O2 (-), H2O2, SOD, O2 (-)/SOD, and H2O2/CAT among neonates born after fetal distress were significantly higher than in neonates without fetal distress (p < 0.01). In neonates with fetal distress, the total number of RBCs at delivery was significantly lower, accompanied with higher bilirubin content. Also neonates with fetal distress had lower activity of G6PD and lower CAT activity. Higher values of oxidative stress parameters in newborns delivered after fetal distress do not indicate strictly what occurred first-oxidative stress or basic lower G6PD activity.

Evaluation of oxidant and antioxidant status in infants with hyperbilirubinemia and kernicterus

Objective: The objective of the present study was to determine oxidant and antioxidant status in infants with hyperbilirubinemia and/or kernicterus and to find whether there is a relationship between bilirubin level and oxidant/antioxidant status. Patients: The study includes 69 full-term newborns (neonates with hyperbilirubinemia needing phototherapy [Group 1, n = 36] and neonates with kernicterus [Group 2, n = 33]) and 25 age-matched healthy newborn. Results: Plasma total antioxidant capacity (TAC) and serum total oxidant status (TOS) were significantly higher in Groups 1 and 2 than the control group. There was a significant difference between Group 1 and control cases for malondialdehyde (MDA; p < 0.001). Total free sulfhydryl group (TTHI) values were significantly elevated in Group 1 compared to Group 2 and control cases. Correlation analysis showed that the correlation between total bilirubin (TB) and TAC, TOS, MDA and oxidative stress index may be expressed by a quadratic curve. After phototherapy, a statistically significant increase in nitrite level was observed. Conclusion: We demonstrated that the relationship between serum TB and antioxidants and oxidative stress could be expressed by a quadratic correlation curve.

Free radical metabolism in human erythrocytes

As the red cell emerges from the bone marrow, it loses its nucleus, ribosomes, and mitochondria and therefore all capacity for protein synthesis. However, because of the high O(2) tension in arterial blood and heme Fe content, reactive oxygen species (ROS) are continuously produced within red cells. Erythrocytes transport large amount of oxygen over their lifespan resulting in oxidative stress. Various factors can lead to the generation of oxidizing radicals such as O(2)(-), H(2)O(2), HO in erythrocytes. Evidence indicates that many physiological and pathological conditions such as aging, inflammation, eryptosis develop through ROS action. As such, red cells have potent antioxidant protection consisting of enzymatic and nonenzymatic pathways that modify highly ROS into substantially less reactive intermediates. The object of this review is to shed light on the role of ROS both at physiological and pathological levels and the structural requirements of antioxidants for appreciable radical-scavenging activity. Obviously, much is still to be discovered before we clearly understand mechanisms of free radical systems in erythrocytes. Ongoing trends in the field are recognition of undetermined oxidant/antioxidant interactions and elucidation of important signaling networks in radical metabolism.