Calycosin Preserves BDNF/TrkB Signaling and Reduces Post-Stroke Neurological Injury after Cerebral Ischemia by Reducing Accumulation of Hypertrophic and TNF-α-Containing Microglia in Rats

A novel framework for uncovering the coordinative spectrum-effect correlation of the effective components of Yangyin Tongnao Granules on cerebral ischemia-reperfusion injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is currently a major public health hazard.Yangyin Tongnao Granules (YYTN), a traditional Chinese medicinal prescription, exerts potential therapeutic effects on subsequent cerebral ischemia-reperfusion injury (CIRI) after ischemic stroke. However, further studies are required to comprehend the underlying mechanism of YYTN for treating CIRI and the associated spectrum-effect mechanisms.

AIM OF THE STUDY

To investigate the coordinated correlation between the fingerprint and the pharmacodynamic indexes of the effective components (total flavonoids, total saponins, total alkaloids, and total phenolic acids) in YYTN for treating CIRI in rats.

METHODS

The fingerprints of five specific components (ligustrazine, puerarin, ferulic acid, calycosin, and formononetin) of YYTN in rats with middle cerebral artery occlusion (MCAO) were established using high-performance liquid chromatography (HPLC), and their peak areas were quantified in plasma samples. The pharmacodynamic indexes of tumor necrosis factor-alpha (TNF-α), cytochrome c (Cyt-C), and total superoxide dismutase (T-SOD) were integrated using the Criteria Importance Through Intercriteria Correlation (CRITIC) method to create a comprehensive evaluation index. Spectrum-effect correlation was analyzed by performing gray relation analysis (GRA), correlation analysis (CA), and partial least squares regression (PLSR). The Borda method was then applied to integrate the obtained results.

RESULTS

In MCAO rats, the effective components of YYTN reduced TNF-α and Cyt-C and increased T-SOD, which indicates their anti-inflammatory, antiapoptotic, and antioxidant effects. Spectrum-effect CA revealed certain associations between the chromatographic peaks of the five main components and the comprehensive pharmacodynamic evaluation index. Of these components, formononetin displayed the highest correlation, whereas ferulic acid exhibited the lowest correlation. All components showed a positive correlation. Using the Borda method, the components were ranked as follows based on correlation: formononetin > calycosin > ligustrazine > puerarin > ferulic acid.

CONCLUSIONS

The effective components of YYTN exhibited synergistic effects in the treatment of MCAO rats, which could potentially be attributed to their multitarget and multipathway mechanisms. The Borda method-based spectrum-effect correlation analysis provides a coordinated approach to investigate the relationship between fingerprint and pharmacodynamics of traditional Chinese medicine (TCM).

Herbal medicines for SOD1G93A mice of amyotrophic lateral sclerosis: preclinical evidence and possible immunologic mechanism

Currently, there is no cure or effective treatment for Amyotrophic Lateral Sclerosis (ALS). The mechanisms underlying ALS remain unclear, with immunological factors potentially playing a significant role. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), a systematic review of preclinical studies was conducted, searching seven databases including PubMed, covering literature from the inception of the databases to April 10, 2024. Methodological quality of the included literature was assessed using CAMARADES, while the risk of bias in the included studies was evaluated using SYRCLE's ROB tool. Review Manager 5.4.1 statistical software was used for meta-analysis of the outcomes. The scoping review followed the Joanna Briggs Institute Methodological Guidelines and reporting of this review followed the PRISMA-extension for Scoping Reviews (PRISMA -ScR) checklist to explore the immunological mechanisms of Herbal Medicine (HM) in treating ALS. This systematic review and meta-analysis involved 18 studies with a total of 443 animals. The studies scored between 4 to 8 for methodological quality and 3 to 7 for risk of bias, both summing up to 10.A remarkable effects of HM in ALS mice, including onset time(Standardized Mean Difference(SMD): 1.75, 95% Confidence Interval(CI) (1.14 ~ 2.36), Z = 5.60, P < 0.01), survival time(SMD = 1.42, 95% CI (0.79 ~ 2.04), Z = 4.44, P < 0.01), stride length(SMD=1.90, 95% CI (1.21 to 2.59), Z = 5.39, P < 0.01) and duration time (Mean Difference(MD)=6.79, 95% CI [-0.28, 13.87], Z=1.88, P =0.06), showing HM's certain efficiency in treating ALS mice. The scoping review ultimately included 35 articles for review. HMs may treat ALS through mechanisms such as combating oxidative stress, excitatory amino acid toxicity, and calcium cytotoxicity, understanding and exploring the mechanisms will bring hope to patients. Individual herbs and their formulations within HM address ALS through a variety of immune pathways, including safeguarding the blood-brain barrier, countering neuroinflammation, impeding complement system activation, mitigating natural killer cell toxicity, and regulating T cell-mediated immune pathways. The preclinical evidence supports the utilization of HM as a conventional treatment for ALS mice. Growing evidence indicates that HM may potentially delay neurological degeneration in ALS by activating diverse signaling pathways, especially immune pathways.

Calycosin activates Nrf2/Keap1 signaling to ameliorate hydrogen peroxide-induced spinal cord neuron death and mitochondrial dysfunction

Oxidative stress is a hallmark of secondary injury of spinal cord injuries. Controlling oxidative stress is crucial for mitigating secondary injury and promoting functional recovery after spinal cord injuries. Calycosin is an O-methylated isoflavone with antioxidant activity. To evaluate the effect of calycosin on spinal cord neurons under oxidative stress and clarify the molecular mechanism underlying the effect, we tested the neuroprotective activity of calycosin in a primary spinal cord neuron culture model. We found that calycosin protected neurons from H2O2-induced neuronal death in a dose-dependent manner. Further experiments revealed that calycosin decreased H2O2-induced mitochondrial fragmentation and mitochondrial membrane potential loss, and subsequently reduced H2O2-triggered release of mitochondrial cytochrome c into the cytoplasm. In addition, calycosin inhibited H2O2-induced reactive oxygen species generation and activation of NF-κB signaling in spinal cord neurons. Furthermore, the expression of several antioxidant enzymes such as HO-1, NQO1, GCLC, GCLM, TrxR1, and Trx1 was significantly promoted by calycosin. More importantly, we revealed that the Nrf2/Keap1 signal is crucial for the effect of calycosin, because calycosin increased the amount of nuclear Nrf2 while decreasing the amount of cytoplasmic Nrf2. Nrf2 knockdown with siRNA transfection abolished the neuroprotective effect of calycosin. Taken together, this study disclosed a novel mechanism by which calycosin combats oxidative stress. Our study thus sheds light on the potential clinical application of calycosin in SCI treatment.

Microglia in Ischemic Stroke: Pathogenesis Insights and Therapeutic Challenges

Ischemic stroke is the most common type of stroke, which is the main cause of death and disability on a global scale. As the primary immune cells in the brain that are crucial for preserving homeostasis of the central nervous system microenvironment, microglia have been found to exhibit dual or even multiple effects at different stages of ischemic stroke. The anti-inflammatory polarization of microglia and release of neurotrophic factors may provide benefits by promoting neurological recovery at the lesion in the early phase after ischemic stroke. However, the pro-inflammatory polarization of microglia and secretion of inflammatory factors in the later phase of injury may exacerbate the ischemic lesion, suggesting the therapeutic potential of modulating the balance of microglial polarization to predispose them to anti-inflammatory transformation in ischemic stroke. Microglia-mediated signaling crosstalk with other cells may also be key to improving functional outcomes following ischemic stroke. Thus, this review provides an overview of microglial functions and responses under physiological and ischemic stroke conditions, including microglial activation, polarization, and interactions with other cells. We focus on approaches that promote anti-inflammatory polarization of microglia, inhibit microglial activation, and enhance beneficial cell-to-cell interactions. These targets may hold promise for the creation of innovative therapeutic strategies.

A potential research target for cardiac rehabilitation: brain-derived neurotrophic factor

Cardiovascular diseases pose a major threat to human life, functional activity, and quality of life. Once the disease is present, patients can experience varying degrees of problems or limitations on three levels: physical, psychological, and social. Patients with cardiovascular disease are always at risk for adverse cardiac events, decreased physical activity, psychoemotional disturbances, and limited social participation due to their varying pathologies. Therefore, personalized cardiac rehabilitation is of great significance in improving patients' physical and mental functions, controlling disease progression, and preventing deterioration. There is a consensus on the benefits of cardiac rehabilitation in improving patients' quality of life, enhancing functional activity, and reducing mortality. As an important part of cardiac rehabilitation, Exercise plays an irreplaceable role. Aerobic exercise, resistance training, flexibility training, and other forms of exercise are recommended by many experts. Improvements in exercise tolerance, lipid metabolism, cardiac function, and psychological aspects of the patients were evident with appropriate exercise interventions based on a comprehensive assessment. Further studies have found that brain-derived neurotrophic factor may be an important mediator of exercise's ability to improve cardiovascular health. Brain-derived neurotrophic factor exerts multiple biological effects on the cardiovascular system. This article provides another perspective on the cardiac effects of exercise and further looks at the prospects for the use of brain-derived neurotrophic factor in cardiac rehabilitation. Meanwhile, the new idea that brain-derived neurotrophic factor is a key mediator connecting the brain-cardiac axis is proposed in light of the current research progress, to provide new ideas for clinical rehabilitation and scientific research.

Rehabilitation training enhanced the therapeutic effect of calycosin on neurological function recovery of rats following spinal cord injury

BACKGROUND

Calycosin (CA), a flavonoids component, has demonstrated potential neuroprotection effects by inhibiting oxidative stress in spinal cord injury (SCI) models. This study aims to investigate the impact of combined rehabilitation training (RT) and calycosin therapy on neurological function following SCI, primarily by assessing changes in motor function recovery, neuronal survival, neuronal oxidative stress levels, and neural proliferation, in order to provide novel insights for the treatment of SCI.

MATERIALS AND METHODS

The SCI model was constructed by compressing the spinal cord using vascular clamps. Calycosin was injected intraperitoneally into the SCI model rats, and a group of 5 rats underwent RT. The motor function of rats after SCI was evaluated using the Basso Beattle Bresnaha (BBB) score and the inclined plate test. Histopathological changes were evaluated by NeuN immunohistochemistry, HE and Nissl staining. Apoptosis was detected by TUNEL staining. The antioxidant effect of combined treatment was assessed by measuring changes in oxidative stress markers after SCI. Western blot analysis was conducted to examine changes in Hsp90-Akt/ASK1-p38 pathway-related proteins. Finally, cell proliferation was detected by BrdU and Ki67 assays.

RESULTS

RT significantly improved the BBB score and angle of incline promoted by calycosin, resulting in enhanced motor function recovery in rats with SCI. Combining rehabilitation training with calycosin has a positive effect on morphological recovery. Similarly, combined RT enhanced the Nissl and NeuN staining signals of spinal cord neurons increased by calycosin, thereby increasing the number of neurons. TUNEL staining results indicated that calycosin treatment reduced the apoptosis signal in SCI, and the addition of RT further reduced the apoptosis. Moreover, RT combined with calycosin reduced oxidative stress by increasing SOD and GSH levels, while decreasing MDA, NO, ROS, and LDH expressions compared to the calycosin alone. RT slightly enhanced the effect of calycosin in activating Hsp90 and Akt and inhibiting the activation of ASK1 and p38, leading to enhanced inhibition of oxidative stress by calycosin. Additionally, the proliferation indexes (Ki67 and BrdU) assays showed that calycosin treatment alone increased both, whereas the combination treatment further promoted cell proliferation.

CONCLUSION

Our research findings demonstrate that rehabilitation training enhances the ability of calycosin to reduce oxidative stress, resulting in a decrease in neuronal apoptosis and an increase in proliferation, ultimately promoting neuronal survival.

Acteoside alleviates blood-brain barrier damage induced by ischemic stroke through inhibiting microglia HMGB1/TLR4/NLRP3 signaling

Ischemic stroke (IS) can cause severe harm, inducing oxidative stress, inflammation, and pyroptotic death. IS treatment efficacy remains limited, and microglia are important regulators of IS-related blood-brain barrier (BBB) damage. It is thus vital that new therapeutic agents capable of targeting microglia be identified to treat IS-related damage to the BBB. Acteoside (ACT), which is a compound derived from Cistanche tubulosa (Schenk) Wight., offers promising bioactivity, but its ability to protect against central nervous system injury remains to be documented. To clarify the protective benefits and mechanisms through which ACT can protect against damage to the BBB, a rat middle cerebral artery occlusion (MCAO) model system was herein employed. These in vivo analyses demonstrated that ACT was able to significantly reduce cerebral infarct size while improving their neurological scores and altering neurotrophic and inflammatory factor release. RNA sequencing and molecular docking studies highlighted the ability of ACT to exert its protective benefits via the HMGB1/TLR4/NLRP3 axis. Western immunoblotting and immunofluorescent staining for tight junction proteins additionally confirmed the ability of ACT to preserve BBB integrity. The underlying mechanisms were then explored with an oxygen-glucose deprivation (OGD) model in vitro with BV2 cells. This strategy thus confirmed that the ability of ACT to suppress microglial inflammatory and pyroptotic activity was HMGB1/TLR4/NLRP3 pathway-dependent. These data thus offer novel evidence that ACT can protect against IS-related damage to the BBB through the abrogation of inflammatory and pyroptotic activity, underscoring its promise as a novel lead compound for the therapeutic treatment of IS.

Annexin A6 mitigates neurological deficit in ischemia/reperfusion injury by promoting synaptic plasticity

AIMS

Alleviating neurological dysfunction caused by acute ischemic stroke (AIS) remains intractable. Given Annexin A6 (ANXA6)'s potential in promoting axon branching and repairing cell membranes, the study aimed to explore ANXA6's potential in alleviating AIS-induced neurological dysfunction.

METHODS

A mouse middle cerebral artery occlusion model was established. Brain and plasma ANXA6 levels were detected at different timepoints post ischemia/reperfusion (I/R). We overexpressed and down-regulated brain ANXA6 and evaluated infarction volume, neurological function, and synaptic plasticity-related proteins post I/R. Plasma ANXA6 levels were measured in patients with AIS and healthy controls, investigating ANXA6 expression's clinical significance.

RESULTS

Brain ANXA6 levels initially decreased, gradually returning to normal post I/R; plasma ANXA6 levels showed an opposite trend. ANXA6 overexpression significantly decreased the modified neurological severity score (p = 0.0109) 1 day post I/R and the infarction area at 1 day (p = 0.0008) and 7 day (p = 0.0013) post I/R, and vice versa. ANXA6 positively influenced synaptic plasticity, upregulating synaptophysin (p = 0.006), myelin basic protein (p = 0.010), neuroligin (p = 0.078), and tropomyosin-related kinase B (p = 0.150). Plasma ANXA6 levels were higher in patients with AIS (1.969 [1.228-3.086]) compared to healthy controls (1.249 [0.757-2.226]) (p < 0.001), that served as an independent risk factor for poor AIS outcomes (2.120 [1.563-3.023], p < 0.001).

CONCLUSIONS

This study is the first to suggest that ANXA6 enhances synaptic plasticity and protects against transient cerebral ischemia.

Exploring Chinese herbal medicine for ischemic stroke: insights into microglia and signaling pathways

Ischemic stroke is a prevalent clinical condition affecting the central nervous system, characterized by a high mortality and disability rate. Its incidence is progressively rising, particularly among younger individuals, posing a significant threat to human well-being. The activation and polarization of microglia, leading to pro-inflammatory and anti-inflammatory responses, are widely recognized as pivotal factors in the pathogenesis of cerebral ischemia and reperfusion injury. Traditional Chinese herbal medicines (TCHMs) boasts a rich historical background, notable efficacy, and minimal adverse effects. It exerts its effects by modulating microglia activation and polarization, suppressing inflammatory responses, and ameliorating nerve injury through the mediation of microglia and various associated pathways (such as NF-κB signaling pathway, Toll-like signaling pathway, Notch signaling pathway, AMPK signaling pathway, MAPK signaling pathway, among others). Consequently, this article focuses on microglia as a therapeutic target, reviewing relevant pathway of literature on TCHMs to mitigate neuroinflammation and mediate IS injury, while also exploring research on drug delivery of TCHMs. The ultimate goal is to provide new insights that can contribute to the clinical management of IS using TCHMs.

Spatial and temporal mapping of neuron-microglia interaction modes in acute ischemic stroke

Ischemic stroke (IS) is a major cause of morbidity and mortality worldwide, accounting for 75-80% of all strokes. Under conditions of ischemia and hypoxia, neurons suffer damage or death, leading to a series of secondary immune reactions. Microglia, the earliest activated immune cells, can exert neurotoxic or neuroprotective effects on neurons through secretion of factors. There exists a complex interaction between neurons and microglia during this process. Moreover, the interaction between them becomes even more complex due to differences in the infarct area and reperfusion time. This review first elaborates on the differences in neuronal death modes between the ischemic core and penumbra, and then introduces the differences in microglial markers across different infarct areas with varying reperfusion time, indicating distinct functions. Finally, we focus on exploring the interaction modes between neurons and microglia in order to precisely target beneficial interactions and inhibit harmful ones, thus providing new therapeutic strategies for the treatment of IS.

Network pharmacology-guided and TCM theory-supported in vitro and in vivo component identification of Naoluoxintong

Naoluoxintong (NLXT) has been used to treat ischemic stroke (IS) in China for more than two hundred years. However, the pharmacodynamic material basis of NLXT has not been fully studied. Under the guidance of the former network pharmacological analysis, a rapid and reliable method combining UPLC-Q-TOF-MSE with the novel informatics UNIFI™ platform was established which was used to study the composition of NLXT and its prototype components and metabolites in vivo. A total of 102 compounds were identified. 13 compounds were sourced from "Monarch herb", mainly involving flavonoids and their glycosides. 54 compounds were sourced from "Minister herb", mainly involving triterpenoid saponins, organic acids and lactones. 11 compounds were from the "Assistant herb", mostly containing citric acid and esters of citric acid. 24 compounds were from the "Guide herb", mostly including flavonoids and their glycosides, organic acids and lactones. Moreover, 24 prototype components and 30 metabolites were detected, and in vivo transformation pathways for different types of chemical components were provided. This is a comprehensive report on the identification of major chemical components in NLXT and metabolic components in rats by UPLC-Q-TOF-MS combined with UNIFI platform under the guidance of network pharmacology, which is helpful for the quality control of NLXT and the study of quality markers.

Huangqi Guizhi Wuwu decoction promotes M2 microglia polarization and synaptic plasticity via Sirt1/NF-κB/NLRP3 pathway in MCAO rats

Huangqi Guizhi Wuwu decoction (HGWD) has been demonstrated to ameliorate cerebral ischemia-reperfusion injury in clinical application. Nevertheless, the exact mechanisms of HGWD have not been conclusively elucidated. This study aimed to investigate the potential role and mechanism of HGWD on neurological deficits in a rat model of middle cerebral artery occlusion (MCAO). Our results showed that HGWD significantly alleviated neurological deficits in MCAO rats, evidenced by high mNSS score, reduced cerebral infarction area, and improved brain pathological injury. Besides, HGWD reduced the levels of TNF-α, IL-1β, IL-6, SOD, MDA and GSH in the brain tissue. Further study suggested that HGWD promoted microglia polarization towards M2 by inhibiting M1 activation (Iba1+/CD16+, iNOS) and enhancing M2 activation (Iba1+/CD206+, Arg-1). Additionally, HGWD increased dendritic spine density and enhanced levels of synapse marker proteins (PSD95, Synapsin I). HGWD also up-regulated Sirt1 expression while inhibited p-NF-κB, NLRP3, ASC, and cleaved caspase-1 level in the hippocampus of MCAO rats. Sirt1 specific inhibitor EX527 notably weakened the neuroprotective efficacy of HGWD against cerebral ischemia, and significantly abolished its modulation on microglia polarization and synaptic plasticity in vivo. Collectively, our findings suggested that HGWD ameliorated neuronal injury in ischemic stroke by modulating M2 microglia polarization and synaptic plasticity, at least partially, via regulating Sirt1/NF-κB/NLRP3 pathway, further supporting HGWD as a potential therapy for neuroprotection after ischemic stroke.

A review of the botany, phytochemistry, traditional uses, pharmacology, toxicology, and quality control of the Astragalus memeranaceus

Astragali Radix (Huangqi) is mainly distributed in the Northern Hemisphere, South America, and Africa and rarely in North America and Oceania. It has long been used as an ethnomedicine in the Russian Federation, Mongolia, Korea, Kazakhstan, and China. It was first recorded in the Shennong Ben Cao Jing and includes the effects of reinforcing healthy qi, dispelling pathogenic factors, promoting diuresis, reducing swelling, activating blood circulation, and dredging collaterals. This review systematically summarizes the botanical characteristics, phytochemistry, traditional uses, pharmacology, and toxicology of Astragalus to explore the potential of Huangqi and expand its applications. Data were obtained from databases such as PubMed, CNKI, Wan Fang Data, Baidu Scholar, and Google Scholar. The collected material also includes classic works of Chinese herbal medicine, Chinese Pharmacopoeia, Chinese Medicine Dictionary, and PhD and Master's theses. The pharmacological effects of the isoflavone fraction in Huangqi have been studied extensively; The pharmacological effects of Huangqi isoflavone are mainly reflected in its anti-inflammatory, anti-tumor, anti-oxidant, anti-allergic, and anti-diabetic properties and its ability to treat several related diseases. Additionally, the medicinal uses, chemical composition, pharmacological activity, toxicology, and quality control of Huangqi require further elucidation. Here, we provide a comprehensive review of the botany, phytochemistry, traditional uses, pharmacology, toxicology, and quality control of Astragalus to assist future innovative research and to identify and develop new drugs involving Huangqi.

Calycosin attenuates the inflammatory damage of microglia induced by oxygen and glucose deprivation through the HMGB1/TLR4/NF-κB signaling pathway

Stroke seriously threatens human life and health worldwide, but only very few effective stroke medicines are currently available. Our previous studies have indicated that the phytoestrogen calycosin exerts neuroprotective effects in cerebral ischemia and reperfusion injury rats. Therefore, the objective of this study is to further explore the protective effect of calycosin on inflammatory injury in microglia after oxygen-glucose deprivation/reoxygenation (OGD/R) and to clarify whether its protective effect is related to the HMGB1/TLR4/NF-κB signaling pathway. Here, the OGD/R model of rodent microglia is established in vitro to simulate cerebral ischemia-reperfusion injury. Through the CCK-8 test, ELISA, qRT-PCR, and western blot analysis, we find that the activity of microglia is decreased, the expressions of HMGB1 and TLR4 and the phosphorylation of NF-κB (p-NF-κB) are increased, and the releases of the inflammatory factors IL-6, IL-1β, and TNF-α are increased after OGD/R. Pretreatment with calycosin could ameliorate these states, increase cell viability, reduce HMGB1, TLR4 and p-NF-κB expression, and reduce inflammatory cytokine production. In addition, the effect of calycosin is similar to that of TAK-242 (an inhibitor of TLR4), and the effect of the combined treatment is better than that of the single treatment. The results indicate that calycosin protects microglia from OGD/R injury and reduces the inflammatory response. Calycosin might alleviate cerebral ischemia-reperfusion injury by inhibiting the HMGB1/TLR4/NF-κB pathway.

Mitochondrial dysfunction-targeting therapeutics of natural products in Parkinson's disease

Parkinson's disease (PD), the second most common neurodegenerative disease worldwide, often occurs in middle-aged and elderly individuals. The pathogenesis of PD is complex and includes mitochondrial dysfunction, and oxidative stress. Recently, natural products with multiple structures and their bioactive components have become one of the most important resources for small molecule PD drug research targeting mitochondrial dysfunction. Multiple lines of studies have proven that natural products display ameliorative benefits in PD treatment by regulating mitochondrial dysfunction. Therefore, a comprehensive search of recent published articles between 2012 and 2022 in PubMed, Web of Science, Elesvier, Wliey and Springer was carried out, focusing on original publications related to natural products against PD by restoring mitochondrial dysfunction. This paper presented the mechanisms of various kinds of natural products on PD-related mitochondrial dysfunction regulation and provided evidence that natural products are promising to be developed as drugs for PD therapeutics.

Protective effects and mechanisms of Yi Qi Huo Xue Fang in cerebral ischemic stroke based on network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Yi Qi Huo Xue Fang (YQHXF) is an effective formula for treating cerebral ischemic stroke (CIS). However, its active ingredients and mechanism of action remain unclear.

AIM OF THE STUDY

This study aimed to reveal the mechanism of action of YQHXF in the treatment of ischemic stroke based on network pharmacology and experimental validation.

MATERIALS AND METHODS

This study identified the chemical components in YQHXF and the components absorbed by rat serum based on UPLC-Q-TOF/MS technology and used network pharmacology to predict key candidate targets. A protein-protein-interaction (P-P-I) network was constructed using String 11.0 database and Cytoscape, and R software for gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Finally, molecular docking combined with animal experiments was used to verify network pharmacology results.

RESULTS

This study identified and confirmed 36 chemical components of YQHXF and five chemical ingredients that were absorbed into the blood of rats and screened 66 key candidate targets. All targets in the P-P-I network were mainly related to inflammation and vascular processes. KEGG enrichment results revealed that these 66 key candidate targets were primarily involved in the "AGE-RAGE signaling pathway," "TNF-α signaling pathway, and "T cell receptor signaling pathway." Molecular docking results revealed that Prostaglandin-endoperoxidase synthase 2(PTGS-2), Nitric oxide synthase, endothelial (NOS3), and peroxisome proliferator-activated receptor gamma (PPARG) were more stably bound to their active ingredients. Animal experiments demonstrated that YQHXF promoted M2 polarization, inhibited M1 polarization in microglia, and promoted angiogenesis, which may be related to the PPARG pathway.

CONCLUSION

This study revealed the key active components and effective targets of YQHXF, identified the mechanism of action of YQHXF, laid the foundation for further research on YQHXF, and provided ideas for developing new drugs for CIS.

Calycosin alleviates cerebral ischemia/reperfusion injury by repressing autophagy via STAT3/FOXO3a signaling pathway

BACKGROUND

As a common cerebrovascular disease (CVD) of the elderly, ischemic stroke (IS) is characterized by high disability and mortality. Excessive autophagy induced by IS is implicated in neuronal death, therefore, the inhibition of immoderate autophagy is viewed as a potential therapeutic avenue to treat IS. Calysoin (CA) is a bioactive component of Radix Astragali, which has been widely used to treat CVDs. However, the mechanism of the treatment of IS by CA is still problematic.

PURPOSE

Based on the result of network pharmacology, whether CA inhibited autophagy by regulating the STAT3/FOXO3a pathway to alleviate cerebral ischemia-reperfusion injury (CIRI) was investigated in vivo and in vitro for the first time.

STUDY DESIGN

Integrate computational prediction and experimental validation based on network pharmacology.

METHODS

In current study, network pharmacology was applied to predict the mechanism of the treatment of IS by CA, and it was shown that CA alleviated CIRI by inhibiting autophagy via STAT3/FOXO3a signaling pathway. One hundred and twenty adult male specific pathogen-free Sprague-Dawley rats in vivo and PC12 cells in vitro were used to verify the above prediction results. The rat middle cerebral artery occlusion/reperfusion (MCAO/R) model was established by suture method, and oxygen glucose deprivation/re-oxygenation (OGD/R) model was used to simulate cerebral ischemia in vivo. The content of MDA, TNF-α, ROS and TGF-β1 in rat serum were detected by ELISA kits. The mRNA and protein expressions in brain tissue were detected by RT-PCR and Western Blotting. The expressions of LC3 in brain were detected immunofluorescent staining.

RESULTS

The experimental results demonstrated that administration of CA dosage-dependently improved rat CIRI as evidenced by the reduction in the cerebral infarct volume, amelioration of the neurological deficits. HE staining and transmission electron microscopy results revealed that CA ameliorated cerebral histopathological damage, abnormal mitochondrial morphology, and damaged mitochondrial cristae structure in MCAO/R rats. CA treatment exerted protective effects in CIRI by inhibiting inflammation response, oxidative stress injury, and cell apoptosis in rat and PC12 cells. CA relieved excessive autophagy induced by MCAO/R or OGD/R through downregulating the LC3Ⅱ/LC3Ⅰ ratio and upregulating the SQSTM1 expression. CA treatment also decreased p-STAT3/STAT3 and p-FOXO3a/FOXO3a ratio in the cytoplasm and modulated the autophagy-related gene expression both in vivo and in vitro.

CONCLUSION

Treatment with CA attenuated CIRI by reducing excessive autophagy via STAT3/FOXO3a signal pathway in rat and PC12 cells.

Gut-brain axis: Mechanisms and potential therapeutic strategies for ischemic stroke through immune functions

After an ischemic stroke (IS) occurs, immune cells begin traveling to the brain and immune system from the gut and gastrointestinal tract, where most of them typically reside. Because the majority of the body's macrophages and more than 70% of the total immune cell pool are typically found within the gut and gastrointestinal tract, inflammation and immune responses in the brain and immune organs require the mobilization of a large number of immune cells. The bidirectional communication pathway between the brain and gut is often referred to as the gut-brain axis. IS usually leads to intestinal motility disorders, dysbiosis of intestinal microbiota, and a leaky gut, which are often associated with poor prognosis in patients with IS. In recent years, several studies have suggested that intestinal inflammation and immune responses play key roles in the development of IS, and thus may become potential therapeutic targets that can drive new therapeutic strategies. However, research on gut inflammation and immune responses after stroke remains in its infancy. A better understanding of gut inflammation and immune responses after stroke may be important for developing effective therapies. This review discusses the immune-related mechanisms of the gut-brain axis after IS and compiles potential therapeutic targets to provide new ideas and strategies for the future effective treatment of IS.

Calycosin decreases cerebral ischemia/reperfusion injury by suppressing ACSL4-dependent ferroptosis

Ischemic stroke is the second leading cause of death globally. Calycosin is a typical phytoestrogen that protects against cerebral ischemia/reperfusion (I/R) injury. However, the role of ferroptosis in this effect remains unknown. In the present study, we investigated the ferroptosis mechanism of calycosin against cerebral I/R injury using transient middle cerebral artery occlusion/reperfusion (tMCAO/R)-exposed rats and oxygen-glucose deprivation/reperfusion (OGD/R)-stimulated PC12 cells. We found that calycosin treatment significantly improved neurological deficits, brain edema, blood-brain barrier (BBB) breakdown, infarction volume, and neuronal injuries in rats that underwent tMCAO/R; similar to ferrostatin-1 (a ferroptosis inhibitor), calycosin prevented cell viability loss in PC12 cells exposed to OGD/R stimulation. In addition, calycosin intervention decreased ferroptosis, as assessed by iron accumulation, malondialdehyde (MDA), superoxide dismutase (SOD), ceramide, and reactive oxygen species (ROS) levels, as well as ferroptosis-related protein expression (ACSL4, TfR1, FTH1, and GPX4). Furthermore, overexpression of ACSL4 reversed calycosin-induced beneficial efficacy in OGD/R-stimulated PC12 cells. The molecular docking analysis demonstrated that calycosin binds to ACSL4 by forming stable hydrogen bonds at G465, K690, and D573. Collectively, these findings indicate that calycosin ameliorates cerebral I/R injury by depressing ACSL4-dependent ferroptosis.

Exploring the Causality Between Plasma Brain-Derived Neurotrophic Factor and Neurological Diseases: A Mendelian Randomization Study

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a protein synthesized in the brain and widely expressed in the nervous system. Previous studies have demonstrated a controversial role of BDNF in neurological diseases.

OBJECTIVE

In this study, we aimed to assess the association between BDNF levels and the risk of neurological diseases by Mendelian randomization analysis.

METHODS

From a genome-wide association analysis of plasma proteins comprising 3,301 European participants, we isolated 25 genetic variations as instrumental variables for BDNF levels. Summary statistics data on six common neurological diseases as outcome variables. Two-sample Mendelian randomization (MR) analysis was used to assess whether plasma BDNF is causally related to neurological diseases. We also performed sensitivity analysis to ensure the robustness of the results and reverse MR to exclude potential reverse causality.

RESULTS

We confirmed the significant causal relationship between BDNF levels and the risk of Alzheimer's disease (AD) (OR, 0.92; 95% CI, 0.85, 0.98; p = 0.013). Other methods have also shown similar results. We infer that BDNF also reduces the risk of epilepsy (OR, 0.94; 95% CI, 0.90, 0.98; p = 0.004). In reverse MR analysis, we also found that AD can affect the level of BDNF.

CONCLUSIONS

Our study suggests higher plasma BDNF was associated with the reduced risk of AD. Moreover, higher plasma BDNF is a protective factor on AD and focal epilepsy. The results provide credence to the idea that BDNF may play a significant role in the development of focal epilepsy and AD.

Microglia-mediated neuroinflammation and neuroplasticity after stroke

Stroke remains a major cause of long-term disability and mortality worldwide. The immune system plays an important role in determining the condition of the brain following stroke. As the resident innate immune cells of the central nervous system, microglia are the primary responders in a defense network covering the entire brain parenchyma, and exert various functions depending on dynamic communications with neurons, astrocytes, and other neighboring cells under both physiological or pathological conditions. Microglia activation and polarization is crucial for brain damage and repair following ischemic stroke, and is considered a double-edged sword for neurological recovery. Microglia can exist in pro-inflammatory states and promote secondary brain damage, but they can also secrete anti-inflammatory cytokines and neurotrophic factors and facilitate recovery following stroke. In this review, we focus on the role and mechanisms of microglia-mediated neuroinflammation and neuroplasticity after ischemia and relevant potential microglia-based interventions for stroke therapy.

BDNF Therapeutic Mechanisms in Neuropsychiatric Disorders

Brain-derived neurotrophic factor (BDNF) is the most abundant neurotrophin in the adult brain and functions as both a primary neurotrophic signal and a neuromodulator. It serves essential roles in neuronal development, maintenance, transmission, and plasticity, thereby influencing aging, cognition, and behavior. Accumulating evidence associates reduced central and peripheral BDNF levels with various neuropsychiatric disorders, supporting its potential utilization as a biomarker of central pathologies. Subsequently, extensive research has been conducted to evaluate restoring, or otherwise augmenting, BDNF transmission as a potential therapeutic approach. Promising results were indeed observed for genetic BDNF upregulation or exogenous administration using a multitude of murine models of neurological and psychiatric diseases. However, varying mechanisms have been proposed to underlie the observed therapeutic effects, and many findings indicate the engagement of disease-specific and other non-specific mechanisms. This is because BDNF essentially affects all aspects of neuronal cellular function through tropomyosin receptor kinase B (TrkB) receptor signaling, the disruptions of which vary between brain regions across different pathologies leading to diversified consequences on cognition and behavior. Herein, we review the neurophysiology of BDNF transmission and signaling and classify the converging and diverging molecular mechanisms underlying its therapeutic potentials in neuropsychiatric disorders. These include neuroprotection, synaptic maintenance, immunomodulation, plasticity facilitation, secondary neuromodulation, and preservation of neurovascular unit integrity and cellular viability. Lastly, we discuss several findings suggesting BDNF as a common mediator of the therapeutic actions of centrally acting pharmacological agents used in the treatment of neurological and psychiatric illness.

Simultaneous optimization of the extraction process of Yangyin Yiqi Huoxue prescription with natural deep eutectic solvents for optimal extraction yield and antioxidant activity: A comparative study of two models

INTRODUCTION

Natural deep eutectic solvents (NaDESs) are green and effective solvents that are used to extract 3 flavonoids from Yangyin Yiqi Huoxue prescription, a traditional Chinese prescription.

METHODS

A total of 6 types of NaDESs were systematically screened and evaluated for the total extraction yield of puerarin, calycosin, and formononetin by high-performance liquid chromatography. Then, a 4-factor-three-level experimental scheme designed by the Box-Benhnken Design was applied on the basis of a single experiment to determine the extraction yield and the antioxidant property. Finally, the extraction process was optimized through response surface methodology (RSM) and the genetic neural network (GNN), respectively.

RESULTS

The use of betaine-lactic acid as an extractant displayed significant advantages in the screening process. The optimum extraction parameters provided by GNN were as follows: water content 25% (v/v), liquid to material ratio 190 mg/ml, extraction time 37 min, and extraction temperature 63 °C. Under this condition, the average experimental comprehensive evaluation values of the extraction yield and antioxidant properties were 3.12 mg/g and 86.27%, and the relative deviations to the predicted values were 0.30% and 1.44%, respectively. In addition, the experimental results of GNN were better than those of RSM (p < 0.01).

CONCLUSIONS

We found the application of GNN to be effective and credible for bi-objective optimization of extraction yields and antioxidant activity in this study. Moreover, our results provide a reference and a theoretical basis for experimental and future industrial extraction for multi-objective situations.

The Role of Brain-Derived Neurotrophic Factor Signaling in Central Nervous System Disease Pathogenesis

Recent studies have found abnormal levels of brain-derived neurotrophic factor (BDNF) in a variety of central nervous system (CNS) diseases (e.g., stroke, depression, anxiety, Alzheimer's disease, and Parkinson's disease). This suggests that BDNF may be involved in the pathogenesis of these diseases. Moreover, regulating BDNF signaling may represent a potential treatment for such diseases. With reference to recent research papers in related fields, this article reviews the production and regulation of BDNF in CNS and the role of BDNF signaling disorders in these diseases. A brief introduction of the clinical application status of BDNF is also provided.

Changes in microglia during drug treatment of stroke

Microglia are the main immune cells in the brain and the first defense barrier of the nervous system. Microglia play a complex role in the process of stroke. A growing number of studies focus on the mechanism of action of drugs functions and how to regulate microglia. Therefore, we talk about the pathophysiological mechanisms of stroke and elaborate on the microglia signaling pathways of drug action in stroke models and how these drugs play a role in stroke treatment in this review. Understanding how drugs modulate proinflammatory and anti-inflammatory responses of microglia may be critical to implementing therapeutic strategies using immune interventions in stroke.

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.

Exercise Rehabilitation and/or Astragaloside Attenuate Amyloid-beta Pathology by Reversing BDNF/TrkB Signaling Deficits and Mitochondrial Dysfunction

We aim to investigate the mechanisms underlying the beneficial effects of exercise rehabilitation (ER) and/or astragaloside (AST) in counteracting amyloid-beta (Aβ) pathology. Aβ oligomers were microinjected into the bilateral ventricles to induce Aβ neuropathology in rats. Neurobehavioral functions were evaluated. Cortical and hippocampal expressions of both BDNF/TrkB and cathepsin D were determined by the western blotting method. The rat primary cultured cortical neurons were incubated with BDNF and/or AST and ANA12 followed by exposure to aggregated Aβ for 24 h. In vivo results showed that ER and/or AST reversed neurobehavioral disorders, downregulation of cortical and hippocampal expression of both BDNF/TrkB and cathepsin D, neural pathology, Aβ accumulation, and altered microglial polarization caused by Aβ. In vitro studies also confirmed that topical application of BDNF and/or AST reversed the Aβ-induced cytotoxicity, apoptosis, mitochondrial distress, and synaptotoxicity and decreased expression of p-TrkB, p-Akt, p-GSK3β, and β-catenin in rat cortical neurons. The beneficial effects of combined ER (or BDNF) and AST therapy in vivo and in vitro were superior to ER (or BDNF) or AST alone. Furthermore, we observed that any gains from ER (or BDNF) and/or AST could be significantly eliminated by ANA-12, a potent BDNF/TrkB antagonist. These results indicate that whereas ER (or BDNF) and/or AST attenuate Aβ pathology by reversing BDNF/TrkB signaling deficits and mitochondrial dysfunction, combining these two potentiates each other's therapeutic effects. In particular, AST can be an alternative therapy to replace ER.

Calycosin Alleviates Paraquat-Induced Neurodegeneration by Improving Mitochondrial Functions and Regulating Autophagy in a Drosophila Model of Parkinson's Disease

Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder with limited clinical treatments. The occurrence of PD includes both genetic and environmental toxins, such as the pesticides paraquat (PQ), as major contributors to PD pathology in both invertebrate and mammalian models. Calycosin, an isoflavone phytoestrogen, has multiple pharmacological properties, including neuroprotective activity. However, the paucity of information regarding the neuroprotective potential of calycosin on PQ-induced neurodegeneration led us to explore whether calycosin can mitigate PD-like phenotypes and the underlying molecular mechanisms. We used a PQ-induced PD model in Drosophila as a cost-effective in vivo screening platform to investigate the neuroprotective efficacy of natural compounds on PD. We reported that calycosin shows a protective role in preventing dopaminergic (DA) neuronal cell death in PQ-exposed Canton S flies. Calycosin-fed PQ-exposed flies exhibit significant resistance against PQ-induced mortality and locomotor deficits in terms of reduced oxidative stress, loss of DA neurons, the depletion of dopamine content, and phosphorylated JNK-caspase-3 levels. Additionally, mechanistic studies show that calycosin administration improves PQ-induced mitochondrial dysfunction and stimulates mitophagy and general autophagy with reduced pS6K and p4EBP1 levels, suggestive of a maintained energy balance between anabolic and catabolic processes, resulting in the inhibition of neuronal cell death. Collectively, this study substantiates the protective effect of calycosin against PQ-induced neurodegeneration by improving DA neurons' survival and reducing apoptosis, likely via autophagy induction, and it is implicated as a novel therapeutic application against toxin-induced PD pathogenesis.

Identification of Active Ingredients of Huangqi Guizhi Wuwu Decoction for Promoting Nerve Function Recovery After Ischemic Stroke Using HT22 Live-Cell-Based Affinity Chromatography Combined with HPLC-MS/MS

Objective

The Chinese medicine Huangqi Guizhi Wuwu Decoction (HGWD) has been reported to improve the clinical symptoms and restore nerve function after ischemic stroke; however, its active ingredients are not well-determined. Therefore, this study aimed to investigate the bioactive compounds of HGWD and explore the possible mechanism of action.

Methods

The methods, including live HT22 cells, solid-phase extraction, and HPLC-MS/MS were utilized. The potential ingredients were identified through comparisons with literature and monomer compounds. Then, oxygen-glucose deprivation reperfusion (OGD/R)-treated HT22 cells were utilized to investigate the effect of HGWD components with specific binding affinities. Reactive oxygen species (ROS), superoxide dismutase (SOD), lactate dehydrogenase (LDH), and Tunel staining were used as testing indexes to analyze the protective effects of potential active ingredients on OGD/R-induced damage.

Results

Eleven compounds with specific binding affinities were identified as calycosin-7-O-glucoside, calycosin, formononetin, cinnamic alcohol, cinnamic acid, betaine, dl-2-phenylpropionic acid, 4-hydroxycinnamic acid, 6-methylcoumarin, wogonin, and paeoniflorin. Among them, six compounds had a protective effect on OGD/R-treated HT22 cells. Furthermore, calycosin-7-O-glucoside, calycosin, paeoniflorin, 4-hydroxycinnamic acid, wogonin, and formononetin could regulate oxidative stress and apoptosis to attenuate the cell damage caused by OGD/R.

Conclusion

The mechanism of action of HGWD to promote neurological recovery after ischemic stroke was related to the regulation of oxidative stress and apoptosis. This study suggested that cell membrane affinity chromatography combined with HPLC-MS/MS could be applied to screen potential active components in traditional Chinese medicines (TCM).

Hydrogen-Rich Water Improves Cognitive Ability and Induces Antioxidative, Antiapoptotic, and Anti-Inflammatory Effects in an Acute Ischemia-Reperfusion Injury Mouse Model

Background

Cerebral ischemia and its reperfusion injury facilitate serious neurodegenerative diseases such as dementia due to cell death; however, there is currently no treatment for it. Reactive oxygen species is one of the many factors that induce and worsen the development of such diseases, and it can be targeted by hydrogen treatment. This study examined the effect of molecular hydrogen in cerebral ischemia-reperfusion injury, which is emerging as a novel therapeutic agent for various diseases.

Methods

Ischemia-reperfusion injury was generated through bilateral common carotid artery occlusion in C57BL/6 mice. The test group received hydrogen-rich water orally during the test period. To confirm model establishment and the effect of hydrogen treatment, behavioural tests, biochemical assays, immunofluorescence microscopy, and cytokine assays were conducted.

Results

Open field and novel object recognition tests revealed that the hydrogen-treated group had improved cognitive function and anxiety levels compared to the nontreated group, while hematoxylin and eosin stain showed abundant pyknotic cells in a model mouse brain, and this was attenuated in the hydrogen-treated mouse brain. Total antioxidant capacity and thiobarbituric acid reactive substance assays revealed that hydrogen treatment induced antioxidative effects in the mouse brain. Immunofluorescence microscopy revealed attenuated apoptosis in the striatum, cerebral cortex, and hippocampus of hydrogen-treated mice. Western blotting showed that hydrogen treatment reduced Bax and TNFα levels. Finally, cytokine assays showed that IL-2 and IL-10 levels significantly differed between the hydrogen-treated and nontreated groups.

Conclusion

Hydrogen treatment could potentially be a future therapeutic strategy for ischemia and its derived neurodegenerative diseases by improving cognitive abilities and inducing antioxidative and antiapoptotic effects. Hydrogen treatment also decreased Bax and TNFα levels and induced an anti-inflammatory response via regulation of IL-2 and IL-10. These results will serve as a milestone for future studies intended to reveal the mechanism of action of molecular hydrogen in neurodegenerative diseases.

Diffusion tensor imaging of the hippocampus reflects the severity of hippocampal injury induced by global cerebral ischemia/reperfusion injury

At present, predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury (GCI/RI) is a clinical problem. After such an injury, clinical indicators that can directly reflect neurological dysfunction are lacking. The change in hippocampal microstructure is the key to memory formation and consolidation. Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure. Although hippocampal microstructure, brain-derived neurotrophic factor (BDNF), and tropomyosin-related kinase B (TrkB) levels are closely related to nerve injury and the repair process after GCI/RI, whether these indicators can reflect the severity of such hippocampal injury remains unknown. To address this issue, we established rat models of GCI/RI using the four-vessel occlusion method. Diffusion tensor imaging parameters, BDNF, and TrkB levels were correlated with modified neurological severity scores. The results revealed that after GCI/RI, while neurological function was not related to BDNF and TrkB levels, it was related to hippocampal fractional anisotropy. These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI. The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University, China (approval No. AEEI-2015-139) on November 9, 2015.

Inhibition of P2X4R attenuates white matter injury in mice after intracerebral hemorrhage by regulating microglial phenotypes

Background

White matter injury (WMI) is a major neuropathological event associated with intracerebral hemorrhage (ICH). P2X purinoreceptor 4 (P2X4R) is a member of the P2X purine receptor family, which plays a crucial role in regulating WMI and neuroinflammation in central nervous system (CNS) diseases. Our study investigated the role of P2X4R in the WMI and the inflammatory response in mice, as well as the possible mechanism of action after ICH.

Methods

ICH was induced in mice via collagenase injection. Mice were treated with 5-BDBD and ANA-12 to inhibit P2X4R and tropomyosin-related kinase receptor B (TrkB), respectively. Immunostaining and quantitative polymerase chain reaction (qPCR) were performed to detect microglial phenotypes after the inhibition of P2X4R. Western blots (WB) and immunostaining were used to examine WMI and the underlying molecular mechanisms. Cylinder, corner turn, wire hanging, and forelimb placement tests were conducted to evaluate neurobehavioral function.

Results

After ICH, the protein levels of P2X4R were upregulated, especially on day 7 after ICH, and were mainly located in the microglia. The inhibition of P2X4R via 5-BDBD promoted neurofunctional recovery after ICH as well as the transformation of the pro-inflammatory microglia induced by ICH into an anti-inflammatory phenotype, and attenuated ICH-induced WMI. Furthermore, we found that TrkB blockage can reverse the protective effects of WMI as well as neuroprotection after 5-BDBD treatment. This result indicates that P2X4R plays a crucial role in regulating WMI and neuroinflammation and that P2X4R inhibition may benefit patients with ICH.

Conclusions

Our results demonstrated that P2X4R contributes to WMI by polarizing microglia into a pro-inflammatory phenotype after ICH. Furthermore, the inhibition of P2X4R promoted pro-inflammatory microglia polarization into an anti-inflammatory phenotype, enhanced brain-derived neurotrophic factor (BDNF) production, and through the BDNF/TrkB pathway, attenuated WMI and improved neurological function. Therefore, the regulation of P2X4R activation may be beneficial for the reducing of ICH-induced brain injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02239-3.

Pharmaceutical Values of Calycosin: One Type of Flavonoid Isolated from Astragalus

Astragalus is a popular Materia Medica in China, and it could be applied in the treatment of various diseases. It contains a variety of chemically active ingredients, such as saponins, flavonoids, and polysaccharides. Plant-derived bioactive chemicals are considered natural, safe, and beneficial. Among the infinite plant-identified and isolated molecules, flavonoids have been reported to have positive effects on human health. Calycosin is the most important active flavonoid substance identified predominantly within this medicinal plant. In recent years, calycosin has been reported to have anticancer, antioxidative, immune-modulatory, and estrogenic-like properties. This review collected recent relevant literatures on calycosin and summarized its potential pharmaceutical properties and working mechanism involved, which provided solid basis for future clinical research.

Neuroprotective Phytochemicals in Experimental Ischemic Stroke: Mechanisms and Potential Clinical Applications

Ischemic stroke is a challenging disease with high mortality and disability rates, causing a great economic and social burden worldwide. During ischemic stroke, ionic imbalance and excitotoxicity, oxidative stress, and inflammation are developed in a relatively certain order, which then activate the cell death pathways directly or indirectly via the promotion of organelle dysfunction. Neuroprotection, a therapy that is aimed at inhibiting this damaging cascade, is therefore an important therapeutic strategy for ischemic stroke. Notably, phytochemicals showed great neuroprotective potential in preclinical research via various strategies including modulation of calcium levels and antiexcitotoxicity, antioxidation, anti-inflammation and BBB protection, mitochondrial protection and antiapoptosis, autophagy/mitophagy regulation, and regulation of neurotrophin release. In this review, we summarize the research works that report the neuroprotective activity of phytochemicals in the past 10 years and discuss the neuroprotective mechanisms and potential clinical applications of 148 phytochemicals that belong to the categories of flavonoids, stilbenoids, other phenols, terpenoids, and alkaloids. Among them, scutellarin, pinocembrin, puerarin, hydroxysafflor yellow A, salvianolic acids, rosmarinic acid, borneol, bilobalide, ginkgolides, ginsenoside Rd, and vinpocetine show great potential in clinical ischemic stroke treatment. This review will serve as a powerful reference for the screening of phytochemicals with potential clinical applications in ischemic stroke or the synthesis of new neuroprotective agents that take phytochemicals as leading compounds.

Neuroprotective Effect for Cerebral Ischemia by Natural Products: A Review

Natural products have a significant role in the prevention of disease and boosting of health in humans and animals. Stroke is a disease with high prevalence and incidence, the pathogenesis is a complex cascade reaction. In recent years, it’s reported that a vast number of natural products have demonstrated beneficial effects on stroke worldwide. Natural products have been discovered to modulate activities with multiple targets and signaling pathways to exert neuroprotection via direct or indirect effects on enzymes, such as kinases, regulatory receptors, and proteins. This review provides a comprehensive summary of the established pharmacological effects and multiple target mechanisms of natural products for cerebral ischemic injury in vitro and in vivo preclinical models, and their potential neuro-therapeutic applications. In addition, the biological activity of natural products is closely related to their structure, and the structure-activity relationship of most natural products in neuroprotection is lacking, which should be further explored in future. Overall, we stress on natural products for their role in neuroprotection, and this wide band of pharmacological or biological activities has made them suitable candidates for the treatment of stroke.

Polygala sabulosa A.W. Bennett extract mitigates motor and cognitive deficits in a mouse model of acute ischemia

Stroke is considered one of the leading causes of death worldwide. The treatment is limited; however, the Brazilian flora has a great source of natural products with therapeutic potentials. Studies with the medicinal plant Polygala sabulosa W. Bennett provided evidence for its use as an anti-inflammatory and neuroprotective drug. In the case of ischemic stroke due to lack of oxygen, both acute and chronic inflammatory processes are activated. Thus, we hypothesized that P. sabulosa (HEPs) has the potential to treat the motor and cognitive deficits generated by ischemic stroke. Male mice were subjected to global ischemia for 60 min, followed by reperfusion and orally treated with HEPs (100 mg/kg in saline + 3% tween 20) twice a day (12 h apart) for 48 h starting 3 h after surgery. Motor skills were assessed using grip force and open field tasks. Hippocampi were then collected for mRNA quantification of the cytokines IL-1-β and TNF-α levels. After 48 h of acute treatment, spatial reference memory was evaluated in a Morris water maze test for another group of animals. We show that HEPs treatment significantly prevented motor weakness induced by ischemia. Brain infarct area was reduced by 22.25% with downregulation of the levels of IL-1β and TNF-α mRNA. Learning performance and memory ability on Morris water maze task were similar to the sham group. Our data demonstrates the neuroprotective properties of HEPs through its anti-inflammatory activities, which prevent motor and cognitive impairments, suggesting that HEPs may be an effective therapy for ischemic stroke.

Combinational Pretreatment of Colony-Stimulating Factor 1 Receptor Inhibitor and Triptolide Upregulates BDNF-Akt and Autophagic Pathways to Improve Cerebral Ischemia

Ki20227, a selective inhibitor of colony-stimulating factor 1 receptor (CSF1R), has been suggested to regulate microglia inflammatory function and neuronal synaptic plasticity. Triptolide (TP) pretreatment has neuroprotective effects through its anti-inflammatory and antiapoptotic features in ischemic stroke mice. However, the underlying mechanism and pathway are presently unclear. We thus investigated the association between neuroprotective effects of combined TP and Ki20227 and BDNF-Akt and autophagy pathways. Ki20227 was administrated for 7 days, and TP was administered once 24 hours prior to building the ischemic stroke model in C57BL/6 mice. Behavioral tests, Golgi staining, immunofluorescence, and western blot analyses were employed to examine neuroprotective effects of TP and Ki20227. TP and Ki20227 pretreatments improved the neurobehavioral function in stroke mice. Synaptic protein expressions and density of dendritic spine density were upregulated in Ki20227 and TP pretreated stroke mice. Further, optimized integration of TP and Ki20227 pretreatments upregulated the NeuN expression and downregulated Iba1 expression after stroke. In addition, both TP and Ki20227 pretreatments significantly upregulated BDNF, p-Akt/Akt, and Erk1/2 protein expressions and autophagy related proteins (LC3II/I, Atg5, and p62), indicating the activation of BDNF and autophagic pathways. Optimized integration of TP and Ki20227 can improve cerebral ischemia by inhibiting CSF1R signal and trigger autophagy and BDNF-Akt signaling pathways to increase dendritic spine density and synaptic protein expressions, which in turn enhances neurobehavioral function.

Pharmacological targets and mechanisms of calycosin against meningitis

This report aimed to identity the potential anti-meningitis targets and mechanisms functioned by calycosin through network pharmacology approach. The bioinformatics databases were used to screen and collect the candidate genes/targets of calycosin and meningitis prior to identification of vital biotargets of calycosin-anti-meningitis. Additionally, the functional processes, signaling pathways of calycosin-anti-meningitis were screened and identified before further data visualization. As a result, all candidate and mapped biotargets of calycosin and meningitis were harvested before the vital targets of epidermal growth factor receptor (EGFR), tumor necrosis factor (TNF), epidermal growth factor (EGF), ataxia telangiectasia mutated protein (ATM), estrogen receptor alpha (ESR1), caspase-8 (CASP8), nerve growth factor (NGF) of calycosin-anti-meningitis were identified. The molecular processes of calycosin-anti-meningitis were screened and identified, including reduction of inflammatory development. Furthermore, the molecular pathways of calycosin-anti-meningitis were revealed, including suppression of NF-kappa B, Toll-like receptor, TNF signaling pathways. Molecular docking findings uncovered the docking capacity of calycosin with meningitis and potential pharmacological activity of calycosin against meningitis. In conclusion, these bioinformatic data uncovered the network targets and mechanisms of calycosin-anti-meningitis. And the current findings indicated that the vital targets might be used as potent biomarkers for detecting meningitis.