Tetramethylpyrazine

Tetramethylpyrazine inhibits CoCl2 -induced neurotoxicity through enhancement of Nrf2/GCLc/GSH and suppression of HIF1α/NOX2/ROS pathways.[Pubmed: 25952107]

J Neurochem. 2015 May 8.

Hypoxia-mediated neurotoxicity contributes to various neurodegenerative disorders, including Alzheimer's disease and multiple sclerosis. Tetramethylpyrazine (TMP), a major bioactive component purified from Ligusticum wallichii Franchat, exhibited potent neuroprotective effect. However, the mechanism of TMP-exerted neuroprotective effect against hypoxia was not clear.
METHODS AND RESULTS:
In the study, we investigated the mechanism of the neuroprotective effect of TMP against hypoxia induced by CoCl2 in vitro and in vivo. The results showed that TMP could protect against CoCl2 -induced neurotoxicity in PC12 cells and in rats, as evidenced by enhancement of cell viability in PC12 cells and improvement of learning and memory ability in rats treated with CoCl2 . TMP could inhibit mitochondrial dysfunction, mitochondrial apoptotic molecular events, and thus apoptosis induced by CoCl2 . TMP inhibited CoCl2 -increased reactive oxygen species (ROS) level, which may contribute to hypoxia-related neurotoxicity induced by CoCl2 . The antioxidant and neuroprotective activities of TMP involved two pathways: one was the enhancement of nuclear factor erythroid 2-related factor 2 (Nrf2)/catalytic subunit of γ-glutamylcysteine ligase-mediated regulation of GSH and the other was the inhibition of hypoxia-inducible factor 1 α/NADPH oxidase 2 (NOX2)-mediated ROS generation. These two pathways contributed to improvement of oxidative stress and thus the amelioration of apoptosis under hypoxic conditions.
CONCLUSIONS:
These results have appointed a new path toward the understanding of pathogenesis and TMP-related therapy of hypoxia-related neurodegenerative diseases. We proposed two cascades for Tetramethylpyrazine-exhibited protective effects against CoCl2 -induced neurotoxicity: One is enhancement of nuclear factor erythroid 2-related factor 2-catalytic subunit of γ-glutamylcysteine ligase-mediated regulation of glutathone and the other was the inhibition of hypoxia-inducible factor 1 α-NADPH oxidase-2-mediated ROS generation. We think these findings should provide a new understanding of pathogenesis and Tetramethylpyrazine-related therapy of hypoxia-related neurodegenerative diseases.

Tetramethylpyrazine reduces inflammation in liver fibrosis and inhibits inflammatory cytokine expression in hepatic stellate cells by modulating NLRP3 inflammasome pathway.[Pubmed: 25847612]

IUBMB Life. 2015 Apr 3.

Hepatic fibrosis is concomitant with liver inflammation, which has been highlighted as significant treatment of chronic liver disease. We previously demonstrated that Tetramethylpyrazine (TMP), the effective component of Ligusticum chuanxiong Hort, can inhibit the activation of HSCs and consequential anti-hepatic fibrosis.
METHODS AND RESULTS:
In this study, our work demonstrated that TMP improved liver histological architecture, decreased hepatic enzyme levels and attenuated collagen deposition in the rat fibrotic liver. In addition, TMP significantly protected the liver from CCl4-caused injury and fibrogenesis by suppressing inflammation with reducing levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), NLRP3, nuclear factor-kappa B (NF-κB) and interleukin-1β (IL-1β). Experiments in vitro showed that TMP inhibited inflammatory cytokine expression in HSCs associated with disrupting platelet-derived growth factor-b receptor (PDGF-βR)/NLRP3/caspase1 pathway.
CONCLUSIONS:
These data collectively indicate that TMP can attenuate liver inflammation in liver fibrosis and possibly by targeting HSCs via PDGF-βR/NLRP3/caspase1 pathway. It provides novel mechanistic insights into TMP as a potential therapeutic remedy for hepatic fibrosis.

The antiplatelet activity of tetramethylpyrazine is mediated through activation of NO synthase.[Pubmed: 10946853]

Life Sci., 2000, 67(8):937-47.

Tetramethylpyrazine (TMPZ) is an active ingredient of a Chinese herbal medicine (Ligusticum wallichii Franchat).
METHODS AND RESULTS:
In this study, TMPZ (50-200 microM) significantly increased production of nitrate and cyclic GMP in human platelets within a 15-min incubation period. TMPZ concentration-dependently inhibited intracellular Ca2+ mobilization in human platelets stimulated by collagen (5 microg/ml). Furthermore, TMPZ concentration (50 and 200 microM)- and time (15 and 30 min)-dependently triggered endothelial-type constitutive nitric oxide synthase (ecNOS) protein expression in human platelets.
CONCLUSIONS:
These results indicated that TMPZ at micromolar concentrations stimulated nitric oxide production in human platelets via a novel mechanism that activated ecNOS protein expression.

Tetramethylpyrazine (TMP) exerts antitumor effects by inducing apoptosis and autophagy in hepatocellular carcinoma.[Pubmed: 25841319]

Int Immunopharmacol. 2015 May;26(1):212-20.

Hepatocellular carcinoma (HCC) is one of the most common types of liver cancers with high recurrence rate and mortality rate. Recent studies have indicated that Tetramethylpyrazine (TMP), a purified chemical extracted from Ligusticum wallichii Franchat (ChuanXiong), possessed antitumor effects on HCC, but detailed mechanism remains unclear.
METHODS AND RESULTS:
Our study aims at investigating the antitumor effect of TMP on HCC and its underlying mechanism. We found that TMP inhibited cell proliferation of HepG2 cells in a dose-dependent way, and xenograft tumor models also indicated that high concentrations of TMP administration inhibited tumor growth. Next, flow cytometric analysis and transmission electron microscope images showed that TMP enhanced cell apoptosis in HepG2 cells, and western blot results showed that TMP promoted cleavage of caspase-3 and PARP in vitro and in vivo. We also found that TMP caused autophagy in HCC in vitro and in vivo. In order to examine the role of autophagy in TMP-induced apoptosis, 3-methyladenine (3-MA) was used to block the action of autophagy. Our data showed TMP-induced autophagy might be a pro-apoptosis process in HCC. Furthermore, the results of anti-oxidative enzymes and oxidation-sensitive fluorescent probe 2, 7-dichlorofluorescein diacetate (DCFH-DA) indicated that TMP induced ROS generation and inhibition of ROS diminished the anticancer function of TMP.
CONCLUSIONS:
In conclusion, our studies provide new insights into the mechanisms underlying the antitumor effect of TMP and suggest that TMP can be a novel therapeutic regimen for HCC.

Antiinflammatory effect of tetramethylpyrazine and ferulic acid.[Pubmed: 1525949]

Chem Pharm Bull (Tokyo). 1992 Apr;40(4):954-6.

Tetramethylpyrazine (TMP) is one of the alkaloids contained in Ligusticum wallichii Franch (L. wallichii). Ferulic acid (FA) is a phenolic compound contained in L. wallichii and Angelica sinensis (Oliv.) Diels (A. sinensis).
METHODS AND RESULTS:
The present study was carried out to examine the antiinflammatory effect and to elucidate the mode of the effect of TMP and FA. Both compounds significantly inhibited the edema induced by carrageenin, the increase of the dye leakage induced by acetic acid and the granuloma formation induced by cotton pellet. And also, TMP and FA inhibited the number of writhes induced by acetic acid.
CONCLUSIONS:
From these results, it is suggested that both compounds have the antiinflammatory effect and the analgesic effect, and both compounds exert an antiinflammatory effect at the early and the late stages of processes in the inflammatory pathology.

Beneficial effects of tetramethylpyrazine, an active constituent of Chinese herbs, on rats with endotoxemia.[Pubmed: 9536520]

Relaxation effect of a novel Danshensu/tetramethylpyrazine derivative on rat mesenteric arteries.[Pubmed: 25952729]

Eur J Pharmacol. 2015 May 4. pii: S0014-2999(15)00403-3.

Danshen (Radix Salviae miltiorrhizae) and ChuanXiong (Ligusticum wallichii) are two traditional herbal medicines commonly used in China for the treatment of cardiovascular diseases. The active components in Danshen and ChuanXiong are Danshensu (DSS, (R)-3, 4-dihydroxyphenyllactic acid) and Tetramethylpyrazine (TMP), respectively. In the present study, a new compound named ADTM, which is a conjugation of DSS and TMP, was synthesized and its effect on the contractility of rat mesenteric arteries was examined.
METHODS AND RESULTS:
The relaxation effect of ADTM on rat mesenteric arteries was studied using myography. The effects of ADTM on Ca(2+) channels were measured by Ca(2+) imaging and patch-clamp techniques. The results showed that ADTM caused a concentration-dependent relaxation of rat mesenteric arteries. This relaxation effect was not affected by the removal of endothelium or inhibitors of nitric oxide synthase, cyclooxygenase, guanylyl cyclase and adenylyl cyclase. Potassium channel blockers including tetraethylammonium, iberiotoxin, apamin, 4-aminopyridine, BaCl2 and glibenclamide also failed to inhibit the relaxation response to ADTM. ADTM inhibited CaCl2-induced contractions and reduced the Ca(2+) influx in isolated mesenteric arterial muscle cells.
CONCLUSIONS:
Our results suggest that ADTM may be a novel relaxing agent. Its mechanism of action involves the direct blockade of voltage-gated Ca(2+) channels in vascular smooth muscle cells, resulting in a decrease in Ca(2+) influx into the cells.

Proc Natl Sci Counc Repub China B. 1998 Jan;22(1):46-54.

Cell lines:HL-60 cells
Concentrations: 300 μg/mL
Incubation Time: 24, 48, 60, 72 h
Method:
Cell viability is determined by the MTT assay. HL-60 cells are treated with 300 μg/mL TMP, 0.5 μM As2O3, and 300 μg/mL TMP combined with 0.5 μM As2O3, respectively.

Neuroprotective effects of tetramethylpyrazine against dopaminergic neuron injury in a rat model of Parkinson's disease induced by MPTP.[Pubmed: 24719552 ]

Int J Biol Sci. 2014 Mar 13;10(4):350-7.

Animal Models: A rat model of Parkinson's disease induced by MPTP (Wistar rats)
Formulation: 3% DMSO
Dosages:20 mg/kg/d
Administration: i.p.