Neuroprotective effect of lercanidipine in middle cerebral artery occlusion model of stroke in rats

Exercise-with-melatonin therapy improves sleep disorder and motor dysfunction in a rat model of ischemic stroke

JOURNAL/nrgr/04.03/01300535-202406000-00038/inline-graphic1/v/2023-10-30T152229Z/r/image-tiff

Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer’s disease, but its effect on stroke is still poorly understood. In this study, we established a rat model of ischemic stroke by occluding the middle cerebral artery for 60 minutes. We treated the rats with exercise and melatonin therapy for 7 consecutive days. Results showed that exercise-with-melatonin therapy significantly prolonged sleep duration in the model rats, increased delta power values, and regularized delta power rhythm. Additionally, exercise-with-melatonin therapy improved coordination, endurance, and grip strength, as well as learning and memory abilities. At the same time, it led to higher hippocampal CA1 neuron activity and postsynaptic density thickness and lower expression of glutamate receptor 2 than did exercise or melatonin therapy alone. These findings suggest that exercise-with-melatonin therapy can alleviate sleep disorder and motor dysfunction by increasing glutamate receptor 2 protein expression and regulating hippocampal CA1 synaptic plasticity.

Lercanidipine ameliorated doxorubicin-induced neuroinflammation and maintained the expressions of choline acetyltransferase via enhancing the levels of PI3K/AKT/HIF1-α expressions

BACKGROUND

Doxorubicin (DOX) may cause various neurological side effects in the brain. Lercanidipine (LRD) has antioxidant, anti-inflammatory, and anti-apoptotic properties. The aim of this study was to investigate the potential benefits of.

METHODS AND RESULTS

Lercanidipine in reducing doxorubicin-induced neuroinflammation and maintaining the expressions of choline acetyltransferase. Thirty-two adult Wistar albino female rats were divided into four groups as Control, DOX (20 mg/kg intraperitoneally), DOX + LRD 0.5 (0.5 mg/kg orally), and DOX + LRD2(2 mg/kg orally). Twenty-four hours after the last drug administration (9th day), brain tissues were taken for histopathological, immunohistochemical (choline acetyltransferase [CHAT], interleukin-10 [IL-10], and caspase-3 [Cas-3] staining), biochemical (total antioxidant status [TAS], total oxidant status [TOS], and oxidative stress index [OSI]), and genetic analyzes (PI3K/AKT/HIF1-α and IL-6 gene expressions). Histopathological analyses revealed hyperemia, slight hemorrhage, degeneration, neuronal loss, gliosis in the cerebellum, and neuronal loss in the brain cortex and hippocampus in the DOX group. According to other analyzes, decreased CHAT, PI3K, AKT, HIF1-α and increased IL-6, IL-10, Cas-3 expression were observed in the DOX group.

CONCLUSIONS

Both LRD doses reversed all these findings, but LRD2 was observed to be more effective. In conclusion, we determined that LRD has potential therapeutic effect by reducing DOX-induced neuroinflammation, oxidative stress and apoptosis in brain tissues.

Investigation of cardioprotective effect of lercanidipine on doxorubicin-induced cardiotoxicity

Although doxorubicin (DOX) is an effective anti-neoplastic drug for many types of cancer, particularly dose-related cardiotoxicity limits the use of the drug. In this study, it was aimed to investigate the protective effect of lercanidipine (LRD) against DOX-induced cardiotoxicity. In our study, 40 Wistar albino female rats were randomly divided into 5 groups as control, DOX, LRD 0.5 (DOX + 0.5 mg/kg LRD), LRD 1 (DOX + 1 mg/kg LRD), and LRD 2 (DOX + 2 mg/kg LRD). At the end of the experiment, the rats were sacrificed, and their blood, heart, and endothelial tissues were examined biochemically, histopathologically, immunohistochemically, and genetically. According to our findings, necrosis, tumor necrosis factor alpha activity, vascular endothelial growth factor activity, and oxidative stress were increased in the heart tissues of the DOX group. In addition, DOX treatment caused the deteriorations in biochemical parameters, and levels of autophagy-related proteins, Atg5, Beclin1, and LC3-I/II were detected. Significant dose-related improvements in these findings were observed with LRD treatment. Besides, Atg5, LC3-I/II, and Beclin1 levels evaluated by western blot revealed that LRD exerts a tissue protective effect by regulating autophagy in endothelial tissue. LRD treatment, which is a new-generation calcium channel blocker, showed antioxidant, anti-inflammatory, and anti-apoptotic properties in heart and endothelial tissue in a dose-dependent manner and also showed protective activity by regulating autophagy in endothelial tissue. With studies evaluating these mechanisms in more detail, the protective effects of LRD will be revealed more clearly.

Lercanidipine alleviates doxorubicin-induced lung injury by regulating PERK/CHOP and Bax/Bcl 2/Cyt c pathways

Doxorubicin (DOX), which is used to treat various cancers and hematological malignancies, has limited therapeutic application due to its toxicity in tissues and organs. These toxic effects occur through alterations in intracellular calcium regulation, elevated cell stress and oxidative damage, and increased apoptosis. Lercanidipine (LRD) is a long-acting antihypertensive calcium channel blocker with anti-inflammatory, anti-apoptotic, and antioxidant effects. The aim of this study was to investigate the effect of LRD on DOX-induced lung toxicity. Four groups (control, DOX, DOX + 0.5 LRD, and DOX + 2 LRD) totaling 32 rats were established. TNF-α levels in the lung tissues were detected by immunohistochemistry, and the tissues were subjected to histopathological examination. In determining oxidative stress, total antioxidant status (TAS) and total oxidative stress (TOS) were determined using spectrophotometry, and the oxidative stress index (OSI) value was calculated. The mRNA relative expression levels of the genes were evaluated by RT-qPCR. It was determined that inflammatory and oxidative stress markers and pro-apoptotic gene levels were increased and anti-apoptotic gene levels were decreased in the lung tissues of the DOX-administered group. In addition, histopathological changes were significantly increased. Although it was not statistically significant, inflammation, oxidative stress, and apoptosis were reduced, as were other histopathological indicators, in the group that received LRD (0.5 mg/kg). Inflammation, oxidative stress, and apoptosis were found to be statistically reduced and corroborated by histological findings in the group given LRD (2 mg/kg). In conclusion, it was determined that LRD had an ameliorative effect on DOX-induced lung toxicity in an experimental animal model.

USPIO-SWI Shows Fingolimod Enhanced Alteplase Action on Angiographic Reperfusion in eMCAO Rats

BACKGROUND

Noninvasive evaluation of the status of cerebral arteriole perfusion remains a practical challenge in murine stroke models, because conventional magnetic resonance imaging (MRI) is no longer capable of capturing these very small vessels.

PURPOSE

To investigate the feasibility of ultrasmall superparamagnetic iron oxide particles (USPIO)-based susceptibility weighted imaging (SWI)-MRI (USPIO-SWI) and T2* map-MRI (USPIO-T2* map) for monitoring angiographic perfusion in stroke rats.

STUDY TYPE

A preclinical randomized controlled trial.

ANIMAL MODEL

Normal rats (N = 9), embolic middle cerebral artery occlusion (eMCAO) rats (N = 66).

FIELD STRENGTH/SEQUENCE

7 T; T2* map (multigradient echo), SWI (3D gradient echo).

ASSESSMENT

Experiment 1: To develop a method for angiographic reperfusion evaluation with USPIO-SWI. Normal rats were used to optimize the USPIO dosage (5.6, 16.8, and 56 mg/kg ferumoxytol) as well as scan time points for cerebral arterioles. Contrast-to-noise ratio (CNR) was measured. Stroke rats were further used and the number of visual cortical vessels were counted. Experiment 2: To examine whether fingolimod (lymphocytes inhibitor) enhances the action of tissue plasminogen activator (tPA) in eMCAO rats on cerebral angiographic reperfusion.

STATISTICAL TESTS

Mann-Whitney test and two way-ANOVA were used. P < 0.05 was considered statistically significant.

RESULTS

CNR values of cerebral cortical penetrating arteries in normal rats were significantly increased to 4.4 ± 0.5 (5.6 mg/kg), 6.1 ± 0.5 (16.8 mg/kg), and 3.4 ± 0.9 (56 mg/kg) after USPIO injection. The number of visual cortical vessels on USPIO-SWI images in ischemic regions was significantly less than in control regions (5 ± 2 vs. 56 ± 20) of eMCAO rats. Compared with eMCAO rats who received tPA only, eMCAO rats who received the combination of fingolimod and tPA exhibited significantly higher proportion of complete angiographic reperfusion (69% vs. 17%).

DATA CONCLUSION

This study supports the feasibility of angiographic perfusion evaluation with USPIO-SWI in stroke rats.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 1.

Compatibility of ingredients of Danshen (Radix Salviae Miltiorrhizae) and Honghua (Flos Carthami) and their protective effects on cerebral ischemia-reperfusion injury in rats

Danshen (Radix Salviae Miltiorrhizae) and Honghua (Flos Carthami) (Danhong) are two drugs commonly prescribed together, which are often used in the treatment of cerebrovascular diseases in China. Due to the complexity of the ingredients of Danhong, the present study focused on performing the orthogonal compatibility method on the primary effective molecules of this drug: Tanshinol, salvianolic acid A, salvianolic acid B and hydroxysafflor yellow A. These four molecules were studied to determine their protective effects and to screen for the most compatible ingredients to improve cerebral ischemia-reperfusion injury (IR) in rats. Focal middle cerebral artery occlusion was performed to establish the cerebral IR model in rats. Male Sprague-Dawley rats were randomly divided into sham operation group, IR group and nine orthogonal administration groups with different ratios of Danhong effective ingredients and Danhong injection group. Neurological deficit score and cerebral infarction volume were measured postoperatively. Morphological pathological alterations were observed via H&E staining. Bcl-2 and Bax were quantified using ELISA. Immunohistochemistry was conducted to analyze the expression of caspase-3 in the hippocampus. The expression levels of cytochrome c, apoptotic peptidase activating factor 1 (apaf-1), caspase-9, caspase-3 and p53 mRNA in the hippocampus were assessed via reverse transcription-quantitative PCR. The results demonstrated that different compatibility groups significantly reduced the neurological function score and decreased the volume of cerebral infarct compared with the IR group. These groups were also indicated to improve the pathological damage to the brain tissue. In addition, certain compatibility groups significantly decreased the number of caspase-3 positive cells in the hippocampus and the expression levels of cytochrome c, apaf-1, caspase-9, caspase-3 and p53 mRNA in the brain tissue. Orthogonal group 4 (30 mg/kg tanshinol; 2.5 mg/kg salvianolic acid A; 16 mg/kg salvianolic acid B; 8 mg/kg hydroxysafflor yellow A) was indicated to be the most effective. The four effective ingredients of Danhong exhibited a protective effect on rats with cerebral IR injury, potentially through the inhibition of apoptosis via the downregulation of key targets upstream of the caspase-3 pathway. In addition, the present study provided novel insights for the continued study of the drug compatibility rules of TCM.

Metabolomics and metabolites in ischemic stroke

Stroke is a major reason for disability and the second highest cause of death in the world. When a patient is admitted to a hospital, it is necessary to identify the type of stroke, and the likelihood for development of a recurrent stroke, vascular dementia, and depression. These factors could be determined using different biomarkers. Metabolomics is a very promising strategy for identification of biomarkers. The advantage of metabolomics, in contrast to other analytical techniques, resides in providing low molecular weight metabolite profiles, rather than individual molecule profiles. Technically, this approach is based on mass spectrometry and nuclear magnetic resonance. Furthermore, variations in metabolite concentrations during brain ischemia could alter the principal neuronal functions. Different markers associated with ischemic stroke in the brain have been identified including those contributing to risk, acute onset, and severity of this pathology. In the brain, experimental studies using the ischemia/reperfusion model (IRI) have shown an impaired energy and amino acid metabolism and confirmed their principal roles. Literature data provide a good basis for identifying markers of ischemic stroke and hemorrhagic stroke and understanding metabolic mechanisms of these diseases. This opens an avenue for the successful use of identified markers along with metabolomics technologies to develop fast and reliable diagnostic tools for ischemic and hemorrhagic stroke.

Computational drug repositioning for ischemic stroke: neuroprotective drug discovery

Background: A comprehensive approach to drug repositioning will be required to overcome translational hurdles and identify more neuroprotective drugs. Results & methods: Gene Set Enrichment Analysis was applied to identify related pathways and enriched genes. Candidate genes were optimized using ToppGene, ToppGenet and pBRIT. From the perspective of the local structures, gene-domain-substructure-drug relationships were constructed. Using the MCODE algorithm and K-means clustering, 31 functional subnetworks were obtained, and 252 drugs with proposed neuroprotective function were identified. Using computational analysis, 72 substructures with different scores were found to correspond to neuroprotective functions. The protective effects of benidipine and barnidipine were confirmed in vitro. Conclusion: The authors' research has great potential to discover more neuroprotective drugs and obtain more information regarding mechanisms of action and functional substructures.

Mechanisms of neuronal cell death in ischemic stroke and their therapeutic implications

Ischemic stroke caused by arterial occlusion is the most common type of stroke, which is among the most frequent causes of disability and death worldwide. Current treatment approaches involve achieving rapid reperfusion either pharmacologically or surgically, both of which are time-sensitive; moreover, blood flow recanalization often causes ischemia/reperfusion injury. However, even though neuroprotective intervention is urgently needed in the event of stroke, the exact mechanisms of neuronal death during ischemic stroke are still unclear, and consequently, the capacity for drug development has remained limited. Multiple cell death pathways are implicated in the pathogenesis of ischemic stroke. Here, we have reviewed these potential neuronal death pathways, including intrinsic and extrinsic apoptosis, necroptosis, autophagy, ferroptosis, parthanatos, phagoptosis, and pyroptosis. We have also reviewed the latest results of pharmacological studies on ischemic stroke and summarized emerging drug targets with a focus on clinical trials. These observations may help to further understand the pathological events in ischemic stroke and bridge the gap between basic and translational research to reveal novel neuroprotective interventions.

Mesenchymal Stem Cells for Neurological Disorders

Neurological disorders are becoming a growing burden as society ages, and there is a compelling need to address this spiraling problem. Stem cell-based regenerative medicine is becoming an increasingly attractive approach to designing therapies for such disorders. The unique characteristics of mesenchymal stem cells (MSCs) make them among the most sought after cell sources. Researchers have extensively studied the modulatory properties of MSCs and their engineering, labeling, and delivery methods to the brain. The first part of this review provides an overview of studies on the application of MSCs to various neurological diseases, including stroke, traumatic brain injury, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Huntington's disease, Parkinson's disease, and other less frequently studied clinical entities. In the second part, stem cell delivery to the brain is focused. This fundamental but still understudied problem needs to be overcome to apply stem cells to brain diseases successfully. Here the value of cell engineering is also emphasized to facilitate MSC diapedesis, migration, and homing to brain areas affected by the disease to implement precision medicine paradigms into stem cell-based therapies.

Enhancement in brain uptake of vitamin D3 nanoemulsion for treatment of cerebral ischemia: formulation, gamma scintigraphy and efficacy study in transient middle cerebral artery occlusion rat models

AIM

For the treatment of cerebral ischaemia, vitamin-D₃ loaded nanoemulsions were developed.

METHOD

Tween 20 and polyethylene glycol were chosen as surfactant/co-surfactant, while oleic acid as the oil phase. The formulation was characterised for various in-vitro parameters. Targeting efficiency was investigated through radiometry, gamma scintigraphy and efficacy was studied in transient middle cerebral artery occlusion (MCAo) rat model.

RESULT

Vitamin D₃-nanoemulsion showed a mean size range of 49.29 ± 10.28 nm with polydispersity index 0.17 ± 0.04 and zeta potential 13.77 mV. The formulation was found stable during thermodynamic stability study and permeated within 180 min through sheep nasal mucosa (permeation coefficient 7.873 ± 0.884 cm/h). Gamma scintigraphy and radiometry assay confirmed better percentage deposition (2.53 ± 0.17%) of ^99mTc-vitamin D₃-nanoemulsion through nasal route compared to IV administered ^99mTc-vitamin D₃ solution (0.79 ± 0.03%). Magnetic Resonance Imaging (MRI) of the ischaemic model confirmed better efficacy of vitamin D₃-nanoemulsion.

CONCLUSION

This work demonstrated better permeation, deposition, and efficacy of vitaminD₃-nanoemulsion through the intranasal route.

1 H NMR metabolomic profiling elucidated attenuation of neurometabolic alterations by lercanidipine in MCAo model in rats

OBJECTIVES

Stroke is a leading cause of death and disability worldwide with limited therapeutic interventions. The current study explored proton nuclear magnetic resonance spectroscopy (¹ H NMR)-based metabolomic approach to elucidate the effect of lercanidipine on neurometabolic alterations in transient model of ischaemic stroke in rats.

METHODS

In the present investigation, male Wistar rats were subjected to middle cerebral artery occlusion (MCAo) for 2 h followed by reperfusion using intraluminal filament method. Rats were randomly divided into three groups as vehicle-treated sham control, vehicle-treated MCAo control and lercanidipine-treated MCAo. Vehicle or lercanidipine (0.5 mg/kg, i.p.) was administered 120 min post-reperfusion. The rat brain cortex tissues were isolated 24 h post-MCAo and were investigated by ¹ H NMR spectroscopy through perchloric extraction method.

KEY FINDINGS

A total of 23 metabolites were altered significantly after cerebral ischaemic-reperfusion injury in MCAo control as compared to sham control rats. Lercanidipine significantly reduced the levels of valine, alanine, lactate, acetate and tyrosine, while N-acetylaspartate, glutamate, glutamine, aspartate, creatine/phosphocreatine, choline, glycerophosphorylcholine, taurine, myo-inositol and adenosine di-phosphate were elevated as compared to MCAo control.

CONCLUSIONS

Present study illustrates effect of lercanidipine on neurometabolic alterations which might be mediated through its antioxidant, anti-inflammatory, vasodilatory and anti-apoptotic property in MCAo model of stroke.

Study of the new 4-phenylpyrrolidinone-2 derivative pharmacokinetics and neuroprotective effect in the ischemic stroke animal model

The development of methods of drug therapy and rehabilitation in different periods of ischemic cerebral lesion is currently an urgent problem. Our study was aimed to investigate the pharmacokinetics and anti-ischemic effect of the new 4-phenylpyrrolidone-2 derivative in rats. To study the drug pharmacokinetics, the Wistar rats were once administered with the substance at a dose of 250 mg/kg, then, the substance distribution in blood and cerebral cortex was evaluated. Elimination half-life value was determined, which was 83.2 min. The substance remained in the brain tissue for 24 hours. To assess the anti-ischemic effect, the stroke was modeled by endovascular middle brain artery transition occlusion, and the drug was administered intravenously for 5 days at two doses, 250 and 125 mg/kg. After that the lesion focus volume was evaluated by MRI, as well as the neurological deficit severity, locomotor and explorative behavior. The studied drug significantly decreased the neurological deficit in model animals compared to control group (1.72 vs 4.4, p < 0.05). According to the MRI data, the effect on the ischemic focus was negligible, while the explorative behavior significantly increased under the influence of the 4-phenylpyrrolidone-2 derivative (hole board test, horizontal activity 12.1 ± 6.8, 22.5 ±10.5, p < 0.05). The data obtained allow us to conclude that the studied substance penetrates the blood-brain barrier (BBB), and accumulates in the brain tissue promoting the neurological deficit correction and increasing the explorative behavior in the ischemic stroke model animals.

Upregulation of GLT-1 via PI3K/Akt Pathway Contributes to Neuroprotection Induced by Dexmedetomidine

Perioperative ischemic stroke usually leads to neurological dysfunction caused by neuron death. During the ischemic condition, excitotoxity due to extracellular glutamate accumulation is a main mechanism of neuron damage. The clearance of glutamate mainly depends on glutamate transporter-1 (GLT-1) which is expressed in astrocytes. Dexmedetomidine, an α2 adrenergic receptor agonist, is proved to induce neuroprotection. This study was set out to investigate the glutamate-related mechanism involved in the neuroprotective effect of dexmedetomidine. Middle cerebral artery occlusion (MCAO) was used as a model of ischemic stroke in our study. We determined Neurological deficit scores (NDS) and Magnetic resonance imaging (MRI) at three points (2, 6, and 24 h) after middle cerebral artery occlusion (MCAO) to evaluate the neuroprotective effect of dexmedetomidine. Besides, we performed western blot (6 and 24 h after MACO) and immunofluorescent staining (24 h after MCAO) to observe the expression of GLT-1. The effect and mechanism of dexmedetomidine on GLT-1 in primary cultured astrocytes were investigated using western blot and RT-PCR. Our results showed that pretreatment with dexmedetomidine improved NDS and reduced infarct volume as well as upregulating GLT-1 expression. Furthermore, using Atipamezole and LY294002, we found that dexmedetomidine significantly increased GLT-1 levels in astrocytes via activating α2 adrenergic receptor and PI3K/AKT pathway both in vitro and in vivo study. Overall, our present study indicated that dexmedetomidine had neuroprotective effects on ischemia stroke and upregulation of GLT-1 levels by PI3K/AKT dependent pathway might be the potential mechanism.

Lercanidipine boosts the efficacy of mesenchymal stem cell therapy in 3-NP-induced Huntington's disease model rats via modulation of the calcium/calcineurin/NFATc4 and Wnt/β-catenin signalling pathways

3-Nitropropionic acid (3-NP) induces a spectrum of Huntington's disease (HD)-like neuropathologies in the rat striatum. The present study aimed to demonstrate the neuroprotective effect of lercanidipine (LER) in rats with 3-NP-induced neurotoxicity, address the possible additional protective effect of combined treatment with bone marrow-derived mesenchymal stem cells (BM-MSCs) and LER, and investigate the possible involvement of the Ca²⁺/calcineurin (CaN)/nuclear factor of activated T cells c4 (NFATc4) and Wnt/β-catenin signalling pathways. Rats were injected with 3-NP (10 mg/kg/day, i.p.) for two weeks and were divided into four subgroups; the first served as the control HD group, the second received a daily dose of LER (0.5 mg/kg, i.p.), the third received a single injection of BM-MSCs (1 x 106/rat, i.v.) and the last received a combination of both BM-MSCs and LER. The combined therapy improved motor and behaviour performance. Meanwhile, this treatment led to a marked reduction in striatal cytosolic Ca^2+, CaN, tumour necrosis factor-alpha, and NFATc4 expression and the Bax/Bcl2 ratio. Combined therapy also increased striatal brain-derived neurotrophic factor, FOXP3, Wnt, and β-catenin protein expression. Furthermore, haematoxylin-eosin and Nissl staining revealed an amelioration of striatum tissue injury with the combined treatment. In conclusion, the current study provides evidence for a neuroprotective effect of LER and/or BM-MSCs in 3-NP-induced neurotoxicity in rats. Interestingly, combined LER/BM-MSC therapy was superior to cell therapy alone in inhibiting 3-NP-induced neurological insults via modulation of the Ca²⁺/CaN/NFATc4 and Wnt/β-catenin signalling pathways. LER/BM-MSC combined therapy may represent a feasible approach for improving the beneficial effects of stem cell therapy in HD.

A NMR-Based Metabonomics Approach to Determine Protective Effect of a Combination of Multiple Components Derived from Naodesheng on Ischemic Stroke Rats

Naodesheng (NDS) is a widely used traditional Chinese medicine (TCM) prescription for the treatment of ischemic stroke. A combination of 10 components is derived from NDS. They are: Notoginsenoside R1, ginsenoside Rg1, ginsenoside b1, ginsenoside Rd, hydroxysafflor yellow A, senkyunolide I, puerarin, daidzein, vitexin, and ferulic acid. This study aimed to investigate the protective effect of the ten-component combination derived from NDS (TCNDS) on ischemic stroke rats with a middle cerebral artery occlusion (MCAO) model by integrating an NMR-based metabonomics approach with biochemical assessment. Our results showed that TCNDS could improve neurobehavioral function, decrease the cerebral infarct area, and ameliorate pathological features in MCAO model rats. In addition, TCNDS was found to decrease plasma lactate dehydrogenase (LDH) and malondialdehyde (MDA) production and increase plasma superoxide dismutase (SOD) production. Furthermore, ¹H-NMR metabonomic analysis indicated that TCNDS could regulate the disturbed metabolites in the plasma, urine, and brain tissue of MCAO rats, and the possible mechanisms were involved oxidative stress, energy metabolism, lipid metabolism, amino acid metabolism, and inflammation. Correlation analysis were then performed to further confirm the metabolites involved in oxidative stress. Correlation analysis showed that six plasma metabolites had high correlations with plasma LDH, MDA, and SOD. This study provides evidence that an NMR-based metabonomics approach integrated with biochemical assessment can help to better understand the underlying mechanisms as well as the holistic effect of multiple compounds from TCM.

4-Imidazo[2,1-b]thiazole-1,4-DHPs and neuroprotection: preliminary study in hits searching

In the present work we describe the synthesis, characterization and evaluation of neuroprotective effects of a focused library of 4-imidazo[2,1-b]thiazole-1,4-dihydropyridines. Furthermore, the new dihydropyridines were subjected to functional in vitro assays in cardiac tissues and vascular smooth muscle to determine their possible selectivity in counteracting the effects of neurodegeneration. In particular the strategy adopted for designing the compounds involves the imidazo[2,1-b]thiazole nucleus. The observed properties show that substituents at C2 and C6 of the bicyclic scaffold are able to influence the cardiovascular parameters and the neuroprotective activity. In comparison to nifedipine, a set of derivatives such as compound 6, showed a neuroprotective profile of particular interest.

Leptomeningeal anastomosis and early ischemic lesions on diffusion-weighted imaging in male murine focal cerebral ischemia

Leptomeningeal anastomosis is a key factor for determining early ischemic lesions on diffusion-weighted imaging (DWI) in human stroke. However, few studies have validated this relationship in an experimental model. This study sought to clarify the involvement of leptomeningeal anastomosis in early ischemic lesions using a murine model. Adult male C57BL/6 mice were subjected to unilateral common carotid artery (CCA) occlusion or sham surgery. Seven or 14 days later, the middle cerebral artery (MCA) was occluded for 45 min. In the first experiment, the leptomeningeal collaterals were visualized using magnetic resonance imaging (MRI) DWI. In the second experiment, DWI was performed immediately after MCA occlusion, and the infarct sizes were determined 24 hr after recirculation. Unilateral CCA occlusion reduced the size of early ischemic lesions, enlarged the pial vessel diameter, and mitigated infarct size. The relationship between the DWI lesion size and pial vessel diameter was significant (r = 0.84, p < 0.01). The association between infarct size and DWI lesion size was also significant (r = 0.96, p < 0.01). In conclusion, involvement of the collateral circulation in early ischemic lesions was evident in the murine model. Both MRI and evaluation of leptomeningeal anastomosis could be used to develop a novel strategy targeting enhancement of the collateral circulation.

1H NMR-Based Metabolomics Reveals Refined-Huang-Lian-Jie-Du-Decoction (BBG) as a Potential Ischemic Stroke Treatment Drug With Efficacy and a Favorable Therapeutic Window

Huang-Lian-Jie-Du-Decoction (HLJDD) is a traditional Chinese medicine (TCM) used to treat ischemic stroke. However, the complexity of its chemical composition makes quality control difficult. Berberine, baicalin, and geniposide are the three main ingredients in HLJDD. Here, a formula of BBG comprised of berberine, baicalin, and geniposide, known as Refined-Huang-Lian-Jie-Du-Decoction, was investigated for its efficacy, therapeutic window, and mechanisms of action. BBG was assessed on two major types of ischemic stroke, cerebral ischemia-reperfusion (I/R) injury, and continuous ischemia injury, respectively. BBG showed efficacy comparable to HLJDD in the treatment of cerebral I/R injury within 5 h after injury initiation but did poorly in treating continuous ischemia injury. BBG exhibited neuroprotective effects on cerebral I/R injury by regaining the balance in energy metabolism, oxidative stress, amino acid metabolism, inflammation, and nucleic acid metabolism. These results suggested that BBG could be a good alternative to HLJDD, with high efficacy and a long therapeutic window, which shows great potential for drug development to treat stroke.

Neuroanatomy- and Pathology-Based Functional Examinations of Experimental Stroke in Rats: Development and Validation of a New Behavioral Scoring System

In experimental stroke studies, a neuroanatomy-based functional examination of behaviors is critical to predict the pathological extent of infarcts because brain-imaging studies are not always available. However, there is a lack of systematic studies to examine the efficiency of a behavioral test for this purpose. Our work aimed to design a new score for this goal in stroke rats, by simplifying the Garcia score (with subscore 1–6) and adding circling as subscore 7. MRI and 2,3,5-triphenyltetrazolium chloride staining were used to determine the pathological extent after transient middle cerebral artery occlusion. The modified summations of subscores were designed according to the predictability of each subscore for locations and sizes of infarcts in one group of stroke rats, and were validated in another group. The original Garcia score was able to predict the pathological extent of edema-adjusted infarct size ≥30%, and the summation of subscore 4, 6, and 7 (4: climbing, 6: vibrissae sensation, 7: circling) also could predict it well. The original Garcia score failed to predict infarct at the primary motor cortex, while the summation of subscore 4, 6, and 7 potentially could predict not only the primary motor cortex, but also the forelimb, hindlimb, and barrel field regions of the primary sensory cortex. Accordingly, this neuroanatomy-correlated functional assessment system composed of subscore 4, 6, and 7 was proposed, with less examination time and better inter-rater reliability than the original Garcia score. In summary, this new scoring system, summation (4,6,7) score, examined motor and sensory functions based on neuroanatomical involvement, having the potential to predict the pathological extent and specific relevant brain areas of infarcts, respectively.

Diltiazem Promotes Regenerative Axon Growth

Axotomy results in permanent loss of function after brain and spinal cord injuries due to the minimal regenerative propensity of the adult central nervous system (CNS). To identify pharmacological enhancers of axon regeneration, 960 compounds were screened for cortical neuron axonal regrowth using an in vitro cortical scrape assay. Diltiazem, verapamil, and bromopride were discovered to facilitate axon regeneration in rat cortical cultures, in the presence of chondroitin sulfate proteoglycans (CSPGs). Diltiazem, an L-type calcium channel blocker (L-CCB), also promotes axon outgrowth in adult primary mouse dorsal root ganglion (DRG) and induced human sensory (iSensory) neurons.

Advances in stroke pharmacology

Stroke occurs when a cerebral blood vessel is blocked or ruptured, and it is the major cause of death and adult disability worldwide. Various pharmacological agents have been developed for the treatment of stroke either through interrupting the molecular pathways leading to neuronal death or enhancing neuronal survival and regeneration. Except for rtPA, few of these agents have succeeded in clinical trials. Recently, with the understanding of the pathophysiological process of stroke, there is a resurrection of research on developing neuroprotective agents for stroke treatment, and novel molecular targets for neuroprotection and neurorestoration have been discovered to predict or offer clinical benefits. Here we review the latest major progress of pharmacological studies in stroke, especially in ischemic stroke; summarize emerging potential therapeutic mechanisms; and highlight recent clinical trials. The aim of this review is to provide a panorama of pharmacological interventions for stroke and bridge basic and translational research to guide the clinical management of stroke therapy.

Citalopram attenuated neurobehavioral, biochemical, and metabolic alterations in transient middle cerebral artery occlusion model of stroke in male Wistar rats

Oxidative stress and inflammation are implicated as cardinal mechanisms of neuronal death following stroke. In the present study citalopram (Cit) was investigated in a 2 h middle cerebral artery occlusion (MCAo) model of stroke in male Wistar rats. Pretreatment, posttreatment (Post Cit) and pre plus posttreatment (Pre + Post Cit) with Cit were evaluated for its neuroprotective effect. In pretreatment protocol, effect of Cit at three doses (2, 4, and 8 mg/kg) administered i.p., 1 h prior to MCAo was evaluated using neurological deficit score (NDS), motor deficit paradigms, and cerebral infarction 24 h post-MCAo. In posttreatment and pre plus posttreatment protocol, the effective dose of Cit (4 mg/kg) was administered i.p., 0.5 h post-reperfusion (Post Cit) only, and 1 h prior to MCAo and again at 0.5 h post-reperfusion (Pre + Post Cit), respectively. These two groups were assessed for NDS and cerebral infarction. Though NDS was significantly reduced in both Post Cit and Pre + Post Cit groups, significant reduction in cerebral infarction was evident only in Pre + Post Cit group. Infarct volume assessed by magnetic resonance imaging was significantly attenuated in Pre + Post Cit group (10.6 ± 1.1%) compared to MCAo control group (18.5 ± 3.0%). Further, Pre + Post Cit treatment significantly altered 17 metabolites along with attenuation of malondialdehyde, reduced glutathione, matrix metalloproteinases, and apoptotic markers as compared to MCAo control. These results support the neuroprotective effect of Cit, mediated through amelioration of oxidative stress, inflammation, apoptosis, and altered metabolic profile.

The Phenolic Components of Gastrodia elata improve Prognosis in Rats after Cerebral Ischemia/Reperfusion by Enhancing the Endogenous Antioxidant Mechanisms

Pharmacological or spontaneous thrombolysis in ischemic stroke triggers an outbreak of reactive oxygen species and results in neuron death. Nrf2-mediated antioxidation in cells has been proved as a pivotal target for neuroprotection. This research reports that phenolic components of Gastrodia elata Blume (PCGE), a traditional Chinese medicine, can alleviate the pathological lesions in the penumbra and hippocampus by increasing the survival of neurons and astrocytes and improve neurofunction and cognition after reperfusion in a rat model of middle cerebral artery occlusion. LDH assay indicated that pretreatment of cells with PCGE (25 μg/ml) for 24 h significantly reduced H₂O₂-induced cell death in astrocytes and SH-SY5Y cells. Western blot showed that the nucleus accumulation of Nrf2 and the expression of cellular HO-1 and NQO-1, two of Nrf2 downstream proteins, were increased in both cells. BDNF, an Nrf2-dependent neurotrophic factor, was also upregulated by PCGE in astrocytes. These results illustrated that PCGE can reduce the cerebral ischemia/reperfusion injury and improve prognosis by remedying the cell damage within affected tissues. The protective effects of PCGE seem to be via activation of a Nrf2-mediated cellular defense system. Therefore, PCGE could be a therapeutic candidate for ischemic stroke and other oxidative stress associated neurological disorders.

Multi-targeting effects of a new synthetic molecule (JM-20) in experimental models of cerebral ischemia

Ischemic stroke is a major cause of death and disability worldwide. Thrombolysis by tissue plasminogen activator is the only pharmacological treatment approved for clinical practice, but has a narrow therapeutic window and poor efficacy when the cell death cascade is activated. Numerous drugs that are thought to protect neurons against injury have previously failed in human trials despite showing efficacy in experimental models of stroke. Herein, we reviewed the main pre-clinical results of the neuroprotective effects of JM-20, a new hybrid molecule, against brain ischemia. JM-20 appears to protect the brain from ischemic damage by interfering with several elements of the ischemic cascade: antiexcitotoxic, anticalcic, antioxidant, antiapoptotic, and anti-inflammatory. Its ability to protect not only neurons but also glial cells together with its ability to target and preserve mitochondrial function makes JM-20 a promising molecule that may be able to shield the whole neurovascular unit. The multimodal and multi-cell action of JM-20 may explain the high degree of protection observed in a rat model of brain ischemia, as assayed through histological (hematoxylin-eosin, and luxol fast blue staining), neurochemical (glutamate and aspartate levels in cerebrospinal fluid), mitochondrial functionality and behavioural (neurological scale) analysis at doses of 4 and 8mg/kg. Furthermore, the wide therapeutic window of JM-20 of 8h also suggests that this molecule could be of potential interest in situations where brain perfusion is compromised.

Anti-inflammatory and anti-apoptotic effects of the combination of Ligusticum chuanxiong and Radix Paeoniae against focal cerebral ischaemia via TLR4/MyD88/MAPK/NF-κB signalling pathway in MCAO rats

Objective

This study was performed to assess the anti-inflammatory and anti-apoptotic effects of the combination of Ligusticum chuanxiong and Radix Paeoniae (XS) on focal cerebral ischaemic stroke.

Methods

MCAO rats were used to evaluate the effect of XS on stroke. Cerebral water content was measured, and the levels of IFN-γ, IL-1β, IL-6 and IL-12 in serum and brain were assessed by ELISA kits. Protein expressions including p-p38, p-38, TLR-4, p-ERK, ERK, TLR-5, NF-κBp65, Myd88, Caspase-3 and Caspase-12 were examined by WB and IHC. Q-PCR was applied to examine IL-1β and IL-6 mRNA levels in the rat brain of each group.

Key findings

XS treatment remarkedly decreased the levels of IFN-γ, IL-1β, IL-6 and IL-12 in serum and brain tissues of MCAO rats. In the ischaemic brain, the expressions of TLR-4, TLR-5, p-p38, p-ERK, Myd88, NF-κBp65, Caspase-3 and Caspase-12 were increased significantly, while the treatment attenuated the activated expressions by MCAO. XS also downregulated Caspase-3 and Caspase-12 expressions. IL-1β and IL-6 mRNA levels in MCAO brain tissue were decreased by XS treatment.

Conclusions

XS could protect MCAO rats by anti-inflammation and anti-apoptosis through TLR4/MyD88/MAPK/NF-κB signalling pathway. Furthermore, the combination has a more meaningful improvement on focal cerebral ischaemic stroke.

Lercanidipine attenuates angiotensin II-induced cardiomyocyte hypertrophy by blocking calcineurin-NFAT3 and CaMKII-HDAC4 signaling

Previous studies have demonstrated that lercanidipine, a calcium channel blocker, may protect against cardiac hypertrophy; however, the underlying mechanisms remain unclear. In the present study, the effects of lercanidipine on hypertrophy and the mechanisms involved were investigated. Cardiomyocytes isolated from neonatal rats were cultured and treated with angiotensin II (Ang II) in the presence or absence of lercanidipine or tacrolimus (FK506, a calcineurin inhibitor). Reverse transcription-quantitative polymerase chain reaction was used to assess the mRNA expression of genes of interest, whereas the protein expression of calcium-dependent signaling molecules was detected using western blot analysis. In addition, the cell surface area and the nuclear translocation of target proteins were evaluated using immunofluorescence. The results of the present study demonstrated that lercanidipine and FK506 inhibited Ang II-induced cardiomyocyte hypertrophy, as evidenced by decreases in fetal gene (atrial natriuretic peptide and brain natriuretic peptide) expression levels and cell surface area. Notably, lercanidipine suppressed Ang II-induced activation of calcineurin A (CnA) and nuclear factor of activated T cells 3 (NFAT3). In addition, calcium/calmodulin-dependent kinase II (CaMKII)-histone deacetylase 4 (HDAC4) signaling was also inhibited by lercanidipine. In conclusion, the present study demonstrated that lercanidipine may ameliorate cardiomyocyte hypertrophy, possibly partially by blocking Cn-NFAT3 and CaMKII-HDAC4 signaling.