The effect of zinc salts on serum bilirubin levels in hyperbilirubinemic rats

Effects of dietary zinc chloride hydroxide and zinc methionine on the immune system and blood profile of healthy adult horses and ponies

The effects of dietary zinc on the immune function of equines have not been evaluated in detail so far. In the present study, eight healthy adult ponies and two healthy adult horses were fed a diet supplemented with either zinc chloride hydroxide or zinc methionine in six feeding periods of four weeks each (according to maintenance zinc requirement, 120 mg zinc/kg dry matter, and 240 mg zinc/kg dry matter, for both dietary zinc supplements, respectively). All animals received the six diets, with increasing amounts of zinc chloride hydroxide in the feeding periods 1-3, and with increasing amounts of zinc methionine in the feeding periods 4-6. At the end of each feeding period, blood samples were collected for a blood profile and the measurement of selected immune variables. Increasing dietary zinc chloride hydroxide doses increased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the erythrocyte lysate, decreased the numbers of total leukocytes and granulocytes in the blood, and also decreased the interleukin-2 concentrations in the plasma of the animals. The dietary supplementation of increasing doses of zinc methionine enhanced the mitogen-stimulated proliferative activity of peripheral blood mononuclear cells, and decreased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the plasma of the animals. The percentage of blood monocytes with oxidative burst after in vitro stimulation with E. coli decreased with increasing dietary zinc concentrations, independently of the zinc compound used. The blood profile demonstrated effects of the zinc supplements on the red blood cells and the bilirubin metabolism of the horses and ponies, which require further investigation. Overall, high doses of dietary zinc modulate the equine immune system, for the most part also depending on the zinc compound used.

Effect of Zinc on Hyperbilirubinemia of Newborns, a Randomized Double Blinded Clinical Trial

Background: Jaundice is one of the most common causes of hospitalization in newborn infants. Zinc may have a possible role as a cofactor of enzymes in the metabolism of bilirubin and can prevent red blood cell destruction as an antioxidant agent. The present study aims to investigate the effect of zinc in the treatment of neonatal hyperbilirubinemia. Material&Methods: In this double-blind, randomized clinical trial, 112 healthy newborns with idiopathic neonatal hyperbilirubinemia were divided into two groups receiving zinc and placebo. The case and control group received 10mg of zinc and placebo daily. The total bilirubin levels in the second, third, fourth and fifth day and duration of hospitalization and phototherapy were compared. Results: The mean total bilirubin value in the second to fifth days in the zinc group were 11.95±2.35, 9.49±1.79, 8.54±1.63 and 8.64±0.96 respectively, and in the placebo group were 12.95±2.73, 9.88±2.35, 9.5±2.9 and 10.16±0.86 respectively and there was no significant difference between two groups. The duration of phototherapy and hospitalization in the zinc and placebo groups did not show any significant difference. Conclusion: We did not find a significant reduction in serum bilirubin levels nor the duration of hospitalization in neonates receiving zinc sulfate compared to control group.

Earlier Nutrient Fortification of Breastmilk Fed LBW Infants Improves Jaundice Related Outcomes

This study aimed to evaluate jaundice outcomes of low-birthweight premature infants commenced on earlier versus later nutrient supplementation (80 mL/kg/day vs. 160 mL/kg/day; total fluid intake, F80 vs. F160). Demographics, feeding regimens, and clinical outcomes data were collected. Infant and maternal characteristics were similar. Earlier nutrient supplementation was associated with multiple improved jaundice outcomes: total (TSBR), unconjugated and conjugated (CSBR) serum bilirubin values (196 ± 46 vs. 228 ± 52, 184 ± 44 vs. 212 ± 50, 12 ± 4 vs. 16 ± 5, respectively, all p < 0.001); phototherapy (39% vs. 64%, p < 0.0001). % CSBR/TSBR ratio was similar between groups. For those on phototherapy, duration and median irradiance were similar. F80 infants experienced reduced: feeding intolerance (26.0% vs. 45.2%, p = 0.007); length of stay (16.0 ± 0.64 vs. 18.8 ± 0.74 days, p = 0.03), maximum weight loss as % birth weight (5% vs. 6%, p = 0.03); decrease in weight Z-score at 10 days (-0.70 ± 0.03 vs. -0.79 ± 0.03, p = 0.01). F80 infants regained birthweight earlier (10.0 ± 0.3 days vs. 11.5 ± 0.3 days, p < 0.0001) and had no differences in adverse clinical outcomes. We speculate that earlier nutrient supplementation improved jaundice outcomes due to enhanced excretion/elimination of bilirubin.

Efficacy of oral agar in management of indirect hyperbilirubinemia in full-term neonates

Aim: This prospective randomized case control study aimed to investigate effect of oral agar administration in reducing total serum bilirubin (TSB) levels in full-term neonates with jaundice in comparison with control.Materials and methods: One hundred sixty full-term neonates were enrolled with TSB 10-19 mg/dl at first week of age from Assiut University Children's Hospital. Neonates were divided according to TSB into outpatient group (n = 100) (TSB 10-15 mg/dl) and admitted group (n = 60) (TSB > 15-19 mg/dl). Outpatients group were subdivided into agar group received oral agar and control group received placebo. Admitted group were subdivided into agar group received oral agar plus phototherapy combination and control group received phototherapy alone. Neonates in the agar supplementation received oral agar 600 mg/kg/day dissolved in 10 ml distilled water twice daily till TSB decreased to 7 mg/dl. Daily weight, stool frequency and side effects of treatment were observed for each group. TSB was determined pretreatment then serially every 48 h until TSB level reaching ≤7 mg/dl.Results: Agar fed was effective in lowering TSB in neonates with TSB 10-15 mg/dl. TSB percentage changes were not significantly lower in agar-fed newborn with TSB >15-19 mg/dl compared with control groups after 24 h and 7 days. Age fed shortened the time required to decrease TSB and increased stooling frequency.Conclusions: Oral agar supplemented feeding at 600 mg/kg/day is safe for full-term neonates and useful in decreasing TSB and phototherapy duration. The efficacy of phototherapy in decreasing TSB level in neonatal hyperbilirubinemia can be augmented with oral agar usage.

Efficacy of zinc sulfate on indirect hyperbilirubinemia in premature infants admitted to neonatal intensive care unit: a double-blind, randomized clinical trial

Background

Hyperbilirubinemia is a common neonatal problem. Studies conducted on the effectiveness of zinc salts on serum indirect bilirubin levels in newborns have yielded different results, all calling for further research. This study aimed to determine the effect of oral zinc sulfate on indirect hyperbilirubinemia in preterm infants admitted to the neonatal intensive care unit.

Methods

A randomized double-blind clinical trial was performed in the neonatal intensive care unit of Vali-e-Asr Hospital in Birjand, Iran. The study population comprised neonates aged between 31 and 36 gestational weeks, who required phototherapy in the neonatal intensive care unit. A total of 60 neonates were selected by census and allocated into an experimental group and a control group. In addition to phototherapy, the experimental group received 1 cc/Kg zinc sulfate syrup (containing 5 mg/5 cc zinc sulfate; Merck Company, Germany), and the control group received a placebo syrup (containing 1 cc/kg sucrose). Data were analyzed in SPSS-21 software using the independent t-test, repeated-measures ANOVA, Bonferroni post-hoc test, and Mann-Whitney test. P-values smaller than 0.05 were considered significant.

Results

Bilirubin level changes in the experimental and control groups six hours after intervention were − 1.45 ± 3.23 and − 0.49 ± 0.37 (p = 0.024), respectively. The changes 24 and 48 h after intervention were-3.26 ± 2.78 and − 1.89 ± 1.20 (p = 0.017) in the experimental group and − 4.89 ± 2.76 and − 3.98 ± 2.32 (p = 0.23) in the control group, respectively. There was no significant difference in the phototherapy duration between the two groups (p = 0.24).

Conclusions

The results of this study showed that the use of zinc sulfate syrup in preterm infants with indirect hyperbilirubinemia significantly reduced bilirubin levels within 48 h of treatment.

Trial registration

Trial registration: IRCT, IRCT2015120825439N1. Registered 21 February 2016, http://irct.ir/trial/21277

Bilirubin enhances the activity of ASIC channels to exacerbate neurotoxicity in neonatal hyperbilirubinemia in mice

Neonatal hyperbilirubinemia is a common clinical condition that can lead to brain encephalopathy, particularly when concurrent with acidosis due to infection, ischemia, and hypoxia. The prevailing view is that acidosis increases the permeability of the blood-brain barrier to bilirubin and exacerbates its neurotoxicity. In this study, we found that the concentration of the cell death marker, lactate dehydrogenase (LDH) in cerebrospinal fluid (CSF), is elevated in infants with both hyperbilirubinemia and acidosis and showed stronger correlation with the severity of acidosis rather than increased bilirubin concentration. In mouse neonatal neurons, bilirubin exhibits limited toxicity but robustly potentiates the activity of acid-sensing ion channels (ASICs), resulting in increases in intracellular Ca2+ concentration, spike firings, and cell death. Furthermore, neonatal conditioning with concurrent hyperbilirubinemia and hypoxia-induced acidosis promoted long-term impairments in learning and memory and complex sensorimotor functions in vivo, which are largely attenuated in ASIC1a null mice. These findings suggest that targeting acidosis and ASICs may attenuate neonatal hyperbilirubinemia complications.

Evaluation of Serum Zinc Levels in Hyperbilirubinemic Neonates Before and After Phototherapy

Background

The existing therapeutic methods for neonatal jaundice are costly, time-consuming and potentially risky. Zinc salts can reduce phototherapy duration by precipitating unconjugated bilirubin in the intestine (bilirubin and zinc can form a complex in physiologic pH); however, zinc toxicity is an issue that must be considered since theoretically bilirubin reduction by phototherapy may increase serum zinc levels, making additional zinc supplementation the potential cause of zinc toxicity.

Objectives

So, our purpose was evaluating the serum zinc level alterations before and after phototherapy, in hyperbilirubinemic newborns.

Materials and Methods

A prospective cohort study was performed at the children’s medical center of Tehran University of Medical Sciences from 2012 to 2014. Healthy, full-term exclusively breast fed newborns with non-hemolytic jaundice were enrolled in the study. Participants were divided into two groups based on serum bilirubin levels (TSB < 18 mg/dL and TSB ≥ 18 mg/dL) at admission. Pre- and post-phototherapy total serum zinc level was measured before and 12 - 24 hours after termination of phototherapy.

Results

Phototherapy was associated with a significant increase in the serum zinc level in neonates with severe hyperbilirubinemia (TSB ≥ 18 mg/dL) but not in those with mild-moderate hyperbilirubinemia (TSB < 18 mg/dL). In addition, phototherapy caused a significant increase in the rate of zinc with potentially toxic levels (zinc > 200) in only neonates with severe hyperbilirubinemia.

Conclusions

Phototherapy increases serum zinc level by reducing bilirubin level so that additional supplementation of this element can lead potentially to zinc toxicity.

Oral zinc for the prevention of hyperbilirubinaemia in neonates

BACKGROUND

Between 6% and 15% of neonates develop hyperbilirubinaemia requiring treatment. Successful management of neonatal hyperbilirubinaemia relies on prevention and early treatment, with phototherapy being the mainstay of treatment. Oral zinc has been reported to decrease the serum total bilirubin (STB), presumably by decreasing the enterohepatic circulation.

OBJECTIVES

To determine the effect of oral zinc supplementation compared to placebo or no treatment on the incidence of hyperbilirubinaemia in neonates during the first week of life and to assess the safety of oral zinc in enrolled neonates.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library 2014, Issue 1), MEDLINE (1966 to November 30, 2014), and EMBASE (1990 to November 30, 2014).

SELECTION CRITERIA

Randomised controlled trials were eligible for inclusion if they enrolled neonates (term and preterm) to whom oral zinc, in a dose of 10 to 20 mg/day, was initiated within the first 96 hours of life, for any duration until day seven, compared with no treatment or placebo.

DATA COLLECTION AND ANALYSIS

We used the standard methods of The Cochrane Collaboration and its Neonatal Review Group for data collection and analysis.

MAIN RESULTS

Only one study met the criteria of inclusion in the review. This study compared oral zinc with placebo. Oral zinc was administered in a dose of 5 mL twice daily from day 2 to day 7 postpartum. The drug was administered into the mouth of the infant by the plastic measure provided with the bottle or with a spoon. Incidence of hyperbilirubinaemia, defined as serum total bilirubin (STB) ≥ 15 mg/dL, was similar between groups (N = 286; risk ratio (RR) 0.94, 95% confidence interval (CI) 0.58 to 1.52). Mean STB levels, mg/dL, at 72 ± 12 hours were comparable in both the groups (N = 286; mean difference (MD) -0.20; 95% CI -1.03 to 0.63). Although the duration of phototherapy in the zinc group was significantly shorter compared to the placebo group (N = 286; MD -12.80, 95% CI -16.93 to -8.67), the incidence of need for phototherapy was comparable across both the groups (N = 286; RR 1.20; 95% CI 0.66 to 2.18). Incidences of side effects like vomiting (N = 286; RR 0.65, 95% CI 0.19 to 2.25), diarrhoea (N = 286; RR 2.92, 95% CI 0.31 to 27.71), and rash (N = 286; RR 2.92, 95% CI 0.12 to 71.03) were found to be rare and statistically comparable between groups.

AUTHORS' CONCLUSIONS

The limited evidence available has not shown that oral zinc supplementation given to infants up to one week old reduces the incidence of hyperbilirubinaemia or need for phototherapy.

Zinc supplementation for neonatal hyperbilirubinemia: a randomized controlled trial

OBJECTIVE

To determine the efficacy of oral zinc for treatment of idiopathic neonatal hyperbilirubinemia in near-term and term (35-41 weeks) neonates.

DESIGN

Randomized placebo-controlled trial.

SETTING

Tertiary-care teaching hospital.

PARTICIPANTS

Eighty newborns with idiopathic neonatal hyperbilirubinemia.

INTERVENTION

Neonates were randomized to receive either oral zinc sulfate (10 mg/d) or placebo for 7 days.

MAIN OUTCOME MEASURES

Primary: total serum bilirubin levels at 48 (±12) h, 96 (±12) h and 144 (±12) h after intervention. Secondary: duration of phototherapy, and serum zinc and copper levels.

RESULTS

Baseline mean (SD) total serum bilirubin levels were 14.8 (3.8) and 14.4 (3.5) mg/dL in zinc and placebo groups, respectively. No significant differences were observed in total bilirubin levels between the two groups after the intervention. Mean (SD) total serum bilirubin levels in zinc and placebo groups were 13.9 (2.5) vs. 13.4 (1.9) mg/dL (mean difference 0.566; 95% CI -0.535, 1.668, P=0.038) at 48 h, 13.1 (2.7) vs. 12.8 (2.3) mg/dL (mean difference 0.234; 95% CI -1.011, 1.479, P =0.708) at 96 h and 8.0 (2.0) vs. 8.6 (1.2) mg/dL (mean difference -0.569, 95% CI -1.382, 0.242, P=0.166) at 144 h. Although the mean duration of phototherapy in the zinc group was less by 21.3 h (95% CI 11.6, 30.9, P=0.052), the difference was not significant. Post-intervention, serum zinc levels were significantly higher in the zinc-supplemented group while serum copper levels were comparable between the two groups.

CONCLUSIONS

Oral zinc sulfate, in a dose of 10 mg/day, is not effective in the management of idiopathic neonatal hyperbilirubinemia.

Protective effects of bilirubin in an experimental rat model of pyelonephritis

OBJECTIVE

To investigate the effects of bilirubin in a rat model of pyelonephritis.

METHODS

Experimental pyelonephritis was induced in 32 wistar rats and 4 groups were formed: group 1 (no treatment), group 2 (antibiotic), group 3 (bilirubin), and group 4 (antibiotic + bilirubin). Antibiotic was given on days 3 to 8, and bilirubin was administered between days 0 and 8 of bacterial inoculation. Half of the rats were killed on the 9th day (early period) and histopathological parameters, immunohistochemical renal fibrosis markers, apoptosis, and oxidant/antioxidant system activities were evaluated. The rest of the rats were killed at the 6th week of the study and evaluated for histopathological parameters and renal fibrosis markers.

RESULTS

Inflammatory activity was significantly lower in rats treated with antibiotic + bilirubin vs no treatment group both in the early and late periods. In the late period, inflammatory cell intensity was lower in rats treated with bilirubin vs no treatment and the antibiotic + bilirubin groups. Interstitial fibrosis/tubular atrophy was lower in the antibiotic + bilirubin group vs the no treatment and antibiotic groups, and in bilirubin vs antibiotic group. Tissue inhibitor of metalloproteinase-1 expression was lower in the bilirubin vs antibiotic group. Terminal deoxynucleotidyl transferase mediated 2'-deoxyuridine, 5'-triphosphate nick end labeling(+) cells were significantly lower in bilirubin and antibiotic + bilirubin groups vs no treatment group. Malondialdehyde levels were significantly lower in the antibiotic + bilirubin vs the no treatment group and superoxide dismutase activity was significantly higher in the antibiotic and antibiotic + bilirubin groups vs the no treatment group.

CONCLUSION

Bilirubin may have protective effects on pyelonephritis-associated inflammation in both early and late periods in addition to fibrosis and apoptosis when applied with antibiotics. When used alone, bilirubin may also prevent inflammation (in the late period) and apoptosis.

Bile pigment pharmacokinetics and absorption in the rat: therapeutic potential for enteral administration

BACKGROUND AND PURPOSE

Bilirubin and biliverdin possess antioxidant and anti-inflammatory properties and their exogenous administration protects against the effects of inflammation and trauma in experimental models. Despite the therapeutic potential of bile pigments, little is known about their in vivo parenteral or enteral absorption after exogenous administration. This study investigated the absorption and pharmacokinetics of bile pigments after i.v., i.p. and intraduodenal (i.d.) administration in addition to their metabolism and routes of excretion.

EXPERIMENTAL APPROACH

Anaesthetized Wistar rats had their bile duct, jugular and portal veins cannulated. Bile pigments were infused and their circulating concentrations/biliary excretion were measured over 180 min. KEY RESULTS After i.v. administration of unconjugated bilirubin, biliverdin and bilirubin ditaurate, their plasma concentrations decreased exponentially over time. Subsequently, native and metabolized compounds appeared in the bile. When administered i.p., their absolute bioavailabilities equalled 14.0, 16.1 and 33.1%, respectively, and correspondingly 38, 28 and 34% of the same bile pigment doses were excreted in the bile. Administration of unconjugated bilirubin and bilirubin ditaurate i.d. increased their portal and systemic concentrations and their systemic bioavailability equalled 1.0 and 2.0%, respectively. Correspondingly, 2.7 and 4.6%, of the doses were excreted in the bile. Biliverdin was rapidly metabolized and these products were absorbed and excreted via the urine and bile.

CONCLUSIONS AND IMPLICATIONS

Bile pigment absorption from the peritoneal and duodenal cavities demonstrate new routes of administration for the treatment of inflammatory and traumatic pathology. Oral biliverdin administration may lead to the production of active metabolite that protect from inflammation/complement activation.

Efficacy of zinc in reducing hyperbilirubinemia among at-risk neonates: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the efficacy of oral zinc salt on the incidence of hyperbilirubinemia and need for phototherapy between 25 and 168 h of age in term and late-preterm at-risk neonates cared at a tertiary care hospital in New Delhi, India.

METHODS

In all neonates born at ≥35 wks' gestation, serum total bilirubin (STB) was assayed at 24 ± 6 h of age. At-risk neonates, neonates with STB levels ≥6 mg/dL, were given either 10 mg of zinc gluconate salt (n = 148) or placebo (n = 146) in twice daily doses till day seven of age. Jaundice was assessed clinically and STB was measured by spectrophotometry. Neonates were followed up until day seven of age. Primary outcome measure was incidence of hyperbilirubinemia (STB ≥ 15 mg/dl). Secondary outcome measures were mean STB level at 72 ± 12 h of age, proportion of infants requiring phototherapy, and duration there of.

RESULTS

Risk factors for hyperbilirubinemia, including male gender, gestational age, birth-weight, incidence of birth trauma, ABO incompatibility, hyperbilirubinemia in previous sib, etc. were comparable in zinc and placebo groups. The incidence of hyperbilirubinemia was comparable in both the groups (17.9% vs 19.1% in zinc and placebo groups respectively; OR = 0.95, 95% CI: 0.50 to 1.67; P = 0.92). The requirement of phototherapy (14.5% and 12.0% in zinc and placebo groups respectively; OR = 1.24, 95% CI: 0.95 to 2.6; P = 0.54) was comparable in both the groups; however, duration of phototherapy was shorter in zinc group (duration in hours, 22.8 ± 19.4 vs 35.6 ± 16.1 in zinc and placebo group respectively; mean difference = -12.8, 95% CI: -24.73 to -0.92; P = 0.04). There was no difference in the mean STB levels at 72 ± 12 h of age between zinc and placebo groups (mean difference in mg/dL: 0.20, 95% CI: 1.0 to -0.64). No significant adverse effects related to oral zinc administration were noted.

CONCLUSIONS

Twice daily administration of oral zinc in a dose of 10 mg/day does not reduce the incidence of hyperbilirubinemia in at-risk term and late-preterm neonates during first wk of age.