Diazepam reduces brain lesion size in a photothrombotic model of focal ischemia in rats

Ameliorative effect of diazepam against ethanol-induced mitochondrial disruption in brains of the mice

Brain oxidative damage and neurodegeneration by ethanol (ETH) are considered as important factors that triggered by oxidative stress. Recently, the abuse of diazepam (DZM) has increased by alcoholism-addicted patients. The present study evaluated the effects of combination treatment of ETH with DZM on oxidative damage induced in brain mitochondria of the mice. Only ETH (0.3, 0.6, and 2.5 g / kg) and ETH+ DZM (2.5 mg / kg) were administered intraperitoneally (ip) to the mice. Pathological changes and oxidative stress biomarkers including ROS, lipid peroxidation, carbonyl protein, mitochondrial function, and glutathione content were evaluated in brain mitochondria after 42 days. Results indicated that co-treatment of DZM and ETH significantly reduced mitochondrial toxicity, oxidative damage, pathological changes and increased level of glutathione. Subchronic ETH administration induced brain oxidative damage, mitochondrial disruption, and serious damage to the brain cells. Whereas, combination treatment improved oxidative damage, mitochondrial function, and pathological changes in brain cells after intoxication by ETH. These findings suggest antioxidant effect of DZM in combination with ETH and can be considered in reducing oxidative stress and mitochondrial damage attenuation in the brain. Combination therapy may be a better therapeutic candidate for prevention of brain oxidative damage induced by ETH.

Network-based drug repurposing for potential stroke therapy

Stroke is the leading cause of death and disability worldwide, with a growing number of incidences in developing countries. However, there are currently few medical therapies for this disease. Emerged as an effective drug discovery strategy, drug repurposing which owns lower cost and shorter time, is able to identify new indications from existing drugs. In this study, we aimed at identifying potential drug candidates for stroke via computationally repurposing approved drugs from Drugbank database. We first developed a drug-target network of approved drugs, employed network-based approach to repurpose these drugs, and altogether identified 185 drug candidates for stroke. To validate the prediction accuracy of our network-based approach, we next systematically searched for previous literature, and found 68 out of 185 drug candidates (36.8 %) exerted therapeutic effects on stroke. We further selected several potential drug candidates with confirmed neuroprotective effects for testing their anti-stroke activity. Six drugs, including cinnarizine, orphenadrine, phenelzine, ketotifen, diclofenac and omeprazole, have exhibited good activity on oxygen-glucose deprivation/reoxygenation (OGD/R) induced BV2 cells. Finally, we showcased the anti-stroke mechanism of actions of cinnarizine and phenelzine via western blot and Olink inflammation panel. Experimental results revealed that they both played anti-stroke effects in the OGD/R induced BV2 cells via inhibiting the expressions of IL-6 and COX-2. In summary, this study provides efficient network-based methodologies for in silico identification of drug candidates toward stroke.

Acute and chronic effects of diazepam on the polychaete Hediste diversicolor: Antioxidant, metabolic, pharmacologic, neurotoxic and behavioural mechanistic traits

Pharmaceutical drugs are widespread environmental contaminants, but data about their adverse effects are still limited to a few compounds. This study analyzed the acute (96 h) and chronic (28 days) impacts of environmentally realistic levels of diazepam (acute exposure: 0.001, 0.01, 0.1, 1, 10 μg/L; chronic exposure: 0.1, 1, 10, 100, 1000 ng/L), in the polychaete Hediste diversicolor, by measuring behavioral and biochemical (catalase [CAT], glutathione-S-transferases [GSTs], cholinesterases [ChEs], glutathione peroxidase [GPx], lipid peroxidation [TBARS]) parameters. Acute exposure to diazepam altered behavioral traits, decreasing burrowing times and causing hyperactivity, whilst burrowing time increased and hypoactivity resulted after chronic exposure. All biomarkers were affected after the chronic exposure, with the exception of lipid peroxidation. Our data demonstrate that realistic levels of diazepam may impair behavioral and biochemical traits in polychaetes, suggesting that diazepam exposure presents a significant challenge to the environment that supports these organisms.

Neuronal networks provide rapid neuroprotection against spreading toxicity

Acute secondary neuronal cell death, as seen in neurodegenerative disease, cerebral ischemia (stroke) and traumatic brain injury (TBI), drives spreading neurotoxicity into surrounding, undamaged, brain areas. This spreading toxicity occurs via two mechanisms, synaptic toxicity through hyperactivity, and excitotoxicity following the accumulation of extracellular glutamate. To date, there are no fast-acting therapeutic tools capable of terminating secondary spreading toxicity within a time frame relevant to the emergency treatment of stroke or TBI patients. Here, using hippocampal neurons (DIV 15-20) cultured in microfluidic devices in order to deliver a localized excitotoxic insult, we replicate secondary spreading toxicity and demonstrate that this process is driven by GluN2B receptors. In addition to the modeling of spreading toxicity, this approach has uncovered a previously unknown, fast acting, GluN2A-dependent neuroprotective signaling mechanism. This mechanism utilizes the innate capacity of surrounding neuronal networks to provide protection against both forms of spreading neuronal toxicity, synaptic hyperactivity and direct glutamate excitotoxicity. Importantly, network neuroprotection against spreading toxicity can be effectively stimulated after an excitotoxic insult has been delivered, and may identify a new therapeutic window to limit brain damage.

Seizure susceptibility and the brain regional sensitivity to oxidative stress in male and female rats in the lithium-pilocarpine model of temporal lobe epilepsy

Several studies have shown the existence of sex differences in the sensitivity to various convulsants in animals and to the development of some epilepsy types in humans. The purpose of this study was to investigate whether there are sex differences in seizure susceptibility and sensitivity of different brain regions to oxidative stress in rats with status epilepticus (SE) induced by lithium-pilocarpine administration, that provides a common experimental model of temporal lobe epilepsy (TLE) in humans. Latencies to isolated full limbic seizures or SE onset as well as the number of the animals presenting full limbic seizures, SE or full limbic seizures that progressed to SE were recorded for 2 h after pilocarpine administration. Number of animals which survived 24 h after SE onset was also monitored. Levels of lipid peroxidation as well as the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the piriform and entorhinal cortices, temporal neocortex, thalamus, and hippocampus in rats of both sexes, at 24 h after SE onset were determined. Results of our study showed that males developed full limbic seizures and SE more rapidly and in greater number than females. Levels of lipid peroxidation in all brain regions examined, the SOD activities in the piriform and entorhinal cortices, and temporal neocortex as well as the GSH-Px activities in the piriform and entorhinal cortices, and thalamus were significantly higher in rats with SE in comparison to the values of mentioned biochemical parameters in rats of the control groups. Lipid peroxidation level in the temporal neocortex as well as the GSH-Px activity in the hippocampus in male rats were significantly higher in comparison to the values registered in females. With the exception of the thalamus, where SOD activity in male rats with SE was significantly higher in relation to the respective control group and also to females with SE, sex differences in the response of other brain regions investigated to oxidative stress were not obtained, at 24 h after SE.

Drug therapies for stroke and traumatic brain injury often display U-shaped dose responses: occurrence, mechanisms, and clinical implications

This article explores the occurrence of U-shaped dose responses induced by neuroprotective agents in animal stroke and traumatic brain injury (TBI) screening/preclinical studies. The assessment was stimulated by suggestions that U-shaped dose responses may be common for neuroprotective agents in stroke and TBI models, and its lack of both recognition and understanding may be a factor contributing to the failure of many promising drugs to be protective in clinical trials. Over 30 agents with neuroprotective properties in animal stroke/TBI models were identified that act via U-shaped dose responses in a broad range of experimental protocols. These findings suggest that U-shaped dose responses in animal stroke/TBI models may be a general occurrence and have significant implications for drug discovery, drug development, and clinical practice.

Common drugs in acute ischemic stroke and their influence on outcome: an observational study in 1013 stroke patients

OBJECTIVE

Various drugs, when used during acute stroke, may affect stroke outcome. Some advise against the use of certain drugs that may be potentially harmful when used in acute stroke. However, for many of such drugs, the evidence is scarce. Therefore, we studied the use of various drugs at stroke onset as independent predictors of outcome at 3 months.

METHODS

In an observational study of 1013 acute ischemic stroke patients, medication on admission was registered and divided in 10 categories. Functional outcome at 3 months was rated using the modified Rankin scale as functional independent (Rankin 0, 1, and 2) or as functional dependent or dead (Rankin 3, 4, and 5, or 6). Independent predictive values of medication use on outcome were analyzed using multivariate regression modeling.

RESULTS

Vasodilator use was independently associated with less favorable functional outcome at 3 months (odds ratio [OR], 0.37 [95% confidence interval {CI}, 0.16-0.89]; P = 0.025) in lacunar stroke, as was the use of diuretics (OR, 0.43 [95% CI, 0.22-0.82]; P = 0.010) in atherothrombotic stroke. Calcium antagonists were independently associated with better outcome at 3 months (OR, 2.64 [95% CI, 1.04-6.69]; P = 0.042) in cardioembolic stroke.

CONCLUSIONS

Our study does not yield strong evidence in favor of testing various commonly used drugs as potential neuroprotectives in acute stroke.

Neuroprotective effect of taurine against focal cerebral ischemia in rats possibly mediated by activation of both GABAA and glycine receptors

To investigate the neuroprotective effect of taurine and the involved mechanisms, middle cerebral artery occlusion (MCAO) was induced with suture for 2h in rat, and the brain tissue was then reperfused. The infarct volume and cerebral damage area were measured, respectively, with 2,3,5-triphenyltetrazolium chloride (TTC) staining and MRI. Nissl staining was used for histological observation, and immunohistochemistry and Western-blot analysis for detecting the activated caspase-3 expression. Both pre- (200mgkg(-1)) and post-treatment of taurine decreased the neurology deficit score, infarct volume and brain water content. Taurine post-treatment (67, 200 and 600mgkg(-1)) showed a dose-dependent neuroprotective effect. Taurine (200mgkg(-1)) significantly decreased neuronal loss in the cerebral cortex and hippocampus, and reduced the expression of caspase-3 as well. The neuroprotective effect of taurine was partly blunted by strychnine or bicuculline alone, and almost completely blocked by coapplication of both antagonists of glycine and GABA(A) receptors. It is suggested that taurine exerts a neuroprotective role on the brain when administered before or after MCAO. Such effect is possibly mediated by the activation of both GABA(A) receptors and strychnine-sensitive glycine receptors. Moreover, inhibition of caspase-3 expression is involved in this neuroprotective effect. These results imply a potential therapeutic use of taurine for stroke.

Neuroprotection afforded by diazepam against oxygen/glucose deprivation-induced injury in rat cortical brain slices

The aim of the present investigation was to assess neuroprotection exerted by diazepam (0.1-25 microM) in rat cortical brain slices subjected to oxygen-glucose deprivation and reoxygenation. Neuronal injury and neuroprotection were assessed by measuring the release of glutamate and lactate dehydrogenase and tissue water content. Results demonstrate that diazepam exerted neuroprotective effects according to a "U-shaped", hormetic-like, concentration-response curve, with an efficacy window of 0.5-5 microM concentration. Flumazenil (20 microM) fully antagonised neuroprotection afforded by 5 microM diazepam. In conclusion, the hormetic response of diazepam should be taken into consideration when designing experiments aimed at assessing diazepam neuroprotection against ischemia/reoxygenation injury.

Diazepam to Improve Acute Stroke Outcome: Results of the Early GABA-Ergic Activation Study In Stroke Trial

BACKGROUND

We tested whether diazepam, a GABA-ergic drug that also inhibits brain nitric monoxide formation, improves acute stroke prognosis.

METHODS

880 patients, randomized within 12 h of acute stroke, received diazepam 10 mg or placebo by rectiole, as soon as possible, followed by 10-mg tablets twice daily for 3 days. Primary outcome was independence (Rankin score <3) at 3 months; secondary outcome was complete recovery (Barthel index >or=95 or Rankin score <or=1).

RESULTS

Intention-to-treat analyses on all 849 patients with full follow-up (50.4% on diazepam): odds ratio (OR) 1.14, 95% CI 0.87-1.49 for primary endpoint, and an OR of 1.26 (0.90-1.76) for complete recovery, both favoring diazepam. Adjusted analyses for all stroke patients (843): OR 1.20 (0.87-1.65), and 1.25 (0.89-1.74), respectively, and for all infarct patients (748): OR 1.31 (0.93-1.85), and 1.46 (1.02-2.09; p=0.037), respectively. Analyses restricted to cardioembolic infarct patients (200) showed treatment benefit for the primary outcome: OR 2.26, 95% CI 1.07-4.76, p=0.032, and complete recovery: OR 2.65, 95% CI 1.06-6.59, p=0.037. About one third of ischemic stroke patients had 'any adverse event', without any difference between treatment groups. In 95 intracerebral hemorrhage patients, frequency of pneumonia and death were higher in the diazepam group than in the placebo group: 35 and 10%, 22 and 12%, respectively.

CONCLUSIONS

Although point estimates favored diazepam treatment in various analyses, our data did not confirm our primary hypothesis. Diazepam treatment seems beneficial in cardioembolic infarct patients, is safe in acute ischemic stroke, but may better be avoided in intracerebral hemorrhage.