Use of melatonin as an adjuvant therapy in neonatal sepsis

Efficacy of taurine-enhanced enteral nutrition in improving the outcomes of critically ill patients: A systematic review and meta-analysis

BACKGROUND

Taurine is considered an immunomodulatory agent. From current reports on clinical studies, we conducted a systematic review and meta-analysis to investigate the effects of taurine-enhanced enteral nutrition (EN) on the outcomes of critically ill patients to resolve conflicting evidence in literature.

METHODS

Literature from PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, SINOMED, and WanFang databases were retrieved, and randomized controlled trials (RCTs) were identified. The time range spanned from January 1, 2000, to January 31, 2024. The Cochrane Collaboration Tool was used to evaluate the risk of bias. We used the GRADE approach to rate the quality of evidence and the I2 test to assess the statistical heterogeneity of the results. Risk ratio (RR), mean difference (MD), and 95% confidence interval (95% CI) were used to analyze measurement data.

RESULTS

Four trials involving 236 patients were finally included. The meta-analysis results indicated that taurine-enhanced EN did not reduce mortality (RR = 0.70, p = 0.45, 95% CI [0.28, 1.80], two trials, 176 participants, low quality). There was also no significant difference in length of stay in the intensive care unit (ICU) between the taurine-enhanced EN and control groups. Taurine-enhanced EN may reduce pro-inflammatory factor interleukin-6 (IL-6) levels in critically ill patients（the result about IL-6 cannot be pooled）. However, taurine-enhanced EN had no significant impact on high-sensitivity-C-reactive protein levels (MD = -0.41, p = 0.40, 95% CI [-1.35, 0.54], two trials, 60 participants, low quality).

DISCUSSION

Taurine-enhanced EN may reduce IL-6 levels and is not associated with improved clinical outcomes in critically ill patients, which may have potential immunoregulatory effects in critically ill patients. Given that published studies have small samples, the above conclusions need to be verified by more rigorously designed large-sample clinical trials.

Rapid Versus Slow Cooling Pasteurization of Donor Breast Milk: Does the Cooling Rate Effect Melatonin Reduction?

Background and Objective: There is a question as to whether melatonin levels in breast milk are impacted by the cooling rate postpasteurization. Past research that has used in the Australian donor bank's breast milk Holder Pasteurization technique has reported varying findings regarding melatonin levels postpasteurization. Where breast milk was cooled slowly, a significant reduction in breast milk melatonin levels was observed. Conversely, where a rapid cooling method was used, there was no significant reduction in melatonin levels. The aim of this study was to investigate whether the cooling process between the different pasteurization techniques impact on melatonin levels in breast milk postpasteurization. Materials and Methods: Twenty-seven nighttime breast milk samples were collected, with each sample divided into three; one remained unpasteurized, one was pasteurized and rapidly cooled to 4°C, and the other was pasteurized and cooled slowly to 4°C. Results: Melatonin levels were significantly reduced in both the rapidly cooled and slow cooled breast milk samples when compared to their unpasteurized counterpart (p < 0.001). There was no significant difference in melatonin levels between the two cooling methods (p = 0.91). Conclusion: This study showed that both the rapid and cooling pasteurization processes had a similar reduction in melatonin levels in breast milk. However, even after pasteurization melatonin was still present. Therefore, it is recommended that donor banks still take into consideration circadian timing hormones such as melatonin and the time of day breast milk is expressed.

Safety and efficacy of melatonin as an adjuvant therapy in COVID-19 patients: Systematic review and meta-analysis

BACKGROUND

Melatonin might be beneficial to coronavirus disease 2019 (COVID-19) patients in terms of both prevention and treatment. We investigated how melatonin affected various clinical and laboratory results in COVID-19 patients.

METHODS

PubMed, Scopus, Cochrane Library and Web of Science databases were utilized for searching eligible articles fulfilling our inclusion criteria up to December 2022. We used random effect model in case of significant heterogeneity; in other cases, a fixed model was applied. RevMan was used for meta-analysis.

RESULTS

We included 11 studies in our review. Clinical improvement rate was found to be statistically significantly higher in patients taking melatonin than in the control group (OR: 5.09; 95% CI: 2.60-9.96, p ​< ​0.001). Patients receiving melatonin showed a non-significant difference in mortality rate compared to the control group (OR: 0.37; 95% CI: 0.07-1.81, p ​= ​0.22). However, in the randomized controlled trials subgroup, melatonin-treated patients showed significantly lower mortality than did the controls (OR: 0.17; 95% CI: 0.08-0.38, p ​< ​0.001). CRP level was statistically significantly lower due to melatonin treatment (weighted mean difference [WMD] ​= ​-9.85; 95% CI: -18.54 to -1.16, p ​= ​0.03). Length of hospital stay was statistically significantly shorter in patients taking melatonin compared to controls (WMD ​= ​-4.05; 95% CI: -5.39 to -2.7, p ​< ​0.001).

CONCLUSION

Melatonin was found to have substantial effects on COVID-19 patients when used as adjuvant therapy, enhancing clinical improvement and decreasing time to recovery with a shorter length of hospital stay and a shorter duration of mechanical ventilation.

High-Temperature Pasteurization Used at Donor Breast Milk Banks Reduces Melatonin Levels in Breast Milk

Background and Objective: Donor human milk banks are used when breast milk directly from mothers is unavailable or insufficient. Breast milk contains melatonin, which exhibits a 24-hour pattern. Melatonin promotes sleep onset and is barely detected in daytime milk but rises in the evening and peaks early in the morning. Melatonin supports the development of an infant's own circadian rhythm and is important for neurodevelopment. Currently, donor banks pasteurize breast milk using a Holder Pasteurization (HoP) technique where breast milk is treated at a high temperature (+62°) for 30 minutes before cooling to eliminate any pathogens before it is given to infants. It is not known how the pasteurization process affects the melatonin levels in breast milk. The aim of this study was to investigate whether the pasteurization process reduces melatonin levels in breast milk. Materials and Methods: Ten night-time breast milk samples were collected and each divided into two groups; one group remained unpasteurized and the other group was pasteurized using the HoP technique. Results: Melatonin levels between the unpasteurized and pasteurized groups were compared. Results showed that there was a significant reduction after pasteurization (mean ± standard deviation = 51.92 pg/mL ± 19.54 versus 39.66 pg/mL ± 13.05, p = 0.01). Conclusions: It is important to understand that pasteurization can reduce melatonin levels in breast milk because this hormone is considered important to support the neurodevelopment of infants, especially those born preterm. Further focus on the effect of pasteurization techniques on melatonin in donor breast milk is warranted.

Maternal melatonin supplementation shapes gut microbiota and protects against inflammation in early life

BACKGROUND

Gut microbiota colonization is critical for immune education and nutrient metabolism. Research shows that melatonin has beneficial effects as a therapy for many diseases via modulating gut dysbiosis. However, it is unclear whether melatonin alters gut microbiota colonization in early life.

METHODS

In the experimental group (Mel), mice were intraperitoneally injected with melatonin at 10 mg/kg body weight for embryonic days 14-16 and received drinking water containing 0.4 mg/mL melatonin until 28 days postpartum. In the control group (Ctrl), mice were injected with the same volume of 2.5% ethanol in saline and provided with standard water. Two more groups were created by treating neonatal mice with 20 mg/kg lipopolysaccharide (LPS) to induce inflammation, resulting in the groups Ctrl + LPS and Mel + LPS, respectively. We examined the gut microbiota of the neonatal mice in the Ctrl and Mel group on Days 7, 14, 21, and 28 post-birth. On Day 14, melatonin and short-chain fatty acids (SCFAs) concentrations were measured in the Ctrl and Mel group and the mice were treated with LPS to be evaluated for intestinal injury and inflammatory response 15 h post treatment. According to the result of the SCFAs concentrations, some neonatal mice were intraperitoneally injected with 500 mg/kg sodium butyrate (SB) from Days 11-13, intraperitoneally injected with 20 mg/kg LPS on Day 14, and then euthanized by carbon dioxide inhalation the next morning. Intestinal injury and inflammatory responses were evaluated in the Ctrl + LPS and SB + LPS groups, respectively.

RESULTS

By Day 14, it was evident that maternal melatonin supplementation significantly increased the relative abundance of Firmicutes in the ileal [61.03 (35.35 - 76.18) % vs. 98.02 (86.61 - 99.01) %, P = 0.003] and colonic [73.88 (69.77 - 85.99) % vs. 96.16 (94.57 - 96.34) %, P = 0.04] microbiota, the concentration of melatonin (0.79 ± 0.49 ng/ml vs. 6.11 ± 3.48 ng/ml, P = 0.008) in the gut lumen, and the fecal butyric acid (12.91 ± 5.74 μg/g vs. 23.58 ± 10.71 μg/g, P = 0.026) concentration of neonatal mice. Melatonin supplementation, and sodium butyrate treatment markedly alleviated intestinal injury and decreased inflammatory factors in neonatal mice.

CONCLUSION

This study suggests that maternal melatonin supplementation can shape the gut microbiota and metabolism of offspring under normal physiological conditions and protect them against LPS-induced inflammation in early life.

Protection of melatonin treatment and combination with traditional antibiotics against septic myocardial injury

BACKGROUND

Heart failure is a common complication of sepsis with a high mortality rate. It has been reported that melatonin can attenuate septic injury due to various properties. On the basis of previous reports, this study will further explore the effects and mechanisms of melatonin pretreatment, posttreatment, and combination with antibiotics in the treatment of sepsis and septic myocardial injury.

METHODS AND RESULTS

Our results showed that melatonin pretreatment showed an obvious protective effect on sepsis and septic myocardial injury, which was related to the attenuation of inflammation and oxidative stress, the improvement of mitochondrial function, the regulation of endoplasmic reticulum stress (ERS), and the activation of the AMPK signaling pathway. In particular, AMPK serves as a key effector for melatonin-initiated myocardial benefits. In addition, melatonin posttreatment also had a certain degree of protection, while its effect was not as remarkable as that of pretreatment. The combination of melatonin and classical antibiotics had a slight but limited effect. RNA-seq detection clarified the cardioprotective mechanism of melatonin.

CONCLUSION

Altogether, this study provides a theoretical basis for the application strategy and combination of melatonin in septic myocardial injury.

A phase II, single-center, double-blind, randomized placebo-controlled trial to explore the efficacy and safety of intravenous melatonin in surgical patients with severe sepsis admitted to the intensive care unit

To determine whether IV melatonin therapy improves redox status and inflammatory responses in surgical patients with severe sepsis, a unicenter, phase II double-blind, randomized, placebo-controlled trial was carried out. The study included patients with severe sepsis marked by infectious systemic inflammatory response syndrome (SIRS), associated with organ dysfunction, hypoperfusion or hypotension requiring surgical intervention. IV melatonin at a daily dose of 60 mg, which was dissolved in 500 ml of 5% dextrose serum, was continuously administered to the patients for over 30 min starting on the day of the diagnoses during a 5-day period. A total of 14 patients received a placebo treatment and 15 melatonin doses. Redox status decreased in melatonin-treated patients during the 5 days of treatment as compared to the placebo-treated patients. Procalcitonin performed better in the melatonin group, whose neutrophil to lymphocyte ratio was also significantly reduced, resulting in an improved evolution of the disease. Moreover, hospital stays decreased by 19.60% from 26.64 days for the placebo group to 21.42 days for the melatonin group. The placebo group recorded five mortalities, as compared to three for the melatonin group. IV melatonin administration improved the course of the disease in surgical patients with severe sepsis, with no side effects. Additional studies with higher doses of melatonin and a long duration of therapy need to be carried out to assess its clinical use.

Melatonin: A window into the organ-protective effects of sepsis

Sepsis is an uncontrolled host response to infection. In some cases, it progresses to multi-organ insufficiency, leading to septic shock and increased risk of mortality. Various organ support strategies are currently applied clinically, but they are still inadequate in terms of reducing mortality. Melatonin is a hormone that regulates sleep and wakefulness, and it is associated with a reduced risk of death in patients with sepsis. Evidence suggests that melatonin may help protect organ function from sepsis-related damage. Here, we review information related to the role of melatonin in protecting organ function during sepsis and explore its potential clinical applications, with the aim of providing an effective therapeutic strategy for treating sepsis-induced organ insufficiency.

High dose melatonin as an adjuvant therapy in intubated patients with COVID-19: A randomized clinical trial

Objective

In the COVID-19 pandemic, the SARS-CoV-2 virus has infected millions of people worldwide. Mortality primarily results from the inflammation state and its complications. High-dose melatonin has been established as an anti-inflammatory agent. This study evaluated high-dose melatonin as an adjuvant therapy in critically ill patients with SARS-CoV-2 infection.

Methods

We conducted a double-blinded, randomized clinical trial of 21 mg of melatonin per day compared with a placebo in 67 patients with COVID-19. We enrolled patients older than 18 years of age with documented SARS-CoV-2 infection, who were admitted to the intensive care unit and underwent invasive mechanical ventilation. Administration of melatonin and placebo through a nasogastric tube continued for 5 days. The main outcomes were mortality rate, duration of mechanical ventilation, changes in oxygenation indices, and C-reactive protein (CRP) levels.

Results

No significant differences were observed in mortality and duration of mechanical ventilation between the control and intervention groups. After 5 days of the intervention, the mean (±standard deviation) CRP and platelet count were 47.28 (±38.86) mg/L and 195.73 (±87.13) × 1000/μL, respectively, in the intervention group and 75.52 (±48.02) mg/L and 149.62 (±68.03) × 1000/μL, respectively, in the control group (P < 0.05).

Conclusion

High-dose melatonin in intubated patients with COVID-19 was associated with a decrease in CRP levels. However, this treatment did not apparently affect patient outcomes.

Effects of Melatonin and Propolis Supplementation on Inflammation, Oxidative Stress, and Clinical Outcomes in Patients with Primary Pneumosepsis: A Randomized Controlled Clinical Trial

Background & Objective: The present study aimed to investigate the effects of propolis and melatonin supplementation on inflammation, clinical outcomes, and oxidative stress markers in patients with primary pneumosepsis. Materials and Methods: This pilot randomized controlled trial was conducted on 55 patients with primary pneumosepsis who were randomly assigned to the intervention and control groups. In the three intervention groups, the patients received propolis alone (1,000 mg/day), propolis (1,000 mg/day) plus melatonin (20 mg/day), and melatonin alone (20 mg/day). The control group received placebo. The inflammatory and oxidative stress markers as well as clinical outcomes were evaluated before and after the intervention, and the 28-day survival rate was also recorded. Results: After the intervention, the combination of propolis and melatonin significantly reduced interleukin-6 (-55.282 pg/ml ) and C-reactive protein (-21.656 mg/l ) levels, while increasing gavage intake (326.680 ml/day ) and improving some clinical outcomes (APACHE II, SOFA and NUTRIC scores) compared to control group. However, no significant difference was observed between the groups in terms of oxidative stress and hematological indices. In addition, the 28-day survival rate had no significant difference between the groups (P=0.07). Conclusion: Supplementation with propolis and melatonin may improve clinical outcomes by reducing inflammation. Further investigations are required to confirm these findings.

Melatonin as an immunomodulator in children with Down syndrome

BACKGROUND

Down syndrome (DS) is a disorder characterised by marked immune dysfunction, increased mortality from sepsis, chronic inflammation, increased oxidative stress, sleep disturbance and possibly abnormal endogenous melatonin levels. Melatonin has a myriad of immune functions, and we hypothesised that this therapeutic agent could modulate the innate immune system in this cohort.

METHODS

We investigated neutrophil and monocyte function (CD11b, TLR4 expression by flow cytometry), genes involved in TLR signalling (MyD88, IRAK4, TRIF), the inflammasome (NLRP3, IL-1β), and circadian rhythm (BMAL, CLOCK, CRY) by qPCR, and inflammatory cytokines (IL-2, IL-6, IL-8, IL-18, IL-1β, TNF-α, IFN-γ, IL-10, IL-1ra, VEGF, Epo, GM-CSF) by enzyme-linked immunosorbent assay (ELISA) following immunomodulation with LPS endotoxin and melatonin. 47 children with DS and 23 age- and sex-matched controls were recruited.

RESULTS

We demonstrated that melatonin has several significant effects by reducing CD11b and TLR4 expression, attenuating TLR signalling, genes involved in the inflammasome and has the potential to reduce LPS-induced inflammatory responses.

CONCLUSIONS

Immunomodulatory effects of melatonin were found in both paediatric cohorts with more marked effects in the children with DS. Melatonin mediates immune response through a wide array of mechanisms and this immunomodulator may buffer the inflammatory response by regulating pro and anti-inflammatory signalling.

IMPACT

We highlight that melatonin mediates its immune response through a wide array of mechanisms, its effects appear to be dose dependant and children with Down syndrome may be more receptive to treatment with it. Immunomodulatory effects of melatonin were demonstrated with marked effects in the children with Down syndrome with a reduction of MyD88, IL-1ß and NLRP3 expression in whole-blood samples. Melatonin is a proposed anti-inflammatory agent with a well-established safety profile, that has the potential for mitigation of pro- and anti-inflammatory cytokines in paediatric Down syndrome cohorts, though further clinical trials are warranted.

A pilot study on the melatonin treatment in patients with early septic shock: results of a single-center randomized controlled trial

BACKGROUND

We assessed the potential impact of a high dose of melatonin treatment in patients with early septic shock.

METHODS

Forty patients with early septic shock were randomly allocated to the melatonin or placebo groups. Besides standard-of-care treatment, melatonin and placebo were administered at a dose of 50 mg for five consecutive nights. The efficacy outcomes were severity of organ dysfunction based on the Sequential Organ Failure Assessment (SOFA) score, the number of patients requiring mechanical ventilation and ventilator-free days, the mean required vasopressor dose and vasopressor-free days, and 28 days all-cause mortality.

RESULTS

After 5-day treatment, the mean SOFA scores decreased 4.05 ± 4.75 score in the melatonin group and 2.25 ± 4.87 in the placebo group. On day 28, 60% of the melatonin-treated patients and 35% of the placebo-treated patients had a SOFA score below six. Thirteen cases in the placebo group and nine cases in the melatonin group required mechanical ventilation; however, there was no statistically significant difference between the groups regarding these outcomes. The melatonin-treated patients had more ventilator-free days than placebo-treated patients over the 28-day (16.90 ± 9.24 vs. 10.00 ± 10.94; p value = 0.035). The mean reduction in the required dose of vasopressor was 6.2 ± 5.12 in the melatonin-treated patients compared to 3.20 ± 3.95 in the placebo-treated patients (p value = 0.045). Vasopressor-free days in the melatonin-treated group were also significantly more than the placebo-treated group (12.75 ± 7.43 days vs. 10.15 ± 6.12 days; p value = 0.046).

CONCLUSIONS

Our pilot study supported the potential benefits of melatonin in treating septic shock. Further clinical evidence is required for expanding and confirming these findings.

TRIAL REGISTRATION

The trial was registered at Clinicaltrials.gov (ID code: IRCT20120215009014N296). Registration date: 15/09/2019.

Influence of innate immune activation on endocrine and metabolic pathways in infancy

Prematurity is the leading cause of neonatal morbidity and mortality worldwide. Premature infants often require extended hospital stays, with increased risk of developing infection compared with term infants. A picture is emerging of wide-ranging deleterious consequences resulting from innate immune system activation in the newborn infant. Those who survive infection have been exposed to a stimulus that can impose long-lasting alterations into later life. In this review, we discuss sepsis-driven alterations in integrated neuroendocrine and metabolic pathways and highlight current knowledge gaps in respect of neonatal sepsis. We review established biomarkers for sepsis and extend the discussion to examine emerging findings from human and animal models of neonatal sepsis that propose novel biomarkers for early identification of sepsis. Future research in this area is required to establish a greater understanding of the distinct neonatal signature of early and late-stage infection, to improve diagnosis, curtail inappropriate antibiotic use, and promote precision medicine through a biomarker-guided empirical and adjunctive treatment approach for neonatal sepsis. There is an unmet clinical need to decrease sepsis-induced morbidity in neonates, to limit and prevent adverse consequences in later life and decrease mortality.

Melatonin for the prevention of fetal injury associated with intrauterine inflammation

Intrauterine inflammation is shown to be associated with preterm birth, fetal inflammatory response syndrome, and other pregnancy-related comorbidities such as central nervous system diseases including cerebral palsy and periventricular leukomalacia, pulmonary diseases such as bronchopulmonary dysplasia and respiratory distress syndrome, and necrotizing enterocolitis, to name a few. Many animal studies on intrauterine inflammation demonstrate that ascending infection of reproductive organs or the production of proinflammatory cytokines by some stimuli in utero results in such manifestations. Melatonin, known for its primary function in maintaining circadian rhythm, is now recognized as one of the most potent antioxidant and anti-inflammatory drugs. In some studies, melatonin injection in pregnant animals with intrauterine inflammation significantly reduced the number of preterm births, the severity of structural disintegration of the fetal lungs observed in bronchopulmonary dysplasia, and perinatal brain injuries with improvement in neuromotor function. These implicated benefits of melatonin in pregnant women with intrauterine inflammation seem promising in many research studies, strongly supporting the hypothesis that melatonin has antioxidative and anti-inflammatory properties that can potentially be taken by pregnant women who are at risk of having intrauterine inflammation. In this review, the potential of melatonin for improving outcomes of the pregnancies with intrauterine inflammation will be discussed.

Evaluating the Neuroprotective Effect of Melatonin on Patients with Hemorrhagic Stroke Using Serum S100B Protein as a Prognostic Marker

Background: Intracerebral hemorrhage (ICH) is one of the most debilitating kinds of stroke. Recent evidence shows that the proper initiation of neuroprotective agents might save at risk neurons and improve the outcome. Objectives: The focus of this study is to evaluate the neuroprotective effect of melatonin on patients with hemorrhagic stroke. Methods: Forty adult patients with confirmed nontraumatic ICH, who were admitted to the ICU within 24 hours of the stroke onset were enrolled in this study. Subjects in the melatonin group received 30 mg of melatonin every night for 5 consecutive nights. In order to evaluate the intensity of the neuronal injury, S100B was assessed once on day 1 and, day 5 post ICU admission. Additionally, the length of ICU stay, mortality, and the duration of mechanical ventilation were also recorded. Results: Forty patients completed the study. In both groups the plasma concentrations of S100B decreased after 5 days compared with their baseline values. However, this reduction was more significant in the melatonin compared to the control group (P-value < 0.05). The duration of mechanical ventilation and length of ICU stay was shorter in the melatonin group, and this difference was statistically significant for the length of ICU stay (P-value < 0.05), and marginally significant for the duration of mechanical ventilation (P-value = 0.065). The in-ICU mortality rate of the melatonin group was 15%, almost half of that of the control group (30%). However, this difference was not statistically significant. Conclusions: In conclusion, melatonin can be considered as a harmless and effective nueroprotective agent with some unique features which has made it an appropriate adjunctive medicine for critically ill intubated patients.

Therapeutics on the clock: Circadian medicine in the treatment of chronic inflammatory diseases

The circadian clock is a collection of endogenous oscillators with a periodicity of ~ 24 h. Recently, our understanding of circadian rhythms and their regulation at genomic and physiologic scales has grown significantly. Knowledge of the circadian influence on biological processes has provided new possibilities for novel pharmacological strategies. Directly targeting the biological clock or its downstream targets, and/or using timing as a variable in drug therapy are now important pharmacological considerations. The circadian machinery mediates many aspects of the inflammatory response and, reciprocally, an inflammatory environment can disrupt circadian rhythms. Therefore, intense interest exists in leveraging circadian biology as a means to treat chronic inflammatory diseases such as sepsis, asthma, rheumatoid arthritis, osteoarthritis, and cardiovascular disease, which all display some type of circadian signature. The purpose of this review is to evaluate the crosstalk between circadian rhythms, inflammatory diseases, and their pharmacological treatment. Evidence suggests that carefully rationalized application of chronotherapy strategies - alone or in combination with small molecule modulators of circadian clock components - can improve efficacy and reduce toxicity, thus warranting further investigation and use.

Oxidative Stress and Inflammation in COVID-19-Associated Sepsis: The Potential Role of Anti-Oxidant Therapy in Avoiding Disease Progression

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak emerged, countless efforts are being made worldwide to understand the molecular mechanisms underlying the coronavirus disease 2019 (COVID-19) in an attempt to identify the specific clinical characteristics of critically ill COVID-19 patients involved in its pathogenesis and provide therapeutic alternatives to minimize COVID-19 severity. Recently, COVID-19 has been closely related to sepsis, which suggests that most deceases in intensive care units (ICU) may be a direct consequence of SARS-CoV-2 infection-induced sepsis. Understanding oxidative stress and the molecular inflammation mechanisms contributing to COVID-19 progression to severe phenotypes such as sepsis is a current clinical need in the effort to improve therapies in SARS-CoV-2 infected patients. This article aims to review the molecular pathogenesis of SARS-CoV-2 and its relationship with oxidative stress and inflammation, which can contribute to sepsis progression. We also provide an overview of potential antioxidant therapies and active clinical trials that might prevent disease progression or reduce its severity.

Hypothermia Plus Melatonin in Asphyctic Newborns: A Randomized-Controlled Pilot Study

OBJECTIVES

To investigate the effect of adding melatonin to hypothermia treatment on neurodevelopmental outcomes in asphyctic newborns.

DESIGN

Pilot multicenter, randomized, controlled, double-blind clinical trial. Statistical comparison of results obtained in two intervention arms: hypothermia plus placebo and hypothermia plus melatonin.

SETTING

Level 3 neonatal ICU.

PATIENTS

Twenty-five newborns were recruited.

INTERVENTIONS

The hypothermia plus melatonin patients received a daily dose of IV melatonin, 5 mg per kg body weight, for 3 days. General laboratory variables were measured both at neonatal ICU admission and after intervention. All infants were studied with amplitude-integrated electroencephalography and brain MRI within the first week of life. The neurodevelopmental Bayley III test, the Gross Motor Function Classification System, and the Tardieu scale were applied at the ages of 6 and 18 months.

MEASUREMENTS AND MAIN RESULTS

Clinical characteristics, laboratory evaluations, MRI findings, and amplitude-integrated electroencephalography background did not differ between the treatment groups. The newborns in the hypothermia plus melatonin group achieved a significantly higher composite score for the cognitive section of the Bayley III test at 18 months old, with respect to the hypothermia plus placebo group (p = 0.05). There were no differences between the groups according to the Gross Motor Function Classification System and Tardieu motor assessment scales.

CONCLUSIONS

The early addition of IV melatonin to asphyctic neonates is feasible and may improve long-term neurodevelopment. To our knowledge, this is the first clinical trial to analyze the administration of IV melatonin as an adjuvant therapy to therapeutic hypothermia.

Melatonin Use in Hospitalized Children for Non-Anesthetic Indications: A Systematic Review

Melatonin, a potent free radical scavenger, plays an important role in homeostasis of cell and organ physiology. The increased demand and synthesis from the pineal gland during times of oxidative stress suggests a potential benefit of melatonin supplementation during hospitalization for acute illness. Yet, the paucity of clinical studies for non-anesthetic-associated indications in pediatric populations hampers the safe, effective, and consistent use of melatonin. The objective of this study was to systematically review published studies of melatonin use for non-sedative and non-analgesic indications in hospitalized pediatric patients. We conducted a search of PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and Scopus databases for articles on the use of melatonin for pediatric patients in a hospital setting. Thirteen eligible studies, all in neonates, were identified. Data elements extracted included study design, number of study subjects, indication for melatonin therapy, and melatonin regimen (formulation, dosage, and duration). Because study methodologies were very heterogeneous, a quantitative synthesis of the published findings was not possible. The identified studies were therefore categorized by the indication of melatonin (adjuvant-antioxidant or anti-inflammatory therapy) in the following specific disease states: (i) acute infections, (ii) respiratory distress syndrome, (iii) neurologic injury, and (iv) jaundice. The current data suggest that melatonin is safe for use in hospitalized neonates. Melatonin may be beneficial for reducing inflammatory markers in neonatal patients with disease states and clinical sequelae that are associated with increased inflammation and oxidative stress. Melatonin, in conjunction with phototherapy, is not superior to use of vitamin D with phototherapy for treatment of neonatal jaundice. However, studies in other pediatric populations are needed given widespread use across clinical inpatient settings.

Melatonin for the treatment of sepsis: the scientific rationale

Sepsis affects 30 million people worldwide, leading to 6 million deaths every year (WHO), and despite decades of research, novel initiatives are drastically needed. According to the current literature, oxidative imbalance and mitochondrial dysfunction are common features of septic patients that can cause multiorgan failure and death. Melatonin, alongside its traditionally accepted role as the master hormonal regulator of the circadian rhythm, is a promising adjunctive drug for sepsis through its anti-inflammatory, antiapoptotic and powerful antioxidant properties. Several animal models of sepsis have demonstrated that melatonin can prevent multiorgan dysfunction and improve survival through restoring mitochondrial electron transport chain (ETC) function, inhibiting nitric oxide synthesis and reducing cytokine production. The purpose of this article is to review the current evidence for the role of melatonin in sepsis, review its pharmacokinetic profile and virtual absence of side effects. While clinical data is limited, we propose the adjunctive use of melatonin is patients with severe sepsis and septic shock.

Melatonin as an adjuvant therapy in preterm infants with neonatal sepsis, randomized trial

Background

Neonatal sepsis (NS) is a systemic uncontrolled inflammatory response to an infectious agent, resulting in oxidative stress. Melatonin antioxidant and free radical scavenger proved to be safe in neonates. We aimed to evaluate the efficacy and safety of melatonin as adjuvant therapy in NS. This was an interventional trial conducted on 40 preterm neonates with NS diagnosed on the basis of clinical and laboratory criteria. They were simply randomized to melatonin treated (MT) (n = 20) and conventionally treated (CT) (n = 20) groups. Melatonin was administered at a total dose of 20 mg enterally in two divided doses of 10 mg each, 1 h apart. Malondialdehyde (MDA) was assessed in patients at enrollment, 4 and 72 h later in MT, and 72hours later in CT. Fifteen healthy matched neonates were included as a control.

Results

There were no significant differences between MT and CT groups regarding baseline sepsis workup. However, total leucocytic count, absolute neutrophil count, and C-reactive protein were significantly higher and platelets were significantly lower in CT compared to MT after 72 h. MDA was doubled in CT while reduced in MT 72 h after intervention (p = 0.000). Mortality was significantly lower in MT. No side effects following melatonin administration were reported.

Conclusion

Melatonin is effective and safe adjuvant for treatment of NS that improves clinical and laboratory outcomes.

Trial registration

clinicalTrials.gov Identifier: NCT03295162. Registered 27 September 2017—Retrospectively registered.

Variations in melatonin levels in preterm and term human breast milk during the first month after delivery

The objectives of the present study were to examine the dynamic changes in breast milk melatonin throughout the course of lactation and to explore factors associated with changes in melatonin concentrations and rhythms in both preterm and term breast milk. Breast milk was collected sequentially at 03:00, 09:00, 15:00, and 21:00 in one day. Melatonin was analyzed in 392 breast milk samples from 98 healthy nursing mothers at 0 to 30 days postpartum. In both preterm and term breast milk, the melatonin concentration presented a circadian rhythm with the acrophase at around 03:00. Subgroup analysis showed the peak melatonin concentrations differed significantly across lactation stages, with the highest concentration in the colostrum, followed by transitional and mature breast milk. At 03:00, preterm breast milk had a higher concentration of melatonin than term breast milk in the colostrum (28.67 pg/mL vs. 25.31 pg/mL, p < 0.022), transitional breast milk (24.70 pg/mL vs. 22.55 pg/mL), and mature breast milk (22.37 pg/mL vs. 20.12 pg /mL). Further studies are warranted for their roles and significance on melatonin in breast milk in nutrition and metabolism of neonates.

Efficacy of pentoxifylline treatment for neonatal sepsis: a meta-analysis of randomized controlled studies

Introduction

Pentoxifylline may be an important approach to treat neonatal sepsis. However, its use has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of pentoxifylline treatment for neonatal sepsis.

Methods

PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials (RCTs) assessing the influence of pentoxifylline treatment on neonatal sepsis are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. This meta-analysis is performed using the random-effect model.

Results

Seven RCTs involving 439 patients are included in the meta-analysis. Compared with control intervention for neonatal sepsis, pentoxifylline treatment is associated with reduced hospital stay (Std. MD = -0.61; 95% CI = -0.93 to − 0.29; P = 0.0002) and metabolic acidosis (RR = 0.38; 95% CI = 0.22 to 0.66; P = 0.0006), but has no remarkable impact on mortality (RR = 0.59; 95% CI = 0.30 to 1.16; P = 0.13), serum TNF-α (Std. MD = -0.38; 95% CI = -1.29 to 0.52; P = 0.41), serum CRP (Std. MD = -0.25; 95% CI = -0.92 to 0.42; P = 0.47), plasma IL-6 (Std. MD = -0.13; 95% CI = -0.41 to 0.15; P = 0.37), disseminated intravascular coagulopathy (RR = 0.55; 95% CI = 0.25 to 1.21; P = 0.14), and oliguria/anuria (RR = 0.77; 95% CI = 0.28 to 2.16; P = 0.62). In addition, pentoxifylline treatment can significantly reduce mortality (RR = 0.50; 95% CI = 0.29 to 0.88; P = 0.02) after excluding the study conducted by Akdag during the sensivity analysis.

Conclusions

Pentoxifylline treatment may be associated with reduced mortality and hospital stay in neonatal sepsis.

Influency of pentoxifylline treatment for neonatal sepsis: A meta-analysis of randomized controlled studies

Introduction:

Pentoxifylline may be an important approach to treat neonatal sepsis. However, its use has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of pentoxifylline treatment for neonatal sepsis.

Methods:

PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials assessing the influence of pentoxifylline treatment on neonatal sepsis are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. This meta-analysis is performed using the random-effect model.

Results:

Seven randomized controlled trials involving 439 patients are included in the meta-analysis. Compared with control intervention for neonatal sepsis, pentoxifylline treatment is associated with reduced hospital stay (standard mean differences = −0.61; 95% confidence interval = −0.93 to −0.29; p = 0.0002) and metabolic acidosis (risk ratio = 0.38; 95% confidence interval = 0.22 to 0.66; p = 0.0006), but has no remarkable impact on mortality (risk ratio = 0.59; 95% confidence interval = 0.30 to 1.16; p = 0.13), serum tumor necrosis factor-α (standard mean differences = −0.38; 95% confidence interval = −1.29 to 0.52; p = 0.41), serum C-reactive protein (standard mean differences = −0.25; 95% confidence interval = −0.92 to 0.42; p = 0.47), plasma interleukin-6 (standard mean differences = −0.13; 95% confidence interval = −0.41 to 0.15; p = 0.37), disseminated intravascular coagulopathy (risk ratio = 0.55; 95% confidence interval = 0.25 to 1.21; p = 0.14), and oliguria/anuria (risk ratio = 0.77; 95% confidence interval = 0.28 to 2.16; p = 0.62).

Conclusion:

Pentoxifylline treatment may be associated with reduced mortality and hospital stay in neonatal sepsis with caution.

Effects of propolis and melatonin on oxidative stress, inflammation, and clinical status in patients with primary sepsis: Study protocol and review on previous studies

BACKGROUND

Previous studies have explored the anti-inflammatory, anti-infection and oxidative stress reduction effects of propolis and melatonin in experimental studies. However, there are no studies at present exploring the effects of propolis and melatonin in patients with primary sepsis. The present study aims to evaluate the potential effects of propolis and melatonin as a pharmaceutical agent in patients with primary sepsis.

METHODS/DESIGN

The study will be conducted as a randomized controlled clinical trial at the Imamreza hospital. Patients with primary sepsis, in four equal groups, will be recruited for the study. The treatment drugs are propolis and melatonin and the placebo. The following primary and secondary outcome measures will be evaluated: APACHE II Score, SOFA score, NUTRIC score, inflammatory factors, and oxidative stress markers.

DISCUSSION

We describe the protocol for a clinical trial design evaluating the effects of simultaneous administration of propolis and melatonin in patients with primary sepsis. The result of the present study, positive or negative, should provide a step change in the evidence guiding current and future policies regarding the use of propolis and melatonin as an auxiliary treatment in patients with primary sepsis.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials: IRCT20181025041460N1. Registered on 6 November 2018.

Melatonin as a master regulator of cell death and inflammation: molecular mechanisms and clinical implications for newborn care

Melatonin, more commonly known as the sleep hormone, is mainly secreted by the pineal gland in dark conditions and regulates the circadian rhythm of the organism. Its intrinsic properties, including high cell permeability, the ability to easily cross both the blood–brain and placenta barriers, and its role as an endogenous reservoir of free radical scavengers (with indirect extra activities), confer it beneficial uses as an adjuvant in the biomedical field. Melatonin can exert its effects by acting through specific cellular receptors on the plasma membrane, similar to other hormones, or through receptor-independent mechanisms that involve complex molecular cross talk with other players. There is increasing evidence regarding the extraordinary beneficial effects of melatonin, also via exogenous administration. Here, we summarize molecular pathways in which melatonin is considered a master regulator, with attention to cell death and inflammation mechanisms from basic, translational and clinical points of view in the context of newborn care.

Altered endotoxin responsiveness in healthy children with Down syndrome

BACKGROUND

Down syndrome (DS) is the most common syndromic immunodeficiency with an increased risk of infection, mortality from sepsis, and autoinflammation. Innate immune function is altered in DS and therefore we examined responses in CD11b and Toll like receptor 4 (TLR-4), which are important immune cell surface markers upregulated in response to Lipopolysaccharide (LPS) endotoxin, and the immunomodulator melatonin. Neutrophil and monocyte responses to LPS and melatonin in children with Down syndrome (DS) who were clinically stable were compared to age-matched controls. Whole blood was incubated with LPS and melatonin and the relative expression of CD11b and TLR-4 evaluated by flow cytometry.

RESULTS

Children with DS had an increased response to LPS in neutrophils and intermediate monocytes, while also having elevated TLR-4 expression on non-classical monocytes compared to controls at baseline. Melatonin reduced CD11b expression on neutrophils, total monocytes, both classical and intermediate sub-types, in children with DS and controls.

CONCLUSION

Melatonin could represent a useful clinical adjunct in the treatment of sepsis as an immunomodulator. Children with DS had increased LPS responses which may contribute to the more adverse outcomes seen in sepsis.

Sepsis and Oxidative Stress in the Newborn: From Pathogenesis to Novel Therapeutic Targets

Sepsis is at present one of the leading causes of morbidity and mortality in the neonatal population. Together with inflammation, oxidative stress is involved in detrimental pathways activated during neonatal sepsis, eventually leading to organ dysfunction and death. The redox cascade during sepsis is mainly initiated by IL-6 and IL-8 stimulation in newborns and includes multiple noxious processes, as direct cell damage induced by reactive oxygen species, activation of gene expression leading to amplification of inflammation and oxidative stress, and impairment of mitochondrial function. Once proinflammatory and prooxidant pathways are established as stimulated by causing pathogens, self-maintaining unfavorable redox cycles ensue, leading to oxidative stress-related cellular damage, independently from the activating pathogens themselves. Despite antioxidant systems are induced during neonatal sepsis, as an adaptive response to an increased oxidative burden, a condition of redox imbalance favoring oxidative pathways occurs, resulting in increased markers of oxidative stress damage. Therefore, antioxidant treatment would exert beneficial effects during neonatal sepsis, potentially interrupting prooxidant pathways and preventing the maintenance of detrimental redox cycles that cannot be directly affected by antibiotic treatment. Among others, antioxidant agents investigated in clinical settings as adjunct treatment for neonatal sepsis include melatonin and pentoxifylline, both showing promising results, while novel antioxidant molecules, as edaravone and endothelin receptor antagonists, are at present under investigation in animal models. Finally, mitochondria-targeted antioxidant treatments could represent an interesting line of research in the treatment of neonatal sepsis.

Immunomodulation to Prevent or Treat Neonatal Sepsis: Past, Present, and Future

Despite continued advances in neonatal medicine, sepsis remains a leading cause of death worldwide in neonatal intensive care units. The clinical presentation of sepsis in neonates varies markedly from that in older children and adults, and distinct acute inflammatory responses results in age-specific inflammatory and protective immune response to infection. This review first provides an overview of the neonatal immune system, then covers current mainstream, and experimental preventive and adjuvant therapies in neonatal sepsis. We also discuss how the distinct physiology of the perinatal period shapes early life immune responses and review strategies to reduce neonatal sepsis-related morbidity and mortality. A summary of studies that characterize immune ontogeny and neonatal sepsis is presented, followed by discussion of clinical trials assessing interventions such as breast milk, lactoferrin, probiotics, and pentoxifylline. Finally, we critically appraise future treatment options such as stem cell therapy, other antimicrobial protein and peptides, and targeting of pattern recognition receptors in an effort to prevent and/or treat sepsis in this highly vulnerable neonatal population.

Use of melatonin as adjunctive therapy in neonatal sepsis: A systematic review and meta-analysis

BACKGROUND

Sepsis remains one of the major causes of neonatal mortality and morbidity. Increased production of free radicals and pro-inflammatory cytokines, combined with the innately low levels of plasma antioxidants in neonates, have been implicated in the pathogenesis and complications of neonatal sepsis. To date, few clinical trials on the beneficial effects of exogenous melatonin on improvement of clinical outcomes in septic neonates have been conducted.

METHODS

The electronic databases including PubMed, Embase, and Cochrane Central Register of Controlled Trials were systematically searched on July 2017 for clinical studies that reported the effects of melatonin as an adjuvant therapy in neonatal sepsis. Serum levels of C-reactive protein (CRP) as biomarker endpoint and recovery of sepsis as clinical endpoint were used to compare treatment responses between groups. The Risk of Bias Assessment tool for Non-Randomized Studies (RoBANS) and the Cochrane Collaboration Risk of Bias tool were used to assess the quality of included studies.

RESULTS

Three studies with a total of 120 participants were included in the systematic review and meta-analysis. Pooled analysis revealed statistically significant mean differences in CRP serum levels (mg/L) between groups at 24 h post-adjunctive therapy with melatonin (-1.739 mg/L; 95% CI: -3.205 to -0.273; P = 0.020). Additionally, adjunctive therapy with melatonin significantly improved clinical condition of sepsis in neonates from the intervention group, compared to the control group, within 3 days of therapy (RR: 2.212; 95% CI: 1.452 to 3.371; P < 0.0005).

CONCLUSIONS

Findings showed that administration of melatonin as adjunctive therapy significantly reduced an inflammatory biomarker and improved sepsis status in neonate. Larger scale studies with higher validity are needed to demonstrate clear clinical benefits of the therapy.

Melatonin Supplementation, a Strategy to Prevent Neurological Diseases through Maintaining Integrity of Blood Brain Barrier in Old People

Blood brain barrier (BBB) plays a crucial role in maintaining homeostasis of microenvironment that is essential to neural function of the central nervous system (CNS). When facing various extrinsic or intrinsic stimuli, BBB is damaged which is an early event in pathogenesis of a variety of neurological diseases in old patients including acute and chronic cerebral ischemia, Alzheimer’s disease and etc. Treatments that could maintain the integrity of BBB may prevent neurological diseases following various stimuli. Old people often face a common stress of sepsis, during which lipopolysaccharide (LPS) is released into circulation and the integrity of BBB is damaged. Of note, there is a significant decrease of melatonin level in old people and animal. Melatonin has been shown to preserves BBB integrity and permeability via a variety of pathways: inhibition of matrix metalloproteinase-9 (MMP-9), inhibition of NADPH oxidase-2, and impact on silent information regulator 1 (SIRT1) and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. More important, a recent study showed that melatonin supplementation alleviates LPS-induced BBB damage in old mice through activating AMP-activated protein kinase (AMPK) and inhibiting gp91^phox, suggesting that melatonin supplementation may help prevent neurological diseases through maintaining the integrity of BBB in old people.

Utilizing melatonin to combat bacterial infections and septic injury

Melatonin, also known as N-acetyl-5-methoxytryptamine, is a ubiquitously acting molecule that is produced by the pineal gland and other organs of animals, including humans. As melatonin and its metabolites are potent antioxidants and free radical scavengers, they are protective against a variety of disorders. Moreover, multiple molecular targets of melatonin have been identified, and its actions are both receptor-mediated and receptor-independent. Recent studies have shown that melatonin may be useful in fighting against sepsis and septic injury due to its antioxidative and anti-inflammatory actions; the results generally indicate a promising therapeutic application for melatonin in the treatment of sepsis. To provide a comprehensive understanding regarding the protective effects of melatonin against septic injury, in the present review we have evaluated the published literature in which melatonin has been used to treat experimental and clinical sepsis. Firstly, we present the evidence from studies that have used melatonin to resist bacterial pathogens. Secondly, we illustrate the protective effect of melatonin against septic injury and discuss the possible mechanisms. Finally, the potential directions for future melatonin research against sepsis are summarized.

Breast Feeding and Melatonin: Implications for Improving Perinatal Health

The biological underpinnings that drive the plethora of breastfeeding benefits over formula-feeding is an area of intense research, given the cognitive and emotional benefits as well as the offsetting of many childhood- and adult-onset medical conditions that breast-feeding provides. In this article, we review the research on the role of melatonin in driving some of these breastfeeding benefits. Melatonin is a powerful antioxidant, anti-inflammatory and antinociceptive as well as optimizing mitochondrial function. Melatonin is produced by the placenta and, upon parturition, maternal melatonin is passed to the infant upon breastfeeding with higher levels in night-time breast milk. As such, some of the benefits of breastfeeding may be mediated by the higher levels of maternal circulating night-time melatonin, allowing for circadian and antioxidant effects, as well as promoting the immune and mitochondrial regulatory aspects of melatonin; these actions may positively modulate infant development. Herein, it is proposed that some of the benefits of breastfeeding may be mediated by melatonin's regulation of the infant's gut microbiota and immune responses. As such, melatonin is likely to contribute to the early developmental processes that affect the susceptibility to a range of adult onset conditions. Early research on animal models has shown promising results for the regulatory role of melatonin.