N-Butylphthalide Alleviates Blood-Brain Barrier Impairment in Rats Exposed to Carbon Monoxide

Evaluation of drug interactions of Saposhnikoviae Radix and its major components with astragaloside IV and paeoniflorin using in vitro and in vivo experiments

Saposhnikoviae Radix (SR) may enhance the pharmacodynamics of Huangqi Chifeng Tang (HQCFT) in the treatment of cerebral infarction according to our previous research, but the underlying mechanism is unknown. Herein, an in vivo pharmacokinetic assay in rats and in vitro MDCK-MDR1 cell assays were used to investigate the possible mechanism of SR, its main components, and its interactions with Astragali Radix (AR) and Paeoniae Radix (PR). An ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC‒MS/MS)-based analytical method for quantifying astragaloside IV (ASIV) and paeoniflorin (PAE) in microdialysis and transport samples was developed. The pharmacokinetic parameters of SR were determined using noncompartmental analyses CCK-8 assays were used to detect the cytotoxicity of ASIV, PAE, cimifugin (CIM), prim-o-glucosylcimifugin (POG) and their combinations. Moreover, drug transport was studied using MDCK-MDR1 cells. Western blotting was performed to measure the protein expression levels of P-GP and MRP1. Claudin-5, ZO-1, and F-actin expression was determined via immunohistochemical staining of MDCK-MDR1 cells. harmacokinetic studies revealed that, compared with those of Huangqi Chifeng Tang-Saposhnikoviae Radix (HQCFT-SR), the Tmax of ASIV increased by 11.11 %, and the MRT0-t and Tmax of PAE increased by 11.19 % and 20 %, respectively, in the HQCFT group. Transport studies revealed that when ASIV was coincubated with 28 μM CIM or POG, the apparent permeability coefficient (Papp) increased by 71.52 % and 50.33 %, respectively. Coincubation of PAE with 120 μM CIM or POG increased the Papp by 87.62 % and 60.95 %, respectively. Moreover, CIM and POG significantly downregulated P-gp and MRP1 (P < 0.05), inhibited the expression of Claudin-5, ZO-1, and F-actin (P < 0.05), and affected intercellular tight junctions (TJs). In conclusion, our study successfully established a selective, sensitive and reproducible UPLC‒MS/MS analytical method to detect drug‒drug interactions between SR, AR and PR in vivo and in vitro, which is beneficial for enhancing the therapeutic efficacies of AR and PR. Moreover, this study provides a theoretical basis for further research on the use of SR as a drug carrier.

Efficacy and Safety of Butylphthalide in Patients With Acute Ischemic Stroke: A Randomized Clinical Trial

Importance

DL-3-n-butylphthalide (NBP) is a drug for treating acute ischemic stroke and may play a neuroprotective role by acting on multiple active targets. The efficacy of NBP in patients with acute ischemic stroke receiving reperfusion therapy remains unknown.

Objective

To assess the efficacy and safety of NBP in patients with acute ischemic stroke receiving reperfusion therapy of intravenous thrombolysis and/or endovascular treatment.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled, parallel randomized clinical trial was conducted in 59 centers in China with 90-day follow-up. Of 1236 patients with acute ischemic stroke, 1216 patients 18 years and older diagnosed with acute ischemic stroke with a National Institutes of Health Stroke Scale score ranging from 4 to 25 who could start the trial drug within 6 hours from symptom onset and received either intravenous recombinant tissue plasminogen activator (rt-PA) or endovascular treatment or intravenous rt-PA bridging to endovascular treatment were enrolled, after excluding 20 patients who declined to participate or did not meet eligibility criteria. Data were collected from July 1, 2018, to May 22, 2022.

Interventions

Within 6 hours after symptom onset, patients were randomized to receive NBP or placebo in a 1:1 ratio.

Main Outcomes and Measures

The primary efficacy outcome was the proportion of patients with a favorable outcome based on 90-day modified Rankin Scale score (a global stroke disability scale ranging from 0 [no symptoms or completely recovered] to 6 [death]) thresholds of 0 to 2 points, depending on baseline stroke severity.

Results

Of 1216 enrolled patients, 827 (68.0%) were men, and the median (IQR) age was 66 (56-72) years. A total of 607 were randomly assigned to the butylphthalide group and 609 to the placebo group. A favorable functional outcome at 90 days occurred in 344 patients (56.7%) in the butylphthalide group and 268 patients (44.0%) in the placebo group (odds ratio, 1.70; 95% CI, 1.35-2.14; P < .001). Serious adverse events within 90 days occurred in 61 patients (10.1%) in the butylphthalide group and 73 patients (12.0%) in the placebo group.

Conclusions and Relevance

Among patients with acute ischemic stroke receiving intravenous thrombolysis and/or endovascular treatment, NBP was associated with a higher proportion of patients achieving a favorable functional outcome at 90 days compared with placebo.

Trial Registration

ClinicalTrials.gov Identifier: NCT03539445.

Microbial Metabolites of 3-n-butylphthalide as Monoamine Oxidase A Inhibitors

Novel compounds with antidepressant activity via monoamine oxidase inhibition are being sought. Among these, derivatives of 3-n-butylphthalide, a neuroprotective lactone from Apiaceae plants, may be prominent candidates. This study aimed to obtain the oxidation products of 3-n-butylphthalide and screen them regarding their activity against the monoamine oxidase A (MAO-A) isoform. Such activity of these compounds has not been previously tested. To obtain the metabolites, we used fungi as biocatalysts because of their high oxidative capacity. Overall, 37 strains were used, among which Penicillium and Botrytis spp. were the most efficient, leading to the obtaining of three main products: 3-n-butyl-10-hydroxyphthalide, 3-n-butylphthalide-11-oic acid, and 3-n-butyl-11-hydroxyphthalide, with a total yield of 0.38-0.82 g per g of the substrate, depending on the biocatalyst used. The precursor-3-n-butylphthalide and abovementioned metabolites inhibited the MAO-A enzyme; the most active was the carboxylic acid derivative of the lactone with inhibitory constant (K_i) < 0.001 µmol/L. The in silico prediction of the drug-likeness of the metabolites matches the assumptions of Lipinski, Ghose, Veber, Egan, and Muegge. All the compounds are within the optimal range for the lipophilicity value, which is connected to adequate permeability and solubility.

The Vessel Has Been Recanalized: Now What?

When treating acute ischemic stroke patients in our daily clinical practice, we strive to achieve recanalization of the occluded blood vessel as fast as possible using pharmacological thrombolysis and mechanical clot removal. However, successful recanalization does not equal successful reperfusion of the ischemic tissue due to mechanisms such as microvascular obstruction. Even if successful reperfusion is achieved, numerous other post-recanalization tissue damage mechanisms may impair patient outcomes, namely blood-brain barrier breakdown, reperfusion injury and excitotoxicity, late secondary changes, and post-infarction local and global brain atrophy. Several cerebroprotectants are currently evaluated as adjunctive treatments to pharmacological thrombolysis and mechanical clot removal, many of which interfere with post-recanalization tissue damage pathways. However, our current lack of knowledge about the prevalence and importance of the various post-recanalization tissue damage mechanisms makes it difficult to reliably identify the most promising cerebroprotectants and to design appropriate clinical trials to evaluate them. Serial human MRI studies with complementary animal studies in higher order primates could provide answers to these critical questions and should be first conducted to allow for adequate cerebroprotection trial design, which could accelerate the translation of cerebroprotective agents from bench to bedside to further improve patient outcomes.

Evidence of clinical efficacy and pharmacological mechanism of N-butylphthalide in the treatment of delayed encephalopathy after acute carbon monoxide poisoning

Objective

Based on network meta-analysis (NMA) and network pharmacology approaches, we explored the clinical efficacy of different regimens, and clarified the pharmacological mechanisms of N-butylphthalide (NBP) in the treatment of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP).

Methods

Firstly, NMA was conducted to obtain the ranking of the efficacy of different regimens for the treatment of DEACMP. Secondly, the drug with a relatively high efficacy ranking was selected and its mechanism of treatment for DEACMP was identified through a network pharmacology analysis. By the use of protein interaction and enrichment analysis, the pharmacological mechanism was predicted, and molecular docking was subsequently carried out to verify the reliability of the results.

Results

A total of 17 eligible randomized controlled trials (RCTs) involving 1293 patients and 16 interventions were eventually included in our analysis from NMA. Mesenchymal stem cells (MSCs) + NBP significantly increased mini-mental state examination (MMSE) and Barthel index (BI) scores; NBP + dexamethasone (DXM) was the most effective treatment in improving the activity of daily living (ADL) scores; NBP significantly decreased national institutes of health stroke scale (NIHSS) scores; Xingzhi-Yinao granules (XZYN) had more advantages in improving Montreal cognitive assessment (MoCA) scores, translational direct current stimulation (tDCS) had a significant effect in improving P300 latency and P300 amplitude and Kinnado + Citicoline had the most obvious effect in improving malondialdehyde (MDA). Meanwhile, by network pharmacology analysis, 33 interaction genes between NBP and DEACMP were obtained, and 4 of them were identified as possible key targets in the process of MCODE analysis. 516 Gene ontology (GO) entries and 116 Kyoto Encyclopedia of Gene and Genome (KEGG) entries were achieved by enrichment analysis. Molecular docking showed that NBP had good docking activity with the key targets.

Conclusion

The NMA screened for regimens with better efficacy for each outcome indicator in order to provide a reference for clinical treatment. NBP can stably bind ALB, ESR1, EGFR, HSP90AA1, and other targets, and may play a role in neuroprotection for patients with DEACMP by modulating Lipid and atherosclerosis, IL-17 signaling pathway, MAPK signaling pathway, FoxO signaling pathway, PI3K/AKT signaling pathway.

Lethal diquat poisoning manifests as acute central nervous system injury and circulatory failure: A retrospective cohort study of 50 cases

BACKGROUND

The mortality rate of patients with diquat (DQ) poisoning is extremely high due to insufficient understanding of DQ-induced injury. This study aimed to summarize the characteristics of DQ poisoning as well as analyse the correlation between plasma DQ concentration and patient outcomes, thus providing a new strategy for diagnosis and treatment.

METHODS

This single-centre retrospective cohort study was conducted at the Emergency Department of the First Affiliated Hospital, Zhejiang University School of Medicine, China, between Oct 9, 2019 and March 10, 2022. 50 patients, whose plasma or urine samples tested positive for diquat and negative for paraquat by high performance liquid chromatography-tandem mass spectrometry, were included in the study.

FINDINGS

The mortality rate of acute DQ poisoning was 25 (50%) of 50. Compared with the survival group, the death group presented significantly higher initial plasma DQ concentration (Cp₁), aspartate aminotransferase, alanine aminotransferase, serum creatinine, and creatine kinase-MB (P < 0.05). We found that six (24.0%) patients died of central nervous system injury, six (24.0%) patients died of refractory circulatory failure, and 13 (52.0%) patients died of central nervous system injury combined with circulatory failure. Receiver operator characteristic curve analysis showed that the area under the curve of Cp₁ was 0.967 (95% CI: 0.911, 1.000), and the cut-off value was 3516.885 ng/mL (sensitivity, 90.9%; specificity, 96.0%).

INTERPRETATION

Lethal DQ poisoning is primarily associated with serious brain and vascular injury, as well as a high rate of mortality. Further research into the mechanisms of refractory circulatory failure and central nerve system damage could help reduce mortality.

FUNDING

There are no funding sources to declare.

Efficacy and safety of butylphthalide in secondary prevention of stroke: study protocol for a multicenter, real world trial based on Internet

Background

As one of the leading causes of morbidity and mortality, stroke and its recurrence has attracted more and more attention. Dl-3-n-butylphthalidle(NBP) has been widely used for treating acute ischemic stroke in China and shows a great clinical effect. NBP plays a role in different pathophysiological processes in the treatment of ischemic stroke, including antioxidants, anti-inflammatory, anti-apoptotic, anti-thrombosis, and mitochondrial protection. Many randomized, double-blind, placebo-controlled, multicenter clinical trials suggest that NBP is a safe and effective treatment for ischemic stroke. To sum up, the current research is mainly focused on the short-term treatment of stroke patients with RCT (randomized controlled trial). Therefore, we designed this study to confirm the role of butylphthalide in secondary stroke prevention in the real world.

Methods

This study will be a multicenter, prospective real-world trial. We would recruit 8000 patients with ischemic stroke from 78 public hospitals in China. All participants will be allocated to one of two parallel treatment groups according to their own wills: (1) butylphthalide group: 0.2 g of butylphthalide capsules three times daily plus routine treatment (aspirin 50-300 mg/d, clopidogrel 75 mg/d, etc.); (2) control group: routine treatment (aspirin 50-300 mg/d, clopidogrel 75 mg/d, etc.). Treatment duration is 90 consecutive days or more. The primary outcome is recurrence rate of stroke within 1 month, 3 months, 6 months and 1 year in butylphthalide group and control group. The secondary outcomes included NIHSS score, the mRS score, other clinical cardiovascular events within one year (sudden death / myocardial infarction / arrhythmia / heart failure, etc.), and adverse events of patients in groups. NIHSS will be captured in the first month after discharge, and the others will be captured at the same time points as the primary end point.

Discussion

This trial will be exploring the efficacy and safety of butylphthalide in secondary prevention of ischemic stroke to expand the scope of application of butylphthalide soft capsules and provide new ideas for enriching the secondary prevention of stroke.

Trial registration

Chinese Clinical Trial Registry (ChiCTR). Trial registration number: ChiCTR2000034481. Registered on 6 July 2020, http://www.chictr.org.cn/showproj.aspx?proj=55800

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02815-x.

Therapeutic effect and molecular mechanism of Salvia Miltiorrhiza on rats with acute brain injury after carbon monoxide poisoning based on the strategy of internet pharmacology

The pathogenesis of brain injury caused by carbon monoxide poisoning (COP) is very complex, and there is no exact and reliable treatment in clinic. In the present study, we screened the therapeutic target and related signal pathway of Salvia Miltiorrhiza for acute COP brain injury, and clarified the pharmacological mechanism of multicomponent, multitarget, and multisignal pathway in Salvia Miltiorrhiza by network pharmacology. To further verify the therapeutic effect of Salvia Miltiorrhiza on acute brain injury based on the results of network analysis, a total of 216 male healthy Sprague Dawley rats were collected in the present study and randomly assigned to a normal control group, a COP group and a Tanshinone IIA sulfonate treatment group (72 rats in each group). The rat model of acute severe COP was established by the secondary inhalation in a hyperbaric oxygen chamber. We found that Salvia Miltiorrhiza had multiple active components, and played a role in treating acute brain injury induced by COP through multiple targets and multiple pathways, among them, MAPK/ERK1/2 signaling pathway was one of the most important. COP can start apoptosis process, activate the MAPK/ERK1/2 signaling pathway, and promote the expression of VEGF-A protein and the formation of brain edema. Tanshinone IIA can effectively inhibit apoptosis, up-regulate the expressions of VEGF-A, P-MEK1/2 and P-ERK1/2 proteins, thereby protect endothelial cells, promote angiogenesis and microcirculation, and finally alleviate brain edema.

Hepatic Ischemia-Reperfusion Impairs Blood-Brain Barrier Partly Due to Release of Arginase From Injured Liver

Aim: Hepatic ischemia-reperfusion (HIR) induces remote organs injury, including the brain. The homeostasis of the brain is maintained by the blood-brain barrier (BBB); thus, we aimed to investigate whether HIR impaired BBB and attempted to elucidate its underlying mechanism.

Methods: Cell viability of human cerebral microvascular endothelial cells (hCMEC/D3) was measured following 24 h incubation with a serum of HIR rat undergoing 1 h ischemia and 4 h reperfusion, liver homogenate, or lysate of primary hepatocytes of the rat. The liver homogenate was precipitated using (NH₄)₂SO₄ followed by separation on three columns and electrophoresis to identify the toxic molecule. Cell activity, apoptosis, proliferation, cell cycle, and expressions of proteins related to cell cycle were measured in hCMEC/D3 cells incubated with identified toxic molecules. HIR rats undergoing 1 h ischemia and 24 h reperfusion were developed to determine the release of an identified toxic molecule. BBB function was indexed as permeability to fluorescein and brain water. Endothelial cell proliferation and expressions of proteins related to the cell cycle in cerebral microvessels were measured by immunofluorescence and western blot.

Results: Toxic molecule to BBB in the liver was identified to be arginase. Arginase inhibitor nor-NOHA efficiently attenuated hCMEC/D3 damage caused by liver homogenate and serum of HIR rats. Both arginase and serum of HIR rats significantly lowered arginine (Arg) in the culture medium. Arg addition efficiently attenuated the impairment of hCMEC/D3 caused by arginase or Arg deficiency, demonstrating that arginase impaired hCMEC/D3 via depriving Arg. Both arginase and Arg deficiency damaged hCMEC/D3 cells by inhibiting cell proliferation, retarding the cell cycle to G1 phase, and downregulating expressions of cyclin A, cyclin D, CDK2, and CDK4. HIR notably increased plasma arginase activity and lowered Arg level, increased the BBB permeability accompanied with enhanced brain water, and decreased the proliferative cells (marked by Ki67) in cerebral microvessels (marked by CD31) and protein expressions of cyclin A, cyclin D, CDK2 and CDK4 in isolated brain microvessels. Oral supplement of Arg remarkably attenuated these HIR-induced alterations.

Conclusion: HIR leads to substantial release of arginase from the injured liver and then deprives systemic Arg. The Arg deficiency further impairs BBB via inhibiting the proliferation of brain microvascular endothelial cells by cell cycle arrest.

Mitochondrial Fusion Promoter Alleviates Brain Damage in Rats with Cardiac Ischemia/Reperfusion Injury

BACKGROUND

Cardiac ischemia/reperfusion (I/R) injury induces brain damage through increased blood-brain barrier (BBB) breakdown, microglial hyperactivity, pro-inflammatory cytokines, amyloid-β deposition, loss of dendritic spines, brain mitochondrial dysfunction, and imbalanced mitochondrial dynamics. Previous studies demonstrated that mitochondrial fusion promoter reduced cardiac damage from cardiac I/R injury; however, following cardiac I/R injury, the roles of mitochondrial dynamics on the brain have not been investigated.

OBJECTIVE

To investigate the effects of pharmacological modulation using mitochondrial fusion promoter (M1) in the brain of rats following cardiac I/R injury.

METHODS

Twenty-four male Wistar rats were separated into two groups; 1) sham-operation (n = 8) and 2) cardiac I/R injury (n = 16). Rats in the cardiac I/R injury group were randomly received either normal saline solution as a vehicle or a mitochondrial fusion promoter (M1, 2 mg/kg) intravenously. Both treatments were given to the rats 15 minutes before cardiac I/R injury. At the end of the reperfusion protocol, the brain was rapidly removed to investigate brain mitochondrial function, mitochondrial dynamics proteins, microglial activity, and Alzheimer's disease (AD) related proteins.

RESULTS

Cardiac I/R injury induced brain mitochondrial dynamics imbalance as indicated by reduced mitochondrial fusion proteins expression without alteration in mitochondrial fission, brain mitochondrial dysfunction, BBB breakdown, increased macrophage infiltration, apoptosis, and AD-related proteins. Pretreatment with M1 effectively increased the expression of mitofusin 2, a mitochondrial outer membrane fusion protein, reduced brain mitochondrial dysfunction, BBB breakdown, macrophage infiltration, apoptosis, and AD-related proteins in rats following cardiac I/R injury.

CONCLUSION

This mitochondrial fusion promoter significantly protected rats with cardiac I/R injury against brain damage.

Novel brain-targeting 3-n-butylphthalide prodrugs for ischemic stroke treatment

Currently, ischemic stroke is the leading cause of disability and death worldwide, and the performance of corresponding drugs is often unsatisfactory owing to the complex pathological processes and the impediment of the blood-brain barrier (BBB). Here, we employed various tertiary amino groups, including different linear, cyclic, and bimolecular drug structures, to modify 3-n-butylphthalide (NBP), a natural product used for ischemic stroke treatment, which has poor bioavailability, to generate a series of six prodrugs. These prodrugs showed significantly improved solubility and cellular uptake, which were primarily driven by putative pyrilamine cationic transporters. They also displayed more efficient brain delivery in vivo, reaching as high as 21.5-fold brain accumulation increase compared with NBP, leading to much higher bioavailability and stronger therapeutic effects. The toxicity of these molecules is also lower or similar to that of unmodified NBP. We showed that the tertiary amino group-modified NBP prodrugs are effective and safe for treating ischemic stroke with significantly enhanced druggability; hence, they have potential for further clinical development.

miR-7-5p Affects Brain Edema After Intracerebral Hemorrhage and Its Possible Mechanism

Objective: To explore the relationship between miR-7-5p and brain edema after intracerebral hemorrhage and the role of butylphthalide (NBP) in brain edema after intracerebral hemorrhage. Method: Routine blood testing, C-reactive protein results, and computed tomography data were collected 1, 7, and 14 days after intracerebral hemorrhage in six patients. Levels of MMP-9, ZO-1, occludin, IL-6, TNF-α, and miR-7-5p were detected in each patient's serum. Sixty male Sprague-Dawley rats were randomly divided into sham operation, intracerebral hemorrhage, and NBP treatment groups. Dry-wet weight was used to assess brain edema, and Evans blue staining was used to assess the permeability of the blood-brain barrier. Expression levels of IL-6, TNF-α, ZO-1 and occludin, PI3K, AKT, p-AKT, AQP4, and miR-7-5p were analyzed in the rat brains. Result: The blood neutrophil-lymphocyte ratio (NLR) on day 1 was associated with the area of brain edema on day 7. The expression of miR-7-5p decreased after intracerebral hemorrhage, and as a result, the inhibition of the PI3K/AKT pathway was weakened. The decreased inhibition of the PI3K/AKT pathway resulted in an increase in AQP4 expression, which further aggravated brain edema. NBP can upregulate the expression of miR-7-5p, affecting these pathways to reduce brain edema. Conclusion: After intracerebral hemorrhage, miR-7-5p expression in brain tissue is reduced, which may increase the expression of AQP4 by activating the PI3K/AKT pathway. NBP can inhibit this process and reduce brain edema.

From Seeds of Apium graveolens Linn. to a Cerebral Ischemia Medicine: The Long Journey of 3-n-Butylphthalide

3-n-Butylphthalide (NBP) as well as its derivatives and analogues (NBPs), in racemic or enantiomerically pure forms, possess potent and diverse pharmacological properties and have shown a great potential therapeutic interest for many human conditions, especially for cerebral ischemia. This Perspective outlines the synthesis and therapeutic applications of NBPs.

DL-3-n-butylphthalide protects the blood-brain barrier against ischemia/hypoxia injury via upregulation of tight junction proteins

BACKGROUND

The increased permeability of the blood-brain barrier (BBB) induced by ischemia/hypoxia is generally correlated with alteration of tight junctions (TJs). DL-3-n-butylphthalide (NBP) has been shown to exert neuroprotective effects after ischemic injury. However, few studies have assessed the correlation between NBP and TJs. This study aimed to investigate the potential effect of NBP on the TJ proteins claudin-5, zonula occludens-1 (ZO-1), and occludin during brain ischemia.

METHODS

A chronic cerebral hypoperfusion (CCH) Sprague-Dawley rat model was established, and NBP (20, 40, or 80 mg/kg, gavage, once a day) treatment was performed for 14 days. NBP (0.1 or 1.0 μmol/L) pre-treatment was applied to an in vitro hypoxia microvascular endothelial cell model (1% O2, 24 h). BBB permeability was assessed by performing the Evans blue assay. The expressions and localization of claudin-5, ZO-1, occludin, phosphorylated/total protein kinase B (p-Akt/Akt), phosphorylated/total glycogen synthase kinase 3β (GSK-3β)/GSK-3β, and β-catenin/β-actin were evaluated by Western blotting or immunofluorescence. Reactive oxygen species (ROS) generation was measured by flow cytometry analysis. TJ ultrastructure was observed by transmission electron microscopy.

RESULTS

In CCH rats, treatment with 40 and 80 mg/kg NBP decreased the Evans blue content in brain tissue (9.0 ± 0.9 μg/g vs. 12.3 ± 1.9 μg/g, P = 0.005; 6.7 ± 0.6 μg/g vs. 12.3 ± 1.9 μg/g, P < 0.01), increased the expression of claudin-5 (0.79 ± 0.08 vs. 0.41 ± 0.06, P < 0.01; 0.97 ± 0.07 vs. 0.41 ± 0.06, P < 0.01), and elevated the ZO-1 protein level (P < 0.05) in brain microvascular segments in a dose-dependent manner in comparison with the corresponding values in the model group. There was no significant difference in occludin expression (P > 0.05). In the hypoxia cell model, NBP pre-treatment improved TJ ultrastructure, decreased intracellular ROS level, and increased the expression of claudin-5 (P < 0.01) and ZO-1 (P < 0.01) in comparison with the corresponding values in the hypoxia group. NBP treatment also elevated the relative expression levels of p-Akt/Akt, p-GSK-3β/GSK-3β, and β-catenin/β-actin in comparison with the corresponding values in the hypoxia group (all P < 0.05).

CONCLUSION

NBP improves the barrier function of BBB against ischemic injury by upregulating the expression of TJ proteins, possibly by reducing oxidative stress and activating the Akt/GSK-3β/β-catenin signaling pathway.

Dl-3-n-butylphthalide Reduces Neurovascular Inflammation and Ischemic Brain Injury in Mice

Dl-3-n-butylphthalide (NBP) is a synthetic compound that has been approved for the treatment of ischemic stroke in China. The mechanisms underlying the treatment efficacy of NBP have been reported in multiple studies and remain controversial. Here, we show that NBP treatment attenuated ischemic brain injury in mice subjected to transient middle cerebral artery occlusion or photothrombosis-induced permanent cerebral ischemia. NBP induced downregulation of intercellular adhesion molecule 1 and protease-activated receptor 1 in cerebrovascular endothelial cells after cerebral ischemia and reperfusion. This effect was associated with the reduced brain infiltration of myeloid cells and improved cerebral blood flow after reperfusion. The beneficial effects of NBP were diminished in mice subjected to the depletion of Gr1⁺ myeloid cells before brain ischemia. Therefore, the restriction of neurovascular inflammation is a key mode of action for NBP in ischemic stroke.

Application and prospects of butylphthalide for the treatment of neurologic diseases

OBJECTIVE

The 3-N-butylphthalide (NBP) comprises one of the chemical constituents of celery oil. It has a series of pharmacologic mechanisms including reconstructing microcirculation, protecting mitochondrial function, inhibiting oxidative stress, inhibiting neuronal apoptosis, etc. Based on the complex multi-targets of pharmacologic mechanisms of NBP, the clinical application of NBP is increasing and more clinical researches and animal experiments are also focused on NBP. The aim of this review was to comprehensively and systematically summarize the application of NBP on neurologic diseases and briefly summarize its application to non-neurologic diseases. Moreover, recent progress in experimental models of NBP on animals was summarized.

DATA SOURCES

Literature was collected from PubMed and Wangfang database until November 2018, using the search terms including "3-N-butylphthalide," "microcirculation," "mitochondria," "ischemic stroke," "Alzheimer disease," "vascular dementia," "Parkinson disease," "brain edema," "CO poisoning," "traumatic central nervous system injury," "autoimmune disease," "amyotrophic lateral sclerosis," "seizures," "diabetes," "diabetic cataract," and "atherosclerosis."

STUDY SELECTION

Literature was mainly derived from English articles or articles that could be obtained with English abstracts and partly derived from Chinese articles. Article type was not limited. References were also identified from the bibliographies of identified articles and the authors' files.

RESULTS

NBP has become an important adjunct for ischemic stroke. In vascular dementia, the clinical application of NBP to treat severe cognitive dysfunction syndrome caused by the hypoperfusion of brain tissue during cerebrovascular disease is also increasing. Evidence also suggests that NBP has a therapeutic effect for neurodegenerative diseases. Many animal experiments have found that it can also improve symptoms in other neurologic diseases such as epilepsy, cerebral edema, and decreased cognitive function caused by severe acute carbon monoxide poisoning. Moreover, NBP has therapeutic effects for diabetes, diabetes-induced cataracts, and non-neurologic diseases such as atherosclerosis. Mechanistically, NBP mainly improves microcirculation and protects mitochondria. Its broad pharmacologic effects also include inhibiting oxidative stress, nerve cell apoptosis, inflammatory responses, and anti-platelet and anti-thrombotic effects.

CONCLUSIONS

The varied pharmacologic mechanisms of NBP involve many complex molecular mechanisms; however, there many unknown pharmacologic effects await further study.

A Systematic Review of Neuroprotective Efficacy and Safety of DL-3-N-Butylphthalide in Ischemic Stroke

DL-3-n-butylphthalide (NBP) is widely used as a neuroprotective drug for ischemic stroke in China. There is, however, no established evidence on its efficacy and safety for patients with ischemic stroke. We, therefore, conducted a systematic review and meta-analysis. Major databases were searched to identify randomized controlled trials that assessed the efficacy and safety of NBP on ischemic stroke, reporting outcomes among patients treated with NBP alone or combined with standard anti-ischemic stroke drugs vs. standard anti-ischemic stroke drugs. Continuous data were validated, extracted and synthesized of standardized mean differences (SMDs) by random effects models, while dichotomous data were validated, extracted and synthesized of relative risk (RR) by random effects models. Twelve randomized controlled trials involving 1160 patients were identified. Results suggested that NBP monotherapy is not superior to standard anti-ischemic stroke drugs based on the Barthel Index (SMD, 0.25; 95% CI [Formula: see text]0.14 to 0.63; [Formula: see text]) and the National Institutes of Health Stroke Scale (SMD, 0.73; 95% CI [Formula: see text]0.14 to 1.59; [Formula: see text]). In contrast, the combination of NBP and standard anti-ischemic stroke drugs appears to be superior to standard drugs alone, again based on both the Barthel index (SMD, 1.65; 95% CI 1.25 to 2.04; [Formula: see text]) and National Institutes of Health Stroke Scale (SMD, 1.40; 95% CI 0.72 to 2.09; [Formula: see text]). However, the use of NBP may cause adverse event on the function of the liver (RR, 3.55; 95% CI 1.19 to 10.56; [Formula: see text]). The combination use of NBP and standard anti-ischemic stroke drugs is more effective than standard drugs. However, more attention should be payed to the adverse effects on liver function. Our findings provided an established evidence of NBP as a neuroprotective drug, which may improve the current guideline for treatment of ischemic stroke.

The role of CNS macrophages in streptococcal meningoencephalitis

In the healthy brain, microglia and other CNS macrophages are the most abundant immune cell type. Thus, they form the natural immune cell interface with streptococci, which are the leading cause of bacterial meningitis and encephalitis in infants and young children. In homeostasis, the blood-brain barrier allows for very limited access of immune cells circulating in the periphery. During bacterial meningoencephalitis, however, origin and fate of CNS macrophages are massively altered. This review summarizes the emerging knowledge on the sequence of reciprocal events between streptococci and CNS macrophages leading to host resistance, acute inflammation, changes in resident innate immune cells of the brain, and long-term neuronal damage.

N-Butylphthalide Improves Cognitive Function in Rats after Carbon Monoxide Poisoning

Cognitive impairment is the most common neurologic sequelae after carbon monoxide (CO) poisoning, and the previous investigations have demonstrated that N-Butylphthalide (NBP) could exert a broad spectrum of neuroprotective properties. The current study aimed to investigate the effect of NBP on cognitive dysfunction in rats after acute severe CO poisoning. Rats were randomly divided into a normal control group, a CO poisoning group and a CO+NBP group. The animal model of CO poisoning was established by exposure to CO in a chamber, and then all rats received hyperbaric oxygen therapy once daily, while rats in CO+NBP group were administered orally NBP (6 mg/ 100g) by gavage twice a day additionally. The results indicated that CO poisoning could induce cognitive impairment. The ultrastructure of hippocampus was seriously damaged under transmission electron microscopy, and the expressions of calpain 1 and CaMK II proteins were significantly elevated after CO exposure according to the analysis of immunofluorescence staining and western blot. NBP treatment could evidently improve cognitive function, and maintain ultrastructure integrity of hippocampus. The expression levels of both calpain 1 and CaMK II proteins in CO+NBP group were considerably lower than that of CO poisoning group (P < 0.05). Taken together, this study highlights the molecular mechanism of cognitive dysfunction in rats after CO exposure via the upregulation of both calpain 1 and CaMK II proteins. The administration of NBP could balance the expressions of calpain 1 and CaMK II proteins and improve cognitive function through maintaining ultrastructural integrity of hippocampus, and thus may play a neuroprotective role in brain tissue in rats with CO poisoning.