Oxiracetam can improve cognitive impairment after chronic cerebral hypoperfusion in rats

Effect of l-oxiracetam and oxiracetam on memory and cognitive impairment in mild-to-moderate traumatic brain injury patients: Study protocol for a randomized controlled trial

Objectives

Patients with traumatic brain injury (TBI) often suffer memory and cognitive impairments, and oxiracetam-like drugs are considered to have a positive impact on these symptoms potentially. However, the efficacy and safety of l-oxiracetam and oxiracetam in TBI patients have not been sufficiently investigated.

Methods

The study adopts a multicenter, randomized, double-blind, parallel-group, phase 3 clinical trial design in 74 centers across 51 hospitals in China. A total of 590 TBI patients meeting criteria will be randomly allocated into three groups in a 2:2:1 ratio: l-oxiracetam group, oxiracetam group, and placebo group. The treatment period is 14 days, with a follow-up period of 90 days. The primary outcome measure is the change in the Loewenstein Occupational Therapy Cognitive Assessment score at 90 days after treatment. Secondary outcomes include changes in other cognitive assessments, neurological function, activities of daily living, and safety assessments.

Discussion

There is no robust evidence to suggest that l-oxiracetam and oxiracetam can enhance memory and cognitive function in patients with mild to moderate TBI. This study has the potential to answer this crucial clinical question.

Trial registration

chinadrugtrials.org.cn, identifier CTR20192539; ClinicalTrials.gov, identifier NCT04205565.

Upregulation of RasGRF1 ameliorates spatial cognitive dysfunction in mice after chronic cerebral hypoperfusion

Chronic cerebral hypoperfusion (CCH)-mediated cognitive impairment is a serious problem worldwide. However, given its complexity, the underlying mechanisms by which CCH induces cognitive dysfunction remain unclear, resulting in a lack of effective treatments. In this study, we aimed to determine whether changes in the expression of RasGRF1, an important protein associated with cognition and synaptic plasticity, underlie the associated impairments in cognition after CCH. We found that RasGRF1 levels markedly decreased following CCH. Through prediction and validation studies, we observed that miRNA-323-3p was upregulated after CCH and could bind to the 3'-untranslated region of Rasgrf1 mRNA and regulate its expression in vitro. Moreover, the inhibition of miRNA-323-3p upregulated Rasgrf1 expression in the hippocampus after CCH, which was reversed by Rasgrf1 siRNA. This suggests that miRNA-323-3p is an important regulator of Rasgrf1. The Morris water maze and Y maze tests showed that miRNA-323-3p inhibition and Rasgrf1 upregulation improved spatial learning and memory, and electrophysiological measurements revealed deficits in long-term potentiation after CCH that were reversed by Rasgrf1 upregulation. Dendritic spine density and mature mushroom spine density were also improved after miRNA-323-3p inhibition and Rasgrf1 upregulation. Furthermore, Rasgrf1 upregulation by miRNA-323-3p inhibition improved dendritic spine density and mature mushroom spine density and ameliorated the deterioration of synapses and postsynaptic density. Overall, RasGRF1 regulation attenuated cognitive impairment, helped maintain structural and functional synaptic plasticity, and prevented synapse deterioration after CCH. These results suggest that Rasgrf1 downregulation by miRNA-323-3p plays an important role in cognitive impairment after CCH. Thus, RasGRF1 and miRNA-323-3p may represent potential therapeutic targets for cognitive impairment after CCH.

Protective Effects of 4-Trifluoromethyl-(E)-cinnamoyl]-L-4-F-phenylalanine Acid against Chronic Cerebral Hypoperfusion Injury through Promoting Brain-Derived Neurotrophic Factor-Mediated Neurogenesis

Vascular dementia (VaD), one of the major consequences after stroke, is the second reason for the cognitive decline in aged people. Chronic cerebral hypoperfusion (CCH) is considered as the main cause for cognitive impairment in VaD patients. In our previous study, a synthetic compound, 4-trifluoromethyl-(E)-cinnamoyl]-L-4-F-phenylalanine acid (AE-18), has been proven to decrease infarct volume and to recover the insufficient blood supply after ischemia-reperfusion in rats, which was reminded that AE-18 may possess the ameliorative effect in CCH. In this study, the bilateral common carotid artery occlusion was performed to establish the CCH model in rats to evaluate the effect and mechanisms of AE-18 in CCH. Results showed that AE-18 (5 and 10 mg/kg, i.g.) could recover the learning and memory and increase the number of neurons in the hippocampus, which may be attributed to its neurogenesis effects and its recovery of cerebral blood flow in CCH rats. In addition, the in vitro studies showed that AE-18 promoted neuronal proliferation, induced differentiation of Neuro-2a cells into a neuron-like morphology, and accelerated the establishment of axon-dendrite polarization of primary hippocampal neurons through upregulating brain-derived neurotrophic factor via the PI3K/Akt/CREB pathway. In conclusion, AE-18 is a promising candidate for the treatment of cognitive decline after CCH injury by restoring blood supply to the brain and promoting neurogenesis in the hippocampus.

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.

Nanodelivery of oxiracetam enhances memory, functional recovery and induces neuroprotection following concussive head injury

Military personnel are the most susceptible to concussive head injury (CHI) caused by explosion, blast or missile or blunt head trauma. Mild to moderate CHI could induce lifetime functional and cognitive disturbances causing significant decrease in quality of life. Severe CHI leads to instant death and lifetime paralysis. Thus, further exploration of novel therapeutic agents or new features of known pharmacological agents are needed to enhance quality of life of CHI victims. Previous reports from our laboratory showed that mild CHI induced by weight drop technique causing an impact of 0.224N results in profound progressive functional deficit, memory impairment and brain pathology from 5h after trauma that continued over several weeks of injury. In this investigation we report that TiO2 nanowired delivery of oxiracetam (50mg/kg, i.p.) daily for 5 days after CHI resulted in significant improvement of functional deficit on the 8th day. This was observed using Rota Rod treadmill, memory improvement assessed by the time spent in finding hidden platform under water. The motor function improvement is seen in oxiracetam treated CHI group by placing forepaw on an inclined mesh walking and foot print analysis for stride length and distance between hind feet. TiO2-nanowired oxiracetam also induced marked improvements in the cerebral blood flow, reduction in the BBB breakdown and edema formation as well as neuroprotection of neuronal, glial and myelin damages caused by CHI at light and electron microscopy on the 7th day after 5 days TiO2 oxiracetam treatment. Adverse biochemical events such as upregulation of CSF nitrite and nitrate, IL-6, TNF-a and p-Tau are also reduced significantly in oxiracetam treated CHI group. On the other hand post treatment of 100mg/kg dose of normal oxiracetam in identical conditions after CHI is needed to show slight but significant neuroprotection together with mild recovery of memory function and functional deficits on the 8th day. These observations are the first to point out that nanowired delivery of oxiracetam has superior neuroprotective ability in CHI. These results indicate a promising clinical future of TiO2 oxiracetam in treating CHI patients for better quality of life and neurorehabilitation, not reported earlier.

Oxiracetam Mediates Neuroprotection Through the Regulation of Microglia Under Hypoxia-Ischemia Neonatal Brain Injury in Mice

In neonatal hypoxic-ischemic brain damage (HIBD), in addition to damage caused by hypoxia and ischemia, over-activation of inflammation leads to further deterioration of the condition, thus greatly shortening the optimal treatment time window. Ischemic penumbra, the edematous area encompassing the infarct core, is characterized by typical activation of microglia and overt inflammation, and prone to incorporate into the infarct core gradually after ischemia onset. If treated in time, the cells located in the penumbra can survive, thereby impeding the expansion of the infarction. We demonstrated for the first time that in the acute phase of HIBD in neonatal mice, treatment of Oxiracetam (ORC) significantly curtailed the size of ischemic penumbra together with drastic reduction of infarction. By staining various cellular markers, we found that the penumbra was defined and concentrated with activated microglia. We also analyzed transmission electron microscopy and Luminex assay results to elucidate the mechanisms involved. We further confirmed that ORC switched polarization of microglia from the inflammatory towards the alternatively activated phenotype, thus promoting microglia from being neurotoxic into neuroprotective. Meanwhile, ORC decreased proliferation of microglia; however, their functions of phagocytosis and autophagy were otherwise enhanced. Last, we clarified that ORC promoted autophagy through the AMPK/mTOR pathway, which further induced the transition of the inflammatory to the alternatively activated phenotype in microglia. The pro-inflammatory factors secretion was inhibited as well, thereby reducing the progression of the infarction. Taken together, it is concluded that Oxiracetam reduced the expansion of ischemic infarction in part via regulating the interplay between microglia activation and autophagy, which would delay the progression of HIBD and effectively prolong the time window for the clinical treatment of HIBD.

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.

Electroacupuncture Improved Chronic Cerebral Hypoperfusion-Induced Anxiety-Like Behavior and Memory Impairments in Spontaneously Hypertensive Rats by Downregulating the ACE/Ang II/AT1R Axis and Upregulating the ACE2/Ang-(1-7)/MasR Axis

Electroacupuncture (EA) can effectively alleviate anxiety disorders and memory impairments caused by various neurodegenerative diseases; however, the molecular mechanisms underlying its neuroprotective effects are unclear. Previous studies have shown that the renin-angiotensin system (RAS) comprises of two axes with mutual antagonism: the classical angiotensin converting enzyme/angiotensin II/angiotensin II type 1 receptor (ACE/Ang II/AT1R) axis and the protective angiotensin converting enzyme 2/angiotensin-(1-7)/Mas receptor (ACE2/Ang-(1-7)/MasR) axis. In this study, we observed that chronic cerebral hypoperfusion (CCH) mediated anxiety-like behavior and memory impairments in spontaneously hypertensive rats (SHR) via upregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and the partial hippocampal protective axis (ACE2/Ang-(1-7)). However, Ang II levels were much higher than those of Ang-(1–7), indicating that the ACE/Ang II/AT1R axis plays a dominant role in the comorbidity of CCH and hypertension. Moreover, candesartan cilexetil (Canc) and perindopril (Peril) were used as positive control drugs. We found that EA, Canc, and Peril attenuated CCH-induced anxiety-like behavior and memory impairments in SHR, potentially via downregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and upregulation of the whole hippocampal protective axis (ACE2/Ang-(1-7)/MasR). These results suggest that EA therapy for CCH with hypertension may be mediated by two hippocampal RAS axes.

Oxiracetam and Zinc Ameliorates Autism-Like Symptoms in Propionic Acid Model of Rats

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by restrictive behaviour, deficit in social skills and interaction. The multifactorial etiology, complex pathophysiology and different combination of symptoms (unusual speech patterns, frequent repetition of phrases) make it difficult to treat. Thus, present study aimed to find the protective effects of oxiracetam alone and in combination with zinc on brain behavioral, biochemical, pro-inflammatory cytokines and neurotransmitters level. Rats were administered with propionic acid (250 mg/kg p.o.) for 3 days and immediately on next day treatment were given with oxiracetam (25, 50 mg/kg i.p), zinc (4 mg/kg) as well as oxiracetam (25 mg/kg i.p) in combination with zinc (4 mg/kg p.o). Behavioral parameters were performed from 22th to 28th day. On 29th day, all the animals were sacrificed by cervical dislocation and the brain was preserved for biochemical (LPO, GSH, nitrite, mitochondrial complex I, IV and cAMP), neuroinflammatory (TNF-α, IL-1β, IL-6) and neurotransmitters (5-HT, GABA, glutamate and acetylcholine) analysis. The propionic acid administration showed memory impairment, restrictive behavior, increased proinflammatory cytokines level, biochemical and neurotransmitters alteration. However, treatment with oxiracetam alone and in combination with zinc significantly attenuated behavioral, biochemical, inflammatory cytokines and restored neurotransmitters level. The finding of present study demonstrated that oxiracetam alone and in combination with zinc afforded superior anti-autistic effect through antioxidant, anti-inflammatory and anti-excitotoxic mechanisms and could serve as attractive strategy in managing autism.

Glucagon-Like Peptide-2 Receptor is Involved in Spatial Cognitive Dysfunction in Rats After Chronic Cerebral Hypoperfusion

Chronic cerebral hypoperfusion (CCH) affects the aging population and especially patients with neurodegenerative diseases, such as Alzheimer's disease or Parkinson's disease. CCH is closely related to the cognitive dysfunction in these diseases. Glucagon-like peptide-2 receptor (GLP2R) mRNA and protein are highly expressed in the gut and in hippocampal neurons. This receptor is involved in the regulation of food intake and the control of energy balance and glucose homeostasis. The present study employed behavioral techniques, electrophysiology, western blotting, immunohistochemistry, quantitative real time polymerase chain reaction (qRT-PCR), and Golgi staining to investigate whether the expression of GLP2R changes after CCH and whether GLP2R is involved in cognitive impairment caused by CCH. Our findings show that CCH significantly decreased hippocampal GLP2R mRNA and protein levels. GLP2R upregulation could prevent CCH-induced cognitive impairment. It also improved the CCH-induced impairment of long-term potentiation and long-term depression. Additionally, GLP2R modulated after CCH the AKT-mTOR-p70S6K pathway in the hippocampus. Moreover, an upregulation of the GLP2R increased the neurogenesis in the dentate gyrus, neuronal activity, and density of dendritic spines and mushroom spines in hippocampal neurons. Our findings reveal the involvement of GLP2R via a modulation of the AKT-mTOR-p70S6K pathway in the mechanisms underlying CCH-induced impairments of spatial learning and memory. We suggest that the GLP2R and the AKT-mTOR-p70S6K pathway in the hippocampus are promising targets to treat cognition deficits in CCH.

Oxiracetam ameliorates cognitive deficits in vascular dementia rats by regulating the expression of neuronal apoptosis/autophagy-related genes associated with the activation of the Akt/mTOR signaling pathway

Oxiracetam (ORC) is a commonly used nootropic drug for improving cognition and memory impairments. The therapeutic effect and underlying mechanism of ORC in vascular dementia (VaD) treatment remain unknown. In this study, 3-month-old male Sprague-Dawley rats with permanent bilateral common carotid artery occlusion-induced VaD were treated orally with low (100 mg/kg) or high (200 mg/kg) dose ORC once a day for 4 weeks. The results of the Morris water maze test and Nissl staining showed that ORC treatment significantly alleviated learning and memory deficits and neuronal damage in rats with VaD. Mechanistically, the protein levels of a panel of genes associated with neuronal apoptosis (Bcl-2, Bax) and autophagy (microtubule-associated protein 1 chain 3, Beclin1, p62) were significantly altered by ORC treatment compared with VaD, suggesting a protective role of ORC against VaD-induced neuronal apoptosis and autophagy. Moreover, the Akt/mTOR pathway, which is known to be the upstream signaling governing apoptosis and autophagy, was found to be activated in ORC-treated rats, suggesting an involvement of Akt/mTOR activation in ORC-rendered protection in VaD rats. Taken together, this study demonstrated that ORC may alleviate learning and memory impairments and neuronal damage in VaD rats by altering the expression of apoptosis/autophagy-related genes and activation of the Akt/mTOR signaling pathway in neurons.

Tripchlorolide May Improve Spatial Cognition Dysfunction and Synaptic Plasticity after Chronic Cerebral Hypoperfusion

Chronic cerebral hypoperfusion (CCH) is a common pathophysiological mechanism that underlies cognitive decline and degenerative processes in dementia and other neurodegenerative diseases. Low cerebral blood flow (CBF) during CCH leads to disturbances in the homeostasis of hemodynamics and energy metabolism, which in turn results in oxidative stress, astroglia overactivation, and synaptic protein downregulation. These events contribute to synaptic plasticity and cognitive dysfunction after CCH. Tripchlorolide (TRC) is an herbal compound with potent neuroprotective effects. The potential of TRC to improve CCH-induced cognitive impairment has not yet been determined. In the current study, we employed behavioral techniques, electrophysiology, Western blotting, immunofluorescence, and Golgi staining to investigate the effect of TRC on spatial learning and memory impairment and on synaptic plasticity changes in rats after CCH. Our findings showed that TRC could rescue CCH-induced spatial learning and memory dysfunction and improve long-term potentiation (LTP) disorders. We also found that TRC could prevent CCH-induced reductions in N-methyl-D-aspartic acid receptor 2B, synapsin I, and postsynaptic density protein 95 levels. Moreover, TRC upregulated cAMP-response element binding protein, which is an important transcription factor for synaptic proteins. TRC also prevented the reduction in dendritic spine density that is caused by CCH. However, sham rats treated with TRC did not show any improvement in cognition. Because CCH causes disturbances in brain energy homeostasis, TRC therapy may resolve this instability by correcting a variety of cognitive-related signaling pathways. However, for the normal brain, TRC treatment led to neither disturbance nor improvement in neural plasticity. Additionally, this treatment neither impaired nor further improved cognition. In conclusion, we found that TRC can improve spatial learning and memory, enhance synaptic plasticity, upregulate the expression of some synaptic proteins, and increase the density of dendritic spines. Our findings suggest that TRC may be beneficial in the treatment of cognitive impairment induced by CCH.

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.