Tetramethylpyrazine reduces blood-brain barrier permeability associated with enhancement of peripheral cholinergic anti-inflammatory effects for treating traumatic brain injury

Metabolomics integrated with network pharmacology of blood-entry constituents reveals the bioactive component of Xuefu Zhuyu decoction and its angiogenic effects in treating traumatic brain injury

BACKGROUND

Xuefu Zhuyu decoction (XFZYD) has been extensively utilized to treat traumatic brain injury (TBI). However, the bioactive compounds and the underlying mechanisms have not yet been elucidated.

OBJECTIVES

This study aimed to investigate the bioactive constituents of XFYZD that are absorbed in the blood and the mechanisms in treating TBI.

METHODS

The study presents an integrated strategy in three steps to investigate the material basis and pharmacological mechanisms of XFZYD. The first step involves: (1) performing metabolomics analysis of XFZYD to obtain the main functions and targets; (2) screening the blood-entry ingredients and targets of XFZYD from databases; (3) obtaining the potential components targeting the key functions by integrated analysis of metabolomics and network pharmacology. The second step involves screening pharmacological effects with active ingredients in vitro. In the third step, the effects of the top active compound were validated in vivo, and the mechanisms were explored by protein antagonist experiments.

RESULTS

Metabolomics analysis revealed that XFZYD treated TBI mice mainly through affecting the functions of blood vessels. We screened 62 blood-entry ingredients of XFZYD by network pharmacology. Then, we focused on 39 blood-entry ingredients related to vascular genes enriched by XFZYD-responsive metabolites. Performing the natural products library, we verified that hydroxysafflor yellow A (HSYA), vanillin, ligustilide, paeoniflorin, and other substances promoted endothelial cell proliferation significantly compared to the control group. Among them, the efficacy of HSYA was superior. Further animal studies demonstrated that HSYA treatment alleviated neurological dysfunction in TBI mice by mNSS and foot fault test, and decreased neuronal damage by HE, nissl, and TUNEL staining. HSYA increased the density of cerebral microvessels, raised the expression of angiogenesis marker proteins VEGFA and CD34, and activated the PI3K/Akt/mTOR signaling pathway significantly. The angiogenic effects disappeared after the intervention of PI3K antagonist LY294002.

CONCLUSION

By applying a novel strategy of integrating network pharmacology of constituents absorbed in blood with metabolomics, the research screened HSYA as one of the top bioactive constituents of XFZYD, which stimulates angiogenesis by activating the PI3K/Akt/mTOR signaling pathway after TBI.

Bitter yet beneficial: The dual role of dietary alkaloids in managing diabetes and enhancing cognitive function

With the rising prevalence of diabetes and its association with cognitive impairment, interest in the use of dietary alkaloids and other natural products has grown significantly. Understanding how these compounds manage diabetic cognitive dysfunction (DCD) is crucial. This comprehensive review explores the etiology of DCD and the effects of alkaloids in foods and dietary supplements that have been investigated as DCD therapies. Data on how dietary alkaloids like berberine, trigonelline, caffeine, capsaicin, 1-deoxynojirimycin, nuciferine, neferine, aegeline, tetramethylpyrazine, piperine, and others regulate cognition in diabetic disorders were collected from PubMed, Research Gate, Web of Science, Science Direct, and other relevant databases. Dietary alkaloids could improve memory in behavioral models and modulate the mechanisms underlying the cognitive benefits of these compounds, including their effects on glucose metabolism, gut microbiota, vasculopathy, neuroinflammation, and oxidative stress. Evidence suggests that dietary alkaloids hold promise for improving cognition in diabetic patients and could open exciting avenues for future research in diabetes management.

Neuroprotective Effects of Melittin Against Cerebral Ischemia and Inflammatory Injury via Upregulation of MCPIP1 to Suppress NF-κB Activation In Vivo and In Vitro

Melittin, a principal constituent of honeybee venom, exhibits diverse biological effects, encompassing anti-inflammatory capabilities and neuroprotective actions against an array of neurological diseases. In this study, we probed the prospective protective influence of melittin on cerebral ischemia, focusing on its anti-inflammatory activity. Mechanistically, we explored whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as ZC3H12A), a recently identified zinc-finger protein, played a role in melittin-mediated anti-inflammation and neuroprotection. Male C57/BL6 mice were subjected to distal middle cerebral artery occlusion to create a focal cerebral cortical ischemia model, with melittin administered intraperitoneally. We evaluated motor functions, brain infarct volume, cerebral blood flow, and inflammatory marker levels within brain tissue, employing quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and western blotting. In vitro, an immortalized BV-2 microglia culture was stimulated with lipopolysaccharide (LPS) to establish an inflammatory cell model. Post-melittin exposure, cell viability, and cytokine expression were examined. MCPIP1 was silenced using siRNA in LPS-induced BV-2 cells, with the ensuing nuclear translocation of nuclear factor-κB assessed through cellular immunofluorescence. In vivo, melittin enhanced motor functions, diminished infarction, fostered blood flow restoration in ischemic brain regions, and markedly inhibited the expression of inflammatory cytokines (interleukin-1β, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB). In vitro, melittin augmented MCPIP1 expression in LPS-induced BV-2 cells and ameliorated inflammation-induced cell death. The neuroprotective effect conferred by melittin was attenuated upon MCPIP1 knockdown. Our findings establish that melittin-induced tolerance to ischemic injury is intrinsically linked with its anti-inflammatory capacity. Moreover, MCPIP1 is, at the very least, partially implicated in this process.

The combination of two natural medicines, Chuanxiong and Asarum: A review of the chemical constituents and pharmacological activities

Traditional Chinese medicine has been clinically used in China for many years, with experimental studies and clinical trials having demonstrated that it is safe and valid. Among many traditional natural medicines, Chuanxiong and Asarum have been proven to be effective in the treatment of relieving pain. Actually, as well as analgesic, they have common attributes, such as anti-inflammatory, cardiovascular benefits, and anticancer activities, with volatile oils being their major components. Furthermore, Chuanxiong and Asarum have been combined as drug pairs in the same prescription for thousands of years, with examples being Chuanxiong Chatiao San and Chuanxiongxixintang. More interestingly, their combination has better therapeutic effects on diseases than a single drug. After the combination of Chuanxiong and Asarum forms a blend, a series of changes take place in their chemical components, such as the contents of the main active ingredients, ferulic acid and ligustilide, increased significantly after this progress. At the same time, the pharmacological effects of the combination appearing to be more powerful, such as synergistic analgesic. This review focuses on the chemical constituents and pharmacological activities of Chuanxiong, Asarum, and Chuanxiong Asarum compositions.

Tetramethylpyrazine Preserves the Integrity of Blood-Brain Barrier Associated With Upregulation of MCPIP1 in a Murine Model of Focal Ischemic Stroke

Tetramethylpyrazine (TMP), a prominent ingredient of Chinese herb Ligusticum chuanxiong Hort, is known to suppress neuroinflammation and protect blood-brain barrier (BBB) integrity. We investigated whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as Regnase-1), a newly identified zinc-finger protein, plays a role in TMP-mediated anti-inflammation and neuroprotection. Male C57BL/6 mice were subjected to focal cerebral ischemia induced by middle cerebral artery occlusion (MCAO) for 2 h, followed by reperfusion for 24 h. TMP (25 mg/kg or 50 mg/kg) or vehicle was administered intraperitoneally 12 h before and post MCAO. The TMP significantly upregulated MCPIP1 in the ischemic brain tissues and effectively inhibited extravasation of fluorescein isothiocyanate (FITC)-dextran, resulting in attenuation of brain edema. These effects of the TMP were associated with a significant reduction in levels of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and MMP-9 in the ischemic brain tissues. The TMP upregulated the expression of MCPIP1 in primary cultures of neurons and protected against oxygen-glucose deprivation-induced neuron death, while this neuroprotective effect of TMP was abolished by knockdown of MCPIP1 using MCPIP1-specific siRNA. These results suggest that preservation of BBB integrity by TMP is associated with its anti-inflammatory activity. The effect of TMP is mediated, at least in part, via upregulation of MCPIP1 in the ischemic brain.

Exploring the Regulatory Mechanism of Hedysarum Multijugum Maxim.-Chuanxiong Rhizoma Compound on HIF-VEGF Pathway and Cerebral Ischemia-Reperfusion Injury's Biological Network Based on Systematic Pharmacology

Background: Clinical research found that Hedysarum Multijugum Maxim.-Chuanxiong Rhizoma Compound (HCC) has definite curative effect on cerebral ischemic diseases, such as ischemic stroke and cerebral ischemia-reperfusion injury (CIR). However, its mechanism for treating cerebral ischemia is still not fully explained.

Methods: The traditional Chinese medicine related database were utilized to obtain the components of HCC. The Pharmmapper were used to predict HCC’s potential targets. The CIR genes were obtained from Genecards and OMIM and the protein-protein interaction (PPI) data of HCC’s targets and IS genes were obtained from String database. After that, the DAVID platform was applied for Gene Ontology (GO) enrichment analysis and pathway enrichment analysis. Finally, a series of animal experiments were carried out to further explore the mechanism of HCC intervention in CIR.

Results: The prediction results of systematic pharmacology showed that HCC can regulate CIR-related targets (such as AKT1, MAPK1, CASP3, EGFR), biological processes (such as angiogenesis, neuronal axonal injury, blood coagulation, calcium homeostasis) and signaling pathways (such as HIF-1, VEGF, Ras, FoxO signaling). The experiments showed that HCC can improve the neurological deficit score, decrease the volume of cerebral infarction and up-regulate the expression of HIF-1α/VEGF and VEGFR protein and mRNA (p < 0.05).

Conclusion: HCC may play a therapeutic role by regulating CIR-related targets, biological processes and signaling pathways found on this study.

Tetramethylpyrazine Protects Blood-Spinal Cord Barrier Integrity by Modulating Microglia Polarization Through Activation of STAT3/SOCS3 and Inhibition of NF-кB Signaling Pathways in Experimental Autoimmune Encephalomyelitis Mice

We previously reported that tetramethylpyrazine (TMP) alleviates experimental autoimmune encephalomyelitis (EAE) by decreasing glia activation. Activated microglia has been shown to mediate blood-spinal cord barrier (BSCB) disruption, which is a primary and continuous pathological characteristic of multiple sclerosis (MS). Therefore, in this study, we further investigated whether TMP protects the BSCB integrity by inhibition of glia activation to alleviate EAE. Extravasation of evans blue was used to detect the BSCB disruption. Tumor necrosis factor-α (TNF-α)/interlukine-1β (IL-1β) and interlukine-4 (IL-4)/interlukine-10 (IL-10) were determined by enzyme-linked immunosorbent assay. BV2 glial cells stimulated by interferon-γ (IFN-γ) were co-cultured with human brain microvascular endothelial cells to investigate the effect of TMP on the BSCB disruption. Flow cytometry was used to analyze the microglia phenotype. Western blot was performed to reveal the signaling pathways involved in the microglia activation. In this study, most importantly, we found that TMP protects the BSCB integrity by modulating microglia polarization from M1 phenotype to M2 phenotype through activation of STAT3/SOCS3 and inhibition of NF-кB signaling pathways. Moreover, TMP significantly preserves the tight junction proteins, reduces the secretion of pro-inflammatory cytokines (TNF-α, IL-1β) and increases the secretion of anti-inflammatory cytokines (IL-4, IL-10) from IFN-γ-stimulated BV2 microglia cells. Consequently, protection of the BSCB integrity leads to alleviation of clinical symptoms and demyelination in EAE mice. Therefore, TMP might be an effective therapeutic agent for cerebral disorders with BBB or BSCB disruption, such as ischemic stroke, MS, and traumatic brain injury.

Rapid Screening and Quantitative Analysis of 74 Pesticide Residues in Herb by Retention Index Combined with GC-QQQ-MS/MS

In this research, a very practical QuEChERS-GC-MS/MS analytical approach for 74 pesticide residues in herb based on retention index was established. This novel analytical approach has two important technical advantages. One advantage is to quickly screen pesticide compounds in herbs without having to use a large number of pesticide standard substances at the beginning of the experiment. The other advantage is to assist in identifying the target pesticide compound accurately. A total of 74 kinds of pesticides were quickly prescreened in all chuanxiong rhizoma samples. The results showed that three kinds of pesticides were screened out in all the samples, including chlorpyrifos, fipronil, and procymidone, and the three pesticides were qualitatively and quantitatively determined. The RSD values for interday and intraday variation were acquired to evaluate the precision of the analytical approach, and the overall interday and intraday variations are not more than 1.97% and 3.82%, respectively. The variations of concentrations of the analyzed three pesticide compounds in sample CX16 are 0.74%-4.15%, indicating that the three pesticides in the sample solutions were stable in 48 h. The spiked recoveries of the three pesticides are 95.22%, 93.03%, and 94.31%, and the RSDs are less than ± 6.0%. The methodological verification results indicated the good reliability and accuracy of the new analytical method. This research work is a new application of retention index, and it will be a valuable tool to assist quickly and accurately in the qualitative and quantitative analysis of multipesticide residues in herbs.

The Protective Effects and Potential Mechanisms of Ligusticum chuanxiong: Focus on Anti-Inflammatory, Antioxidant, and Antiapoptotic Activities

Ligusticum chuanxiong (LC) is a Chinese materia medica which is widely used in clinical settings to treat headaches, blood extravasation, and arthritis. Recent studies demonstrate that LC possesses versatile pharmacological functions, including antiatherosclerosis, antimigraine, antiaging, and anticancer properties. Moreover, LC also shows protective effects in the progression of different diseases that damage somatic cells. Oxidative stress and inflammation, which can induce somatic cell apoptosis, are the main factors associated with an abundance of diseases, whose progresses can be reversed by LC. In order to comprehensively review the molecular mechanisms associated with the protective effects of LC, we collected and integrated all its related studies on the anti-inflammatory, antioxidant, and antiapoptotic effects. The results show that LC could exhibit the mentioned biological activities by modulating several signaling pathways, specifically the NF-κB, Nrf2, protein kinase, and caspase-3 pathways. In future investigations, the pharmacokinetic properties of bioactive compounds in LC and the signaling pathway modulation of LC could be focused.

Preparation, preliminary pharmacokinetics and brain tissue distribution of Tanshinone IIA and Tetramethylpyrazine composite nanoemulsions

Objective: Tanshinone IIA (TSN) and Tetramethylpyrazine (TMP) were combined in a composite, oil-in-water nanoemulsions (TSN/TMP O/W NEs) was prepared to prolong in vitro and vivo circulation time, and enhance the bioavailability of TSN. Material and methods: Physicochemical characterization of TSN/TMP O/W NEs was characterized systematically. The in vitro dissolution and in vivo pharmacokinetic experiments of TSN/TMP O/W NEs were also evaluated. Result: A formulation was optimized, yielding a 32.5 nm average particle size, an encapsulation efficiency of over 95 %, and were spherical in shape as shown by TEM. TSN/TMP O/W NEs were shown to extend the release and availability in vitro compared to raw compounds. In pharmacokinetic study, the AUC_0→∞ and t_1/2 of the TSN/TMP O/W NEs were 481.50 mg/L*min and 346.39 min higher than TSN solution, respectively. Brain tissue concentration of TSN was enhanced with TSN/TMP O/W NEs over raw TSN and even TSN O/W NEs. Conclusions: Therefore, nanoemulsions are an effective carrier to increase encapsulation efficiency of drugs, improve bioavailability and brain penetration for TSN - which is further enhanced by pairing with the co-delivery of TMP, providing a promising drug delivery.

Retinal Transcriptome Analysis in the Treatment of Endotoxin-Induced Uveitis with Tetramethylpyrazine Eye Drops

Purpose: To investigate retinal gene expression of tetramethylpyrazine (TMP) eye drop-treated endotoxin-induced uveitis (EIU) in mice and to explore the mechanisms. Methods: The inflammatory signs of the anterior segment were evaluated, and clinical scores were graded. The retinal transcriptome from the TMP eye drop-treated and the untreated mice was identified by RNA sequencing (RNA-seq) strategy. Differentially expressed genes (DEGs) were validated by real-time PCR. The protein-protein interaction was analyzed using the STRING software. Results: Compared with the TMP-treated group, the inflammatory responses of the untreated control group were much severe and clinical score was remarkably higher (P < 0.001) at 24 h after lipopolysaccharide administration. RNA-seq assay identified 407 DEGs, among which 356 were upregulated and 51 were downregulated. There were 12 upregulated gene ontology terms enriched and 27 upregulated pathways. Seven DEGs, including inflammation-related, complement system-related, and interferon-related genes, were validated using quantitative PCR. Conclusions: TMP exerted anti-inflammatory effect in EIU. Local application of TMP inhibited retinal inflammatory response by regulating the inflammation-related genes, suggesting that TMP may be a potential novel therapeutic drug for ocular inflammation.

Tetramethylpyrazine exerts a protective effect against injury from acute myocardial ischemia by regulating the PI3K/Akt/GSK-3β signaling pathway

Objective

We investigated the protective effect of tetramethylpyrazine (TMP) on injury related to acute myocardial ischemia (AMI) induced by isoproterenol (ISO).

Materials and methods

Rats were randomly assigned to five groups: control, ISO, ISO + propranolol (10 mg/kg), ISO + TMP (10 mg/kg) and ISO + TMP (20 mg/kg). The rats in the three ISO + groups were pretreated with propranolol or TMP, while the rats in the control and ISO groups were pretreated with an equal volume of saline. Afterwards, the rats in the four administration groups were subcutaneously injected with ISO for two consecutive days. The levels of creatine kinase (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β in the serum were measured using ELISA. The expressions of B-cell lymphoma-associated X-2 (Bax-2), B-cell lymphoma-2 (Bcl-2), phosphoinositide-3-kinase (PI3K), protein kinase B (Akt), glycogen synthase kinase 3β (GSK-3β), MDA5 and SOD1 were determined using western blotting assay. The phosphorylation of PI3K, Akt and GSK-3β were also determined using western blotting assay. The left ventricles of the rats were extracted and stained using hematoxylin and eosin (H&E). The ST segment was recorded using electrocardiograms (ECGs).

Results

Administration of TMP (10, 20 mg/kg) reduced the levels of MDA and CK and the activities of SOD and LDH in the serum. Pretreatment with TMP significantly reduced the levels of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α. Treatment with TMP also improved the histopathological alteration and decreased the ST elevation. Furthermore, TMP ameliorated the expressions of Cu, SOD1, MDA5, Bax-2, Bcl-2, p-PI3K, p-Akt and p-GSK-3β in ISO-induced rats.

Conclusions

Tetramethylpyrazine protected against injury due to AMI by regulating the PI3K/Akt /GSK-3β signaling pathway.

Breakdown of blood brain barrier as a mechanism of post-traumatic epilepsy

Traumatic brain injury (TBI) accounts for approximately 16% of acute symptomatic seizures which usually occur in the first week after trauma. Children are at higher risk for post-traumatic seizures than adults. Post-traumatic seizures are a risk factor for delayed development of epilepsy. Delayed, chronic post-traumatic epilepsy is preceded by a silent period during which therapeutic interventions may arrest, revert or prevent epileptogenesis. A number of recent review articles summarize the most important features of post-traumatic seizures and epilepsy; this review will instead focus on the link between cerebrovascular permeability, epileptogenesis and ictal events after TBI. The possibility of acting on the blood-brain barrier (BBB) and the neurovascular unit to prevent, disrupt or treat post-traumatic epilepsy is also discussed. Finally, we describe the latest quest for biomarkers of epileptogenesis which may allow for a more targeted intervention.