Oxiracetam or fastigial nucleus stimulation reduces cognitive injury at high altitude

The primary studies of epigallocatechin-3-gallate in improving brain injury induced by chronic high-altitude natural environment in rats by 7.0T high-field MR imaging

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is one of the most abundant and important bioactive polyphenolic compounds in green tea. However, despite its potent antioxidant effects, its neuroprotective effects on chronic high altitude (HA)-induced nerve damage have not been reported. The purpose of this study is to use quantitative susceptibility mapping (QSM) with pathology to dynamically evaluate the status of brain damage and the effect of EGCG.

METHODS

A model of HA environments-induced brain injury was established of Sprague-Dawley (SD) rats in a natural plateau environment for 4 weeks, 8 weeks, 12 weeks and 20 weeks. Behavioral alterations were then observed and assessed with the open field test (OFT) and Morris water maze (MWM) test. The microglial activation, nissl staining and neural degeneration by Fluoro Jade B in the hippocampus of the rats were observed by immunohistochemistry. In the rats, serum erythropoietin (EPO), hippocampal inflammatory cytokines (interleukin-1β [IL-1β], interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]), ferritin, oxidative stress (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], catalase [CAT] and malondialdehyde [MDA]) were detected using ELISA kits and biochemical methods. Iron accumulation was observed by QSM and colorimetry. Iron metabolisms (ceruloplasmin [Cp], transferrin [Tf], divalent metal transport1 [DMT1] and hepcidin [Hep]) were detected using qPCR. Neural ultrastructural changes were evaluated with electron microscope. Salidroside treatment was chosen as the positive control group in ELISA, biochemical detection and electron microscopy.

RESULTS

The susceptibility values in the left and right hippocampus, the hippocampal ferritin, serum and hippocampal iron content increased significantly after HA exposure. The expression of hippocampal Cp and Hep decreased and the expression of Tf increased. Nissl staining revealed that the neurons of hippocampal CA1 region of h-20w group were small and irregular, atrophied, and nuclear shrinkage. Tissue oxidative stress and inflammatory indicators (MDA, TNF-α, IL-1β, IL-6) increased while antioxidant enzymes (SOD, CAT, GSH-Px) decreased. EGCG attenuated HA environments-induced cognitive impairment, iron accumulation, microglial activation and neural degeneration. The effects of EGCG in reducing EPO and the metal chelating property with respect to iron were dose-dependent, with effects of EGCG (50 mg/kg) being similar to those of salidroside (50 mg/kg).

CONCLUSIONS

EGCG can act as a neuroprotective agent against chronic HA environments-mediated neural injuries. QSM provides a potential complementary imaging technique to detect the effect of treating HA diseases.

Salidroside improves blood-brain barrier integrity and cognitive function in hypobaric hypoxia mice by inhibiting microglia activation through GSK3β

Salidroside, an active component found in Rhodiola rosea L., has emerged as a potential therapeutic agent for the prevention and treatment of hypoxic brain injury, while the precise target and mechanism of salidroside were remain unclear. The study utilized techniques such as network pharmacology, transcriptome sequencing to investigate the mechanism and target of salidroside in regulating blood-brain barrier (BBB) function to protect hypoxic brain injury in vivo. Utilized macromolecular docking and molecular biology techniques to explore the molecular mechanism of salidroside in alleviating brain injury induced by hypoxia in BV2 cell model. The results show that salidroside alleviated the learning and memory dysfunction and pathological injury in mice exposed to hypobaric hypoxia, reduced brain water content and attenuate the inflammatory response and oxidative stress, effectively reversed S100β in serum and promoted the repair of BBB. GSK3β is an important therapeutic target of salidroside in the treatment of hypoxic cognitive impairment, and salidroside can specifically bind GSK3β in the ATP binding pocket, inducing the phosphorylation of GSK3β, targeting downstream Nrf-2 to regulate microglia activity, promoting the accumulation of β-catenin, thereby inhibiting microglial activation, improving the BBB integrity injury and achieving a neuroprotective effect. This study demonstrates that salidroside can inhibit the activation of microglia by inducing GSK3β phosphorylation, achieve neuroprotective effects and alleviate learning and memory dysfunction in hypobaric hypoxia mice. This study provides a theoretical basis for the development of salidroside and the clinical application of Rhodiola rosea L.

Elevating understanding: Linking high-altitude hypoxia to brain aging through EEG functional connectivity and spectral analyses

High-altitude hypoxia triggers brain function changes reminiscent of those in healthy aging and Alzheimer's disease, compromising cognition and executive functions. Our study sought to validate high-altitude hypoxia as a model for assessing brain activity disruptions akin to aging. We collected EEG data from 16 healthy volunteers during acute high-altitude hypoxia (at 4,000 masl) and at sea level, focusing on relative changes in power and aperiodic slope of the EEG spectrum due to hypoxia. Additionally, we examined functional connectivity using wPLI, and functional segregation and integration using graph theory tools. High altitude led to slower brain oscillations, that is, increased δ and reduced α power, and flattened the 1/f aperiodic slope, indicating higher electrophysiological noise, akin to healthy aging. Notably, functional integration strengthened in the θ band, exhibiting unique topographical patterns at the subnetwork level, including increased frontocentral and reduced occipitoparietal integration. Moreover, we discovered significant correlations between subjects' age, 1/f slope, θ band integration, and observed robust effects of hypoxia after adjusting for age. Our findings shed light on how reduced oxygen levels at high altitudes influence brain activity patterns resembling those in neurodegenerative disorders and aging, making high-altitude hypoxia a promising model for comprehending the brain in health and disease.

Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure

Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.

The effect of tetrahydrocannabinol:cannabidiol oromucosal spray on cognition: a systematic review

PURPOSE

Previous studies have shown that tetrahydrocannabinol (THC), the main psychoactive component of cannabis, can impair cognitive abilities. There is also some evidence that cannabidiol (CBD), the most abundant non-intoxicating constituent of cannabis, can attenuate these effects. The purpose of this study was to investigate the effects of THC:CBD oromucosal spray (with equal parts THC and CBD) on cognition compared with control conditions in human studies.

METHODS

A systematic literature search was performed on four major bibliographic databases. Studies were included in the present review if they evaluated the cognitive effects of THC:CBD oromucosal spray compared with a control condition.

RESULTS

Ten studies were identified (7 on patients with multiple sclerosis, 1 on those with Huntington, and 2 on healthy volunteers) with 510 participants in total. There was considerable heterogeneity among the studies in terms of dose and duration of administration. All studies have used an equal or nearly equal dose of THC and CBD.

CONCLUSIONS

Although the results across studies were somewhat inconsistent, most evidence revealed that there is no significant difference between THC:CBD oromucosal spray and control treatments in terms of cognitive outcomes. However, more trials are needed with longer follow-up periods, and dose considerations, particularly comparing lower and higher doses of the spray.

Dance activity interventions targeting cognitive functioning in older adults with mild cognitive impairment: A meta-analysis

Objectives

To comprehensively determine the effect of dance activities on the cognitive functions and its sub-domains of older adults with mild cognitive impairment (MCI).

Methods

We obtained data from PubMed, Web of Science, EBSCO, China national knowledge infrastructure, Wanfang data, and VIP databases from 2017/01/01 to 2022/03/01. We included trials of older adults with MCI that underwent dance activity intervention and fulfilled the inclusion criteria. Two researchers independently assessed the quality of the study using the Cochrane risk of the bias assessment tool. Meta-analysis was performed when data were available, with further subgroup analysis, using Review Manager 5.4, and sensitivity analysis was performed using Stata software 15.1.

Results

Search terms yielded 183 articles, of which 12 fulfilled the inclusion criteria. This included 7 high-quality studies and 5 medium-quality studies. A total of 820 older adults were analyzed. Results showed that dance activity had beneficial effects for global cognition [SMDMMSE = 0.65, 95% CIMMSE (0.20, 1.09), p MMSE = 0.004; SMDMoCA = 0.87, 95% CIMoCA (0.44, 1.29), p MoCA < 0.0001], memory [SMD = 0.61, 95% CI (0.35, 0.88), p < 0.00001], visuospatial function [SMD = -0.39, 95% CI (-0.60, -0.19), p = 0.0002], cognitive flexibility [SMD = -0.31, 95% CI (-0.52, -0.11), p = 0.003], attention [SMD = 0.34, 95% CI (0.07, 0.61), p = 0.01], and balance [SMD = 1.25, 95% CI (0.06, 2.44), p = 0.04]. Further subgroup analysis showed that open-skill dance activity (OSDA) was more effective in promoting global cognition in older adults with MCI than closed-skill dance activity (CSDA) because of the different stimulation provided by the two types of dance activities in the brain regions of the older adults (p = 0.0002). It could be speculated that dance activity improved cognitive function mainly by affecting the microstructure and function of the cingulate tract, hippocampus, cardiovascular function, and other brain areas of older adults with MCI.

Conclusion

Dance activities can significantly improve global cognition, memory, visuospatial function, cognitive flexibility, attention, and balance in older adults with MCI. However, more trials with rigorous study designs are necessary to provide more concrete evidence in the future.

Increased cerebral cortex activation in stroke patients during electrical stimulation of cerebellar fastigial nucleus with functional near-infrared spectroscopy

Background

Electrical stimulation of the cerebellar fastigial nucleus (FNS) has been shown to protect animals against cerebral ischemic injury. However, the changes in cortical activation as a response to FNS have not been illustrated in humans.

Objective

This study aims to detect functional connectivity changes in the brain of stroke patients, and investigate the cortical activation caused by FNS through measuring the oxygenated hemoglobin concentration (HBO) in the cerebral cortex of stroke patients and healthy controls (HCs).

Methods

This study recruited 20 patients with stroke and 20 HCs with all the following factors matched: age, gender and BMI. The experiment session was made up of the pre-task baseline, FNS task period, and post-task baseline. FNS task period contains 5 blocks, each block encompassing the resting state (30 s) and the FNS state (30 s). HBO signals were acquired by functional near-infrared spectroscopy (fNIRS) from the Prefrontal Cortex (PFC), the Motor Cortex (MC) and the Occipital Cortex (OC) throughout the experiment. The Pearson correlation coefficient was used to calculate the resting-state functional connectivity strength between the two groups, and the general linear model (GLM) was used to calculate the activation of 39 fNIRS channels during FNS in stroke patients and HCs, respectively.

Results

The coupling strength of stroke patients were significantly decreased in the following regions: right MC and left MC (t = 4.65, p = 0.0007), right MC and left OC (t = 2.93, p = 0.04), left MC and left OC (t = 2.81, p = 0.04). In stroke patients, the changes in cerebral oxygenated hemoglobin (ΔHBO) among 12 channels (CH) in the bilateral PFC and bilateral MC regions were significantly increased during the FNS state (FDR corrected p < 0.05) compared with the resting state. In HCs, only 1 channel was increased (FDR corrected p < 0.05) in the left PFC during FNS.

Conclusion

By using the FNS and fNIRS techniques, the characteristics of functional connectivity were found to decrease in stroke patients. It was also noticed that FNS activates the PFC and MC regions. These findings may help to guide functional rehabilitation in stroke patients.

Epigallocatechin-3-Gallate Ameliorated Iron Accumulation and Apoptosis and Promoted Neuronal Regeneration and Memory/Cognitive Functions in the Hippocampus Induced by Exposure to a Chronic High-Altitude Hypoxia Environment

We aimed to explore the protective effects and potential treatment mechanism of Epigallocatechin-3-gallate (EGCG) in an animal model of chronic exposure in a natural high-altitude hypoxia (HAH) environment. Behavioral alterations were assessed with the Morris water maze test. Iron accumulation in the hippocampus was detected by using DAB enhanced Perls’ staining, MRI, qPCR and colorimetry, respectively. Oxidative stress (malondialdehyde, MDA), apoptosis (Caspase-3), and neural regeneration (brain-derived neurotrophic factor, BDNF) were detected by using ELISA and western blotting. Neural ultrastructural changes were evaluated by transmission electron microscopy (TEM). The results showed that learning and memory performance of rats decreased when exposure to HAH environment. It was followed by iron accumulation, dysfunctional iron metabolism, reduced BDNF and the upregulation of MDA and Caspase-3. TEM confirmed the ultrastructural changes in neurons and mitochondria. EGCG reduced HAH-induced cognitive impairment, iron deposition, oxidative stress, and apoptosis and promoted neuronal regeneration against chronic HAH-mediated neural injury.

Pharmacokinetic Properties of S-oxiracetam After Single and Multiple Intravenous Infusions in Healthy Volunteers

BACKGROUND AND OBJECTIVES

As a chiral drug, oxiracetam (ORT) can exist in two different isomeric forms: S-oxiracetam (S-ORT) and R-oxiracetam (R-ORT). S-ORT has emerged as a promising nootropic drug with the potential to treat brain injury and the resulting loss of neural function, memory and mental impairment as assessed by studies in various animal models. However, limited data are available on the pharmacokinetics of S-ORT in humans, so the present study was designed to evaluate the safety and pharmacokinetic profile of S-ORT in healthy volunteers.

METHODS

In part 1, subjects were intravenously administered single ascending dose (2.0, 4.0 and 8.0 g) S-ORT. In part 2, subjects were treated at a single intravenous infusion dose of 3.0 g S-ORT or 6.0 g racemic ORT using a two-sequence, two-period crossover design. In part 3, subjects were intravenously injected with 4.0 g S-ORT once a day for 7 days. Blood and urine samples were collected to evaluate the pharmacokinetic parameters and urine excretion rate. The safety profile of the drug was also evaluated throughout the study.

RESULTS

Fifty-two subjects (30 in part 1, 12 in part 2, 10 in part 3) completed the study; only one subject displayed a mild adverse event, which possibly was treatment related, and no serious adverse event occurred. In part 1 for a single dose of 2.0, 4.0 and 8.0 g, the maximum concentration (C_max) values were 111.28 ± 18.99, 230.76 ± 29.16 and 352.67 ± 42.94 μg/ml, respectively; the values of area under the plasma concentration-time curve (AUC) from time zero to the time of last quantifiable concentration (AUC_0-t) were 267.09 ± 59.66, 524.50  ± 72.87 and 822.68 ± 95.21 μg·h/ml, respectively; the AUC from 0 h to infinity (AUC_0-∞) values were 274.72 ± 61.65, 536.06 ± 78.13 and 832.07 ± 96.91 μg·h/ml, respectively. The urine excretion rate of the unchanged drug was approximately 60%. After consecutive administration of S-ORT for 7 days, the accumulation index was 1.05 ± 0.08. The plasma drug concentration-time curves for both S-ORT and R-oxiracetam (R-ORT) were almost identical.

CONCLUSIONS

S-ORT was well tolerated, and no serious adverse events occurred in 2.0, 4.0 and 8.0 g in single- and 4.0 g in multiple-dose studies. S-ORT showed dose linearity with increasing doses and no drug accumulation after 7 days of continuous administration was observed.

Effects of oxiracetam combined with ginkgo biloba extract in the treatment of acute intracerebral hemorrhage: A clinical study

PURPOSE

The present clinical study was conducted to investigate the effect of oxiracetam combined with ginkgo biloba extract in treating patients with acute intracerebral hemorrhage.

METHODS

Ninety-eight patients with acute cerebral hemorrhage admitted to our hospital were divided into three groups. The differences of brain edema and cerebral hemorrhage were compared between the three groups after 1 and 2 weeks of treatment, and the recovery of neurological function, serum inflammatory factors, AQP-4, MMP-9, cognitive function, activities of daily living, and adverse reactions were compared between the three groups after 2 weeks of treatment.

RESULTS

There was no significant difference among the three groups before treatment (p > .05). After treatment, the recovery of neurological function, serum inflammatory factors, AQP-4, MMP-9 levels, cognitive function, and activities of daily living were improved. Among them, the neurological function recovery, serum inflammatory factors, AQP-4, MMP-9 levels, cognitive function, and activities of daily living in the combined treatment group and the control group elicited greater results than those in the routine group. The results of the combined treatment group showed the most significant difference (p < .05). The concentration of IL-6 decreased from 135.98 ± 12.54 to 91.83 ± 7.69 pg/ml, AQP-4 from 227.55 μg/L ± 21.06 to 114.31 ± 9.22 μg/L, and MMP-9 from 172.39 ± 9.81 to 94.98 ± 5.01 ng/ml. In addition, the neurological function recovery, the levels of serum inflammatory factors, cognitive function, and activities of daily living in the combined treatment group were better than those in the control group (p < .05). The mean score of MRS in the combined treatment group decreased from 3.36 ± 0.98 at admission to 1.91 ± 0.38.

CONCLUSION

Oxiracetam combined with Ginkgo biloba extract in the treatment of acute cerebral hemorrhage has a significant improvement effect.

An Established Early Rehabilitation Therapy Demonstrating Higher Efficacy and Safety for Care of Intensive Care Unit Patients

BACKGROUND Although survival rates of critically ill patients in Intensive Care Units (ICUs) have improved in recent years, many risk factors cause a few serious complications. This study aimed to evaluate efficacy and safety of comprehensive early rehabilitation therapy for ICU patients. MATERIAL AND METHODS This study recruited ICU patients who were diagnosed as having cerebral hemorrhage or traumatic brain injury. ICU patients were randomly divided into an early rehabilitation therapy group (Observation group, n=21) and a Control group (n=21). Patients in the Control group underwent persistent monitoring of respiratory functions and blood oxygen saturation, as well as electrocardiographic monitoring. ICU patients in the Observation group underwent individualized treatments based on conventional treatments. APACHE II scores, MRC scores, and consciousness improvement rates of ICU patients were evaluated. Incidences of adverse events and complications were also assessed. RESULTS Early rehabilitation therapy significantly decreased APACHE II scores and significantly increased MRC scores compared to the Control group (p<0.05). Early rehabilitation therapy significantly improved consciousness of ICU patients compared to the Control group (p<0.05). Early rehabilitation therapy significantly reduced the incidence of complications compared to the Control group (p<0.05). Early rehabilitation therapy significantly shortened ICU or total hospital stay and mechanical ventilation time compared to the Control group (p<0.05). CONCLUSIONS Early rehabilitation therapy decreased APACHE II scores, enhanced MRC scores, and improved consciousness of ICU patients. Moreover, early rehabilitation therapy also reduced the incidence of complications and shortened ICU or total hospital stay and mechanical ventilation time of ICU patients. Therefore, early rehabilitation therapy was shown to be effective and safe for ICU patients.

Rhodiola crenulata attenuates apoptosis and mitochondrial energy metabolism disorder in rats with hypobaric hypoxia-induced brain injury by regulating the HIF-1α/microRNA 210/ISCU1/2(COX10) signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rhodiola crenulata, a traditional Tibetan medicine, has shown promise in the treatment of hypobaric hypoxia (HH)-induced brain injury. However, the underlying mechanisms remain unclear. This study investigated the protective effects of R. crenulata aqueous extract (RCAE) on HH-induced brain injury in rats.

MATERIALS AND METHODS

An animal model of high-altitude hypoxic brain injury was established in SD rats using an animal decompression chamber for 24 h. Serum and hippocampus levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), oxidized glutathione (GSSG), and lactate dehydrogenase (LDH) were then determined using commercial biochemical kits. Neuron morphology and vitality were also evaluated using H&E and Nissl staining, and TUNEL staining was used to examine apoptosis. Gene and protein expression of HIF-1α, microRNA 210, ISCU1/2, COX10, Apaf-1, cleaved Caspase-3, Caspase-3, Bax, Bcl-2, and Cyto-c were determined by western blot, immunohistochemical and qRT-PCR analysis.

RESULTS

RCAE administration attenuated HH-induced brain injury as evidenced by decreased levels of MDA, LDH, and GSSG, increased GSH and SOD, improvements in hippocampus histopathological changes, increased cell vitality and ATP level, and reduced apoptotic cell numbers. RCAE treatment also enhanced HIF-1α, ISCU1/2, COX10, and Bcl-2 protein expression, while dramatically inhibiting expression of Apaf-1, Bax, Cyto-c, and cleaved Caspase-3. Treatment also increased gene levels of HIF-1α, microRNA 210, ISCU1/2, and COX10, and decreased Caspase-3 gene production.

CONCLUSIONS

RCAE attenuated HH-induced brain injury by regulating apoptosis and mitochondrial energy metabolism via the HIF-1α/microRNA 210/ISCU1/2 (COX10) signaling pathway.

Oxiracetam or fastigial nucleus stimulation reduces cognitive injury at high altitude

BACKGROUND

Cognitive impairment is common in people travelling to high altitude. Oxiracetam and electrical stimulation of cerebellar fastigial nucleus may have beneficial impacts. This study was to investigate the effects of preconditioning with Oxiracetam or fastigial nucleus stimulation (FNS) on cognitive decline following the ascension to high altitude.

METHODS

The study was conducted on 60 male military voluntary members who were divided into control group, Oxiracetam group, and fastigial nucleus stimulation group. Transcranial doppler sonography, auditory evoked potential, electroencephalogram (EEG), and cognitive assessments were performed.

RESULTS

People could still suffer cognitive dysfunction at 4,000 m high altitude despite that they have lived at 1,800 m altitude for several years. The 4,000 m altitude environment also prolonged P300 and N200 latencies. Both Oxiracetam and FNS improved cognitive function, reduced the prolonged latencies of Event Related Potentials (P300 and N200), decreased the average velocity of brain arteries, and enhanced EEG power spectral entropy at 4,000 m altitude.

CONCLUSIONS

Neurophysiological evidences suggest the underlying mechanism of cognitive impairments. Both Oxiracetam and FNS can reduce cognitive decline post arrival at high altitude. They could be a potential pretreatment method for cognitive dysfunction resulted from high altitude.