Dl-3-N-Butylphthalide Alleviates the Blood–Brain Barrier Permeability of Focal Cerebral Ischemia Reperfusion in Mice

Dl-3-n-butylphthalide improves stroke outcomes after focal ischemic stroke in mouse model by inhibiting the pyroptosis-regulated cell death and ameliorating neuroinflammation

Recent studies have highlighted the involvement of pyroptosis-mediated cell death and neuroinflammation in ischemic stroke (IS) pathogenesis. DL-3-n-butylphthalide (NBP), a synthesized compound based on an extract from seeds of Apium graveolens, possesses a broad range of biological effects. However, the efficacy and the underlying mechanisms of NBP in IS remain contentious. Herein, we investigated the therapeutic effects of NBP and elucidated its potential mechanisms in neuronal cell pyroptosis and microglia inflammatory responses. Adult male mice underwent permanent distal middle cerebral artery occlusion (dMCAO), followed by daily oral gavage of NBP (80 mg/kg) for 1, 7, or 21 consecutive days. Gene Expression Omnibus (GEO) dataset of IS patients peripheral blood RNA sequencing was analyzed to identify differentially expressed pyroptosis-related genes (PRGs) during the ischemic process. Our results suggested that NBP treatment effectively alleviated brain ischemic damage, resulting in decreased neurological deficit scores, reduced infarct volume, and improved neurological and behavioral functions. RNA sequence data from human unveiled upregulated PRGs in IS. Subsequently, we observed that NBP downregulated pyroptosis-associated markers at days 7 and 21 post-modeling, at both the protein and mRNA levels. Additionally, NBP suppressed the co-localization of pyroptosis markers with neuronal cells to variable degrees and simultaneously mitigated the accumulation of activated microglia. Overall, our data provide novel evidence that NBP treatment significantly attenuates ischemic brain damage and promotes recovery of neurological function in the early and recovery phases after IS, probably by negatively regulating the pyroptosis cell death of neuronal cells and inhibiting toxic neuroinflammation in the central nervous system.

Therapeutic effectiveness of Donepezil hydrochloride in combination with butylphthalide for post-stroke cognitive impairment

OBJECTIVE

To study the therapeutic effectiveness of donepezil hydrochloride (DPZ) in combination with butylphthalide (BP) for the treatment of post-stroke cognitive impairment (PSCI).

METHODS

In this retrospective study, the clinical data of 125 PSCI patients treated at the First Affiliated Hospital of Harbin Medical University from December 2019 to December 2023 were collected and analyzed. The patients were grouped into a joint group (n=75, receiving DPZ + BP) and a control group (n=50, receiving DPZ alone) according to their treatment regimen. Inter-group comparisons were then carried out from the perspectives of therapeutic effectiveness, safety (constipation, abdominal distension and pain, and gastrointestinal reactions), cognitive function (Montreal Cognitive Assessment Scale [MoCA], Chinese Stroke Scale [CSS]), Activities of Daily Living Scale (ADL), and serum biochemical indexes (neuron-specific enolase [NSE], high-sensitivity C-reactive protein [hs-CRP], nitric oxide [NO], and malondialdehyde [MDA]). In addition, a univariate analysis was carried out to identify factors affecting therapeutic effectiveness in PSCI patients.

RESULTS

The joint group showed significantly better therapeutic effectiveness compared to the control group (P<0.05). There was a significant correlation between the type of stroke, treatment method, and therapeutic effectiveness in PSCI patients (P<0.05). There was no significant difference in the total incidence of adverse reactions (P>0.05). After the treatment, compared to the control group, the joint group demonstrated significant improvements in MoCA and ADL scores (all P<0.05) and reductions in CSS scores and levels of NSE, hs-CRP, NO, and MDA (all P<0.05).

CONCLUSIONS

DPZ in combination with BP is highly effective for the treatment of PSCI. It positively affects cognitive function and ADL, alleviates neurological deficits, and reduces abnormal serum biochemical indices without increasing the risk of adverse reaction.

Butylphthalide combined with donepezil for the treatment of vascular dementia: a meta-analysis

OBJECTIVE

To systematically evaluate the efficacy and safety of butylphthalide combined with donepezil versus butylphthalide monotherapy for the treatment of vascular dementia.

METHODS

Randomized controlled trials were searched in electronic databases, including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database (VIP), Wan Fang, and China Biology Medicine from inception to 29 November 2022. Two reviewers independently screened the papers and extracted data from the included studies. The data were processed using RevMan5.4 statistical software.

RESULTS

Nine randomized controlled trials (n = 1024) were included in this meta-analysis. Regarding the primary outcomes, compared with butylphthalide monotherapy, combined butylphthalide and donepezil treatment exhibited significantly greater total clinical efficacy (relative risk = 1.24, 95% confidence interval [1.17, 1.31]) and did not increase the adverse event rate (relative risk = 1.39, 95% confidence interval [0.91, 2.14]). Regarding the secondary outcomes, the meta-analysis results for the Mini-Mental State Examination, abilities of daily living, and Montreal Cognitive Assessment scores and the interleukin-6, tumor necrosis factor-α, and superoxide dismutase blood levels all supported combined butylphthalide and donepezil treatment.

CONCLUSION

Butylphthalide combined with donepezil may be a better treatment strategy than donepezil alone for the treatment of vascular dementia in clinical practice.

Dl-3-n-butylphthalide promotes angiogenesis in ischemic stroke mice through upregulating autocrine and paracrine sonic hedgehog

Dl-3-n-butylphthalide (NBP) is a small-molecule drug used in the treatment of ischemic stroke in China, which is proven to ameliorate the symptoms of ischemic stroke and improve the prognosis of patients. Previous studies have shown that NBP accelerates recovery after stroke by promoting angiogenesis. In this study, we investigated the mechanisms underlying the angiogenesis-promoting effects of NBP in ischemic stroke models in vitro and in vivo. OGD/R model was established in human umbilical vein endothelial cells (HUVECs) and human brain microvascular endothelial cells (HBMECs), while the tMCAO model was established in mice. The cells were pretreated with NBP (10, 50, 100 µM); the mice were administered NBP (4, 8 mg/kg, i.v.) twice after tMCAO. We showed that NBP treatment significantly stimulated angiogenesis by inducing massive production of angiogenic growth factors VEGFA and CD31 in both in vitro and in vivo models of ischemic stroke. NBP also increased the tubule formation rate and migration capability of HUVECs in vitro. By conducting the weighted gene co-expression network analysis, we found that these effects were achieved by upregulating the expression of a hedgehog signaling pathway. We demonstrated that NBP treatment not only changed the levels of regulators of the hedgehog signaling pathway but also activated the transcription factor Gli1. The pro-angiogenesis effect of NBP was abolished when the hedgehog signaling pathway was inhibited by GDC-0449 in HUVECs, by Sonic Hedgehog(Shh) knockdown in HUVECs, or by intracerebroventricular injection of AAV-shRNA(shh)-CMV in tMCAO mice. Furthermore, we found that HUVECs produced a pro-angiogenic response not only to autocrine Shh, but also to paracrine Shh secreted by astrocytes. Together, we demonstrate that NBP promotes angiogenesis via upregulating the hedgehog signaling pathway. Our results provide an experimental basis for the clinical use of NBP.

Neurological Applications of Celery (Apium graveolens): A Scoping Review

Apium graveolens is an indigenous plant in the family Apiaceae, or Umbelliferae, that contains many active compounds. It has been used traditionally to treat arthritic conditions, gout, and urinary infections. The authors conducted a scoping review to assess the quality of available evidence on the overall effects of celery when treating neurological disorders. A systematic search was performed using predetermined keywords in selected electronic databases. The 26 articles included upon screening consisted of 19 in vivo studies, 1 published clinical trial, 4 in vitro studies and 2 studies comprising both in vivo and in vitro methods. A. graveolens and its bioactive phytoconstituent, 3-n-butylphthalide (NBP), have demonstrated their effect on neurological disorders such as Alzheimer's disease, Parkinson's disease, stroke-related neurological complications, depression, diabetes-related neurological complications, and epilepsy. The safety findings were minimal, showing that NBP is safe for up to 18 weeks at 15 mg/kg in animal studies, while there were adverse effects (7%) reported when consuming NBP for 24 weeks at 600 mg daily in human trials. In conclusion, the safety of A. graveolens extract and NBP can be further investigated clinically on different neurological disorders based on their potential role in different targeted pathways.

A comparative study of the neuroprotective effects of dl-3-n-butylphthalide and edaravone dexborneol on cerebral ischemic stroke rats

INTRODUCTION

DL-3-n-butylphthalide (NBP) and edaravone dexborneol (Eda-Dex) are two promising reagents for stroke treatment. However, the impacts of NBP and Eda-Dex on poststroke mental deficits are still poorly understood. In this study, we aimed to investigate and compare the influences of NBP and Eda-Dex on neurological function and cognitive behavior in rats with ischemic stroke.

METHODS

An ischemic stroke model was established by middle cerebral artery occlusion (MCAO). After peritoneal administration of the drugs, the rats were subjected to neurological deficit evaluation, cerebral blood flow (CBF) assays, cerebral infarct area evaluations or behavioral tests. Brain tissues were collected and further analyzed by enzyme-linked immunosorbent assay (ELISA), western blotting or immunohistochemistry.

RESULTS

NBP and Eda-Dex significantly decreased the neurological score, reduced the cerebral infarct area and improved CBF. Behavioral changes as assessed in the sucrose preference test, novel object recognition test, and social interaction test were significantly alleviated by NBP and Eda-Dex in rats with ischemic stroke. Moreover, NBP and Eda-Dex significantly suppressed inflammation by targeting the nuclear factor kappa-B/inducible nitric oxide synthase (NF-κB/iNOS) pathway and significantly inhibited oxidative stress by targeting the kelch-1ike ECH-associated protein l/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) pathway. In addition, NBP and Eda-Dex distinctly suppressed the activation of microglia and astrocytes and improved neuronal viability in the ischemic brain.

CONCLUSIONS

NBP and Eda-Dex improved neurological function and alleviated cognitive disorders in rats with ischemic stroke by synergistically inhibiting inflammation and oxidative stress.

DL-3-n-butylphthalide (NBP) alleviates poststroke cognitive impairment (PSCI) by suppressing neuroinflammation and oxidative stress

Currently, the recovery of cognitive function has become an essential part of stroke rehabilitation. DL-3-n-butylphthalide (NBP) is a neuroprotective reagent and has been used in stroke treatment. Clinical studies have confirmed that NBP can achieve better cognitive outcomes in ischemic stroke patients than in healthy controls. In this study, we aimed to investigate the influences of NBP on cognitive function in an ischemic reperfusion (I/R) rat model. Our results showed that NBP profoundly decreased neurological scores, reduced cerebral infarct areas and enhanced cerebral blood flow (CBF). NBP potently alleviated poststroke cognitive impairment (PSCI) including depression-like behavior and learning, memory and social cognition impairments, in I/R rats. NBP distinctly suppressed the activation of microglia and astrocytes and improved neuron viability in the ischemic brain. NBP inhibited the expression of inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), by targeting the nuclear factor kappa B/inducible nitric oxide synthase (NF-κB/iNOS) pathway and decreased cerebral oxidative stress factors, including reactive oxygen species (ROS) and malondialdehyde (MDA), by targeting the kelch like ECH associated protein 1/nuclear factor-erythroid 2 p45-related factor 2 (Keap1/Nrf2) pathway in the ischemic brain. The current study revealed that NBP treatment improved neurological function and ameliorated cognitive impairment in I/R rats, possibly by synergistically suppressing inflammation and oxidative stress.

Efficacy and safety of 3-n-butylphthalide combined with endovascular treatment in acute ischemic stroke due to large vessel occlusion

BACKGROUND

The drug 3-n-butylphthalide (NBP) was developed and approved in China, where it has been used to treat ischemic cerebrovascular diseases. It is also considered to have a neuroprotective effect. This study aimed to evaluate whether NBP combined with endovascular treatment (EVT) can improve the clinical outcome and safety in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO).

METHODS

Data from three studies of patients treated with EVT for AIS due to LVO were combined in this study. Patients of LVO undergoing EVT were dichotomized into NBP and non-NBP subgroups. The primary efficacy outcome was the shift of the modified Rankin Scale (mRS) score at 90 days. The secondary efficacy outcome included favorable functional outcomes, functional independence, and excellent outcome (defined as an mRS score of 3 or less) at 90 days. Safety outcomes included mortality within 90 days and symptomatic intracranial hemorrhage (sICH) within 48 h.

RESULTS

A total of 1820 patients undergoing EVT were included in this study; 628 (37.5%) patients received NBP treatment, whereas 1138 (62.5%) did not. After adjusting for multiple factors, NBP was associated with the improvement of functional outcomes at 90 days (adjusted common odds ratio [OR]: 1.503; 95% confidence interval (CI): 1.254-1.801; p < 0.001). NBP was associated with a higher rate of 90-day favorable outcomes (adjusted OR: 1.589; 95% CI: 1.251-2.020; p < 0.001) and a lower rate of 90-day mortality (adjusted OR: 0.486 [95% CI: 0.372-0.635]; p < 0.001). sICH occurred in 74 of 682 (10.9%) patients in the NBP group and 155 of 1126 (13.8%) patients in the non-NBP group; no statistical difference was detected (adjusted OR: 0.787 [95% CI: 0.567-1.092]; p = 0.152).

CONCLUSION

Among patients with AIS due to LVO, NBP combined with EVT is associated with better functional outcomes and reduced mortality risk without increasing the risk of sICH.

Dl-3-n-Butylphthalide (NBP) Mitigates Muscular Injury Induced by Limb Ischemia/Reperfusion in Mice through the HMGB1/TLR4/NF-κB Pathway

Objective

Limb ischemia/reperfusion (I/R) injury is a clinical syndrome associated with severe damages to skeletal muscles and other fatal outcomes. Oxidative stress and inflammatory response play vital roles in the development of limb I/R injury. Existing evidence further indicates that Dl-3-n-butylphthalide (NBP) has anti-inflammatory and antioxidative properties. However, whether NBP can protect skeletal muscles from limb I/R injury and the mechanism in mediating the action of NBP treatment still remain to be investigated, which are the focuses of the current study.

Methods

The model of limb I/R injury was established and H&E staining was adopted to assess the pathological changes in skeletal muscles following limb I/R injury. Additionally, the W/D ratio of muscle tissue was also measured. ELISA and biochemical tests were carried out to measure the levels of inflammatory cytokines and oxidative stress in mouse models of limb I/R injury. Moreover, the levels of the HMGB1/TLR4/NF-κB pathway-related proteins were also determined using immunohistochemistry and immunoblotting.

Results

It was established that NBP treatment alleviated I/R-induced pathological changes in muscular tissue of mice, accompanied by lower W/D ratio of skeletal muscular tissue. Meanwhile, the limb I/R-induced inflammation and oxidative stress in skeletal muscles of mice were also inhibited by NBP. Mechanistic study indicated that the alleviatory effect of NBP was ascribed to inactivation of the HMGB1/TLR4/NF-κB pathway.

Conclusions

Our findings highlighted the potential of NBP as a novel strategy for limb I/R-driven muscle tissue damages by suppressing inflammatory response and oxidative stress via the HMGB1/TLR4/NF-κB pathway.

DL-3-n-butylphthalide for acute ischemic stroke: An updated systematic review and meta-analysis of randomized controlled trials

Background: DL -3-n-butylphthalide (NBP) is widely used as a neuroprotective drug in stroke patients in China. A systematic review in 2010 suggested NBP to be safe and effective at promoting neurological recovery, but could not conclude whether it decreased risk of long-term death or disability. Since numerous randomized controlled trials (RCTs) have been conducted on NBP since 2010, we performed an updated systematic review and meta-analysis of safety and efficacy data.

Method: We searched electronic databases and reference lists to identify RCTs that compared patients who received NBP or not (including placebo). Methodological quality of RCTs was assessed using the Revised Cochrane Risk of Bias Tool 2.0, and data were meta-analyzed using Review Manager 5.4 software.

Results: Fifty-seven RCTs involving 8,747 participants were included. Twenty trials examined NBP as a capsule, 29 as an injection, and 8 as sequential injection-capsule therapy. Meta-analyses showed that NBP treatment was associated with a reduction in composite outcome of death and dependency (risk ratio 0.59, 95% CI 0.42 to 0.83; 260 participants; 2 studies), death (risk ratio 0.32, 95% CI 0.13 to 0.75; 2,287 participants; 10 studies), modified Rankin Scale score (mean difference -0.80, 95% CI -0.88 to -0.72; 568 participants; 4 studies), and an increase in Barthel Index, which assesses the ability to engage in basic activities of daily living (mean difference 11.08, 95% CI 9.10 to 13.05; 2,968 participants; 22 studies). Meta-analyses found that NBP significantly reduced neurological deficit based on National Institute of Health Stroke Scale (mean difference -3.39, 95% CI -3.76 to -3.03; 7.283 participants; 46 studies) and Chinese Stroke Scale (mean difference -4.16, 95% CI -7.60 to -0.73; 543 participants; 4 studies). Of the adverse events reported in 31 trials, elevated transaminase (incidence, 1.39-17.53%), rash (0-1.96%) and gastrointestinal discomfort (1.09-6.15%) were most frequent and no serious adverse events were reported.

Conclusion: This update review confirms that NBP can help acute ischemic stroke patients regain the ability to perform activities of daily living, reduce their neurological deficit and short-term death rates. However, the available evidence on whether NBP reduces risk of long-term death or dependence after ischemic stroke remains insufficient.

Edaravone Dexborneol Downregulates Neutrophil Extracellular Trap Expression and Ameliorates Blood-Brain Barrier Permeability in Acute Ischemic Stroke

Background

Our previous work has shown that inflammatory processes play a detrimental role in the pathophysiology of acute ischemic stroke (AIS). Neutrophil extracellular traps (NETs) have been recognized as a key contributor to the proinflammatory response in AIS and could aggravate blood-brain barrier (BBB) damage. Recently, experimental and clinical researches showed that Edaravone Dexborneol (Eda.B), which is comprised of two active ingredients, Edaravone and (+)-Borneol, was effective in treatment of AIS. However, it is not clear whether the effects of Eda.B against AIS are related to NETs and BBB permeability.

Methods

Experiment 1 was to detect the effects of Eda.B in AIS patients. Serum samples of volunteers and AIS patients were collected before and 3 days after Edaravone Dexborneol treatment. Markers of NETs and occludin were detected by ELISA kit. Experiment 2 was to explore the effects of Eda.B on experimental stroke mice. Male C57BL/6 mice were subjected to distal middle cerebral artery occlusion (MCAO) and treated with vehicle, Eda.B, or DeoxyribonueleaseI (DNase I). After stroke, the neurobehavioral tests, infarct volume, and cerebral blood flow evaluation were determined. Leakage of Evans blue was to assess the integrity of BBB. Western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence were used to examine the expression of NETs and tight junction- (TJ-) associated proteins.

Results

Eda.B significantly improved neurological function and cerebral blood flow but reduced infarct volume after experimental stroke. Eda.B downregulated level of NETs in serum samples of AIS patients and tissue samples of MCAO mouse cortex. Eda.B and DNase I alleviated BBB permeability by upregulating TJ-associated proteins.

Conclusion

NETs are related to the early stage of AIS. Eda.B exerted neuroprotective effects and ameliorated BBB permeability after AIS.

Potential Protective Effect of Dl-3-n-butylphthalide on Chronic Cerebral Ischemia Brain Injury

Chronic cerebral ischemia is one of the common ischemic cerebrovascular diseases. Chronic cerebral ischemia can lead to brain dysfunction, and its pathophysiological mechanism involves inflammation, blood-brain barrier destruction, oxidative stress, and other factors. As it is difficult to detect, it is easily overlooked, and it is often only observed following the onset of cognitive dysfunction. At present, there are only a few drugs for its treatment. Dl-3-n-butylphthalide (NBP), a compound extracted from celery seed, may play an important role in protecting against brain damage caused by chronic cerebral ischemia. Therefore, here, we have paid attention to the prevention and treatment of chronic cerebral ischemia with NBP.

Factors influencing the blood-brain barrier permeability

The blood-brain barrier (BBB) is a dynamic structure that protects the brain from harmful blood-borne, endogenous and exogenous substances and maintains the homeostatic microenvironment. All constituent cell types play indispensable roles in the BBB's integrity, and other structural BBB components, such as tight junction proteins, adherens junctions, and junctional proteins, can control the barrier permeability. Regarding the need to exchange nutrients and toxic materials, solute carriers, ATP-binding case families, and ion transporter, as well as transcytosis regulate the influx and efflux transport, while the difference in localisation and expression can contribute to functional differences in transport properties. Numerous chemical mediators and other factors such as non-physicochemical factors have been identified to alter BBB permeability by mediating the structural components and barrier function, because of the close relationship with inflammation. In this review, we highlight recently gained mechanistic insights into the maintenance and disruption of the BBB. A better understanding of the factors influencing BBB permeability could contribute to supporting promising potential therapeutic targets for protecting the BBB and the delivery of central nervous system drugs via BBB permeability interventions under pathological conditions.

DL-3-n-butylphthalide Increases Collateriogenesis and Functional Recovery after Focal Ischemic Stroke in Mice

Recent evidence indicates that collateral circulation is critical for the outcome of ischemic stroke. DL-3-n-butylphthalide (NBP), a synthesized compound based on an extract from seeds of celery Apium graveolens Linn, has been used as a therapeutic drug, showing multiple neuroprotective and regenerative activities. A potential effect of NBP on collateral arterial regulation is unknown. We examined the effects of NBP on arteriogenesis of collateral arteries in vitro and a mouse ischemic stroke model. In cultures of mouse iPS cell-derived vascular progenitors, NBP (10 μM) significantly increased α-smooth muscle actin (αSMA)/CD-31 co-labeled cells and the expression of newly formed vasculature marker PDGFRα. A sensorimotor cortex ischemia was induced in transgenic mice expressing αSMA-GFP that allowed direct observation of arterial vasculatures in brain regions. NBP (80 mg/kg) was intranasally delivered 1 hr after stroke and once daily for 14 days. To label proliferating cells, 5-Bromo-2’-deoxyuridine (BrdU, 50 mg/kg, i.p.) was administrated every day from 3 days after stroke. Western blotting of peri-infarct tissue detected increased expressions of VEGF, Ang-1 and reduced nNOS level in NBP-treated mice. The NBP treatment significantly increased αSMA/BrdU co-labeled cells, the diameter of ipsilateral collaterals, and arterial area in ischemic and peri-infarct regions examined 14 days after stroke. Examined 3 days after stroke, NBP prevented functional deficits in the cylinder test and corner test. The NBP treatment of 14 days improved the local cerebral blood flow (LCBF) and functional performance in multiple tests. Thus, NBP promotes collateriogenesis, short and long-term structural and functional improvements after ischemic stroke.

Salvianolic acid A alleviated inflammatory response mediated by microglia through inhibiting the activation of TLR2/4 in acute cerebral ischemia-reperfusion

BACKGROUND

Toll-like receptor 2 and Toll-like receptor 4 (TLR2/4) on microglia have been found as important regulators in the inflammatory response during cerebral ischemia/reperfusion (I/R). In China, traditional Chinese medicine Salvia miltiorrhiza (danshen) and its some components are considered to be effective in rescuing cerebral I/R injury through clinical practice.

HYPOTHESIS/PURPOSE

Here we examined the effect of Salvianolic acid A (SAA), a monomer compound in the water extract of Salvia miltiorrhiza, on TLR2/4 of microglia and its mediated inflammatory injury during cerebral I/R in vivo and in vitro.

STUDY DESIGN

For exploring the effect of SAA on cerebral I/R and TLR2/4, classic middle cerebral artery occlusion (MCAO) model and oxygen glucose deprivation / reoxygenation (OGD/R) model of co-culture with primary hippocampal neurons and microglia in vitro were used. Signal pathway research and gene knockout have been applied to further explain its mechanism.

METHODS

The evaluation indexes of I/R injury included infarct size, edema degree and pathology as well as primary hippocampal neurons and microglia culture, ELISA, western, RT-PCR, HE staining, immunofluorescence, flow cytometry, siRNA gene knockout were also employed.

RESULTS

SAA significantly improved the degree of brain edema and ischemic area in I/R rats accompanied by decreases in levels of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α). Pathological staining revealed that SAA could reduce inflammatory cell infiltration and mcirogila activation after reperfusion. Both protein and gene expression of TLR2 and TLR4 in ischemic hemisphere were obviously inhibited by SAA treatment while changes were not found in the non-ischemic hemisphere. In order to further study its mechanism, OGD/R model was used to mimic inflammatory damage of ischemic tissue by co-culturing primary rat hippocampal neurons and microglial cells. It was found that SAA also inhibited the protein and gene expression of TLR2 and TLR4 after OGD/R injury in microglia. After TLR2/4 knockout, the inhibitory effect of SAA on IL-1β and TNF-α levels in cell supernatant and neuron apoptosis were significantly weakened in each dose group. Moreover, expression levels of myeloid differentiation factor 88 (MyD88), NFκB, IL-1β and IL-6 in TLR2/4 mediated inflammatory pathway were reduced with SAA treatment.

CONCLUSION

SAA could significantly reduce the inflammatory response and injury in cerebral ischemia-reperfusion in vivo and in vitro, and its mechanism may be through the inhibition of TLR2/4 and its related signal pathway.

Natural Products in the Prevention of Metabolic Diseases: Lessons Learned from the 20th KAST Frontier Scientists Workshop

The incidence of metabolic and chronic diseases including cancer, obesity, inflammation-related diseases sharply increased in the 21st century. Major underlying causes for these diseases are inflammation and oxidative stress. Accordingly, natural products and their bioactive components are obvious therapeutic agents for these diseases, given their antioxidant and anti-inflammatory properties. Research in this area has been significantly expanded to include chemical identification of these compounds using advanced analytical techniques, determining their mechanism of action, food fortification and supplement development, and enhancing their bioavailability and bioactivity using nanotechnology. These timely topics were discussed at the 20th Frontier Scientists Workshop sponsored by the Korean Academy of Science and Technology, held at the University of Hawaii at Manoa on 23 November 2019. Scientists from South Korea and the U.S. shared their recent research under the overarching theme of Bioactive Compounds, Nanoparticles, and Disease Prevention. This review summarizes presentations at the workshop to provide current knowledge of the role of natural products in the prevention and treatment of metabolic diseases.

Classical Active Ingredients and Extracts of Chinese Herbal Medicines: Pharmacokinetics, Pharmacodynamics, and Molecular Mechanisms for Ischemic Stroke

Stroke is a leading cause of death and disability worldwide, and approximately 87% of cases are attributed to ischemia. The main factors that cause ischemic stroke include excitotoxicity, energy metabolism disorder, Ca⁺ overload, oxidative damage, apoptosis, autophagy, and inflammation. However, no effective drug is currently available for the comprehensive treatment of ischemic stroke in clinical applications; thus, there is an urgent need to find and develop comprehensive and effective drugs to treat postischemic stroke. Traditional Chinese medicine (TCM) has unique advantages in treating ischemic stroke, with overall regulatory effects at multiple levels and on multiple targets. Many researchers have studied the effective components of TCMs and have achieved undeniable results. This paper reviews studies on the anticerebral ischemia effects of TCM monomers such as tetramethylpyrazine (TMP), dl-3-n-butylphthalide (NBP), ginsenoside Rg1 (Rg1), tanshinone IIA (TSA), gastrodin (Gas), and baicalin (BA) as well as effective extracts such as Ginkgo biloba extract (EGB). Research on the anticerebral ischemia effects of TCMs has focused mostly on their antioxidative stress, antiapoptotic, anti-inflammatory, proangiogenic, and proneurogenic effects. However, the research on the use of TCM to treat ischemic stroke remains incompletely characterized. Thus, we summarized and considered this topic from the perspective of pharmacokinetics, pharmacological effects, and mechanistic research, and we have provided a reference basis for future research and development on anticerebral ischemia TCM drugs.

Blood-Brain Barrier Damage in Ischemic Stroke and Its Regulation by Endothelial Mechanotransduction

Ischemic stroke, a major cause of mortality in the United States, often contributes to disruption of the blood-brain barrier (BBB). The BBB along with its supportive cells, collectively referred to as the “neurovascular unit,” is the brain’s multicellular microvasculature that bi-directionally regulates the transport of blood, ions, oxygen, and cells from the circulation into the brain. It is thus vital for the maintenance of central nervous system homeostasis. BBB disruption, which is associated with the altered expression of tight junction proteins and BBB transporters, is believed to exacerbate brain injury caused by ischemic stroke and limits the therapeutic potential of current clinical therapies, such as recombinant tissue plasminogen activator. Accumulating evidence suggests that endothelial mechanobiology, the conversion of mechanical forces into biochemical signals, helps regulate function of the peripheral vasculature and may similarly maintain BBB integrity. For example, the endothelial glycocalyx (GCX), a glycoprotein-proteoglycan layer extending into the lumen of bloods vessel, is abundantly expressed on endothelial cells of the BBB and has been shown to regulate BBB permeability. In this review, we will focus on our understanding of the mechanisms underlying BBB damage after ischemic stroke, highlighting current and potential future novel pharmacological strategies for BBB protection and recovery. Finally, we will address the current knowledge of endothelial mechanotransduction in BBB maintenance, specifically focusing on a potential role of the endothelial GCX.

Dl-3-n-butylphthalide attenuates hypoxic-ischemic brain injury through inhibiting endoplasmic reticulum stress-induced cell apoptosis and alleviating blood-brain barrier disruption in newborn rats

Dl-3-n-butylphthalide (NBP) has been demonstrated to exert neuroprotective effects in experimental models and human patients. This study was performed to assess the therapeutic effects and the underlying molecular mechanisms of NBP in a neonatal hypoxic-ischemic rat model. The results showed that NBP treatment significantly reduced the infarct volume, improved histological recovery, decreased neuronal cell loss, enhanced neuronal cell rehabilitation, promoted neurite growth and decreased white matter injury. In addition, NBP treatment effectively improved long-term neurobehavioral development and prognosis after HI injury. We further demonstrated an inhibitory effect of NBP on endoplasmic reticulum (ER) stress-induced apoptosis, evidenced by reduction in ER stress-related protein expressions (GRP78, XBP-1, PDI and CHOP), decrease in TUNEL-positive cells, down-regulation in pro-apoptosis protein (Bax and cleaved caspase-3), up-regulation in anti-apoptosis protein (Bcl-2). Moreover, NBP exerted a protective effect in blood-brain barrier disruption, which ameliorated brain edema and reduced the degeneration of the tight junction proteins (Occludin and Claudin-5) and adherens junction proteins (P120-Catenin, VE-Cadherin and β-Catenin). Overall, our findings demonstrated that NBP treatment attenuated HI brain injury through inhibiting ER stress-induced apoptosis and alleviating blood-brain barrier disruption in newborn rats. This work provides an effective therapeutic strategy to reduce brain damage and enhance recovery after neonatal HI brain injury.

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.

Therapeutic targets of oxidative/nitrosative stress and neuroinflammation in ischemic stroke: Applications for natural product efficacy with omics and systemic biology

Oxidative/nitrosative stress and neuroinflammation are critical pathological processes in cerebral ischemia-reperfusion injury, and their intimate interactions mediate neuronal damage, blood-brain barrier (BBB) damage and hemorrhagic transformation (HT) during ischemic stroke. We review current progress towards understanding the interactions of oxidative/nitrosative stress and inflammatory responses in ischemic brain injury. The interactions between reactive oxygen species (ROS)/reactive nitrogen species (RNS) and innate immune receptors such as TLR2/4, NOD-like receptor, RAGE, and scavenger receptors are crucial pathological mechanisms that amplify brain damage during cerebral ischemic injury. Furthermore, we review the current progress of omics and systematic biology approaches for studying complex network regulations related to oxidative/nitrosative stress and inflammation in the pathology of ischemic stroke. Targeting oxidative/nitrosative stress and neuroinflammation could be a promising therapeutic strategy for ischemic stroke treatment. We then review recent advances in discovering compounds from medicinal herbs with the bioactivities of simultaneously regulating oxidative/nitrosative stress and pro-inflammatory molecules for minimizing ischemic brain injury. These compounds include sesamin, baicalin, salvianolic acid A, 6-paradol, silymarin, apocynin, 3H-1,2-Dithiole-3-thione, (-)-epicatechin, rutin, Dl-3-N-butylphthalide, and naringin. We finally summarize recent developments of the omics and systematic biology approaches for exploring the molecular mechanisms and active compounds of Traditional Chinese Medicine (TCM) formulae with the properties of antioxidant and anti-inflammation for neuroprotection. The comprehensive omics and systematic biology approaches provide powerful tools for exploring therapeutic principles of TCM formulae and developing precision medicine for stroke treatment.