cytochrome-c-t and tetramethylpyrazine

Ligustrazine is one of the alkaloid compounds isolated from the traditional Chinese herb, which shows protective effects on cardiovascular disorders. High homocysteine (Hcy) level can predict cardiovascular-related events including death. In this study, we used Hcy to stimulate the human umbilical vein endothelial cells (HUVECs) and investigated the protective effect of ligustrazine on endothelial dysfunction by assessing the cell apoptosis, oxidative damage, mitochondrial dysfunction, and the potential molecular pathways. Our results clearly showed that ligustrazine increased HUVEC cell viability, decreased the dehydrogenase (LDH) level, and inhibited HUVEC apoptosis, which was associated with the attenuation of attenuated oxidative damage. The mitochondrial-dependent pathway was closely related in the regulation of ligustrazine, reflected by the attenuated mitochondrial membrane potential change and decreased cytochrome c release from the mitochondria to the cytosol. Ligustrazine may protect Hcy-induced apoptosis in HUVECs by attenuating oxidative damage and modulating mitochondrial dysfunction.

Topics: Antioxidants; Apoptosis; Cells, Cultured; Cytochromes c; Cytoprotection; Homocysteine; Human Umbilical Vein Endothelial Cells; Humans; Membrane Potential, Mitochondrial; Mitochondria; Oxidative Stress; Pyrazines; Signal Transduction

Tetramethylpyrazine (TMP) was originally isolated from a traditional Chinese herbal medicine, Ligusticum chuanxiong In the present study, TMP exhibits potent antitumor activities in vitro. However, the molecular mechanisms remain to be defined. Hence, this study aims to investigate the antiproliferative and apoptotic effects of TMP on HepG2 and elucidate the underlying mechanisms. Analyses using Cell Counting Kit-8 and real-time cell analyzer indicated that TMP significantly inhibited HepG2 cell proliferation. We also observed that TMP induced cell cycle arrest at the G0/G1 checkpoint and apoptosis, using flow cytometry and high-content screening. Furthermore, our results predicted that TMP could directly decrease mitochondrial membrane potential (Δψm), increase the release of cytochrome c, and increase caspase activation, indicating that mitochondrial pathway apoptosis could be the mechanism for TMP within HepG2 cells. Moreover, TMP altered expression of p53 and the Bcl-2/Bax protein ratio, which revealed that TMP induced cell cycle arrest and caspase-dependent mitochondrial apoptosis in HepG2 cells in vitro. These studies provided mechanistic insights into the antitumor properties of TMP, which may be explored as a potential option for treatment of hepatocellular carcinoma.

Topics: Apoptosis; bcl-2-Associated X Protein; Carcinoma, Hepatocellular; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cytochromes c; G1 Phase Cell Cycle Checkpoints; Hep G2 Cells; Humans; Liver Neoplasms; Membrane Potential, Mitochondrial; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Pyrazines; Resting Phase, Cell Cycle; Signal Transduction; Tumor Suppressor Protein p53

Parkinson's disease (PD) is the second most prevalent progressive neurodegenerative disease. Although several hypotheses have been proposed to explain the pathogenesis of PD, apoptotic cell death and oxidative stress are the most prevalent mechanisms. Tetramethylpyrazine (TMP) is a biological component that has been extracted from Ligusticum wallichii Franchat (ChuanXiong), which exhibits anti-apoptotic and antioxidant roles. In the current study, we aimed to investigate the possible protective effect of TMP against dopaminergic neuron injury in a rat model of Parkinson's disease induced by MPTP and to elucidate probable molecular mechanisms. The results showed that TMP could notably prevent MPTP-induced dopaminergic neurons damage, reflected by improvement of motor deficits, enhancement of TH expression and the content of dopamine and its metabolite, DOPAC. We observed MPTP-induced activation of mitochondrial apoptotic death pathway, evidenced by up-regulation of Bax, down-regulation of Bcl-2, release of cytochrome c and cleavage of caspase 3, which was significantly inhibited by TMP. Moreover, TMP could prevent MPTP-increased TBARS level and MPTP-decreased GSH level, indicating the antioxidant role of TMP in PD model. And the antioxidant role of TMP attributes to the prevention of MPTP-induced reduction of Nrf2 and GCLc expression. In conclusion, in MPTP-induced PD model, TMP prevents the down-regulation of Nrf2 and GCLc, maintaining redox balance and inhibiting apoptosis, leading to the attenuation of dopaminergic neuron damage. The effectiveness of TMP in treating PD potentially leads to interesting therapeutic perspectives.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cytochromes c; Disease Models, Animal; Dopamine; Dopaminergic Neurons; Down-Regulation; Glutamate-Cysteine Ligase; Male; MPTP Poisoning; Neuroprotective Agents; NF-E2-Related Factor 2; Oxidative Stress; Proto-Oncogene Proteins c-bcl-2; Pyrazines; Rats, Wistar; Up-Regulation

Gentamicin, a widely used antibiotic for the treatment of bacterial infection, can cause nephrotoxicity. Tetramethylpyrazine (TMP) is a compound purified from the rhizome of Ligusticum wallichi (Chuanxiong) and has been found to protect against ischaemia-reperfusion injury, nephritis and alcohol-induced toxicity in rat kidneys.. We used rat renal tubular cells (RTCs), NRK-52E, in this study. The cytotoxicity of gentamicin was checked with transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) staining, and the generation of reactive oxygen species was measured using the fluorescent probe 2,7-dichlorofluorescein. We evaluated several apoptotic parameters: cleaved caspase levels, tumour necrosis factor (TNF-alpha) excretion and nuclear factor Kappa B (NF-kappaB) activity. We also examined the TMP protective effect on gentamicin-induced apoptosis in rat kidneys.. The results of this study showed that gentamicin was found to markedly induce apoptosis in NRK-52E cells in a dose-dependent manner; that TMP expressed a dose-dependent protective effect against gentamicin-induced apoptosis; that pre-treatment of the cells with 50 or 100 microM of TMP effectively decreased the reactive oxygen species formation induced by gentamicin; that TMP was found to inactivate the gentamicin-stimulated activities of caspase-3, caspase-8 and caspase-9, to inhibit gentamicin-induced release of cytochrome c, as well as to raise the expression of Bcl-x(L); that TMP inhibited the gentamicin-induced TNF-alpha excretion, and inactivated the transcription factor NF-kappaB; and that the TMP treatment significantly reduced apoptotic injury in rat RTCs.. Based on the results of this study, we suggest that TMP can attenuate gentamicin-induced oxidative stress and apoptotic injury in rat RTCs, and that its character may have therapeutic potential for patients with renal diseases.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; bcl-X Protein; Blotting, Western; Caspase 3; Caspase 8; Caspase 9; Caspase Inhibitors; Cytochromes c; Disease Models, Animal; DNA; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Gene Expression; Gentamicins; In Situ Nick-End Labeling; Kidney Tubules, Proximal; Ligusticum; Male; NF-kappa B; Oxidative Stress; Pyrazines; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Tumor Necrosis Factor-alpha; Vasodilator Agents

In the present study, we investigated the effects of tetramethylpyrazine (TMP) on hydrogen peroxide (H2O2)-induced apoptosis in PC12 cells. The apoptosis in H2O2-induced PC12 cells was accompanied by a decrease in Bcl-2/Bax protein ratio, release of cytochrome c to cytosol and the activation of caspase-3. TMP not only suppressed the down-regulation of Bcl-2, up-regulation of Bax and the release of mitochondrial cytochrome c to cytosol, but also attenuated caspase-3 activation and eventually protected against H2O2-induced apoptosis. These results indicated that TMP blocked H2O2-induced apoptosis by the regulation of Bcl-2 family members, suppression of cytochrome c release, and caspase cascade activation in PC12 cells.

Topics: Animals; Apoptosis; Caspase 3; Caspase 8; Cell Survival; Cytochromes c; Hydrogen Peroxide; Neuroprotective Agents; PC12 Cells; Pheochromocytoma; Pyrazines; Rats

Tetramethylpyrazine (TMP), a compound purified from Rhizoma Ligustici, is a widely used active ingredient in Chinese herbal medicine to treat cardiovascular diseases on account of its vasodilatory actions and antiplatelet activity. Studies have shown that TMP can remove oxygen free radicals and protect rat kidney from ischemia-reperfusion injury. In addition, adriamycin-induced nephrosis in rats is commonly used in pharmacological studies of human chronic renal diseases. Apoptosis of renal tubular cells has been reported in adriamycin-treated rats. To examine the therapeutic potential of TMP on chronic progressive renal diseases, adriamycin-induced injury in rat renal tubular cells NRK-52E has been used to monitor its protective effect. In TUNEL staining, TMP showed a dose-dependent protective effect against adriamycin-induced apoptosis in NRK-52E cells. Pretreatment of the cells with 10 or 100 microM of TMP effectively decreased the reactive oxygen species (ROS) formation induced by adriamycin, as measured in fluorescent assays. TMP was found to reduce the adriamycin-stimulated activities of caspase-3, caspase-8 and caspase-9, inhibit adriamycin-induced release of cytochrome C, and elevate the expression of Bcl-x (L). TMP was also able to inhibit the death receptor signaling pathway and suppress the activation of transcription factor NF-kappaB in adriamycin-treated NRK-52E cells. Based on the results of this study, we suggest that TMP can attenuate adriamycin-induced oxidative stress and apoptotic injury in NRK-52E cells, and that it may have therapeutic potential for patients with renal diseases. TMP: tetramethylpyrazine LDH: lactate dehydrogenase ROS: reactive oxygen species DCF: 2',7'-dichlorofluorescein TNF-alpha: tumor necrosis factor-alpha TUNEL: terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling.

Topics: Animals; Apoptosis; Caspase Inhibitors; Cell Line; Cytochromes c; Doxorubicin; Drug Evaluation, Preclinical; Drugs, Chinese Herbal; Kidney Tubules; NF-kappa B; Oxidative Stress; Pyrazines; Rats