The antioxidant effects of melatonin after intracerebral hemorrhage in rats

Potential application of intranasal insulin delivery for treatment of intracerebral hemorrhage: A review of the literature

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke associated with high morbidity and mortality that is considered a medical emergency, mainly managed with adequate blood pressure control and creating a favorable hemostatic condition. However, to date, none of the randomized clinical trials have led to an effective treatment for ICH. It is vital to better understand the mechanisms underlying brain injury to effectively decrease ICH-associated morbidity and mortality. It is well known that initial hematoma formation and its expansion have detrimental consequences. The literature has recently focused on other pathological processes, including oxidative stress, neuroinflammation, blood-brain barrier disruption, edema formation, and neurotoxicity, that constitute secondary brain injury. Since conventional management has failed to improve clinical outcomes significantly, various neuroprotective therapies are tested in preclinical and clinical settings. Unlike intravenous administration, intranasal insulin can reach a higher concentration in the cerebrospinal fluid without causing systemic side effects. Intranasal insulin delivery has been introduced as a novel neuroprotective agent for certain neurological diseases, including ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury. Since there is an overlap of mechanisms causing neuroinflammation in these neurological diseases and ICH, we believe that preclinical studies testing the role of intranasal insulin therapy in ICH are warranted.

Mortality prediction by serum melatonin levels of patients with spontaneous intracerebral hemorrhage

OBJECTIVE

In one study, higher serum melatonin levels have been reported at diagnosis of spontaneous intracerebral hemorrhage (ICH) in non-surviving than in surviving patients. Now, we carried out this study with the aims to explore whether blood melatonin concentrations in the first 7 days of ICH are different in survivor and non-survivor patients and whether are useful in the prediction of mortality.

METHODS

Six Spanish hospitals participated in this observational study of patients with severe supratentorial ICH (defining severe as Glasgow Coma Scale < 9). We determined serum melatonin levels during the first, fourth, and eighth day of severe ICH.

RESULTS

Surviving (n = 64) compared to non-surviving (n = 53) patients showed lower serum melatonin levels during the first (p < 0.001), fourth (p < 0.001), and eighth day (p < 0.001) of severe ICH. We found in multiple logistic regression analysis an association between serum melatonin levels and 30-day mortality (odds ratio = 8.932; 95% CI = 2.442-32.665; p = 0.001) controlling for midline shift, ICH score, early evacuation of ICH, and glycemia. We found an AUC (95% CI) for the mortality prediction of 0.90 (0.83-0.95; p < 0.001), 0.94 (0.87-0.98; p < 0.001), and 0.90 (0.81-0.96; p < 0.001) by serum melatonin concentrations during the first, fourth, and eighth day.

CONCLUSIONS

In our current study, it appears that novel findings of serum melatonin levels recollected at any moment during the first 7 days of a severe ICH were higher in non-survivor than in survivor patients and could help in mortality prediction.

Neuroprotective Therapies for Spontaneous Intracerebral Hemorrhage

Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.

Efficacy of melatonin in animal models of intracerebral hemorrhage: a systematic review and meta-analysis

Melatonin is a potent antioxidant and anti-inflammatory agent that is showing promising results in acute brain injury. The aim of this study was to systematically evaluate the pre-clinical evidence on the effectiveness of melatonin in improving outcome after intracerebral hemorrhage (ICH). We searched mainstream databases from the inception to the end of June 2020. Outcomes were measured by neurobehavioral scores or brain water content. Meta-analyses were performed with Stata 12.0 and Review Manager 5.3. Finally, 8 articles published from 2008 to 2019 met the inclusion criteria. Meta-analysis of pre-clinical data revealed an overall positive effect on neurobehavioral outcome with a standardized mean difference (SMD) of -0.81 (95% CI: -1.47, -0.15; p = 0.016) with significant heterogeneity (Q = 41.49, I² = 68.7%; p = 0.000). Further subgroup analysis were performed from methodological differences, especially dose and timing of treatments. Furthermore, melatonin reduced cerebral edema by an SMD of -0.78 (95% CI: -1.23, -0.34; p = 0.001) with low heterogeneity. In conclusion, melatonin treatment significantly improves both behavioral and pathological outcomes in animal models of ICH. In addition, the results should be interpreted in light of the limitations in experimental design and methodological quality of the studies included in the meta-analysis.

High serum levels of TAC and early mortality in patients with spontaneous intracerebral haemorrhage

OBJECTIVE

Oxidation contributes to secondary brain injury after spontaneous intracerebral haemorrhage (SIH). One study found lower levels of total antioxidant capacity (TAC) in the blood in patients with SIH than in healthy subjects. However, there are no data on blood TAC levels and survival in patients with SIH. Therefore, the objective of our study was to determine if an association exists between serum TAC levels and mortality in patients with SIH.

METHODS

We included patients with severe supratentorial SIH. We considered severe when Glasgow Coma Scale (GCS) < 9. Patients from 6 Spanish hospitals were included in this observational and prospective study. Serum TAC levels at days 1, 4 and 8 of SIH were determined. Thirty-day mortality was our end-point study.

RESULTS

Non-surviving patients compared with surviving patients showed higher serum TAC levels at day 1 (p < 0.001), 4 (p < 0.001) and 8 (p = 0.001). An area under the curve was found for the prediction of 30-day mortality by serum TAC levels of 0.92 (95% CI = 0.85-96%; p < 0.001). Multiple logistic regression analysis showed an association of serum TAC levels with 30-day mortality (odds ratio = 16.513; 95% CI = 2.548-107.015; p = 0.003) controlling for midline shift, glycemia, early evacuation of SIH, intracerebral haemorrhage (ICH) score, age and volume of SIH.

CONCLUSIONS

The new findings of this study are that serum TAC levels are higher in non-surviving than in surviving patients, and that they are associated with mortality and could be used to predict mortality.

The effect of melatonin on reduction in the need for sedative agents and duration of mechanical ventilation in traumatic intracranial hemorrhage patients: a randomized controlled trial

Purpose

This study aimed to determine the effect of exogenous melatonin on the number of sedative drugs and the duration of mechanical ventilation in traumatic intracranial hemorrhage patients in ICU.

Methods

This double-blind randomized clinical trial study was conducted in the ICU wards of Golestan Hospital, Ahvaz, Iran, from September 2017 to March 2018. In this study, 52 patients with intracerebral hemorrhage were selected by convenient sampling (26 patients in each group) and were randomly assigned to two groups of melatonin and control. Sedation and pain management package was applied to both groups. Outcomes: Amount of the sedative and opioid drug; mechanical ventilation time; ICU staying time; Glasgow Coma Score; hemodynamic parameters.

Results

There was no significant difference between them in terms of demographic characteristics. Cumulative doses of morphine and mechanical ventilation time were significant in two groups. (P < 0.05) The mean length of ICU staying was not significant. Glasgow Coma Score on the 6th day was significant in two groups (P < 0.05). Diastolic blood pressure was significant between groups (P < 0.001).

Conclusion

This study presented that morphine consumption and mechanical ventilation time were significantly lower in the melatonin group than in the control. Also, rise in GCS in the melatonin group was faster in the melatonin group than in the control. The use of melatonin can be recommended for patients with ICH in the ICU for better outcomes.

The Serum Melatonin Levels and Mortality of Patients with Spontaneous Intracerebral Hemorrhage

Objective: Providing melatonin in animal models with spontaneous intracerebral hemorrhage (SIH) has been associated with beneficial effects. However, to our knowledge, there are no published data on circulating melatonin levels regarding the prognosis of SIH patients. Therefore, the objectives of this study were to determine whether serum melatonin levels in SIH patients were associated with early mortality and whether they could be used as prognostic biomarkers. Methods: This observational and prospective study included patients with supratentorial and clinically severe SIH (defined as Glasgow Coma Scale GCS <9) admitted to the Intensive Care Units of six Spanish hospitals. Serum melatonin levels were determined at the time of severe SIH diagnosis. Mortality at 30 days was the study end-point. Results: Non-surviving patients (n = 46) showed higher serum melatonin levels (p < 0.001) than surviving (n = 54) patients. An area under the curve was found for the prediction of 30-day mortality by serum melatonin levels of 0.89 (95% CI = 0.81-0.94; p < 0.001). Multiple logistic regression analysis showed an association of serum melatonin levels with 30-day mortality (Odds Ratio = 8.16; 95% CI = 2.30-28.95; p = 0.001) after controlling for midline shift, glycemia, early evacuation of SIH, and Intracerebral hemorrhage(ICH) score. Conclusions: The novel findings by our study were the presence of higher serum melatonin levels in non-surviving patients than in surviving patients and the association of these levels with mortality.

Melatonin Administration Methods for Research in Mammals and Birds

Endocrine research in animals often entails exogenous hormone administration. Special issues arise when developing administration protocols for hormones with circadian and seasonal periodicity. This article reviews various methods for the exogenous administration of hormones with such periodicities by focusing on melatonin. We discuss that methodological variations across studies can affect experimental results. Melatonin administration techniques used in vertebrates includes infusion pumps, beeswax pellets, oral administration, injections, SILASTIC capsules, osmotic pumps, transdermal delivery, beads, and sponges.

Green Tea and Red Tea from Camellia sinensis Partially Prevented the Motor Deficits and Striatal Oxidative Damage Induced by Hemorrhagic Stroke in Rats

Green tea from Camellia sinensis plays a well-established neuroprotective role in several neurodegenerative diseases, including intracerebral hemorrhage (ICH). However, the other teas of the same plant do not have their properties well understood; but they can be as effective as green tea as an alternative therapy. In this study, we investigated the effects of supplementation with green tea and red tea from Camellia sinensis on motor deficits and striatum oxidative damage in rats submitted to hemorrhagic stroke (ICH). Male Wistar rats were supplemented with green tea, red tea, or vehicle for 10 days prior to ICH induction. After injury, the rats were submitted to motor tests (open field for locomotion, rotarod for balance, and neurological deficit scale (NDS)) 1, 3, and 7 days after ICH induction, while the tea supplementation was maintained. Subsequently, the rats were euthanized to striatal tissue dissection for biochemical analyzes (lipid peroxidation, reactive oxygen species, glutathione levels, and total antioxidant capacity). ICH caused locomotor and balance deficits, as well as increased the neurological deficit (NDS). Only red tea prevented locomotor deficits after injury. Green tea and red tea prevented balance deficits on the seventh day after ICH. On NDS evaluation, green tea presented a better neuroprotection than red tea (until day 3 after ICH injury). In addition, ICH increased reactive oxygen species and lipid peroxidation levels, without altering antioxidant markers. Green and red teas were effective in decreasing the lipid peroxidation levels. Therefore, green and red teas partially prevented the motor deficits and striatal oxidative damage induced by ICH. Based on our results, we can consider that the two teas seem to be equally effective to prevent motor deficits and striatal oxidative damage induced by hemorrhagic stroke in rats.

Resveratrol attenuates neurological deficit and neuroinflammation following intracerebral hemorrhage

Resveratrol (RESV) improves histopathological and behavioral outcomes in diseases of the central nervous system. However, to the best of our knowledge, there have been no studies investigating its neuroprotective effects on secondary brain injury following intracerebral hemorrhage (ICH). The aim of the present study was to evaluate the neuroprotective function of resveratrol following ICH. Male Sprague-Dawley rats were randomly divided into 3 groups: Sham, ICH and ICH+RESV groups. Rats underwent ICH and received an intraperitoneal injection of RESV daily. Rotarod and open field tests were performed to evaluate improvements in motor disturbance pre- and post-surgery. Rats were sacrificed following the final behavioral test; subsequently, neuron injury and cell death in the hippocampus and microglia activation in the cortex were determined using Nissl staining and ionized calcium binding adaptor molecule 1 immunofluorescence staining, respectively. Compared with the ICH group, rats treated with resveratrol for 2 weeks performed significantly better in behavioral tests. Furthermore, less neural damage in the hippocampus and decreased activation of microglia was observed in the ICH+RESV group. The results of the present study therefore indicate that resveratrol may alleviate secondary brain injury following ICH.

Serum Malondialdehyde Levels and Mortality in Patients with Spontaneous Intracerebral Hemorrhage

OBJECTIVE

Oxidative stress has been associated with secondary brain injury after spontaneous intracerebral hemorrhage (SIH). Malondialdehyde (MDA) appears in blood during lipid oxidation. Higher serum MDA levels have been found in patients with SIH than in healthy controls; however, we have not found data indicating an association between elevated serum MDA and early mortality in this population. This was the main objective of our study.

METHODS

MDA levels were measured in serum samples obtained from 100 patients at diagnosis of severe SIH (Glasgow Coma Scale score ≤8) and 80 healthy controls. The endpoint of the study was mortality at 30 days.

RESULTS

Serum MDA levels were significantly higher in patients with severe SIH than in healthy controls (1.46 [1.18-2.2] vs. 1.11 [0.72-1.51]; P < 0.001), and in nonsurviving (n = 46) than in surviving (n = 54) patients (1.68 [1.23-4.02] vs. 1.37 [0.99-1.92]; P = 0.002). The area under the receiving operating characteristic curve of serum MDA levels to predict 30-day mortality was 0.68 (95% CI, 0.58-0.77; P < 0.001). Serum MDA levels were associated with 30-day mortality (OR, 6.279; 95% CI, 1.940-20.319; P = 0.002).

CONCLUSIONS

The most important new finding of our study is that there is an association between serum MDA levels at diagnosis of severe SIH and early mortality.

Neuroprotective Mechanisms of Melatonin in Hemorrhagic Stroke

Hemorrhagic stroke which consists of subarachnoid hemorrhage and intracerebral hemorrhage is a dominant cause of death and disability worldwide. Although great efforts have been made, the physiological mechanisms of these diseases are not fully understood and effective pharmacological interventions are still lacking. Melatonin (N-acetyl-5-methoxytryptamine), a neurohormone produced by the pineal gland, is a broad-spectrum antioxidant and potent free radical scavenger. More importantly, there is extensive evidence demonstrating that melatonin confers neuroprotective effects in experimental models of hemorrhagic stroke. Multiple molecular mechanisms such as antioxidant, anti-apoptosis, and anti-inflammation, contribute to melatonin-mediated neuroprotection against brain injury after hemorrhagic stroke. This review article aims to summarize current knowledge regarding the beneficial effects of melatonin in experimental models of hemorrhagic stroke and explores the underlying mechanisms. We propose that melatonin is a promising neuroprotective candidate that is worthy of further evaluation for its potential therapeutic applications in hemorrhagic stroke.

Melatonin Alleviates Intracerebral Hemorrhage-Induced Secondary Brain Injury in Rats via Suppressing Apoptosis, Inflammation, Oxidative Stress, DNA Damage, and Mitochondria Injury

Intracerebral hemorrhage (ICH) is a cerebrovascular disease with high mortality and morbidity, and the effective treatment is still lacking. We designed this study to investigate the therapeutic effects and mechanisms of melatonin on the secondary brain injury (SBI) after ICH. An in vivo ICH model was induced via autologous whole blood injection into the right basal ganglia in Sprague-Dawley (SD) rats. Primary rat cortical neurons were treated with oxygen hemoglobin (OxyHb) as an in vitro ICH model. The results of the in vivo study showed that melatonin alleviated severe brain edema and behavior disorders induced by ICH. Indicators of blood-brain barrier (BBB) integrity, DNA damage, inflammation, oxidative stress, apoptosis, and mitochondria damage showed a significant increase after ICH, while melatonin reduced their levels. Meanwhile, melatonin promoted further increasing of expression levels of antioxidant indicators induced by ICH. Microscopically, TUNEL and Nissl staining showed that melatonin reduced the numbers of ICH-induced apoptotic cells. Inflammation and DNA damage indicators exhibited an identical pattern compared to those above. Additionally, the in vitro study demonstrated that melatonin reduced the apoptotic neurons induced by OxyHb and protected the mitochondrial membrane potential. Collectively, our investigation showed that melatonin ameliorated ICH-induced SBI by impacting apoptosis, inflammation, oxidative stress, DNA damage, brain edema, and BBB damage and reducing mitochondrial membrane permeability transition pore opening, and melatonin may be a potential therapeutic agent of ICH.

Preclinical Studies and Translational Applications of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) which refers to bleeding in the brain is a very deleterious condition with high mortality and disability rate. Surgery or conservative therapy remains the treatment option. Various studies have divided the disease process of ICH into primary and secondary injury, for which knowledge into these processes has yielded many preclinical and clinical treatment options. The aim of this review is to highlight some of the new experimental drugs as well as other treatment options like stem cell therapy, rehabilitation, and nanomedicine and mention some translational clinical applications that have been done with these treatment options.

T lymphocytes infiltration promotes blood-brain barrier injury after experimental intracerebral hemorrhage

T lymphocytes migrate into the brain after intracerebral hemorrhage (ICH) and promote cerebral inflammation, thus exacerbating neuronal injury. However, the relationship between of T lymphocytes infiltration and blood-brain barrier (BBB) injury after ICH has not been clarified. In this study, we investigated the spatial-temporal distribution of infiltrating T lymphocytes after ICH in C57BL/6 mice by immunofluorescence and flow cytometry, and the accompanying change rules of BBB permeability were detected by Evans blue dye leakage and tight junction protein expression. Furthermore, T lymphocyte-deficient nude mice and T lymphocyte-decreased C57BL/6 mice treated with fingolimod were used to verify the relationship between T lymphocytes infiltration and BBB leakage after ICH. Here, we reported that brain-infiltrating T lymphocytes in the hemorrhagic hemisphere began to accumulate on the first day and peaked on the fifth day after ICH; BBB leakage also at peaked on the fifth day. Moreover, T lymphocyte-deficient nude mice showed minor BBB leakage after ICH compared with C57BL/6 control mice. Similarly, fingolimod treatment can significantly decrease T lymphocyte infiltration and promote BBB integrity compared with a vehicle control. Overall, our results suggested that suppression of T lymphocyte infiltration may be a novel way to improve BBB integrity after ICH.

Treatment of intracerebral hemorrhage in animal models: meta-analysis

OBJECTIVE

Interventions that improve functional outcome after acute intracerebral hemorrhage (ICH) in animals might benefit humans. Therefore, we systematically reviewed the literature to find studies of nonsurgical treatments tested in animal models of ICH.

METHODS

In July 2009 we searched Ovid Medline (from 1950), Embase (from 1980), and ISI Web of Knowledge (from 1969) for controlled animal studies of nonsurgical interventions given after the induction of ICH that reported neurobehavioral outcome. We assessed study quality and performed meta-analysis using a weighted mean difference random effects model.

RESULTS

Of 13,343 publications, 88 controlled studies described the effects of 64 different medical interventions (given a median of 2 hours after ICH induction) on 38 different neurobehavioral scales in 2,616 treated or control animals (median 14 rodents per study). Twenty-seven (31%) studies randomized treatment allocation, and 7 (8%) reported allocation concealment; these studies had significantly smaller effect sizes than those without these attributes (p < 0.001). Of 64 interventions stem cells, calcium channel blockers, anti-inflammatory drugs, iron chelators, and estrogens improved both structural outcomes and neurobehavioral scores in >1 study. Meta-regression revealed that together, structural outcome and the intervention used accounted for 65% of the observed heterogeneity in neurobehavioral score (p < 0.001, adjusted r(2) = 0.65).

INTERPRETATION

Further animal studies of the interventions that we found to improve both functional and structural outcomes in animals, using better experimental designs, could target efforts to translate effective treatments for ICH in animals into randomized controlled trials in humans.

Hydrogen inhalation is neuroprotective and improves functional outcomes in mice after intracerebral hemorrhage

OBJECTIVE

Oxidative stress contributes significantly to the development of secondary brain injury after intracerebral hemorrhage (ICH). It has been previously demonstrated that hydrogen gas can decrease oxidative stress by scavenging reactive oxygen species. We hypothesized that hydrogen therapy will reduce brain oxidative stress in mice after ICH and thereby will lead to reduced brain edema and improved neurological outcomes.

MATERIALS AND METHODS

CD1 male mice (weight 30-35 g) were divided into the following groups: sham, ICH+vehicle (room air), ICH+1-h hydrogen treatment, and ICH+2-h hydrogen treatment. ICH was induced by injection of bacterial collagenase into the right basal ganglia. The evaluation of outcomes was done at two time points: 24 and 72 h post-ICH. Brain water content was measured for assessment of brain edema (wet/dry weight method), and three neurological tests were performed pre- and postoperatively.

RESULTS

Collagenase injection was found to induce brain edema and impair functional performance of rats. The hydrogen inhalation reduced these effects acutely (24 h); however it exhibited only a tendency to improvement in the delayed study (72 h).

CONCLUSIONS

Our results suggest that hydrogen inhalation exerts an acute brain-protective effect in the mouse ICH model. However, the acute hydrogen therapy alone is not sufficient to improve delayed ICH outcomes in this model.

Effects of combination treatment of dexamethasone and melatonin on brain injury in intracerebral hemorrhage model in rats

The study was performed to investigate the effect of combination therapy with melatonin and dexamethasone (DEX) on brain injury in intracerebral hemorrhage (ICH) model in rats. Compared to the control group, combination therapy group with melatonin (10 mg/kg) and DEX (0.025 mg/kg) significantly reduced the degree of (1) brain edema, (2) the permeability of blood brain barrier (measured by Evans blue), (3) Oxidative stress (evaluated by malondialdehyde assay), (4) cytokines expression (tumor necrosis factor-alpha and interleukin-1beta), and (5) apoptosis (measured by Bax and Bcl-2 expression). In addition, we have also clearly demonstrated that the combination therapy significantly ameliorated neurologic scores. Taken together, our results clearly indicated for the first time that strategies targeting multiple proinflammatory pathways may be more effective than a single effector molecule for the treatment of ICH.