Utility of melatonin to treat surgical stress after major vascular surgery--a safety study

Effect of Preoperative Administration of Oral Melatonin on Pneumatic Tourniquet-Induced Ischemia-Reperfusion Injury in Orthopedic Surgery of Lower Extremities: A Randomized Clinical Trial

Background

Ischemic reperfusion injury (IRI) causes cellular damage and dysfunction. The present study aimed to evaluate the effect of melatonin on pneumatic tourniquet-induced IRI in orthopedic surgery of the lower extremities.

Methods

A randomized clinical trial was conducted at Chamran Hospital, Shiraz University of Medical Sciences (Shiraz, Iran), from September to November 2019. The target population was patients scheduled for elective orthopedic surgery of the lower extremities. A total of 67 patients were randomly divided into two groups, placebo (n=34) and melatonin (n=33). The groups received 10 mg melatonin or placebo the night before surgery and two hours before surgery. Primary outcome variables were the serum levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Hemodynamic parameters, sedation score, and drug side effects were also evaluated. Data were analyzed using SPSS version 21.0 software. P<0.05 was considered statistically significant.

Results

In the analysis phase, due to loss to follow-up (n=26), 41 patients divided into two groups of melatonin (n=20) and placebo (n=21) were evaluated. There was no significant difference in demographic data, duration of surgery (P=0.929), and tourniquet time (P=0.496) between the groups. The serum levels of SOD and MDA were not significantly different between the groups (P=0.866 and P=0.422, respectively), nor were the incidence of postoperative nausea (P=0.588) and patients' satisfaction (P=0.088). However, the postoperative sedation score and vomiting between the groups were significantly different (P<0.001).

Conclusion

Administration of 10 mg melatonin provided effective sedation, but had no significant effect on the serum levels of SOD and MDA, nor on pneumatic tourniquet-induced IRI in orthopedic surgery of the lower limbs.

Trial registration number

IRCT20141009019470N87.

CD147-spike protein interaction in COVID-19: Get the ball rolling with a novel receptor and therapeutic target

The combat against the Corona virus disease of 2019 (COVID-19), has created a chaos among the healthcare institutions and researchers, in turn accelerating the dire need to curtail the infection spread. The already established entry mechanism, via ACE2 has not yet successfully aided in the development of a suitable and reliable therapy. Taking in account the constant progression and deterioration of the cases worldwide, a different perspective and mechanistic approach is required, which has thrown light onto the cluster of differentiation 147 (CD147) transmembrane protein, as a novel route for SARS-CoV-2 entry. Despite lesser affinity towards COVID-19 virus, as compared to ACE2, this receptor provides a suitable justification behind elevated blood glucose levels in infected patients, retarded COVID-19 risk in women, enhanced susceptibility in geriatrics, greater infection susceptibility of T cells, infection prevalence in non-susceptible human cardiac pericytes and so on. The manuscript invokes the title role and distribution of CD147 in COVID-19 as an entry receptor and mediator of endocytosis-promoted entry of the virus, along with the "catch and clump" hypothesis, thereby presenting its Fundamental significance as a therapeutic target for potential candidates, such as Azithromycin, melatonin, statins, beta adrenergic blockers, ivermectin, Meplazumab etc. Thus, the authors provide a comprehensive review of a different perspective in COVID-19 infection, aiming to aid the researchers and virologists in considering all aspects of viral entry, in order to develop a sustainable and potential cure for the 2019 COVID-19 disease.

Enhanced anti-angiogenic activity of novel melatonin-like agents

Hypoxia-inducible factor-1 (HIF-1) plays an important role in cellular responses to hypoxia, including the transcriptional activation of several genes involved in tumor angiogenesis. Melatonin, also known as N-acetyl-5-methopxytryptamine, is produced naturally by the pineal gland and has anti-angiogenic effects in cancer through its ability to modulate HIF-1α activity. However, the use of melatonin as a therapeutic is limited by its low oral bioavailability and short half-life. Here, we synthesized melatonin-like molecules with enhanced HIF-1α targeting activity and less toxicity and investigated their effects on tumor growth and angiogenesis, as well as the underlying molecular mechanisms. Among melatonin derivatives, N-butyryl-5-methoxytryptamine (NB-5-MT) showed the most potent HIF-1α targeting activity. This molecule was able to (a) reduce the expression of HIF-1α at the protein level, (b) reduce the transcription of HIF-1α target genes, (c) reduce reactive oxygen species (ROS) generation, (d) decrease angiogenesis in vitro and in vivo, and (e) suppress tumor size and metastasis. In addition, NB-5-MT showed improved anti-angiogenic activity compared with melatonin due to its enhanced cellular uptake. NB-5-MT is thus a promising lead for the future development of anticancer compounds with HIF-1α targeting activity. Given that HIF-1α is overexpressed in the majority of human cancers, the melatonin derivative NB-5-MT could represent a novel potent therapeutic agent for cancer.

Melatonin to Rescue the Aged Heart: Antiarrhythmic and Antioxidant Benefits

Aging comes with gradual loss of functions that increase the vulnerability to disease, senescence, and death. The mechanisms underlying these processes are linked to a prolonged imbalance between damage and repair. Damaging mechanisms include oxidative stress, mitochondrial dysfunction, chronodisruption, inflammation, and telomere attrition, as well as genetic and epigenetic alterations. Several endogenous tissue repairing mechanisms also decrease. These alterations associated with aging affect the entire organism. The most devastating manifestations involve the cardiovascular system and may lead to lethal cardiac arrhythmias. Together with structural remodeling, electrophysiological and intercellular communication alterations during aging predispose to arrhythmic events. Despite the knowledge on repairing mechanisms in the cardiovascular system, effective antiaging strategies able to reduce the risk of arrhythmias are still missing. Melatonin is a promising therapeutic candidate due to its pleiotropic actions. This indoleamine regulates chronobiology and endocrine physiology. Of relevance, melatonin is an antiaging, antioxidant, antiapoptotic, antiarrhythmic, immunomodulatory, and antiproliferative molecule. This review focuses on the protective effects of melatonin on age-induced cardiac functional and structural alterations, potentially becoming a new fountain of youth for the heart.

Can Melatonin Be a Potential "Silver Bullet" in Treating COVID-19 Patients?

The therapeutic potential of melatonin as a chronobiotic cytoprotective agent to counteract the consequences of COVID-19 infections has been advocated. Because of its wide-ranging effects as an antioxidant, anti-inflammatory, and immunomodulatory compound, melatonin could be unique in impairing the consequences of SARS-CoV-2 infection. Moreover, indirect evidence points out to a possible antiviral action of melatonin by interfering with SARS-CoV-2/angiotensin-converting enzyme 2 association. Melatonin is also an effective chronobiotic agent to reverse the circadian disruption of social isolation and to control delirium in severely affected patients. As a cytoprotector, melatonin serves to combat several comorbidities such as diabetes, metabolic syndrome, and ischemic and non-ischemic cardiovascular diseases, which aggravate COVID-19 disease. In view of evidence on the occurrence of neurological sequels in COVID-19-infected patients, another putative application of melatonin emerges based on its neuroprotective properties. Since melatonin is an effective means to control cognitive decay in minimal cognitive impairment, its therapeutic significance for the neurological sequels of SARS-CoV-2 infection should be considered. Finally, yet importantly, exogenous melatonin can be an adjuvant capable of augmenting the efficacy of anti-SARS-CoV-2 vaccines. We discuss in this review the experimental evidence suggesting that melatonin is a potential "silver bullet" in the COVID 19 pandemic.

Role of melatonin in the treatment of COVID-19; as an adjuvant through cluster differentiation 147 (CD147)

COVID-19 caused by the SARS-CoV-2 outbreak quickly has turned into a pandemic. However, no specific antiviral agent is yet available. In this communication, we aimed to evaluate the significance of CD147 protein and the potential protective effect of melatonin that is mediated by this protein in COVID-19. CD147 is a glycoprotein that is responsible for the cytokine storm in the lungs through the mediation of viral invasion. Melatonin use previously was shown to reduce cardiac damage by blocking the CD147 activity. Hence, melatonin, a safe drug, may prevent severe symptoms, reduce symptom severity and the adverse effects of the other antiviral drugs in COVID-19 patients. In conclusion, the use of melatonin, which is reduced in the elderly and immune-compromised patients, should be considered as an adjuvant through its CD147 suppressor and immunomodulatory effect.

COVID-19: Melatonin as a potential adjuvant treatment

This article summarizes the likely benefits of melatonin in the attenuation of COVID-19 based on its putative pathogenesis. The recent outbreak of COVID-19 has become a pandemic with tens of thousands of infected patients. Based on clinical features, pathology, the pathogenesis of acute respiratory disorder induced by either highly homogenous coronaviruses or other pathogens, the evidence suggests that excessive inflammation, oxidation, and an exaggerated immune response very likely contribute to COVID-19 pathology. This leads to a cytokine storm and subsequent progression to acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and often death. Melatonin, a well-known anti-inflammatory and anti-oxidative molecule, is protective against ALI/ARDS caused by viral and other pathogens. Melatonin is effective in critical care patients by reducing vessel permeability, anxiety, sedation use, and improving sleeping quality, which might also be beneficial for better clinical outcomes for COVID-19 patients. Notably, melatonin has a high safety profile. There is significant data showing that melatonin limits virus-related diseases and would also likely be beneficial in COVID-19 patients. Additional experiments and clinical studies are required to confirm this speculation.

Lungs as target of COVID-19 infection: Protective common molecular mechanisms of vitamin D and melatonin as a new potential synergistic treatment

COVID-19 pandemic has a high mortality rate and is affecting practically the entire world population. The leading cause of death is severe acute respiratory syndrome as a consequence of exacerbated inflammatory response accompanied by uncontrolled oxidative stress as well as the inflammatory reaction at the lung level. Until now, there is not a specific and definitive treatment for this pathology that worries the world population, especially the older adults who constitute the main risk group. In this context, it results in a particular interest in the evaluation of the efficacy of existing pharmacological agents that may be used for overcoming or attenuating the severity of this pulmonary complication that has ended the lives of many people worldwide. Vitamin D and melatonin could be good options for achieving this aim, taking into account that they have many shared underlying mechanisms that are able to modulate and control the immune adequately and oxidative response against COVID-19 infection, possibly even through a synergistic interaction. The renin-angiotensin system exaltation with consequent inflammatory response has a leading role in the physiopathology of COVID-19 infection; and it may be down-regulated by vitamin D and melatonin in many organs. Therefore, it is also essential to analyze this potential therapeutic association and their relation with RAS as part of this new approach.

Ebola Hemorrhagic Shock Syndrome-on-a-Chip

Ebola virus, for which we lack effective countermeasures, causes hemorrhagic fever in humans, with significant case fatality rates. Lack of experimental human models for Ebola hemorrhagic fever is a major obstacle that hinders the development of treatment strategies. Here, we model the Ebola hemorrhagic syndrome in a microvessel-on-a-chip system and demonstrate its applicability to drug studies. Luminal infusion of Ebola virus-like particles leads to albumin leakage from the engineered vessels. The process is mediated by the Rho/ROCK pathway and is associated with cytoskeleton remodeling. Infusion of Ebola glycoprotein (GP_1,2) generates a similar phenotype, indicating the key role of GP_1,2 in this process. Finally, we measured the potency of a recently developed experimental drug FX06 and a novel drug candidate, melatonin, in phenotypic rescue. Our study confirms the effects of FX06 and identifies melatonin as an effective, safe, inexpensive therapeutic option that is worth investigating in animal models and human trials.

The Influence of Melatonin on Sleep Quality After Laparoscopic Cholecystectomy: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

The efficacy of melatonin to improve sleep quality after laparoscopic cholecystectomy remains controversial. We conduct a systematic review and meta-analysis to explore the influence of melatonin intervention versus placebo on sleep quality after laparoscopic cholecystectomy.

METHODS

We searched PubMed, EMbase, Web of Science, EBSCO, and Cochrane library databases through July 2018 for randomized controlled trials assessing the effect of melatonin intervention versus placebo on sleep quality after laparoscopic cholecystectomy. This meta-analysis is performed using the random-effect model.

RESULTS

Five randomized controlled trials involving 250 patients are included in the meta-analysis. Overall, compared with control group for laparoscopic cholecystectomy, melatonin intervention shows no substantial impact on well-being [standard mean difference (std MD)=0.05; 95% confidence interval (CI)=-0.26 to 0.36; P=0.76], sleepiness (std MD=-0.10; 95% CI=-0.44 to 0.23; P=0.54), sleep quality (std MD=0.10; 95% CI=-0.21 to 0.41; P=0.53), pain scores after 1 hour (std MD=-0.26; 95% CI=-1.08 to 0.56; P=0.53) and 3 hours (std MD=-0.86; 95% CI=-2.69 to 0.97; P=0.36), headache [risk ratio (RR)=1.25; 95% CI=0.42-3.71; P=0.68], depression (RR=1.03; 95% CI=0.15-7.21; P=0.97), dizziness (RR=1.09; 95% CI=0.14-9.40; P=0.94).

CONCLUSIONS

Melatonin intervention has no significant influence on well-being, sleepiness, sleep quality, pain intensity after 1 and 3 hours, headache, depression, and dizziness for laparoscopic cholecystectomy.

Melatonin: Protection against age-related cardiac pathology

Aging is a complex and progressive process that involves physiological and metabolic deterioration in every organ and system. Cardiovascular diseases are one of the most common causes of mortality and morbidity among elderly subjects worldwide. Most age-related cardiovascular disorders can be influenced by modifiable behaviours such as a healthy diet rich in fruit and vegetables, avoidance of smoking, increased physical activity and reduced stress. The role of diet in prevention of various disorders is a well-established factor, which has an even more important role in the geriatric population. Melatonin, an indoleamine with multiple actions including antioxidant properties, has been identified in a very large number of plant species, including edible plant products and medical herbs. Among products where melatonin has been identified include wine, olive oil, tomato, beer, and others. Interestingly, consumed melatonin in plant foods or melatonin supplementation may promote health benefits by virtue of its multiple properties and it may counteract pathological conditions also related to cardiovascular disorders, carcinogenesis, neurological diseases and aging. In the present review, we summarized melatonin effects against age-related cardiac alterations and abnormalities with a special focus on heart ischemia/reperfusion (IR) injury and myocardial infarction.

Effects of melatonin on the acute inflammatory response associated with endoscopic retrograde cholangiopancreatography: A randomized, double-blind, placebo-controlled trial

INTRODUCTION

Endoscopic retrograde cholangiopancreatography (ERCP) is associated with an acute inflammatory response and melatonin has a variety of immunomodulatory and antioxidant effects studied experimentally in pancreatobiliary pathology.

AIMS

The aim of our study was to evaluate the effects of peri-procedural administration of melatonin on the inflammatory response and lipid peroxidation associated with ERCP.

METHODS

In this proof-of-concept clinical trial, 37 patients with a high probability of choledocholithiasis were randomized to receive peri-procedure (ERCP) melatonin or placebo. We measured the serum concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), lipid peroxidation, amylase, and liver function tests 24h before and after the procedure.

RESULTS

We found no pre-procedure or post-procedure differences between the melatonin group or the placebo group (P>.05) in the serum concentrations of TNF-alpha (melatonin: 153.8 vs. 149.4ng/m; placebo: 103.5 vs. 107.3ng/ml), IL-6 (melatonin: 131.8 vs. 133.3ng/ml; placebo: 177.8 vs. 197.8ng/ml), or VEGF (melatonin: 157.3 vs. 157.8pg/ml; placebo: 97.3 vs. 97.8pg/ml), or in relation to lipid peroxidation (melatonin: 39.2 vs. 72.3μg/ml; placebo: 66.4 vs. 90.5μg/ml). After ERCP, a significant decrease in the AST, ALT, and total bilirubin levels was found only in the melatonin group (P<.05). The administration of melatonin was safe and tolerable.

CONCLUSIONS

Melatonin is safe and tolerable in patients undergoing ERCP, but it does not appear to affect inflammatory cytokine concentrations or lipid peroxidation.

Effect of topical application of melatonin cream 12.5% on cognitive parameters: A randomized, placebo-controlled, double-blind crossover study in healthy volunteers

BACKGROUND

Skin cancer is an increasing problem in modern dermatology. Earlier studies have shown protective effects against ultraviolet radiation (UVR)-induced skin damage by topical treatment with melatonin. However, the potential sedative effects of full body topical application of melatonin have never been investigated. Objectives The aim of this study was to assess the degree of cognitive dysfunction when using melatonin cream as full body topical application.

METHODS

In a randomized, placebo-controlled, double-blind crossover study in healthy volunteers, the degree of cognitive dysfunction when using cream containing 12.5% melatonin as full body application was assessed. A group of ten volunteers had melatonin cream 12.5% applied on 80% of their body surface area, and degree of cognitive dysfunction was assessed using a test battery consisting of Karolinska sleepiness scale (KSS), Finger tapping test (FTT) and Continuous Reaction time (CRT).

RESULTS

No significant effects on cognitive parameters were found. However, great inter-individual variations on cognitive parameters were observed.

CONCLUSION

This study was the first to assess degree of cognitive dysfunction resulting from application of melatonin cream on a full body surface area. The results support that melatonin is a safe drug for dermal application even in a high dosage.

Absence of analgesic effect of intravenous melatonin administration during daytime after laparoscopic cholecystectomy: a randomized trial

STUDY OBJECTIVE

To investigate whether melatonin administered intraoperatively reduced pain following laparoscopic cholecystectomy.

DESIGN

Randomized, placebo-controlled, double-blinded study.

SETTING

Two surgical departments in Copenhagen.

PATIENTS

44 women between 18 and 70 years of age, who were surgical candidates for laparoscopic cholecystectomy.

INTERVENTIONS

Patients were anesthetized by a standard protocol and received a standard multimodal postoperative analgesic regimen. Patients undergoing surgery were admitted on the day of surgery and were discharged the day after surgery. Ten mg of intravenous (IV) melatonin or placebo were administered at the time of surgical incision.

MEASUREMENTS

Pain was assessed by a set of questionnaires documenting "pain at rest" using a visual analog scale (VAS). The use of rescue medication was recorded. Sleep quality and general well-being were measured on separate VAS scales. Sleepiness was assessed by the Karolinska Sleepiness Scale.

MAIN RESULTS

Forty-four patients were included and randomized to the study. Three patients did not complete the study. No differences in VAS pain scores, sleep quality, general well-being, or sleepiness were found between the two groups in the postoperative period. The use of postoperative rescue medication did not differ between the groups.

CONCLUSIONS

The use of 10mg of IV melatonin administered during laparoscopic cholecystectomy did not affect postoperative pain or use of analgesic medication.

Melatonin reduces cardiac morbidity and markers of myocardial ischemia after elective abdominal aortic aneurism repair: a randomized, placebo-controlled, clinical trial

The aim was to examine the effect of perioperative melatonin treatment on clinical cardiac morbidity and markers of myocardial ischemia in patients undergoing elective surgery for abdominal aortic aneurism. Reperfusion injury results in increased cardiac morbidity in patients undergoing surgery for abdominal aortic aneurisms (AAA). A randomized, placebo-controlled, clinical trial including patients undergoing surgery for AAA was performed. The patients received by infusion over a 2-hr period either, 50 mg melatonin or placebo intra-operatively, and 10 mg melatonin or placebo orally, the first three nights after surgery. Postoperative cardiac morbidity was registered, and blood samples for analysis of troponin-I (TpI) were collected preoperatively, and at 5 min, 6, 24, 48, 72, and 96 hr after clamp removal/recirculation of the first leg. Continuous measurement of ST-segment depression was performed by Holter monitoring. A total of 26 patients received melatonin, while 24 received placebo. A significant reduction in cardiac morbidity was seen in the melatonin-treated patients compared with those given placebo [4% versus 29% (P = 0.02)]. Five patients (19%) who received melatonin had increased TpI levels in the postoperative period compared with 12 patients (50%) who were given placebo (P = 0.036). The median number of ST-segment deviations was less in the melatonin-treated patients compared with the placebo group [median 1 (range 0-4) versus 6 (range 0-13) (P = 0.01)], but no differences were found in the duration of ST-segment deviations. Melatonin treatment in the perioperative period decreased clinical cardiac morbidity as well as the occurrence of myocardial ischemia after abdominal aortic aneurism repair.

Melatonin in perioperative medicine: Current perspective

Melatonin, a new addition to the armamentarium of anesthesiologist, has some unique properties that are highly desirable in routine peri-operative care. Available clinical data show that preoperative melatonin is as effective as benzodiazepines in reducing preoperative anxiety with minimal action on psychomotor performance and sleep wake cycle. It may be considered as a safe and effective alternative of benzodiazepines as preoperative anxiolytic. It may have opioid sparing effect, may reduce intraocular pressure, and have role in prevention of postoperative delirium. The short-term administration of melatonin is free from significant adverse effects also.

Protective effects of melatonin in reducing oxidative stress and in preserving the fluidity of biological membranes: a review

Free radicals generated within subcellular compartments damage macromolecules which lead to severe structural changes and functional alterations of cellular organelles. A manifestation of free radical injury to biological membranes is the process of lipid peroxidation, an autooxidative chain reaction in which polyunsaturated fatty acids in the membrane are the substrate. There is considerable evidence that damage to polyunsaturated fatty acids tends to reduce membrane fluidity. However, adequate levels of fluidity are essential for the proper functioning of biological membranes. Thus, there is considerable interest in antioxidant molecules which are able to stabilize membranes because of their protective effects against lipid peroxidation. Melatonin is an indoleamine that modulates a wide variety of endocrine, neural and immune functions. Over the last two decades, intensive research has proven this molecule, as well as its metabolites, to possess substantial antioxidant activity. In addition to their ability to scavenge several reactive oxygen and nitrogen species, melatonin increases the activity of the glutathione redox enzymes, that is, glutathione peroxidase and reductase, as well as other antioxidant enzymes. These beneficial effects of melatonin are more significant because of its small molecular size and its amphipathic behaviour, which facilitates ease of melatonin penetration into every subcellular compartment. In the present work, we review the current information related to the beneficial effects of melatonin in maintaining the fluidity of biological membranes against free radical attack, and further, we discuss its implications for ageing and disease.

Modulation by melatonin of the pathogenesis of inflammatory autoimmune diseases

Melatonin is the major secretory product of the pineal gland during the night and has multiple activities including the regulation of circadian and seasonal rhythms, and antioxidant and anti-inflammatory effects. It also possesses the ability to modulate immune responses by regulation of the T helper 1/2 balance and cytokine production. Autoimmune diseases, which result from the activation of immune cells by autoantigens released from normal tissues, affect around 5% of the population. Activation of autoantigen-specific immune cells leads to subsequent damage of target tissues by these activated cells. Melatonin therapy has been investigated in several animal models of autoimmune disease, where it has a beneficial effect in a number of models excepting rheumatoid arthritis, and has been evaluated in clinical autoimmune diseases including rheumatoid arthritis and ulcerative colitis. This review summarizes and highlights the role and the modulatory effects of melatonin in several inflammatory autoimmune diseases including multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes mellitus, and inflammatory bowel disease.

Melatonin prolongs graft survival of pancreas allotransplants in pigs

Oxidative stress is involved in ischemia-reperfusion injury and allograft rejection after transplantation. We studied two well-known antioxidants, melatonin and ascorbic acid (AA), in relation to the survival of a pancreas transplantation model without immunosuppression. Forty-eight Landrace pigs were divided into three groups (n = 16 each; eight donors and eight recipients) that received melatonin, AA, or no antioxidant therapy (controls). Melatonin and AA were administered (10 mg/kg body weight) intravenously to donors and recipients during surgery and on postoperative days 1-7. The molecules were also added (5 mm) to a University of Wisconsin preservation solution during organ cold storage. Melatonin significantly delayed acute rejection and prolonged allograft survival (25.1 ± 7.7 days) compared with the controls (8.1 ± 0.8 days, P = 0.013) and the AA group (9.4 ± 1.6 days, P = 0.049). Melatonin reduced indicators of oxidative stress, malondialdehyde, and 4-hydroxyalkenals, in pancreatic samples collected during procurement, cold ischemia, and reperfusion. Melatonin also reduced serum pig-major acute-phase protein/inter-α-trypsin inhibitor heavy chain 4 (pMAP/ITIH(4)) in the early post-transplantation period. AA only partially reduced oxidative damage 30 min postreperfusion and failed to prevent pMAP/ITIH(4) elevations. These findings suggested that melatonin may be a useful therapeutic tool for organ transplantation.

Storage-induced increase in biomarkers of oxidative stress and inflammation in red blood cell components

BACKGROUND

Transfusion of blood components may increase the risk of complications in relation to surgery. During storage, red blood cells (RBCs) undergo structural and functional changes that may reduce function and viability after transfusion. The aim of the study was to evaluate the quality of buffy-coat reduced red cells in SAG-M additive solution, by assessing biomarkers of oxidative and inflammatory stress during a storage period of 35 days.

STUDY DESIGN AND METHODS

Ten units of RBCs were stored for 35 days. Samples were collected from the units at storage days 1, 3, 7, 14, 21, 28 and 35, respectively. The samples were analysed for various biomarkers expressing the oxidative stress and inflammation, including malondialdehyde (MDA), α-tocopherol (AT), dehydroascorbic acid (DHA), ascorbate (ASC), YKL-40 and interleukin-6 (IL-6).

RESULTS

The levels ofMDA, ASC, DHA, IL-6 and YKL-40 changed significantly during the storage period (p < 0.001, p < 0.001, p < 0.001, p = 0.004 and p < 0.001 respectively). A significant change in AT levels could not be shown (p = 0.087).

CONCLUSIONS

RBCs displayed significant changes in all measured indices of oxidative and inflammatory stress during a storage period of 35 days except for AT. The data suggest a possible rationale behind the observation that aging blood products may increase the risk of complications following surgery and blood transfusion.

No effect of melatonin on oxidative stress after laparoscopic cholecystectomy: a randomized placebo-controlled trial

BACKGROUND

Melatonin, an endogenous circadian regulator, also has antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the antioxidative effect of melatonin in patients undergoing laparoscopic cholecystectomy.

METHODS

Patients were randomized to receive 10 mg melatonin or placebo during surgery. Blood samples for analysis of malondialdehyde (MDA), ascorbic acid (AA), total ascorbic acid (TAA) dehydroascorbic acid (DHA) and C-reactive protein (CRP) were collected pre-operatively and at 5 min, 6 h and 24 h after operation.

RESULTS

Twenty patients received melatonin and 21 patients received placebo during surgery. No significant differences were observed between the groups in the oxidative stress variables MDA, TAA, AA and DHA or in the inflammatory variable CRP (repeated-measures ANOVA, P>0.05 for all variables).

CONCLUSIONS

Administration of 10 mg melatonin did not reduce variables of oxidative stress in patients undergoing elective laparoscopic cholecystectomy.

Melatonin prolongs islet graft survival in diabetic NOD mice

Islet transplantation has been established as a potential therapy for type 1 diabetes. However, inflammation, allorejection, and on-going autoimmune damage contribute to early graft loss and failure of islet transplantation. Melatonin is the major secretory product of the pineal gland during the dark period of each day and displays multifunctional properties including the regulation of circadian and seasonal rhythms, antioxidation reactions and immune modulation. Based on the immunosuppressive properties of melatonin, we investigated whether melatonin treatment prolonged the survival of islet grafts in non-obese diabetic (NOD) mice. The mean islet graft survival time was 7.33 +/- 1.51 and 7.75 +/- 2.66 days in untreated controls and in the solvent-treated animals, respectively. Strikingly, the mean survival time of islet grafts in recipients treated with melatonin (200 mg/kg/bw) was 17 +/- 7.76 days. Moreover, melatonin treatment reduced the proliferation of splenocytes in NOD mice. Using a T1 and T2 double transgenic mouse model, we found that T helper 1 (Th1) cells in mice treated with melatonin were significantly decreased. The reduction of Th1 cells and T cell proliferation may result from an increase in the immunosuppressive cytokine IL-10. Our results indicate that melatonin treatment suppresses autoimmune recurrence by inhibiting the proliferation of Th1 cells in NOD mice and thus prolongs the survival of syngeneic islet grafts.

Reducing oxidative/nitrosative stress: a newly-discovered genre for melatonin

The discovery of melatonin and its derivatives as antioxidants has stimulated a very large number of studies which have, virtually uniformly, documented the ability of these molecules to detoxify harmful reactants and reduce molecular damage. These observations have clear clinical implications given that numerous age-related diseases in humans have an important free radical component. Moreover, a major theory to explain the processes of aging invokes radicals and their derivatives as causative agents. These conditions, coupled with the loss of melatonin as organisms age, suggest that some diseases and some aspects of aging may be aggravated by the diminished melatonin levels in advanced age. Another corollary of this is that the administration of melatonin, which has an uncommonly low toxicity profile, could theoretically defer the progression of some diseases and possibly forestall signs of aging. Certainly, research in the next decade will help to define the role of melatonin in age-related diseases and in determining successful aging. While increasing life span will not necessarily be a goal of these investigative efforts, improving health and the quality of life in the aged should be an aim of this research.

Melatonin, a potent regulator of hemeoxygenase-1, reduces cardiopulmonary bypass-induced renal damage in rats

Acute renal dysfunction is a frequent complication after cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to evaluate the potential protective effect of melatonin on CPB-induced renal damage in a rat model. Forty male Sprague-Dawley rats were randomly divided into four groups: sham, control (CPB + placebo), low dose of melatonin (CPB + 10 mg/kg melatonin) and high dose of melatonin (CPB + 20 mg/kg melatonin). Blood samples were collected at the beginning, at the end of CPB, and at 0.5, 1, 2, 3, and 24 hr postoperation. Serum creatinine and blood urea nitrogen levels were assayed. Rats were killed 24 hr after surgery, the histologic appearance of the kidney and malondialdehyde (MDA), myeloperoxidase (MPO), catalase (CAT) and superoxide dismutase (SOD) contents were determined. The expression levels of hemeoxygenase-1 (HO-1) protein and gene were determined using western blotting and real-time PCR, respectively. In the control group, CPB surgery significantly increased urea, creatinine levels in serum, MDA and MPO levels in tissues, while decreasing SOD and CAT activities in tissues. Histopathologic findings of the control group confirmed that there was renal impairment by cast formation and tubular necrosis in the tubular epithelium. These changes were markedly reversed in both low dose of melatonin and high dose of melatonin groups. Furthermore, HO-1 gene transcript and protein were significantly upregulated in the kidney tissues after melatonin treatment compared with the placebo treatment. Our findings show that melatonin was effective in preventing CPB-induced renal damage probably through its antioxidant function and upregulation of HO-1.