Efficacy of Ligustrazine Injection as Adjunctive Therapy for Angina Pectoris: A Systematic Review and Meta-Analysis

Targeting neutrophils extracellular traps, a promising anti-thrombotic therapy for natural products from traditional Chinese herbal medicine

Thrombi are the main cause of vascular occlusion and contribute significantly to cardiovascular events and death. Neutrophils extracellular traps (NETs)-induced thrombosis plays a vital role in thrombotic complications and it takes the main responsibility for the resistance of fibrinolysis. However, the conventional anti-thrombotic therapies are inadequate to treat NETs-induced thrombotic complications but carry a high risk of bleeding. Consequently, increased attention has shifted towards exploring novel anti-thrombotic treatments targeting NETs. Interestingly, accumulating evidences prove that natural products from traditional Chinese herbal medicines have a great potential to mitigate thrombosis through inhibiting generous NETs formation and degrading excessive NETs. In this review, we elaborated the formation and degradation of NETs and highlighted its pivotal role in immunothrombosis through interactions with platelets and coagulation factors. Since available anti-thrombotic drugs targeting NETs are deficient, we further summarized the natural products and compounds from traditional Chinese herbal medicines which exert effective actions on regulating NETs formation and also have anti-thrombotic effects. Our findings underscore the diverse effects of natural products in targeting NETs, including relieving inflammation and oxidative stress of neutrophils, inhibiting neutrophils activation and DNA efflux, suppressing granule proteins release, reducing histones and promoting DNA degradation. This review aims to highlight the significance of natural medicines in anti-thrombotic therapies through targeting NETs and to lay a groundwork for developing novel anti-thrombotic agents from traditional Chinese herbal medicines.

[Mechanism of tetramethylpyrazine attenuates inflammatory injury in endothelial cells by activating the SIRT1 signaling pathway]

OBJECTIVES

To study the effects and mechanisms of tetramethylpyrazine (TMP) on tumor necrosis factor-α (TNF-α)-induced inflammatory injury in human coronary artery endothelial cells (HCAEC).

METHODS

HCAEC were randomly divided into four groups: the control group (no treatment), the model group (treated with TNF-α, 50 ng/mL for 24 hours), the TMP group (pre-treated with TMP, 80 μg/mL for 12 hours followed by TNF-α treatment for 24 hours), and the SIRT1 inhibitor group (pre-treated with TMP and the specific SIRT1 inhibitor EX527 for 12 hours followed by TNF-α treatment for 24 hours). Cell viability was assessed using the CCK-8 method, lactate dehydrogenase (LDH) activity was measured using an LDH assay kit, reactive oxygen species (ROS) levels were observed using DCFH-DA staining, expression of pyroptosis-related proteins was detected by Western blot, and SIRT1 expression was analyzed using immunofluorescence staining.

RESULTS

Compared to the control group, the model group showed decreased cell viability, increased LDH activity, ROS level and expression of pyroptosis-related proteins, and decreased SIRT1 expression (P<0.05). Compared to the model group, the TMP group exhibited increased cell viability, decreased LDH activity, ROS level and expression of pyroptosis-related proteins, and increased SIRT1 expression (P<0.05). In comparison to the TMP group, the SIRT1 inhibitor group showed decreased cell viability, increased LDH activity, ROS level and expression of pyroptosis-related proteins, and decreased SIRT1 expression (P<0.05).

CONCLUSIONS

TMP may attenuate TNF-α-induced inflammatory injury in HCAEC, which is associated with the inhibition of pyroptosis and activation of the SIRT1 signaling pathway.

Bibliometric analysis of research progress on tetramethylpyrazine and its effects on ischemia-reperfusion injury

In recent decades, natural products have attracted worldwide attention and become one of the most important resources for pharmacological industries and medical sciences to identify novel drug candidates for disease treatment. Tetramethylpyrazine (TMP) is an alkaloid extracted from Ligusticum chuanxiong Hort., which has shown great therapeutic potential in cardiovascular and cerebrovascular diseases, liver and renal injury, as well as cancer. In this review, we analyzed 1270 papers published on the Web of Science Core Collection from 2002 to 2022 and found that TMP exerted significant protective effects on ischemia-reperfusion (I/R) injury that is the cause of pathological damages in a variety of conditions, such as ischemic stroke, myocardial infarction, acute kidney injury, and liver transplantation. TMP is limited in clinical applications to some extent due to its rapid metabolism, a short biological half-life and poor bioavailability. Obviously, the structural modification, administration methods and dosage forms of TMP need to be further investigated in order to improve its bioavailability. This review summarizes the clinical applications of TMP, elucidates its potential mechanisms in protecting I/R injury, provides strategies to improve bioavailability, which presents a comprehensive understanding of the important compound. Hopefully, the information and knowledge from this review can help researchers and physicians to better improve the applications of TMP in the clinic.

A systematic review and meta-analysis on sodium tanshinone IIA sulfonate injection for the adjunctive therapy of pulmonary heart disease

AIMS

Sodium tanshinone IIA sulfonate (STS) injection has been widely used as adjunctive therapy for pulmonary heart disease (PHD) in China. Nevertheless, the efficacy of STS injection has not been systematically evaluated so far. Hence, the efficacy of STS injection as adjunctive therapy for PHD was explored in this study.

METHODS

Randomized controlled trials (RCTs) were screened from China Science and Technology Journal Database, China National Knowledge Infrastructure, Wanfang Database, PubMed, Sino-Med, Google Scholar, Medline, Chinese Biomedical Literature Database, Cochrane Library, Embase and Chinese Science Citation Database until 20 January 2024. Literature searching, data collection and quality assessment were independently performed by two investigators. The extracted data was analyzed with RevMan 5.4 and STATA 14.0. Basing on the methodological quality, dosage of STS injection, control group measures and intervention time, sensitivity analysis and subgroup analysis were performed.

RESULTS

19 RCTs with 1739 patients were included in this study. Results showed that as adjunctive therapy, STS injection combined with Western medicine showed better therapeutic efficacy than Western medicine alone for PHD by increasing the clinical effective rate (RR = 1.22; 95% CI, 1.17 to 1.27; p < 0.001), partial pressure of oxygen (MD = 10.16; 95% CI, 5.07 to 15.24; p < 0.001), left ventricular ejection fraction (MD = 8.66; 95% CI, 6.14 to 11.18; p < 0.001) and stroke volume (MD = 13.10; 95% CI, 11.83 to 14.38; p < 0.001), meanwhile decreasing the low shear blood viscosity (MD = -1.16; 95% CI, -1.57 to -0.74; p < 0.001), high shear blood viscosity (MD = -0.64; 95% CI, -0.86 to -0.42; p < 0.001), plasma viscosity (MD = -0.23; 95% CI, -0.30 to -0.17; p < 0.001), hematokrit (MD = -8.52; 95% CI, -11.06 to -5.98; p < 0.001), fibrinogen (MD = -0.62; 95% CI, -0.87 to -0.37; p < 0.001) and partial pressure of carbon dioxide (MD = -8.56; 95% CI, -12.09 to -5.02; p < 0.001).

CONCLUSION

STS injection as adjunctive therapy seemed to be more effective than Western medicine alone for PHD. However, due to low quality of the included RCTs, more well-designed RCTs were necessary to verify the efficacy of STS injection.

Ligustrazine mitigates chronic venous disease-induced pain hyperalgesia through desensitization of inflammation-associated TRPA1 activity in DRG

ETHNOPHARMACOLOGICAL RELEVANCE

Ligustrazine, an important active ingredient extracted from Ligusticum chuanxiong hort, has been widely used to cure cardiovascular diseases and exerts an analgesic effect.

AIMS OF THIS STUDY

The aim of this study is to investigate whether ligustrazine mitigates chronic venous disease (CVeD)-induced pain and to explore its underlying mechanisms.

MATERIALS AND METHODS

A mouse model of CVeD was established by vein ligature. Ligustrazine was administered intraperitoneally to CVeD mice for a single injection (20 mg/kg, 100 mg/kg, and 200 mg/kg) or once a day for three weeks (100 mg/kg and 200 mg/kg), and TRPA1 overexpressed HEK 293 cells were treated with ligustrazine (600 μM) in the presence of mustard oil (100 μM) for 2 min. Patch clamp and calcium imaging were used to measure the inhibitory response of ligustrazine on DRG neurons and TRPA1 transfected HEK293 cells.

RESULTS

The present results showed that mice receiving vein ligature surgery exhibited obvious pain hypersensitivity to mechanical, cold and thermal stimuli, whereas ligustrazine significantly reversed the pain hyperalgesia in CVeD mice. Furthermore, ligustrazine desensitized transient receptor potential ankyrin 1 (TRPA1) activity in the dorsal root ganglion (DRG) neurons, resulting in suppressing the DRG neuronal excitability in the CVeD mice. However, ligustrazine could not directly inhibit the response of TRPA1 transfected HEK293 cells to mustard oil. Strikingly, ligustrazine restricted the macrophage infiltration and decreased the mRNA levels of Interleukin-1β (IL-1β) and NOD-like receptor protein 3 (NLRP3) in the DRG neurons of the CVeD mice.

CONCLUSIONS

The present study provided evidence that ligustrazine alleviated pain hypersensitivity to mechanical, cold and thermal stimuli in CVeD mice. Ligustrazine could weaken the activity of TRPA1 in the DRG to mitigate CVeD-induced pain hyperalgesia mainly through inhibition of inflammation. Our findings identify that ligustrazine may be a new therapeutic agent for the treatment of CVeD-induced pain.

Tetramethylpyrazine: A review on its mechanisms and functions

Ligusticum chuanxiong Hort (known as Chuanxiong in China, CX) is one of the most widely used and long-standing medicinal herbs in China. Tetramethylpyrazine (TMP) is an alkaloid and one of the active components of CX. Over the past few decades, TMP has been proven to possess several pharmacological properties. It has been used to treat a variety of diseases with excellent therapeutic effects. Here, the pharmacological characteristics and molecular mechanism of TMP in recent years are reviewed, with an emphasis on the signal-regulation mechanism of TMP. This review shows that TMP has many physiological functions, including anti-oxidant, anti-inflammatory, and anti-apoptosis properties; autophagy regulation; vasodilation; angiogenesis regulation; mitochondrial damage suppression; endothelial protection; reduction of proliferation and migration of vascular smooth muscle cells; and neuroprotection. At present, TMP is used in treating cardiovascular, nervous, and digestive system conditions, cancer, and other conditions and has achieved good curative effects. The therapeutic mechanism of TMP involves multiple targets, multiple pathways, and bidirectional regulation. TMP is, thus, a promising drug with great research potential.

A Systematic Review and Meta-Analysis on the Efficacy of Puerarin Injection as Adjunctive Therapy for Unstable Angina Pectoris

Background

As adjunctive therapy, puerarin injection has been widely applied for the treatment of unstable angina pectoris (UAP) in China during the past decades. However, the efficacy of puerarin injection as adjunctive therapy for UAP has not been well confirmed. The purpose of this meta-analysis was to summarize the available evidence to estimate the efficacy of puerarin injection in treating UAP.

Objective

A systematic review and meta-analysis with subgroup analysis and sensitivity analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principle were carried out to evaluate the efficacy of puerarin injection as adjunctive therapy in treating UAP.

Methods

To obtain the published randomized controlled trials (RCTs) on puerarin injection, databases, namely, China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Biomedical Literature Database, Sino-Med, PubMed, China Science and Technology Journal Database (VIP), Medline, Google Scholar, Cochrane Library, Chinese Science Citation Database, and Embase were systematically searched until June 2021. In this meta-analysis, Review Manager version 5.3 software and Stata version 12.0 software were employed to analyze the collected data. Based on the methodological quality, years of publications, sample size and dosages, sensitivity analysis, and subgroup analysis were performed. The GRADE assessment was conducted by the software GRADEpro version 3.6 software.

Results

A total of 17 RCTs involving 1,459 patients were included in this meta-analysis. Results indicated that puerarin injection as adjunctive therapy was more superior than conventional Western medicine alone in reducing angina symptoms [risk ratio (RR) = 1.22, 95% CI 1.16 to 1.28, Z = 8.11, p < 0.00001] and improving ECG (RR = 1.32, 95% CI 1.20 to 1.44, Z = 6.00, p < 0.00001), meanwhile reducing the frequency of angina attack [mean difference (MD) = −2.22, 95% CI −2.53 to −1.90, Z = 13.97, p < 0.00001] and the duration of angina attack (MD = −2.00, 95% CI −2.39 to −1.61, Z = 9.99, p < 0.00001) for the treatment of UAP. Results from the GRADE assessment suggested that the comprehensive quality of this evidence was low.

Conclusion

This meta-analysis indicated that puerarin injection was more effective than using conventional Western medicine alone in the treatment of UAP. However, because of the low methodological quality of the included RCTs, more evidence was still needed to verify the efficacy of puerarin injection.

Sodium tanshinone ⅡA sulfonate injection as adjunctive therapy for the treatment of heart failure: A systematic review and meta-analysis

BACKGROUND

Sodium tanshinone ⅡA sulfonate (STS) injection has been widely used to treat heart failure over the past years in China. However, to the best of our knowledge, neither systematic review nor meta-analysis on the efficacy of STS injection as adjunctive therapy for heart failure has been reported.

OBJECTIVE

The aim of this study is to summarize relevant evidence from the published randomized controlled trials (RCTs) to evaluate the efficacy of STS injection as adjunctive therapy for heart failure.

METHODS

RCTs on STS injection as adjunctive therapy for the treatment of heart failure were screened from China National Knowledge Infrastructure (CNKI), Wanfang Database, Sino-Med, PubMed, Google Scholar, Medline, China Science and Technology Journal Database (VIP), Chinese Biomedical Literature Database, Cochrane Library, Embase and Chinese Science Citation Database until July 2021. Two authors independently performed the literature searching, data extraction, and quality evaluation. The meta-analysis was carried out by RevMan 5.3. Based on the methodological quality, years of publication, and sample size of the included RCTs, sensitivity analysis and subgroup analysis were investigated.

RESULTS

Fourteen RCTs with a total of 1368 patients were identified in this study. Results from this meta-analysis showed that STS injection as adjunctive therapy was superior to western medicine alone for the treatment of heart failure in improving the total effective rate (RR = 1.23; 95% CI, 1.17 to 1.29; p < 0.00001) and the left ventricular ejection fraction (LVEF; MD = 6.34; 95% CI 5.25 to 7.43; p < 0.00001), meanwhile reducing the left ventricular end-diastolic diameter (LVEDD; MD = -4.79; 95% CI, -6.44 to -3.15; p < 0.00001), left ventricular end-systolic dimension (LVESD; MD = -3.98; 95% CI, -5.79 to -2.17; p < 0.0001) and brain natriuretic peptide (BNP; MD = -118.75; 95% CI, -175.36 to -62.15; p < 0.0001).

CONCLUSIONS

This study indicated that STS injection as adjunctive therapy seemed to be more effective than western medicine alone in treating heart failure. However, due to the poor methodological quality of the included RCTs, further well-designed RCTs are required to confirm the efficacy of STS injection.

Efficacy of Ligustrazine Injection as Adjunctive Therapy in Treating Acute Cerebral Infarction: A Systematic Review and Meta-Analysis

Background: Ligustrazine injection has been widely used as adjunctive therapy in the treatment of acute cerebral infarction (ACI) during the past decades in China, but its clinical efficacy is not yet well confirmed. This study aims to evaluate the efficacy of ligustrazine injection as adjunctive therapy for ACI. Methods: Databases including China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), PubMed, Medline, Google Scholar, Chinese Biomedical Literature Database, Cochrane Library, Embase, Sino-Med, Wanfang Database, and Chinese Science Citation Database were systematically searched for the published randomized controlled trials (RCTs) on ligustrazine injection in the treatment of ACI until November 2020. Meta-analysis was performed on the primary outcome measure (i.e., clinical effective rate) and the secondary outcome measure [i.e., neurological deficit score (NDS), fibrinogen, low shear blood viscosity (LBV), and high shear blood viscosity (HBV)]. The quality of the included RCTs was assessed according to the M scoring system (the refined Jadad scale). Sensitivity analysis and subgroup analysis were conducted according to the methodological quality, years of publication, and sample size. Results: Nineteen RCTs, containing 2022 patients, were included in this study. Meta-analysis indicated that ligustrazine injection combined with Western medicine could achieve a better effect in the treatment of ACI than using Western medicine alone in terms of clinical effective rate (RR = 1.24; 95% CI, 1.19-1.29), NDS (MD = -3.88; 95%CI, -4.51 to -3.61), fibrinogen (MD = -0.59; 95% CI, -0.76 to -0.42), LBV (MD = -2.11; 95% CI, -3.16 to -1.06), and HBV (MD = -0.88; 95% CI, -1.20 to -0.55). Conclusions: This research indicated that ligustrazine injection as adjunctive therapy seemed to be more effective than using western medicine alone in treating ACI. However, more evidence is required to confirm the efficacy of ligustrazine injection due to the low methodological quality of the included RCTs.

Effect of ligustrazine nanoparticles on Th1/Th2 balance by TLR4/MyD88/NF-κB pathway in rats with postoperative peritoneal adhesion

Background

Postoperative peritoneal adhesion (PPA) is regarded as fibrous bands connecting both injured abdominal wall and organs or adjacent tissues. It is associated with T helper (Th)1 and Th2 differentiation. However, the critical role of the immunopathogenesis of adhesion formation was precisely unknown. The aim of this study was to investigate the effect of a new agent polylactic acid (PLA) nanoparticles loaded with ligustrazine, that is, ligustrazine nanoparticles (LN) on PPA and identify the potential mechanism.

Methods

Twenty-four Sprague–Dawley rats were randomly divided into the sham, model, LN, and sodium hyaluronate (SH) groups. The structure of LN, including entrapment efficiency (EE) and loading capacity (LC), and in vitro drug release were calculated. Adhesions were scored and the Masson's trichrome staining was used to determine the collagen deposition. The expressions of TLR4, MyD88, and NF-κB were measured by qRT-PCR, immunohistochemistry, and western blot assay. Moreover, Th1-related cytokines (IFN-γ, IL-12), Th2-related cytokines (IL-4, IL-6) in the cecum tissue and serum were conducted by ELISA.

Results

LN had good EE, LC, and control-release delivery characters with fairly uniform diameter and spherical morphology. It could effectively prevent adhesion formation after surgery. Besides, it could reduce collagen fibers accumulation, downregulate the expression levels of TLR4, MyD88, and NF-κB, and maintain Th1/Th2 balance.

Conclusions

Ligustrazine nanoparticles had effective effects on Th1/Th2 balance by regulating TLR4/MyD88/NF-κB pathway in PPA rats. It may be served as a promising therapy on postoperative adhesion formation.

iTRAQ-based quantitative proteomics and target-fishing strategies reveal molecular signatures on vasodilation of Compound Danshen Dripping Pills

Angina pectoris can be used as an early warning for coronary artery disease. Vasodilation is an important mechanism of angina pectoris. Traditional Chinese medicine - Compound Danshen Dripping Pill (CDDP) is widely used to improve the symptoms of cardiovascular diseases (CVDs). To investigate the influence of vasodilation effect and underlying mechanisms of CDDP, we determined the vasodilation effect of thoracic aorta ring on rat induced by norepinephrine (NE). Then targets-fishing method was used to predict the potential mechanism of CDDP on vasodilation, based on the structures of the main components. Then, iTRAQ-based quantitative proteomics analysis was used for verification of the candidate target proteins and pathways to illustrate the underlying mechanisms. Furthermore, the differentially expressed proteins in the enriched pathways were validated by western blotting. In this study, we found that CDDP could significantly inhibit NE induced aortic contraction tension, and the mechanism may be related to platelet activation, cGMP - PKG signaling pathway and vascular smooth muscle contraction. The method provides a new way to uncover the vasodilation mechanism of CDDP, as well as other multi-component herbal medicines.

RETRACTED: Tetramethylpyrazine alleviates lipopolysaccharide-induced damage in ATDC5 cells via down-regulating MyD88

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief and the authors. Following the concerns raised about the background pattern of the Western Blots from Figures 7A and 7C, the authors have contacted the journal to request the retraction of the article as they were reportedly not confident of the accuracy of the data and the conclusions of the article. Given the comments of Dr Elisabeth Bik regarding this article “This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Classical Chinese Herbal Formulas in the Treatment of Coronary Heart Disease: A Narrative Review

OBJECTIVE

To summarize the current evidence for 8 frequently prescribed Chinese herbal formulas (CHF) as treatments for angina pectoris in patients with coronary heart disease (CHD) and the associated adverse reactions.

METHODS

Seven electronic databases were screened from their inception through July 2018 for all evidence related to classical CHF for the treatment of patients with CHD.

RESULTS

CHF improves CHD outcomes in terms of angina pectoris, electrocardiogram results, Chinese medicine syndromes and biomarkers iomarkers. The combination of CHF and Western medicine (WM) is more effective on CHD than WM alone. The use of CHF to treat CHD shows the same or better clinical effects as the use of WM alone. The 8 investigated CHF do not induce hepatic and renal toxicity or other serious adverse effects.

CONCLUSIONS

The safety and efficacy of 8 frequently prescribed herbal formulas for treating CHD have been confirmed in many studies. The findings of these studies are positive but should be interpreted cautiously due to the poor methodological quality of the randomized controlled trials (RCTs) and meta-analyses. Additional high-quality, multi-center, large-sample RCTs should be performed to confirm these results.

Application of Feedback System Control Optimization Technique in Combined Use of Dual Antiplatelet Therapy and Herbal Medicines

Aim: Combined use of herbal medicines in patients underwent dual antiplatelet therapy (DAPT) might cause bleeding or thrombosis because herbal medicines with anti-platelet activities may exhibit interactions with DAPT. In this study, we tried to use a feedback system control (FSC) optimization technique to optimize dose strategy and clarify possible interactions in combined use of DAPT and herbal medicines.

Methods: Herbal medicines with reported anti-platelet activities were selected by searching related references in Pubmed. Experimental anti-platelet activities of representative compounds originated from these herbal medicines were investigated using in vitro assay, namely ADP-induced aggregation of rat platelet-rich-plasma. FSC scheme hybridized artificial intelligence calculation and bench experiments to iteratively optimize 4-drug combination and 2-drug combination from these drug candidates.

Results: Totally 68 herbal medicines were reported to have anti-platelet activities. In the present study, 7 representative compounds from these herbal medicines were selected to study combinatorial drug optimization together with DAPT, i.e., aspirin and ticagrelor. FSC technique first down-selected 9 drug candidates to the most significant 5 drugs. Then, FSC further secured 4 drugs in the optimal combination, including aspirin, ticagrelor, ferulic acid from DangGui, and forskolin from MaoHouQiaoRuiHua. Finally, FSC quantitatively estimated the possible interactions between aspirin:ticagrelor, aspirin:ferulic acid, ticagrelor:forskolin, and ferulic acid:forskolin. The estimation was further verified by experimentally determined Combination Index (CI) values.

Conclusion: Results of the present study suggested that FSC optimization technique could be used in optimization of anti-platelet drug combinations and might be helpful in designing personal anti-platelet therapy strategy. Furthermore, FSC analysis could also identify interactions between different drugs which might provide useful information for research of signal cascades in platelet.

Tetramethylpyrazine attenuates periorbital allodynia and neuroinflammation in a model of traumatic brain injury

Background

Traumatic brain injury (TBI) is a public health issue. As the major complaint in 51% of TBI patients, chronic pain is an important aspect in TBI treatment. Tetramethylpyrazine (TMP) is an important compound in Ligustrazine, an analgesic drug in traditional Chinese medicine, but its potential in relieving pain symptom in TBI has not been tested. We established a TBI mouse model with controlled cortical impact (CCI), and measured periorbital hypersensitivity with von Frey monofilaments. We examined activated microglia and astrocytes and the levels of substance P (SP) and inducible isoform of nitric oxide synthase (iNOS) with immunohistochemistry, measured mRNA and protein levels of proinflammatory cytokines with qPCR and enzyme-linked immunosorbent assay, respectively. Western blot was employed to detect molecules in NF-κB signaling pathway.

Results

TMP significantly attenuated periorbital hypersensitivity in TBI mice. Within 3 days after CCI, TMP attenuated activation of microglia and astrocytes, levels of SP, iNOS, and CGRP in trigeminal pathway, and levels of proinflammatory cytokines (including IL-6, TNF-α, IL-12). In isolated microglia, TMP attenuated the effects of lipopolysaccharide on the phosphorylation of cytoplasmic IKKα/β and IKB-α, and levels of nucleic p65.

Conclusion

TMP reversed periorbital hypersensitivity by limiting neuroinflammation at the primary stage of TBI, and could be a promising drug for pain treatment in TBI.

Mechanisms and Clinical Application of Tetramethylpyrazine (an Interesting Natural Compound Isolated from Ligusticum Wallichii): Current Status and Perspective

Tetramethylpyrazine, a natural compound from Ligusticum wallichii (Chuan Xiong), has been extensively used in China for cardiovascular and cerebrovascular diseases for about 40 years. Because of its effectiveness in multisystems, especially in cardiovascular, its pharmacological action, clinical application, and the structural modification have attracted broad attention. In this paper its mechanisms of action, the clinical status, and synthetic derivatives will be reviewed briefly.