PMID: 

Bioengineered. 2019 12 ;10(1):172-181. PMID: 31034353

Abstract Title: 

Tetramethylpyrazine (TMP) protects rats against acute pancreatitis through NF-κB pathway.

Abstract: 

Acute pancreatitis (AP) is a digestive disease characterized by pancreatic inflammation. Tetramethylpyrazine (TMP) has been effectively used to ameliorate the damage on intestinal mucosa injury in rats with acute necrotizing pancreatitis (ANP). We aim to study the protective effect of TMP on caerulein-induced AP and to explore the possible mechanism. The mice randomized into control and different experimental groups. AP was induced in mice by 6-hourly intraperitoneal (i.p) injections of caerulein (50 μg/kg at 1 h interval). TMP (i.p, 10 mg/kg, 1 h interval) was administered 3 h before caerulein injection. Administration of TMP attenuated the severity of AP as shown by the histopathology, reduced serum amylase activity and pro-inflammatory cytokines TNF-α and IL-6. Further, TMP enhances the beneficial effect by reducing caerulein-induced NF-κB activation and inducing cell apoptosis in pancreas. Therefore, inhibition of nuclear factor-kappa B(NF-κB) signals by TMP represents a potential therapeutic strategy for the treatment of acute pancreatitis.

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PMID: 

Biochem Biophys Res Commun. 2019 Jun 18 ;514(1):329-335. Epub 2019 Apr 26. PMID: 31036319

Abstract Title: 

Tetramethylpyrazine alleviates LPS-induced inflammatory injury in HUVECs by inhibiting Rho/ROCK pathway.

Abstract: 

Endothelial dysfunction plays an important role in the pathogenesis of acute lung injury (ALI). Tetramethylpyrazine (TMP) has been reported to attenuate harmful changes in ALI rats. However, the effects of TMP on endothelial cell injury and its underlying mechanisms remain unknown. In this study, human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) was used as an inflammatory injury model, also served as LPS group. HUVECs pretreated with TMP for 2 h before induced by LPS was served as LPS + TMP group. Untreated HUVECs was served as control group. After incubation with LPS for 12 h, cell viability and morphology, cell apoptosis rate, CD31-positive endothelial microparticles (EMPs) release, proinflammatory cytokines secretion, and ROCK IIexpression were evaluated. Compared with LPS group, TMP pretreatment improved cell viability and morphology. Besides, cell apoptosis rate, CD31-positive EMPs amount, TNF-α and IL-1β concentrates, and ROCK II mRNA and protein levels in LPS + TMP group were significantly decreased when compared with LPS group. To further confirm the mechanism, HUVECs in all the above groups were pretreated with Y27632 (ROCK II inhibitor) for 30 min before grouping, then treated as above. No significant differences in cell apoptosis rate, CD31-positive EMPs amount, and ROCK II expression between Y27632 + LPS group and Y27632 + LPS + TMP group were found. To sum up, our study found that TMP alleviated LPS-induced inflammatory injury in HUVECs by inhibiting Rho/ROCK pathway.

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PMID: 

Eur J Pharmacol. 2019 Aug 15 ;857:172422. Epub 2019 May 30. PMID: 31152701

Abstract Title: 

Tetramethylpyrazine guards against cisplatin-induced nephrotoxicity in rats through inhibiting HMGB1/TLR4/NF-κB and activating Nrf2 and PPAR-γ signaling pathways.

Abstract: 

Cisplatin-induced acute renal injury is the most common and serious side effect, sometimes requiring discontinuation of the treatment. Thus, the development of new protective strategies is essential. The present study aimed to investigate the potential nephroprotective effect of tetramethylpyrazine (TMP) against acute renal damage induced by cisplatin in rats. Rats were administered 50 and 100 mg/kg TMP intraperitoneally before cisplatin (7 mg/kg). Acute nephrotoxicity was evident in cisplatin-treated rats where relative kidney weight, BUN and serum creatinine were markedly elevated. Cisplatin administration resulted in enhanced oxidative stress, evidenced by depleted GSH level as well as catalase and superoxide dismutase activities. Also, lipid peroxidation was boosted in comparison to the control. This was associated with inhibition of Nrf2 defense pathway. Moreover, cisplatin increased the expression of pro-inflammatory mediators in the kidney tissues. Cisplatin-induced apoptosis was depicted by elevated Bax mRNA expression and caspase-3 activity, as well as decreased Bcl2 mRNA expression. In addition, high mobility group box 1/toll-like receptor 4/nuclear factor-kappa B (HMGB1/TLR4/NF-κB) signaling pathway was significantly upregulated, while peroxisome proliferator-activated receptor-gamma (PPAR-γ) expression was significantly diminished in cisplatin-treated rats. Cisplatin-induced nephrotoxicity, oxidative stress, inflammation, apoptosis and the effect on Nrf2 defense pathway and HMGB1/TLR4/NF-κB as well as PPAR-γ expression were markedly ameliorated by TMP administration. Given the major nephrotoxicity of cisplatin cancer chemotherapy, TMP might be a potential candidate for neoadjuvant chemotherapy due to its antioxidant, anti-inflammatory and anti-apoptotic effects, in addition to its effect on Nrf2, HMGB1/TLR4/NF-κB signaling pathway and PPAR-γexpression.

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PMID: 

Biosci Rep. 2019 Jun 28 ;39(6). Epub 2019 Jun 25. PMID: 31171713

Abstract Title: 

Anti-aging effects exerted by Tetramethylpyrazine enhances self-renewal and neuronal differentiation of rat bMSCs by suppressing NF-kB signaling.

Abstract: 

In order to improve the therapeutic effects of mesenchymal stem cell (MSC)-based therapies for a number of intractable neurological disorders, a more favorable strategy to regulate the outcome of bone marrow MSCs (bMSCs) was examined in the present study. In view of the wide range of neurotrophic and neuroprotective effects, Tetramethylpyrazine (TMP), a biologically active alkaloid isolated from the herbal medicine, was used. It was revealed that treatment with 30-50 mg/l TMP for 4 days significantly increased cell viability, alleviated senescence by suppressing NF-κB signaling, and promoted bMSC proliferation by regulating the cell cycle. In addition, 40-50 mg/l TMP treatment may facilitate the neuronal differentiation of bMSCs, verified in the present study by presentation of neuronal morphology and expression of neuronal markers: microtubule-associated protein 2 (MAP-2) and neuron-specific enolase (NSE). The quantitative real-time polymerase chain reaction (qRT-PCR) revealed that TMP treatment may promote the expression of neurogenin 1 (Ngn1), neuronal differentiation 1 (NeuroD) and mammalian achaete-scute homolog 1 (Mash1). In conclusion, 4 days of40-50 mg/l TMP treatment may significantly delay bMSC senescence by suppressing NF-κB signaling, and enhancing the self-renewal ability of bMSCs, and their potential for neuronal differentiation.

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PMID: 

Int J Mol Med. 2019 Aug ;44(2):503-512. Epub 2019 May 29. PMID: 31173163

Abstract Title: 

Tetramethylpyrazine protects retinal ganglion cells against H2O2‑induced damage via the microRNA‑182/mitochondrial pathway.

Abstract: 

Glaucoma is the leading cause of irreversible blindness worldwide; the apoptosis of the retinal ganglion cells (RGCs) is a hallmark of glaucoma. Tetramethylpyrazine (TMP) is the main active component of Ligusticum wallichii Franchat, and has been demonstrated to improve a variety of injuries through its antioxidative and antiapoptotic properties. However, these effects of TMP on glaucoma have not been studied. The present study aimed to investigate the potential role of TMP in glaucoma and to elucidate its possible mechanisms responsible for these effects. An in vitro model was generated, in which primary RGCs (PRGCs) were treated with H2O2. Our study revealed that TMP protected against H2O2‑induced injury to PRGCs, as evidenced by enhanced cell viability, reduced caspase 3 activity and decreased cell apoptosis. We also reported that TMP treatment inhibited reactive oxygen species (ROS) production and malondialdehyde levels, but upregulated the antioxidative enzyme superoxide dismutase. In particular, TMP significantly increased the expression of microRNA‑182‑5p (miR‑182) in H2O2‑treated PRGCs, which was selected as the target miRNA for further research. In addition, our findings suggested that the protective effects of TMP on H2O2‑induced injury were attenuated by knockdown of miR‑182. The results of a luciferase reporter assay demonstrated that Bcl‑2 interacting protein 3 (BNIP3), an effector of mitochondria‑mediated apoptosis, was a direct target of miR‑182. In addition, TMP treatment significantly decreased the expression of BNIP3, Bax, cleaved‑caspase‑3 and cleaved‑poly(ADP‑ribose)polymerase, but increased that of Bcl‑2. Also, TMP treatment decreased the release of cytochrome c from mitochondria and improved mitochondrial membrane potential in H2O2‑treated RGCs. Of note, the inhibitory effects of TMP on the mitochondrial apoptoticpathway were suggested to be reversed by knockdown of miR‑182. Collectively, our findings provide novel evidence that TMP protects PRGCs against H2O2‑induced damage through suppressing apoptosis and oxidative stress via the miR‑182/mitochondrial apoptotic pathway.

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PMID: 

Artif Cells Nanomed Biotechnol. 2019 Dec ;47(1):2545-2552. PMID: 31213095

Abstract Title: 

Tetramethylpyrazine relieves LPS-induced pancreaticβ-cell Min6 injury via regulation of miR-101/MKP-1.

Abstract: 

Tetramethylpyrazine (TMP) is a traditional Chinese medicine with anti-inflammation and immunomodulatory effects. In this context, our purpose was to investigate the associated regulatory mechanisms of TMP against lipopolysaccharide (LPS)-caused pancreaticβ cell Min6 injury. The injury of Min6 cells was induced by 10 μg/mL of LPS. Viability of Min6 cells was detected through CCK-8 assay, apoptosis process through flow cytometry, and the proteins involved in apoptosis through western blot. Insulin secretion was valued through the glucose-stimulated insulin secretion (GSIS) assay. microRNA-101 (miR-101) was measured through qRT-PCR. Mitogen-activated protein kinase phosphatase 1 (MKP-1) and signaling regulators was measured through western blot. We found that, TMP treatment effectively attenuated LPS-induced injury in Min6 cells by suppressing cell apoptosis and promoting insulin secretion. Further investigation revealed that TMP exerted protective effect through down-regulating miR-101, and MKP-1 was demonstrated as a target of miR-101. Moreover, TMP attenuated LPS-triggered inflammation by inactivating the JNK1/2 and NF-κB through the down-regulation of miR-101. In conclusion, our present study revealed that TMP alleviated LPS-induced injury in pancreatic β-cell Min6 injury via regulation of miR-101/MKP-1 with the bluntness of JNK1/2 and NF-κB pathways.

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PMID: 

Oxid Med Cell Longev. 2019 ;2019:7096912. Epub 2019 May 16. PMID: 31223426

Abstract Title: 

Tetramethylpyrazine Prevents Contrast-Induced Nephropathy via Modulating Tubular Cell Mitophagy and Suppressing Mitochondrial Fragmentation, CCL2/CCR2-Mediated Inflammation, and Intestinal Injury.

Abstract: 

Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired acute kidney injury (AKI), but detailed pathogenesis and effectual remedy remain elusive. Here, we tested the hypothesis that contrast media (CM) impaired mitochondrial quality control (MQC) in tubules, including mitochondrial fragmentation and mitophagy, induced systemic inflammation, and intestinal injury. Since we previously demonstrated that the natural antioxidant 2,3,5,6-tetramethylpyrazine (TMP) can be a protectant against CIN, we moreover investigated the involved renoprotective mechanisms of TMP. In a well-established CIN rat model, renal functions, urinary AKI biomarkers, and renal reactive oxygen species (ROS) production were measured. Mitochondrial damage and mitophagy were detected by transmission electron microscopy (TEM) and western blot. The abundance of Drp1 and Mfn2 by western blot and immunohistochemistry (IHC) was used to evaluate mitochondrial fragmentation. TUNEL staining, TEM, and the abundance of cleaved-caspase 3 and procaspase 9 were used to assay apoptosis. We demonstrated that increased mitophagy, mitochondrial fragmentation, ROS generation, autophagy, and apoptosis occurred in renal tubular cells. These phenomena were accompanied by renal dysfunction and an increased excretion of urinary AKI biomarkers. Meanwhile, CM exposure resulted in concurrent small intestinal injury and villous capillary endothelial apoptosis. The abundance of the inflammatory cytokines CCL2 and CCR2 markedly increased in the renal tubules of CIN rats, accompanied by increased concentrations of IL-6 and TNF-in the kidneys and the serum. Interestingly, TMP efficiently prevented CM-induced kidney injuryby reversing these pathological processes. Mechanistically, TMP inhibited the CM-induced activation of the CCL2/CCR2 pathway, ameliorated renal oxidative stress and aberrant mitochondrial dynamics, and modulated mitophagy in tubular cells. In summary, this study demonstrated novel pathological mechanisms of CIN, that is, impairing MQC, inducing CCL2/CCR2-mediated inflammation and small intestinal injury, and provided novel renoprotective mechanisms of TMP; thus, TMP may be a promising therapeutic agent for CIN.

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PMID: 

Hum Exp Toxicol. 2019 Oct ;38(10):1168-1177. Epub 2019 Jun 28. PMID: 31250662

Abstract Title: 

The protective effect of ligustrazine on rats with cerebral ischemia-reperfusion injury via activating PI3K/Akt pathway.

Abstract: 

The study was to investigate the effects of ligustrazine on rats with cerebral ischemia-reperfusion (I/R) injury and to explore the potential mechanism. Transient focal cerebral ischemia Wistar rat model was established through middle cerebral artery occlusion. The cerebral I/R injury rats were treated with intraperitoneal injection of ligustrazine (1, 3, and 10 mg/kg). Human amniotic epithelial cells (HAECs) were treated with ligustrazine (1, 10, 100μM) and PI3K inhibitor wortmannin (100 μM), following oxygen-glucose deprivation (OGD) treatment. The expression levels of protein kinase B (PKB or AKT), phospho-Akt (p-Akt), endothelial nitric oxide synthase (eNOS), and phosphor-eNOS (p-eNOS) in HAECs and brains of rats were measured by Western blot. The levels of nitric oxide (NO) in HAECs were measured by Griess method using NO/NOAssay Kit. Infarct volume and neurological deficits were evaluated 24 h after reperfusion. The levels of NO, p-Akt/Akt, and p-eNOS/eNOS in HAECs were significantly reduced after OGD, but ligustrazine treatment increased the levels of those factors in a dose-dependent manner, while those increases were reversed by PI3K inhibitor wortmannin. Similarly, p-Akt/Akt and p-eNOS/eNOS in brain tissue of rats with I/R were significantly reduced compared with control group (

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PMID: 

Front Pharmacol. 2019 ;10:707. Epub 2019 Jun 25. PMID: 31293426

Abstract Title: 

Tetramethylpyrazine Enhances the Antitumor Effect of Paclitaxel by Inhibiting Angiogenesis and Inducing Apoptosis.

Abstract: 

Recent published findings have demonstrated the effectiveness of combining molecules from traditional Chinese medicine with chemotherapeutic drugs to treat cancer. Combined administration of these agents can overcome drug-mitigating responses as well as reduce adverse side effects, thereby enhancing the efficacy of the therapy. Tetramethylpyrazine (TMP), an alkaloid monomer from the medicinal herbhort, is known to exert a variety of antitumor effects including inhibition of tumor cell proliferation, metastasis, and drug resistance. In this research, we investigated antitumor effects of TMP combined with paclitaxel (PTX), a frontline chemotherapeutic drug,and. Our results indicate that TMP enhances the antitumor effects of PTX in ovarian cancer A2780 and SKOV3 cells. Furthermore, we found that combined treatment of TMP and PTX suppressed angiogenesis by inhibiting both ERK1/2 and Akt pathways and promoted apoptosis of tumor cells compared to TMP or PTX treatment alone. Moreover, TMP augmented the antitumor effects of PTX in ovarian cancer A2780 xenograft mouse models by significantly decreasing tumor burden and partially decreasing the toxicity of PTX, as evidenced by the decreased expression of proliferation and angiogenesis markers as well as the hematoxylin and eosin (H&E) staining and biochemical indexes assay. Overall, our findings provide novel mechanistic insight into the efficacy of combining of potent molecules present in traditional Chinese medicine with chemotherapeutic drugs for therapeutic intervention in cancer.

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PMID: 

Int J Immunopathol Pharmacol. 2019 Jan-Dec;33:2058738419869055. PMID: 31409163

Abstract Title: 

The combination ofextract and ligustrazine to improve the inflammation in rats with thrombolytic cerebral ischemia.

Abstract: 

The purpose of the study was to evaluate the effect ofextract and ligustrazine combination on ameliorating inflammation in cerebral ischemic rats that have undergone thrombolysis.and ligustrazine per se, or a combination ofand ligustrazine was administered by intraperitoneal injection immediately after surgery and sham surgery. After the induction of thrombolysis, the neurological function was measured and cerebral lesion volume was determined. The regulatory T cells in the spleen were measured by flow cytometry. To explore the protective effects of the combination drug on the neurological function and inflammation, the expression of transcription factor Foxp3 and cytokines, including transforming growth factor beta 1, interleukin 10, interleukin 4, interleukin 1 beta, interferon gamma, interleukin 17, in damaged brain was examined using reverse transcription polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. The cerebral lesion volume was markedly reduced in the combination drug-treated rats compared to the rats treated with eitheror ligustrazine alone ( < 0.05). The neurological function, regulatory T cells, transcription factor Foxp3, transforming growth factor beta 1, interleukin 10, and interleukin 4 were markedly elevated in the rats treated with combination drugs ( < 0.05). The expression of interleukin 1 beta, interferon gamma, and interleukin 17 was reduced in the rats treated with combination drug therapy ( < 0.05). Treatment with a combination ofand ligustrazine can ameliorate inflammation after thrombolysis and regulate the related cytokines by elevating the expression of endogenous regulatory T cells.