Astragaloside IV improves neurobehavior and promotes hippocampal neurogenesis in MCAO rats though BDNF-TrkB signaling pathway

Adaptogens in Long-Lasting Brain Fatigue: An Insight from Systems Biology and Network Pharmacology

Long-lasting brain fatigue is a consequence of stroke or traumatic brain injury associated with emotional, psychological, and physical overload, distress in hypertension, atherosclerosis, viral infection, and aging-related chronic low-grade inflammatory disorders. The pathogenesis of brain fatigue is linked to disrupted neurotransmission, the glutamate-glutamine cycle imbalance, glucose metabolism, and ATP energy supply, which are associated with multiple molecular targets and signaling pathways in neuroendocrine-immune and blood circulation systems. Regeneration of damaged brain tissue is a long-lasting multistage process, including spontaneously regulating hypothalamus-pituitary (HPA) axis-controlled anabolic-catabolic homeostasis to recover harmonized sympathoadrenal system (SAS)-mediated function, brain energy supply, and deregulated gene expression in rehabilitation. The driving mechanism of spontaneous recovery and regeneration of brain tissue is a cross-talk of mediators of neuronal, microglia, immunocompetent, and endothelial cells collectively involved in neurogenesis and angiogenesis, which plant adaptogens can target. Adaptogens are small molecules of plant origin that increase the adaptability of cells and organisms to stress by interaction with the HPA axis and SAS of the stress system (neuroendocrine-immune and cardiovascular complex), targeting multiple mediators of adaptive GPCR signaling pathways. Two major groups of adaptogens comprise (i) phenolic phenethyl and phenylpropanoid derivatives and (ii) tetracyclic and pentacyclic glycosides, whose chemical structure can be distinguished as related correspondingly to (i) monoamine neurotransmitters of SAS (epinephrine, norepinephrine, and dopamine) and (ii) steroid hormones (cortisol, testosterone, and estradiol). In this narrative review, we discuss (i) the multitarget mechanism of integrated pharmacological activity of botanical adaptogens in stress overload, ischemic stroke, and long-lasting brain fatigue; (ii) the time-dependent dual response of physiological regulatory systems to adaptogens to support homeostasis in chronic stress and overload; and (iii) the dual dose-dependent reversal (hormetic) effect of botanical adaptogens. This narrative review shows that the adaptogenic concept cannot be reduced and rectified to the various effects of adaptogens on selected molecular targets or specific modes of action without estimating their interactions within the networks of mediators of the neuroendocrine-immune complex that, in turn, regulates other pharmacological systems (cardiovascular, gastrointestinal, reproductive systems) due to numerous intra- and extracellular communications and feedback regulations. These interactions result in polyvalent action and the pleiotropic pharmacological activity of adaptogens, which is essential for characterizing adaptogens as distinct types of botanicals. They trigger the defense adaptive stress response that leads to the extension of the limits of resilience to overload, inducing brain fatigue and mental disorders. For the first time, this review justifies the neurogenesis potential of adaptogens, particularly the botanical hybrid preparation (BHP) of Arctic Root and Ashwagandha, providing a rationale for potential use in individuals experiencing long-lasting brain fatigue. The review provided insight into future research on the network pharmacology of adaptogens in preventing and rehabilitating long-lasting brain fatigue following stroke, trauma, and viral infections.

Research progress of small-molecule natural medicines for the treatment of ischemic stroke

Stroke is the second leading cause of disability and mortality worldwide, imposing a substantial socioeconomic burden on individuals and healthcare systems. Annually, approximately 14 million people experience stroke, with ischemic stroke comprising nearly 85% of cases, of which 10% to 20% involve large vessel occlusions. Currently, recombinant tissue plasminogen activator (tPA) remains the only approved pharmacological intervention. However, its utility is limited due to a narrow therapeutic window and low recanalization rates, making it applicable to only a minority of patients. Therefore, there is an urgent need for novel therapeutic strategies, including pharmacological advancements and combinatory treatments. Small-molecule natural medicines, particularly those derived from traditional Chinese herbs, have demonstrated significant therapeutic potential in ischemic stroke management. These compounds exert multiple neuroprotective effects, such as antioxidation, anti-inflammatory action, and inhibition of apoptosis, all of which are critical in mitigating stroke-induced cerebral damage. This review comprehensively examines the pathophysiology of acute ischemic stroke (AIS) and highlights the recent progress in the development of small-molecule natural medicines as promising therapeutic agents for cerebral ischemic stroke.

Exploratory review on the effect of Astragalus mongholicus on signaling pathways

Background

Astragalus mongholicus Bunge [Fabaceae; Astragali radix] (AM), a traditional Chinese medicinal (TCM) botanical drug, has been used for centuries and is gaining growing recognition in medical research for its therapeutic potential. The currently accepted scientific name is Astragalus mongholicus Bunge, with Astragalus membranaceus Fisch. ex Bunge recognized as a taxonomic synonym. This review explores the most relevant scientific studies on AM, focusing on its chemical composition, mechanisms of action, and associated health benefits.

Main body

AM is commonly used in clinical practice to treat diabetes mellitus, cardiovascular diseases, oncological processes, lipid metabolism disorders, and ulcerative colitis. Recent research has investigated its potential as a product for anti-aging purposes. These therapeutic effects are attributed to the interactions of bioactive metabolites such as Astragaloside IV, Formononetin, and polysaccharides, with various signaling pathways, leading to the activation or inhibition of gene expression. This review aims to map the signaling pathways affected by these metabolites and their effects on different pathologies. Studies suggest that these metabolites act on signaling pathways such as TLR4/MyD88/NF-κB, PI3K/AKT, RNA expression, and tumor receptors. However, further research is necessary to validate the findings in human trials with better methodological quality.

Conclusion

AM is rich in bioactive metabolites that interact with various signaling pathways, modulating diseases such as diabetes mellitus type 2, cardiovascular diseases, cancer, lipid metabolism disorders, and ulcerative colitis. Although promising, the majority of the studies are conducted in vitro and animal models, and more rigorous human trials are needed to determine the therapeutic potential of AM.

The impact of flavonoids and BDNF on neurogenic process in various physiological/pathological conditions including ischemic insults: a narrative review

OBJECTIVE

Ischemic stroke is the leading cause of mortality and disability worldwide with more than half of survivors living with serious neurological sequelae thus, it has recently attracted considerable attention in the field of medical research. Neurogenesis is the process of formation of new neurons in the brain, including the human brain, from neural stem/progenitor cells [NS/PCs] which reside in neurogenic niches that contain the necessary substances for NS/PC proliferation, differentiation, migration, and maturation into functioning neurons which can integrate into a pre-existing neural network.Neurogenesis can be modulated by many exogenous and endogenous factors, pathological conditions. Both brain-derived neurotrophic factor, and flavonoids can modulate the neurogenic process in physiological conditions and after various pathological conditions including ischemic insults.

AIM

This review aims to discuss neurogenesis after ischemic insults and to determine the role of flavonoids and BDNF on neurogenesis under physiological and pathological conditions with a concentration on ischemic insults to the brain in particular.

METHOD

Relevant articles assessing the impact of flavonoids and BDNF on neurogenic processes in various physiological/pathological conditions including ischemic insults within the timeline of 1965 until 2023 were searched using the PubMed database.

CONCLUSIONS

The selected studies have shown that ischemic insults to the brain induce NS/PC proliferation, differentiation, migration, and maturation into functioning neurons integrating into a pre-existing neural network. Flavonoids and BDNF can modulate neurogenesis in the brain in various physiological/pathological conditions including ischemic insults. In conclusion, flavonoids and BDNF may be involved in post-ischemic brain repair processes through enhancing endogenous neurogenesis.

Astragaloside IV mediates radiation-induced neuronal damage through activation of BDNF-TrkB signaling

BACKGROUND

Electromagnetic radiation is relevant to human life, and radiation can trigger neurodegenerative diseases by altering the function of the central nervous system through oxidative stress, mitochondrial dysfunction, and protein degradation. Astragaloside IV (AS-IV) is anti-oxidative, anti-apoptotic, activates the BDNF-TrkB pathway and enhances synaptic plasticity in radiated mice, which can exert its neuroprotection. However, the exact molecular mechanisms are still unclear.

PURPOSE

This study investigated whether AS-IV could play a neuroprotective role by regulating BDNF-TrkB pathway in radiation damage and its underlying molecular mechanisms.

METHODS

Transgenic mice (Thy1-YFP line H) were injected with AS-IV (40 mg/kg/day body weight) by intraperitoneal injection daily for 4 weeks, followed by X-rays. PC12 cells and primary cortical neurons were also exposed to UVA after 24 h of AS-IV treatment (25 μg/ml and 50 μg/ml) in vitro. The impact of radiation on learning and cognitive functions was visualized in the Morris water maze assay. Subsequently, Immunofluorescence and Golgi-Cox staining analyses were utilized to investigate the structural damage of neuronal dendrites and the density of dendritic spines. Transmission electron microscopy was performed to examine how the radiation affected the ultrastructure of neurons. Finally, western blotting analysis and Quantitative RT-PCR were used to evaluate the expression levels and locations of proteins in vitro and in vivo.

RESULTS

Radiation induced BDNF-TrkB signaling dysregulation and decreased the levels of neuron-related functional genes (Ngf, Bdnf, Gap-43, Ras, Psd-95, Arc, Creb, c-Fos), PSD-95 and F-actin, which subsequently led to damage of neuronal ultrastructure and dendrites, loss of dendritic spines, and decreased dendritic complexity index, contributing to spatial learning and memory deficits. These abnormalities were prevented by AS-IV treatment. In addition, TrkB receptor antagonists antagonized these neuroprotective actions of AS-IV. 7,8-dihydroxyflavone and AS-IV had neuroprotective effects after radiation.

CONCLUSION

AS-IV inhibits morphological damage of neurons and cognitive dysfunction in mice after radiation exposure, resulting in a neuroprotective effect, which were mediated by activating the BDNF-TrkB pathway.

A Combination of Astragaloside IV and Hydroxysafflor Yellow A Attenuates Cerebral Ischemia-Reperfusion Injury via NF-κB/NLRP3/Caspase-1/GSDMD Pathway

Cerebral ischemia-reperfusion injury (IRI), occurring after blood supply restoration, contributes significantly to stroke-related deaths. This study explored the combined impact and mechanisms of astragaloside IV (AS-IV), hydroxysafflor yellow A (HSYA), and their combination in mitigating IRI. Male Sprague-Dawley (SD) rats were randomized to the Sham, MCAO, MCAO+AS-IV, MCAO+HSYA, and MCAO+AS-IV+HSYA groups. Neurological deficits and cerebral infarction were examined after restoring the blood supply to the brain. Pathomorphological changes in the cerebral cortex were observed via HE staining. IL-1β and IL-18 were quantified using ELISA. The expression of NF-κB and GSDMD in the ischemic cerebrum was analyzed using immunohistochemistry. The expression levels of NLRP3, ASC, IL-1β, Caspase-1, and GSDMD in the ischemic cerebrum were evaluated using Western blot. The MCAO+AS-IV, MCAO+HSYA, and MCAO+AS-IV+HSYA groups exhibited notably better neurological function and cerebral infarction compared with the MCAO group. The combined treatment demonstrated superior brain tissue injury alleviation. Reductions in NF-κB, GSDMD positive cells, and NLRP3/ASC/IL-1β/Caspase-1/GSDMD protein expression in the ischemic brain were significantly more pronounced with the combined therapy, indicating a synergistic effect in countering cerebral IRI via the NF-κB/NLRP3/Caspase-1/GSDMD pathway inhibition of cell pyroptosis-induced injury.

Ethanolic extract of Arctium lappa leaves alleviates cerebral ischemia reperfusion-induced inflammatory injury via HDAC9-mediated NF-κB pathway

BACKGROUND

Ischemic stroke (IS) is a major cause of mortality and disability worldwide. Inflammatory response is crucial in the pathogenesis of tissue injury in cerebral infarction. Arctium lappa leaves are traditionally used to treat IS.

PURPOSES

To investigate the neuroprotective effects and molecular mechanisms of the ethanolic extract of A. lappa leaves (ALLEE) on cerebral ischemia-reperfusion (CIR).

METHODS

Middle cerebral artery obstruction reperfusion (MCAO/R) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) cell model were used to evaluate ALLEE pharmacodynamics. Various methods, including neurological function, 2,3,5-triphenyltetrazolium chloride, hematoxylin and eosin, and Nissl, enzyme-linked immunosorbent, and TdT-mediated dUTP nick-end labeling assays, were used to analyze the neuroprotective effects of ALLEE in vitro and in vivo. The major chemical components and potential target genes of ALLEE were screened using network pharmacology. Molecular docking, western blotting, and immunofluorescence analyses were performed to confirm the effectiveness of the targets in related pathways.

RESULTS

ALLEE exerted potent effects on the MCAO/R model by decreasing the neurological scores, infarct volumes, and pathological features (p < 0.01). Furthermore, network pharmacology results revealed that the treatment of IS with ALLEE involved the regulation of various inflammatory pathways, such as the tumor necrosis factor (TNF) and chemokine signaling pathways. ALLEE also played key roles in targeting key molecules, including nuclear factor (NF)-κBIA, NF-κB1, interleukin (IL)-6, TNF-α and IL1β, and regulating the histone deacetylase (HDAC)-9-mediated signaling pathway. In vivo and in vitro analyses revealed that ALLEE significantly regulated the NF-κB pathway, promoted the phosphorylation activation of NF-κB P65, IκB and IKK (p < 0.01 or p < 0.05), and decreased the expression levels of the inflammatory factors, IL-1β, IL-6 and TNF-α (p < 0.01). Moreover, ALLEE significantly decreased the expression of HDAC9 (p < 0.01) that is associated with inflammatory responses. However, HDAC9 overexpression partially reversed the neuroprotective effects of ALLEE and its suppressive effects on inflammation and phosphorylation of NF-κB (p < 0.01).

CONCLUSIONS

In conclusion, our results revealed that ALLEE ameliorates MCAO/R-induced experimental CIR by modulating inflammatory responses via the inhibition of HDAC9-mediated NF-κB pathway.

miR-153 promotes neural differentiation by activating the cell adhesion/Ca2+ signaling pathway and targeting ion channel activity in HT-22 cells by bioinformatic analysis

MicroRNAs have been studied extensively in neurodegenerative diseases. In a previous study, miR-153 promoted neural differentiation and projection formation in mouse hippocampal HT-22 cells. However, the pathways and molecular mechanism underlying miR-153-induced neural differentiation remain unclear. To explore the molecular mechanism of miR-153 on neural differentiation, we performed RNA sequencing on miR-153-overexpressed HT-22 cells. Based on RNA sequencing, differentially expressed genes (DEGs) and pathways in miR-153-overexpressed cells were identified. The Database for Annotation, Visualization and Integrated Discovery and Gene Set Enrichment Analysis were used to perform functional annotation and enrichment analysis of DEGs. Targetscan predicted the targets of miR-153. The Search Tool for the Retrieval of Interacting Genes and Cytoscape, were used to construct protein-protein interaction networks and identify hub genes. Q-PCR was used to detect mRNA expression of the identified genes. The expression profiles of the identified genes were compared between embryonic days 9.5 (E9.5) and E11.5 in the embryotic mouse brain of the GDS3442 dataset. Cell Counting Kit-8 assay was used to determine cell proliferation and cellular susceptibility to amyloid β-protein (Aβ) toxicity in miR-153-overexpressed cells. The results indicated that miR-153 increased cell adhesion/Ca2+ (Cdh5, Nrcam, and P2rx4) and Bdnf/Ntrk2 neurotrophic signaling pathway, and decreased ion channel activity (Kcnc3, Kcna4, Clcn5, and Scn5a). The changes in the expression of the identified genes in miR-153-overexpressed cells were consistent with the expression profile of GDS3442 during neural differentiation. In addition, miR-153 overexpression decreased cellular susceptibility to Aβ toxicity in HT-22 cells. In conclusion, miR-153 overexpression may promote neural differentiation by inducing cell adhesion and the Bdnf/Ntrk2 pathway, and regulating electrophysiological maturity by targeting ion channels. MiR-153 may play an important role in neural differentiation; the findings provide a useful therapeutic direction for neurodegenerative diseases.

Developing Chinese herbal-based functional biomaterials for tissue engineering

The role of traditional Chinese medicine (TCM) in treating diseases is receiving increasing attention. Chinese herbal medicine is an important part of TCM with various applications and the active ingredients extracted from Chinese herbal medicines have physiological and pathological effects. Tissue engineering combines cell biology and materials science to construct tissues or organs in vitro or in vivo. TCM has been proposed by the World Health Organization as an effective treatment modality. In recent years, the potential use of TCM in tissue engineering has been demonstrated. In this review, the classification and efficacy of TCM active ingredients and delivery systems are discussed based on the TCM theory. We also summarized the current application status and broad prospects of Chinese herbal active ingredients in different specialized biomaterials in the field of tissue engineering. This review provides novel insights into the integration of TCM and modern Western medicine through the application of Chinese medicine in tissue engineering and regenerative medicine.

Effect of 2-Week Naringin Supplementation on Neurogenesis and BDNF Levels in Ischemia-Reperfusion Model of Rats

BACKGROUND

Ischemic stroke is the leading cause of mortality and disability worldwide with more than half of survivors living with serious neurological sequelae; thus, it has recently attracted a lot of attention in the field of medical study.

PURPOSE

The aim of this study was to determine the effect of naringin supplementation on neurogenesis and brain-derived neurotrophic factor (BDNF) levels in the brain in experimental brain ischemia-reperfusion.

STUDY DESIGN

The research was carried out on 40 male Wistar-type rats (10-12 weeks old) obtained from the Experimental Animals Research and Application Center of Selçuk University. Experimental groups were as follows: (1) Control group, (2) Sham group, (3) Brain ischemia-reperfusion group, (4) Brain ischemia-reperfusion + vehicle group (administered for 14 days), and (5) Brain ischemia-reperfusion + Naringin group (100 mg/kg/day administered for 14 days).

METHODS

In the ischemia-reperfusion groups, global ischemia was performed in the brain by ligation of the right and left carotid arteries for 30 min. Naringin was administered to experimental animals by intragastric route for 14 days following reperfusion. The training phase of the rotarod test was started 4 days before ischemia-reperfusion, and the test phase together with neurological scoring was performed the day before and 1, 7, and 14 days after the operation. At the end of the experiment, animals were sacrificed, and then hippocampus and frontal cortex tissues were taken from the brain. Double cortin marker (DCX), neuronal nuclear antigen marker (NeuN), and BDNF were evaluated in hippocampus and frontal cortex tissues by Real-Time qPCR analysis and immunohistochemistry methods.

RESULTS

While ischemia-reperfusion increased the neurological score values, DCX, NeuN, and BDNF levels decreased significantly after ischemia in the hippocampus and frontal cortex tissues. However, naringin supplementation restored the deterioration to a certain extent.

CONCLUSION

The results of the study show that 2 weeks of naringin supplementation may have protective effects on impaired neurogenesis and BDNF levels after brain ischemia and reperfusion in rats.

Out of the core: the impact of focal ischemia in regions beyond the penumbra

The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.

Fluid shear stress induced-endothelial phenotypic transition contributes to cerebral ischemia-reperfusion injury and repair

Long-term ischemia leads to insufficient cerebral microvascular perfusion and dysfunction. Reperfusion restores physiological fluid shear stress (FSS) but leads to serious injury. The mechanism underlying FSS-induced endothelial injury in ischemia-reperfusion injury (IRI) remains poorly understood. In this study, a rat model of middle cerebral artery occlusion was constructed to explore cerebrovascular endothelial function and inflammation in vivo. Additionally, the rat brain microvascular endothelial cells (rBMECs) were exposed to a laminar FSS of 0.5 dyn/cm2 for 6 h and subsequently restored to physiological fluid shear stress level (2 dyn/cm2) for 2 and 12 h, respectively. We found that reperfusion induced endothelial-to-mesenchymal transition (EndMT) in endothelial cells, leading to serious blood-brain barrier dysfunction and endothelial inflammation, accompanied by the nuclear accumulation of Yes-associated protein (YAP). During the later stage of reperfusion, cerebral endothelium was restored to the endothelial phenotype with a distinct change in mesenchymal-to-endothelial transition (MEndT), while YAP was translocated and phosphorylated in the cytoplasm. Knockdown of YAP or inhibition of actin polymerization markedly impaired the EndMT in rBMECs. These findings suggest that ischemia-reperfusion increased intensity of FSS triggered an EndMT process and, thus, led to endothelial inflammation and tissue injury, whereas continuous FSS induced a time-dependent reversal MEndT event contributing to the endothelial repair. This study provides valuable insight for therapeutic strategies targeting IRI.

Mechanisms of immune response and cell death in ischemic stroke and their regulation by natural compounds

Ischemic stroke (IS), which is the third foremost cause of disability and death worldwide, has inflammation and cell death as its main pathological features. IS can lead to neuronal cell death and release factors such as damage-related molecular patterns, stimulating the immune system to release inflammatory mediators, thereby resulting in inflammation and exacerbating brain damage. Currently, there are a limited number of treatment methods for IS, which is a fact necessitating the discovery of new treatment targets. For this review, current research on inflammation and cell death in ischemic stroke was summarized. The complex roles and pathways of the principal immune cells (microglia, astrocyte, neutrophils, T lymphocytes, and monocytes/macrophage) in the immune system after IS in inflammation are discussed. The mechanisms of immune cell interactions and the cytokines involved in these interactions are summarized. Moreover, the cell death mechanisms (pyroptosis, apoptosis, necroptosis, PANoptosis, and ferroptosis) and pathways after IS are explored. Finally, a summary is provided of the mechanism of action of natural pharmacological active ingredients in the treatment of IS. Despite significant recent progress in research on IS, there remain many challenges that need to be overcome.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Role of traditional Chinese medicine monomers in cerebral ischemia/reperfusion injury:a review of the mechanism

Ischemia/reperfusion (I/R) injury is a pathological process wherein reperfusion of an ischemic organ or tissue exacerbates the injury, posing a significant health threat and economic burden to patients and their families. I/R triggers a multitude of physiological and pathological events, such as inflammatory responses, oxidative stress, neuronal cell death, and disruption of the blood-brain barrier (BBB). Hence, the development of effective therapeutic strategies targeting the pathological processes resulting from I/R is crucial for the rehabilitation and long-term enhancement of the quality of life in patients with cerebral ischemia/reperfusion injury (CIRI). Traditional Chinese medicine (TCM) monomers refer to bioactive compounds extracted from Chinese herbal medicine, possessing anti-inflammatory and antioxidative effects, and the ability to modulate programmed cell death (PCD). TCM monomers have emerged as promising candidates for the treatment of CIRI and its subsequent complications. Preclinical studies have demonstrated that TCM monomers can enhance the recovery of neurological function following CIRI by mitigating oxidative stress, suppressing inflammatory responses, reducing neuronal cell death and functional impairment, as well as minimizing cerebral infarction volume. The neuroprotective effects of TCM monomers on CIRI have been extensively investigated, and a comprehensive understanding of their mechanisms can pave the way for novel approaches to I/R treatment. This review aims to update and summarize evidence of the protective effects of TCMs in CIRI, with a focus on their role in modulating oxidative stress, inflammation, PCD, glutamate excitotoxicity, Ca2+ overload, as well as promoting blood-brain barrier repairment and angiogenesis. The main objective is to underscore the significant contribution of TCM monomers in alleviating CIRI.

Astragaloside IV: A promising natural neuroprotective agent for neurological disorders

Neurological disorders are characterized by high morbidity, disability, and mortality rates, which seriously threaten human health. However, clinically satisfactory agents for treatment are still currently lacking. Therefore, finding neuroprotective agents with minimum side effects and better efficacy is a challenge. Chinese herbal medicine, particularly natural preparations extracted from herbs or plants, has become an unparalleled resource for discovering new agent candidates. Astragali Radix is an important Qi tonic drug in traditional Chinese medicine and has a long medicinal history. As a natural medicine, it has a good prevention and treatment effect on neurological disorders. Here, the role and mechanism of astragaloside IV in the treatment of neurological disorders were evaluated and discussed through previous research results. Related information from major scientific databases, such as PubMed, MEDLINE, Web of Science, ScienceDirect, Embase, BIOSIS Previews, and the Cochrane Central Register of Controlled Trials and Cochrane Library, covering between 2001 and 2021 was compiled, using "Astragaloside IV" and "Neurological disorders," "Astragaloside IV," and "Neurodegenerative diseases" as reference terms. By summarizing previous research results, we found that astragaloside IV may play a neuroprotective role through various mechanisms: anti-inflammatory, anti-oxidative, anti-apoptotic protection of nerve cells and regulation of nerve growth factor, as well as by inhibiting neurodegeneration and promoting nerve regeneration. Astragaloside IV is a promising natural neuroprotective agent. By determining its pharmacological mechanism, astragaloside IV may be a new candidate drug for the treatment of neurological disorders.

The role of traditional herbal medicine for ischemic stroke: from bench to clinic-A critical review

BACKGROUND

Ischemic stroke (IS) is a leading cause of death and severe long-term disability worldwide. Over the past few decades, considerable progress has been made in anti-ischemic therapies. However, IS remains a tremendous challenge, with favourable clinical outcomes being generally difficult to achieve from candidate drugs in preclinical phase testing. Traditional herbal medicine (THM) has been used to treat stroke for over 2,000 years in China. In modern times, THM as an alternative and complementary therapy have been prescribed in other Asian countries and have gained increasing attention for their therapeutic effects. These millennia of clinical experience allow THM to be a promising avenue for improving clinical efficacy and accelerating drug discovery.

PURPOSE

To summarise the clinical evidence and potential mechanisms of THMs in IS.

METHODS

A comprehensive literature search was conducted in seven electronic databases, including PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the Chinese National Knowledge Infrastructure, the VIP Information Database, the Chinese Biomedical Literature Database, and the Wanfang Database, from inception to 17 June 2022 to examine the efficacy and safety of THM for IS, and to investigate experimental studies regarding potential mechanisms.

RESULTS

THM is widely prescribed for IS alone or as adjuvant therapy. In clinical trials, THM is generally administered within 72 h of stroke onset and are continuously prescribed for over 3 months. Compared with Western medicine (WM), THM combined with routine WM can significantly improve neurological function defect scores, promote clinical total effective rate, and accelerate the recovery time of stroke with fewer adverse effects (AEs). These effects can be attributed to multiple mechanisms, mainly anti-inflammation, antioxidative stress, anti-apoptosis, brain blood barrier (BBB) modulation, inhibition of platelet activation and thrombus formation, and promotion of neurogenesis and angiogenesis.

CONCLUSIONS

THM may be a promising candidate for IS management to guide clinical applications and as a reference for drug development.

Anti-Aging of the Nervous System and Related Neurodegenerative Diseases With Chinese Herbal Medicine

Human beings have always pursued a prolonged lifespan, while the aging of the nervous system is associated with a large variety of diseases. Pathological aging of the nervous system results in a series of neurodegenerative diseases and can cause disability and death in the elderly. Therefore, there is an urgent need for the prevention and treatment of nervous system aging. Chinese herbal medicines have a long history, featuring rich and safe ingredients, and have great potential for the development of anti-aging treatment. We searched the publications on PubMed with key words "anti-aging of the nervous system" and "Chinese herbal medicine" in recent 10 years, and found sixteen Chinese herbal medicines. Then by comparing their popularity of use as well as active components based on the research articles, five common Chinese herbal medicines namely Ginseng Radix, Lycii Fructus, Astragali Radix, Coptidis Rhizoma and Ginkgo Folium, were confirmed to be the most related to anti-nervous system aging and neural degenerative diseases. At the same time, the active ingredients, research models, action mechanisms and curative effects of these five common Chinese herbal medicines were reviewed. From the five common Chinese herbal medicines reviewed in this paper, many encouraging effects of Chinese herbal medicines on treating nervous system aging and related diseases were revealed and more potent herbs would be explored with the help of the proposed possible mechanisms.

Ligustrazine exerts neuroprotective effects via circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury

BACKGROUND

Ligustrazine is a traditional Chinese herbal medicine that has long been used to treat cerebral ischemic disorders. However, the molecular mechanisms of ligustrazine in cerebral ischemia/reperfusion (I/R) damage have not been clear elucidated. The aim of this study was to examine the neuroprotective mechanisms of ligustrazine in cerebral I/R.

METHODS

9 C57BL/6 mice were randomly divided to three groups: Sham group (n = 3), Middle cerebral artery occlusion (MCAO) group (n = 3), and MCAO + Ligustrazine group (n = 3). The neurological deficit score was evaluated, the cerebral infarct volume was measured by triphenylterazolium chloride (TTC) staining. Differentially expressed (DE) messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) were analyzed using the R package DEseq2 based on P-value < 0.05 and Log2 |fold change (FC)| ≥ 2 in sham group vs MCAO group and MCAO group vs ligustrazine group by high-throughput sequencing. Function enrichment analysis, the protein-protein interaction (PPI) of neurogenesis related genes were performed. The neurogenesis related competitive endogenous RNA (ceRNA) network was constructed.

RESULTS

The expression of circ_0008146 was considerably higher in the MCAO group than the Sham group, and ligustrazine treatment markedly decreased the expression of circ_0008146 in MCAO. Next, the circ_0008146 ceRNA network was established, including circ_0008146-miR-709-Cx3cr1 ceRNA network. Besides, real time quantitative polymerase chain reaction (RT-qPCR) assay identified that miR-709 expression was considerably lower and Cx3cr1 expression was higher in the MCAO group than Sham group, and ligustrazine treatment markedly increased the miR-709 expression and reduced Cx3cr1 expression in MCAO. Further, silencing of circ_0008146 inhibited the concentration of Interleukin 6 (IL-6), Tumor Necrosis Factor alpha (TNF-α) and reduced neuron cell death and up-regulated miR-709 expression and down-regulated Cx3cr1 expression in Lipopolysaccharide (LPS) induced BV-2 cells. Dual-Luciferase reporter gene assay verified that circ_0008146 targeted miR-709.

CONCLUSION

Ligustrazine targets circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury.

Authentication of Shenqi Fuzheng Injection via UPLC-Coupled Ion Mobility—Mass Spectrometry and Chemometrics with Kendrick Mass Defect Filter Data Mining

Nearly 5% of the Shenqi Fuzheng Injection’s dry weight comes from the secondary metabolites of Radix codonopsis and Radix astragali. However, the chemical composition of these metabolites is still vague, which hinders the authentication of Shenqi Fuzheng Injection (SFI). Ultra-high performance liquid chromatography with a charged aerosol detector was used to achieve the profiling of these secondary metabolites in SFI in a single chromatogram. The chemical information in the chromatographic profile was characterized by ion mobility and high-resolution mass spectrometry. Polygonal mass defect filtering (PMDF) combined with Kendrick mass defect filtering (KMDF) was performed to screen potential secondary metabolites. A total of 223 secondary metabolites were characterized from the SFI fingerprints, including 58 flavonoids, 71 saponins, 50 alkaloids, 30 polyene and polycynes, and 14 other compounds. Among them, 106 components, mainly flavonoids and saponins, are contributed by Radix astragali, while 54 components, mainly alkaloids and polyene and polycynes, are contributed by Radix codonopsis, with 33 components coming from both herbs. There were 64 components characterized using the KMDF method, which increased the number of characterized components in SFI by 28.70%. This study provides a solid foundation for the authentification of SFIs and the analysis of its chemical composition.

Synergy of "Yiqi" and "Huoxue" components of QishenYiqi formula in ischemic stroke protection via lysosomal/inflammatory mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is one of the leading causes of mortality and long-term disability worldwide. Currently, approved therapies of intravenous thrombolysis and mechanical thrombectomy are limited only to selected patients with rescuable brain tissue. Chinese medicine that benefits Qi (Yiqi, YQ) and activates blood (Huoxue, HX) is widely used in the clinic for treating stroke, but their mechanisms are not well understood yet. We have previously reported that QishenYiqi (QSYQ) formula exerts cerebral protective effect and promotes post-stroke recovery.

AIM OF THE STUDY

This study aimed to explore the chemical basis and molecular mechanism of anti-stroke therapy of QSYQ and its YQ and HX components further.

MATERIALS AND METHODS

Serum pharmacochemistry was performed to identify the bioactive constituents in QSYQ for cerebral protection. The survival rate, mNSS test, open field test, gait analysis, cerebral infarction volume, and blood-brain barrier (BBB) integrity were determined to uncover the synergistic and differential contributions of YQ and HX components in a cerebral ischemia/reperfusion injury (CI/RI) model. Bioinformatic mining of QSYQ proteomics data and experimental validation were executed to access the functional mechanism of YQ and HX components.

RESULTS

Eleven prototype ingredients and six metabolites were successfully identified or tentatively characterized in rat plasma. Therapeutically, YQ and HX components of QSYQ synergistically boosted the survival rate, improved neurological and motor functions, alleviated cerebral infarction as well as protected BBB integrity in CI/RI model in rats. Individually, YQ component contributed more to ameliorating locomotive ability than that of HX component. Mechanistically, HX component played a more prominent role in the modulation of galectin-3 mediated inflammation whereas YQ component regulated lysosomal-autophagy signaling.

CONCLUSIONS

This study identifies major prototype ingredients and metabolites of QSYQ in plasma which may contribute to its cerebral protection. YQ and HX components of QSYQ differentially and synergistically protect the brain from CI/RI by regulating galectin-3-mediated inflammation and lysosomal-autophagy signaling. These findings demonstrate that a maximal stroke protection by a component-based Chinese medicine could be attributed to the combination of its individual components via different mechanisms. It may shed new light on our understanding of the TCM principle of tonifying Qi and activating blood, particularly in a setting of ischemic stroke.

A Review of Traditional Chinese Medicine, Buyang Huanwu Decoction for the Treatment of Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is often referred to as “collaterals disease” in traditional Chinese medicine (TCM), and commonly includes ischemic and hemorrhagic CSVD. TCM has a long history of treating CSVD and has demonstrated unique efficacy. Buyang Huanwu Decoction (BHD) is a classical TCM formula that has been used for the prevention and treatment of stroke for hundreds of years. BHD exerts its therapeutic effects on CSVD through a variety of mechanisms. In this review, the clinical and animal studies on BHD and CSVD were systematically introduced. In addition, the pharmacological mechanisms, active components, and clinical applications of BHD in the treatment of CSVD were reviewed. We believe that an in-depth understanding of BHD, its pharmacological mechanism, disease-drug interaction, and other aspects will help in laying the foundation for its development as a new therapeutic strategy for the treatment of CSVD.

Hippocampal neuroprotection mediated by secretome of human mesenchymal stem cells against experimental stroke

Aims

Regenerative medicine literature has demonstrated that the therapeutic potentials of mesenchymal stem cells (MSCs) in experimental stroke are attributed to secreted bioactive factors rather than to cell replacement. Here, we explored the effects of secretome or conditioned medium (CM) derived from human embryonic stem cell‐derived MSCs (hESC‐MSCs) on hippocampal neurogenesis, inflammation, and apoptosis in experimental stroke.

Methods

Ischemic stroke was induced by right middle cerebral artery occlusion (MCAO) in male Wistar rats, and CM was infused either one time (1‐h post‐stroke; CM1) or three times (1‐, 24‐, and 48‐h post‐stroke; CM3) into left lateral ventricle. Neurogenesis markers (Nestin, Ki67, Doublecortin, and Reelin) were assessed at transcript and protein levels in the dentate gyrus of the hippocampus on day seven following MCAO. In parallel, changes in the gene expression of markers of apoptosis (Bax and Bim, as well as an anti‐apoptotic marker of Bcl2), inflammation (IL‐1β and IL‐6, as well as IL‐10 as an anti‐inflammatory cytokine), trophic factors (BDNF, GDNF, NGF, and NT‐3), and angiogenesis (CD31 and VEGF) in the hippocampus were assessed.

Results

Our results demonstrate that CM3 treatment could stimulate neurogenesis and angiogenesis concomitant with inhibition of inflammation, apoptosis, and neuronal loss in ischemic brains. Furthermore, rats treated with CM3 exhibited upregulation in neurotrophic factors.

Conclusion

Our results suggest that hESC‐MSC‐CM could promote neurogenesis and protect brain tissue from ischemic injury, partly mediated by induction of angiogenesis and neurotrophic factors and inhibition of inflammatory and apoptotic factors expression.

Biological active ingredients of Astragali Radix and its mechanisms in treating cardiovascular and cerebrovascular diseases

BACKGROUND

With the rising age of the global population, the incidence rate of cardiovascular and cerebrovascular diseases (CCVDs) is increasing, which causes serious public health burden. The efforts for new therapeutic approaches are still being sought since the treatment effects of existing therapies are not quite satisfactory. Chinese traditional medicine proved to be very efficient in the treatment of CCVDs. Well described and established in Chinese medicine, Astragali Radix, has been commonly administered in the prophylaxis and cure of CCVDs for thousands of years.

PURPOSE

This review summarized the action mode and mechanisms of Astragali Radix phytochemicals on CCVDs, hoping to provide valuable information for the future application, development and improvement of Astragali Radix as well as CCVDs treatment.

METHODS

A plenty of literature on biological active ingredients of Astragali Radix used for CCVDs treatment were retrieved from online electronic PubMed and Web of Science databases.

RESULTS

This review highlighted the effects of five main active components in Astragali Radix including astragaloside Ⅳ, cycloastragenol, astragalus polysaccharide, calycosin-7-O-β-d-glucoside, and calycosin on CCVDs. The mechanisms mainly involved anti-oxidative damage, anti-inflammatory, and antiapoptotic through signaling pathways such as PI3K/Akt, Nrf2/HO-1, and TLR4/NF-κB pathway. In addition, the majority active constituents in AR have no obvious toxic side effects.

CONCLUSION

The main active components of Astragali Radix, especially AS-IV, have been extensively summarized. It has been proved that Astragali Radix has obvious therapeutic effects on various CCVDs, including myocardial and cerebral ischemia, hypertension, atherosclerosis, cardiac hypertrophy, chronic heart failure. CAG possesses anti-ischemia activity without toxicity, indicating a worthy of further development. However, high-quality clinical and pharmacokinetic studies are required to validate the current studies.

The antidepressant-like effect of formononetin on chronic corticosterone-treated mice

Previous studies reported the neuroprotective effects of formononetin (FMN), however, whether it has antidepressant-like effects have not been reported. To evaluate the antidepressant-like effects of FMN, a mice model of depression was established by chronic corticosterone (CORT) injection. The serum corticosterone levels and hippocampal protein expression were detected by ELISA and Western blot. Nissl staining was used to observe the damage of hippocampal neurons and immunofluorescence was used to observe the neurogenesis in the hippocampus. Our results showed that FMN significantly increased the sucrose preference and shorten the immobility time in the forced swimming test in CORT-treated mice. Moreover, FMN reduced the serum corticosterone levels, upregulated the protein expression levels of the glucocorticoid receptor (GR), and brain-derived neurotrophic factor (BDNF) in the hippocampus, protected against the CORT-induced neuronal impairment, and promoted the neurogenesis in the hippocampus. Taken together, the present study was the first to demonstrate the antidepressant-like effects of FMN in the CORT-induced mice model of depression, which may contribute to the discovery of a new candidate for treating depression.

Astragalus saponins improves stroke by promoting the proliferation of neural stem cells through phosphorylation of Akt

ETHNOPHARMACOLOGICAL RELEVANCE

As one of major components of Buyang Huanwu decoction, Astragali Radix is broadly used for stroke treatment. Astragalus saponins (AST), the main active compound from Astragali Radix has the potentials for neuroprotection and improving spatial memory without clear pharmacological mechanism.

AIM OF THE STUDY

The aim of this study was to investigate that pretreatment of AST is beneficial to protect against focal ischemic stroke in mouse model and its related underlying mechanism.

MATERIALS AND METHODS

The neurological and motor function of MCAO mice were assessed by TTC staining and CatWalk gait analysis. The effect of AST on proliferation of NSCs was showed by the expression of Ki67 of MCAO mice and the number and size of primary neurospheres cultured from adult SVZ. The intersection of stroke-related targets, neurogenesis targets and drug-related targets were identified by the online website (https://www.omicstudio.cn/index). Then GO functional annotation and KEGG pathway enrichment analysis were performed. Candidate target Akt was confirmed to increase proliferation of cultured NSCs from adult SVZ by CCK8 assay and Western blot.

RESULTS

We found that with the prolongation of administration time, AST improved neurological and motor function of MCAO mice, by promoting the proliferation of NSCs both in vivo and in vitro. Then, the primary network among drug, genes and biological pathway was established by using compound-target-disease & function-pathway analysis of astragalus membranaceus. PI3K/Akt which plays a key role in cell proliferation was among the top 10 most significant GO terms from above three aspects. Further analysis using cultured NSCs from adult SVZ confirmed that AST, astragaloside I (A1) and astragaloside III (A3) increased the proliferation of NSCs through targeting Akt.

CONCLUSION

The present study elucidated that Astragalus saponins pretreatment could provide a protective effect on experimental stroke mainly by enhancing proliferation of NSCs through targeting Akt. The findings provided a basis for the development of novel strategies for the treatment of stroke.

Edaravone Alleviated Propofol-Induced Neurotoxicity in Developing Hippocampus by mBDNF/TrkB/PI3K Pathway

Background

To investigate the neuroprotective effect of edaravone on excessive-dose propofol-induced neurotoxicity in the hippocampus of newborn rats and HT22 cells.

Methods

Cell proliferation was investigated by assessing ki67 expression in the neural stem of the hippocampus of newborn rats and by cell counting kit-8 (CCK8) assay in HT22 cells. Cell apoptosis was assessed in vivo by caspase 3 detection in Western blots and measurement of apoptosis in neurons and glial cells by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Apoptosis was analyzed by flow cytometry in HT22 cells. The Morris water maze was used to evaluate the long-term learning and memory ability of rats. Inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA). The expression of mBDNF/TrkB/PI3K pathway-related proteins was detected by Western blot and quantitative reverse transcription-polymerase chain reaction (q-RT PCR).

Results

In neonatal rat hippocampus and HT22 cells, edaravone increased cell proliferation and decreased cell apoptosis after excessive propofol-induced neurotoxicity. In addition, the levels of proinflammatory factors interleukin (IL)-6 and tumor necrosis factor (TNF)-α were reduced by edaravone pretreatment. The use of the tropomyosin receptor kinase B (TrkB) antagonist ANA-12 and TrkB agonist 7,8DHF with propofol groups showed that edaravone mitigated excessive propofol-induced neurotoxicity through the mature brain-derived neurotrophic factor (mBDNF)/TrkB/phosphoinositide 3-kinase (PI3K) pathway. However, the current dose of propofol did not significantly affect long-term learning and memory in rats.

Conclusion

Edaravone pretreatment ameliorated propofol-induced proliferation inhibition, neuroapoptosis, and neural inflammation by activating the mBDNF/TrkB/PI3K pathway.

Traditional Chinese Medicine Monomers: Novel Strategy for Endogenous Neural Stem Cells Activation After Stroke

Stem cell therapy, which has become a potential regenerative medical treatment and a promising approach for treating brain injuries induced by different types of cerebrovascular disease, has various application methods. Activation of endogenous neural stem cells (NSCs) can enable infarcted neuron replacement and promote neural networks’ regeneration without the technical and ethical issues associated with the transplantation of exogenous stem cells. Thus, NSC activation can be a feasible strategy to treat central nervous system (CNS) injury. The potential molecular mechanisms of drug therapy for the activation of endogenous NSCs have gradually been revealed by researchers. Traditional Chinese medicine monomers (TCMs) are active components extracted from Chinese herbs, and some of them have demonstrated the potential to activate proliferation and neurogenesis of NSCs in CNS diseases. Ginsenoside Rg1, astragaloside IV (AST), icariin (ICA), salvianolic acid B (Sal B), resveratrol (RES), curcumin, artesunate (ART), and ginkgolide B (GB) have positive effects on NSCs via different signaling pathways and molecules, such as the Wingless/integrated/β-catenin (Wnt/β-catenin) signaling pathway, the sonic hedgehog (Shh) signaling pathway, brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). This article may provide further motivation for researchers to take advantage of TCMs in studies on CNS injury and stem cell therapy.

Astragaloside IV promotes microglia/macrophages M2 polarization and enhances neurogenesis and angiogenesis through PPARγ pathway after cerebral ischemia/reperfusion injury in rats

Microglia/macrophages play a dual role in brain injury and repair following cerebral ischemia/reperfusion. Promoting microglia/macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotype has been considered as a potential treatment for ischemic stroke. Astragaloside IV (AS-IV) is a primary active ingredient of Chinese herb Radix Astragali, which protects against acute cerebral ischemic/reperfusion injury through its antioxidant, anti-inflammatory, and anti-apoptotic properties. However, it remains unknown whether AS-IV improves ischemic brain tissue repair and its underlying mechanism. A transient middle cerebral artery occlusion (tMCAO) rat model was used in this study. The results showed that AS-IV significantly improved long-term brain injury, reduced the expression of M1 microglia/macrophage markers and increased the expression of M2 microglia/macrophage markers 14 days after cerebral ischemia/reperfusion. AS-IV also increased peroxisome proliferator-activated receptor γ (PPARγ) mRNA and protein expression. Moreover, AS-IV promoted neurogenesis and angiogenesis, and increased the protein expression of brain-derived growth factor (BDNF), insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF). However, these beneficial effects were greatly blocked by PPARγ antagonist T0070907. These results together suggest that AS-IV could enhance neurogenesis, angiogenesis and neurological functional recovery, which may be partially through transforming microglia/macrophage from M1 to M2 phenotype in a PPARγ-dependent manner after cerebral ischemia/reperfusion injury. Therefore, AS-IV can be considered as a promising therapeutic agent for ischemic stroke.

The Cerebroprotein Hydrolysate-I Plays a Neuroprotective Effect on Cerebral Ischemic Stroke by Inhibiting MEK/ERK1/2 Signaling Pathway in Rats

OBJECTIVE

To investigate the neuroprotective effect and mechanism of cerebroprotein hydrolysate-I (CH-I) on cerebral ischemia/reperfusion injury in rats.

METHODS

A total of 100 adult healthy male SD rats were randomly divided into a sham group, model group, CH-I treated group, and cerebrolysin (CBL) positive group, consisting of 20 rats in each group. The middle cerebral artery occlusion/reperfusion (MCAO/R) model of rats was built by inserting a suture into the left external carotid artery (ECA) through the internal carotid artery (ICA). Treatment was performed by intraperitoneal injection of CH-I (20 mg/kg). The neurobehavioral function of rats was evaluated by modified neurological severity scores (mNSS). TTC staining was used to detect the cerebral infarction volume (CIV) of rats. The morphological and structural changes of nerve cells were observed by HE staining and the neuronal apoptosis was counted by TUNEL assay. Immunohistochemical (IHC) analysis was used to detect BDNF and pMEK1/2 expressions. The expressions of BDNF, pMEK1/2, pERK1/2, and pCREB were determined with Western blotting.

RESULTS

After treatment with CH-I, the mNSS and CIV of rats were improved (P<0.05). And the CH-I can reduce the degeneration and apoptosis of nerve cells in rats (P<0.01). Western blotting showed that the expressions of pMEK1/2, pERK1/2, and pCREB in rats were increased, while the expression of BDNF was decreased after modeling (P<0.05). After treatment, the expressions of pMEK1/2, pERK1/2, and pCREB in the CH-I group were decreased (P<0.05), while the expression of BDNF was significantly increased (P<0.05) compared with the model group. IHC showed that the expression of BDNF and pMEK1/2 was consistent with Western blotting.

CONCLUSION

It is suggested that the CH-I might play a neuroprotective role by inhibiting the expression of MEK-ERK-CREB and enhancing the expression of BDNF after cerebral ischemia/reperfusion injury, thus improving the neurobehavioral function of MCAO/R rats.