Recent Advances in Chinese Herbal Medicine for Cerebral Ischemic Reperfusion Injury

Mechanism of Astragalus mongholicus Bunge ameliorating cerebral ischemia-reperfusion injury: Based on network pharmacology analysis and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus mongholicus Bunge (AMB) is a herb with wide application in traditional Chinese medicine, exerting a wealth of pharmacological effects. AMB has been proven to have an evident therapeutic effect on ischemic cerebrovascular diseases, including cerebral ischemia-reperfusion injury (CIRI). However, the specific mechanism underlying AMB in CIRI remains unclear.

AIM OF THE STUDY

This study aimed to investigate the potential role of AMB in CIRI through a comprehensive approach of network pharmacology and in vivo experimental research.

METHODS

The intersection genes of drugs and diseases were obtained through analysis of the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and Gene Expression Omnibus (GEO) database. The protein-protein interaction (PPI) network was created through the string website. Meanwhile, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was carried out using R studio, and thereafter the key genes were screened. Then, the molecular docking prediction was made between the main active ingredients and target genes, and hub genes with high binding energy were obtained. In addition, molecular dynamic (MD) simulation was used to validate the result of molecular docking. Based on the results of network pharmacology, we used animal experiments to verify the predicted hub genes. First, the rat middle cerebral artery occlusion and reperfusion (MACO/R) model was established and the effective dose of AMB in CIRI was determined by behavioral detection and 2,3,5-Triphenyltetrazolium chloride (TTC) staining. Then the target proteins corresponding to the hub genes were measured by Western blot. Moreover, the level of neuronal death was measured using hematoxylin and eosin (HE) and Nissl staining.

RESULTS

Based on the analysis of the TCMSP database and GEO database, a total of 62 intersection target genes of diseases and drugs were obtained. The KEGG enrichment analysis showed that the therapeutic effect of AMB on CIRI might be realized through the advanced glycation endproduct-the receptor of advanced glycation endproduct (AGE-RAGE) signaling pathway in diabetic complications, nuclear factor kappa-B (NF-κB) signaling pathway and other pathways. Molecular docking results showed that the active ingredients of AMB had good binding potential with hub genes that included Prkcb, Ikbkb, Gsk3b, Fos and Rela. Animal experiments showed that AWE (60 g/kg) could alleviate CIRI by regulating the phosphorylation of PKCβ, IKKβ, GSK3β, c-Fos and NF-κB p65 proteins.

CONCLUSION

AMB exerts multi-target and multi-pathway effects against CIRI, and the underlying mechanism may be related to anti-apoptosis, anti-inflammation, anti-oxidative stress and inhibiting calcium overload.

Effects of Nutraceutical Compositions Containing Rhizoma Gastrodiae or Lipoic Acid in an In Vitro Induced Neuropathic Pain Model

BACKGROUND

Peripheral neuropathy is caused by a malfunction in the axons and myelin sheaths of peripheral nerves and motor and sensory neurons. In this context, nonpharmacological treatments with antioxidant potential have attracted much attention due to the issues that some conventional pharmaceutical therapy can generate. Most of these treatments contain lipoic acid, but issues have emerged regarding its use. Considering this, the present study evaluated the beneficial effects of nutraceuticals based on Gastrodiae elata dry extract 10:1 or lipoic acid in combination with other substances (such as citicholine, B vitamins, and acetyl L-carnitine).

METHOD

To assess the combination's absorption and biodistribution and exclude cytotoxicity, its bioavailability was first examined in a 3D intestinal barrier model that replicated oral ingestion. Subsequently, a 3D model of nerve tissue was constructed to investigate the impacts of the new combination on the significant pathways dysregulated in peripheral neuropathy.

RESULTS

Our findings show that the novel combination outperformed in initial pain relief response and in recovering the mechanism of nerve healing following Schwann cell injury by successfully crossing the gut barrier and reaching the target site.

CONCLUSION

This article describes a potential alternative nutraceutical approach supporting the effectiveness of combinations with Gastrodiae elata extract in decreasing neuropathy and regulating pain pathways.

Dracocephalum moldavica L.: An updated comprehensive review of its botany, traditional uses, phytochemistry, pharmacology, and application aspects

Dracocephalum moldavica, known as Xiang-qing-lan (in Chinese), is a traditional folk medicine, which was commonly used by Mongolian and Xinjiang Uyghurs area. Dracocephalum moldavica has the effects of purging liver fire, clearing stomach heat, hemostasis. It is used for treating insufficient heart and blood, weakened brain function, weak feeling and spirit disease etc. This review aimed to summarize the botany, traditional uses, phytochemistry, pharmacology and application of Dracocephalum moldavica, which expected to provide theoretical support for future utilization and highlight the further investigation of this vital plant. In addition to the essential oil, approximately 154 compounds have been isolated and identified from aerial parts of the Dracocephalum moldavica, including flavonoids, terpenoids, lignans, phenylpropanoids, phenols, glycosides, polysaccharide and other compounds. Extensive pharmacological activities of the extracts or compounds of Dracocephalum moldavica in vivo and in vitro were confirmed including cardiovascular protection, antioxidative, antimicrobial, antifungal, anti-complementary and chronic mountain sickness. Moreover, Dracocephalum moldavica is used in a wide range of applications in food, biological pesticides and cosmetics. In the future, Dracocephalum moldavica needs further study, such as paying more attention to quality control, toxicity, pharmacological mechanism and pharmacokinetics.

The role of JAK/STAT signaling pathway in cerebral ischemia-reperfusion injury and the therapeutic effect of traditional Chinese medicine: A narrative review

Cerebral ischemia is a cerebrovascular disease with symptoms caused by insufficient blood or oxygen supply to the brain. When blood supplied is restored after cerebral ischemia, secondary brain injury may occur, which is called cerebral ischemia-reperfusion injury (CIRI). In this process, the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway plays an important role. It mediates neuroinflammation and participates in the regulation of physiological activities, such as cell proliferation, differentiation, and apoptosis. After CIRI, M1 microglia is activated and recruited by the damaged tissue. The inflammatory factors are produced by M1 microglia through the JAK/STAT pathway, eventually leading to cell apoptosis. Meanwhile, the JAK2/STAT3 signaling pathway and the expression of lipocalin-2 and caspase-3 could increase. In the pathway, phosphorylated JAK2 and phosphorylated STAT3 function of 2 ways. They not only promote the proliferation of neurons, but also affect the differentiation direction of neural stem cells by further acting on the Notch signaling pathway. Recently, traditional Chinese medicine (TCM) is a key player in CIRI, through JAK2, STAT3, STAT1 and their phosphorylation. Therefore, the review focuses on the JAK/STAT signaling pathway and its relationship with CIRI as well as the influence of the TCM on this pathway. It is aimed at providing the basis for future clinical research on the molecular mechanism of TCM in the treatment of CIRI.

PFT-α protects the blood-brain barrier through the Wnt/β-catenin pathway after acute ischemic stroke

The dysfunction of blood-brain barrier (BBB) plays a pivotal role in brain injury and subsequent neurological deficits of ischemic stroke. The current study aimed to examine the potential correlation between p53 inhibition and the neuroprotective effect of on the BBB. Rat middle cerebral artery occlusion and reperfusion model (MCAO/R) and oxygen-glucose deprivation/re-oxygenation model (OGD/R) were employed to simulate cerebral ischemia-reperfusion (CI/R) injury occurrence in vivo and in vitro. mNSS and TTC staining were applied to evaluate neurological deficits and brain infarct volumes. Evans blue (EB) staining was carried out to examine the permeability of BBB. RT-qPCR and Western blot to examine the mRNA and protein levels. Cell viabilities were detected by CCK-8. Flow cytometry and ELISA assay were employed to examine apoptosis and neuroinflammation levels. TEER value and sodium fluorescein were carried out to explore the permeability of HBMEC cells. PFT-α inhibited P53 and promoted the expression of β-catenin and cyclin D1, which were reversed by DKK1. PFT-α inhibited neurological deficits, brain infarct volume, neuroinflammation, apoptosis, and BBB integrity than the MCAO/R rats; however, this inhibition was reversed by DKK1. PFT-α promoted OGD/R-induced cell viability in NSCs, and suppressed inflammation and apoptosis, but DKK1 weakened the effect of PFT-α. PFT-α increased OGD/R-induced TEER values in cerebrovascular endothelial cells, inhibited sodium fluorescein permeability, and increased the mRNA levels of tight junction protein, but they were all attenuated by DKK1. PFT-α protects the BBB after acute ischemic stroke via the Wnt/β-catenin pathway, which in turn improves neurological function.

Ursolic Acid Ameliorated Neuronal Damage by Restoring Microglia-Activated MMP/TIMP Imbalance in vitro

Purpose

The oxygen and glucose deprivation-reoxygenation (OGDR) model is widely used to evaluate ischemic stroke and cerebral ischemia-reperfusion (I/R) injury in vitro. Excessively activated microglia produce pro-inflammatory mediators such as matrix metalloproteinases [MMPs] and their specific inhibitors, tissue inhibitors of metalloproteinases [TIMPs], causing neuronal damage. Ursolic acid (UA) acts as a neuroprotective agent in the rat middle cerebral artery occlusion/reperfusion (MCAO/R) model keeping the MMP/TIMP balance with underlying mechanisms unclear. Our study used OGDR model to determine whether and how UA reduces neuronal damage by reversing MMP/TIMP imbalance caused by microglia in I/R injury in vitro.

Methods

SH-SY5Y cells were first cultured with 95% N2 and 5% CO2 and then cultivated regularly for OGDR model. Cell viability was tested for a proper UA dose. We established a co-culture system with SH-SY5Y cells and microglia-conditioned medium (MCM) stimulated by lipopolysaccharide (LPS) and interferon-gamma (IFNγ). MMP9 and TIMP1 levels were measured with ELISA assay to confirm the UA effect. We added recombinant MMP9 (rMMP9) and TIMP1 neutralizing antibody (anti-TIMP1) for reconfirmation. Transmission electron microscopy was used to observe cell morphology, and flow cytometry and Annexin V-FITC and PI labeling for apoptotic conditions. We further measured the calcium fluorescence intensity in SH-SY5Y cells.

Results

The MCM significantly reduced cell viability of SH-SY5Y cells after OGDR (p<0.01), which was restored by UA (0.25 µM) (p<0.05), whereas lactate dehydrogenase activity, intraneuronal Ca2+ concentration, and apoptosis-related indexes were showed significant improvement after UA treatment (p<0.01). UA corrected the MMP/TIMP imbalance by decreasing MMP9 expression and increasing TIMP1 expression in the co-culture system (p<0.01) and the effects of UA on SH-SY5Y cells were mitigated by the administration of rMMP9 and anti-TIMP1 (p<0.01).

Conclusion

We demonstrated that UA inhibited microglia-induced neuronal cell death in an OGDR model of ischemic reperfusion injury by stabilizing the MMP9/TIMP1 imbalance.

Regulatory mechanisms of natural compounds from traditional Chinese herbal medicines on the microglial response in ischemic stroke

BACKGROUND

Development of clinically effective neuroprotective agents for stroke therapy is still a challenging task. Microglia play a critical role in brain injury and recovery after ischemic stroke. Traditional Chinese herbal medicines (TCHMs) are based on a unique therapeutic principle, have various formulas, and have long been widely used to treat stroke. Therefore, the active compounds in TCHMs and their underlying mechanisms of action are attracting increasing attention in the field of stroke drug development.

PURPOSE

To summarize the regulatory mechanisms of TCHM-derived natural compounds on the microglial response in animal models of ischemic stroke.

METHODS

We searched studies published until 10 April 2023 in the Web of Science, PubMed, and ScienceDirect using the following keywords: natural compounds, natural products or phytochemicals, traditional Chinese Medicine or Chinese herbal medicine, microglia, and ischemic stroke. This review was prepared according to PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analysis) guidelines.

RESULTS

Natural compounds derived from TCHMs can attenuate the M1 phenotype of microglia, which is involved in the detrimental inflammatory response, via inhibition of NF-κB, MAPKs, JAK/STAT, Notch, TLR4, P2X7R, CX3CR1, IL-17RA, the NLRP3 inflammasome, and pro-oxidant enzymes. Additionally, the neuroprotective response of microglia with the M2 phenotype can be enhanced by activating Nrf2/HO-1, PI3K/AKT, AMPK, PPARγ, SIRT1, CB2R, TREM2, nAChR, and IL-33/ST2. Several clinical trials showed that TCHM-derived natural compounds that regulate microglial responses have significant and safe therapeutic effects, but further well-designed clinical studies are needed.

CONCLUSIONS

Further research regarding the direct targets and potential pleiotropic or synergistic effects of natural compounds would provide a more reasonable approach for regulation of the microglial response with the possibility of successful stroke drug development.

Network pharmacology to explore the mechanism of scutellarin in the treatment of brain ischaemia and experimental verification of JAK2/STAT3 signalling pathway

Scutellarin is used to treat brain ischaemia. However, its underlying mechanism of action remains unclear. This study aimed to elucidate the potential mechanism of action of scutellarin in brain ischaemia through network pharmacology and experimental verification. The JAK2/STAT3 signalling pathway was identified and experimentally verified. Expression of JAK2/STAT3 signalling related proteins in TNC-1 astrocytes with BV-2 microglia-conditioned medium (CM), CM + lipopolysaccharide (LPS) (CM + L), and CM pretreated with scutellarin + LPS (CM + SL) was analysed by Western Blot and immunofluorescence staining. Expression levels of JAK2, p-JAK2, STAT3, and p-STAT3 were evaluated in astrocytes pre-treated with AG490. Middle cerebral artery occlusion (MCAO) in rats was performed in different experimental groups to detect expression of the above biomarkers. Network pharmacology suggested that the JAK2/STAT3 signalling pathway is one of the mechanisms by which scutellarin mitigates cerebral ischaemic damage. In TNC-1 astrocytes, p-JAK2 and p-STAT3 expression were significantly up-regulated in the CM + L group. Scutellarin promoted the up-regulation of various markers and AG490 neutralised the effect of scutellarin. In vivo, up-regulation of p-JAK2 and p-STAT3 after ischaemia is known. These results are consistent with previous reports. Scutellarin further enhanced this upregulation at 1, 3, and 7 d after MCAO. Scutellarin exerts its therapeutic effects on cerebral ischaemia by activating the astrocyte JAK2/STAT3 signalling, which provides a firm experimental basis for its clinical application.

The Differences of Metabolites in Different Parts of the Brain Induced by Shuxuetong Injection against Cerebral Ischemia-Reperfusion and Its Corresponding Mechanism

Ischemic stroke is often associated with a large disease burden. The existence of ischemia-reperfusion injury brings great challenges to the treatment of ischemic stroke. The purpose of this study was to explore the differences of metabolites in different parts of the brain induced by Shuxuetong injection against cerebral ischemia-reperfusion and to extend the corresponding mechanism. The rats were modeled by transient middle cerebral artery occlusion (t-MCAO) operation, and the success of modeling was determined by neurological function score and TTC staining. UPLC-Q/TOF-MS metabolomics technique and multivariate statistical analysis were used to analyze the changes and differences of metabolites in the cortex and hippocampus of cerebral ischemia-reperfusion rats. Compared with the model group, the neurological function score and cerebral infarction volume of the Shuxuetong treatment group were significantly different. There were differences and changes in the metabolic distribution of the cortex and hippocampus in each group, the distribution within the group was relatively concentrated. The separation trend between the groups was obvious, and the distribution of the Shuxuetong treatment group was similar to that of the sham operation group. We identified 13 metabolites that were differentially expressed in the cortex, including glutamine, dihydroorotic acid, and glyceric acid. We also found five differentially expressed metabolites in the hippocampus, including glutamic acid and fumaric acid. The common metabolic pathways of Shuxuetong on the cortex and hippocampus were D-glutamine and D-glutamate metabolism and nitrogen metabolism, which showed inhibition of cortical glutamine and promotion of hippocampal glutamic acid. Specific pathways of Shuxuetong enriched in the cortex included glyoxylate and dicarboxylate metabolism and pyrimidine metabolism, which showed inhibition of glyceric acid and dihydroorotic acid. Specific pathways of Shuxuetong enriched in the hippocampus include arginine biosynthesis and citrate cycle (TCA cycle), which promotes fumaric acid. Shuxuetong injection can restore and adjust the metabolic disorder of the cortex and hippocampus in cerebral ischemia-reperfusion rats. The expression of Shuxuetong in different parts of the brain is different and correlated.

The Signaling Pathways and Targets of Natural Compounds from Traditional Chinese Medicine in Treating Ischemic Stroke

Ischemic stroke (IS) is a common neurological disorder associated with high disability rates and mortality rates. At present, recombinant tissue plasminogen activator (r-tPA) is the only US(FDA)-approved drug for IS. However, due to the narrow therapeutic window and risk of intracerebral hemorrhage, r-tPA is currently used in less than 5% of stroke patients. Natural compounds have been widely used in the treatment of IS in China and have a wide range of therapeutic effects on IS by regulating multiple targets and signaling pathways. The keywords "ischemia stroke, traditional Chinese Medicine, Chinese herbal medicine, natural compounds" were used to search the relevant literature in PubMed and other databases over the past five years. The results showed that JAK/STAT, NF-κB, MAPK, Notch, Nrf2, and PI3K/Akt are the key pathways, and SIRT1, MMP9, TLR4, HIF-α are the key targets for the natural compounds from traditional Chinese medicine in treating IS. This study aims to update and summarize the signaling pathways and targets of natural compounds in the treatment of IS, and provide a base of information for the future development of effective treatments for IS.