Monoammonium glycyrrhizate suppresses tumor necrosis factor-α induced chemokine production in HMEC-1 cells, possibly by blocking the translocation of nuclear factor-κB into the nucleus

2014 ◽  
Vol 92 (10) ◽  
pp. 859-865 ◽  
Author(s):  
Na Cao ◽  
Tao Chen ◽  
Zai-pei Guo ◽  
Sha Qin ◽  
Meng-meng Li

Monoammonim glycyrrhizate (MAG) derived from licorice has been shown to have anti-inflammatory properties. Chemokines are vital inflammatory mediators that are involved with endothelial damage from leukocyte infiltrates in various inflammatory skin diseases. In this study, we investigated the anti-inflammatory effects and mechanisms of MAG on tumor necrosis factor-α (TNF-α) induced chemokine production in a human dermal microvascular endothelial cell line (HMEC-1). HMEC-1 cells were treated with TNF-α, with or without MAG. The results showed that MAG suppressed TNF-α-induced chemokine (including CXCL8, CX3CL1, and CXCL16) mRNA expression in HMEC-1 cells, in a dose-dependent manner, and reduced the secretion of these chemokines in culture supernatant. Moreover, endothelial activation in the presence of MAG blocked the chemotactic activities of TNF-α-stimulated HMEC-1 cell supernatant on the migration of primary neutrophils and primary monocytes. In addition, Western blot and immunofluorescence data revealed that MAG inhibited nuclear translocation of nuclear factor-κB p65 (NF-κB p65). It is the first report to demonstrate that MAG suppresses TNF-α-induced chemokine production in HMEC-1 cells, and that the mechanism may be inhibiting the translocation of NF-κB p65 into the nucleus to prevent the starting of inflammatory signaling pathway. Our results revealed that MAG is a potential anti-inflammatory agent capable of improving inflammatory skin diseases.

2002 ◽  
Vol 88 (08) ◽  
pp. 267-273 ◽  
Author(s):  
Mehtap Yuksel ◽  
Mitsuhiro Uchiba ◽  
Seikoh Horiuchi ◽  
Hiroaki Okabe ◽  
Kenji Okajima

SummaryActivated protein C (APC), an important natural anticoagulant, inhibits tumor necrosis factor-α (TNF-α) production and attenuates various deleterious events induced by lipopolysaccharide (LPS), contributing thereby to a significant reduction of mortality in patients with severe sepsis. In this study, we investigated the mechanism(s) by which APC inhibits TNF-α production by LPS-stimulated human monocytes in vitro. Although APC inhibited LPS-induced TNF-α production in a concentration-dependent fashion, diisopropyl fluorophosphate-treated APC, an active-site-blocked APC, had no effect. APC inhibited both the binding of nuclear factor-κB (NF-κB) to target sites and the degradation of IκBα. APC also inhibited both the binding of activator protein-1 (AP-1) to target sites and the activation of mitogen-activated protein kinase pathways. These observations strongly suggest that APC inhibited LPS-induced TNF-α production by inhibiting the activation of both NF-κB and AP-1 and that the inhibitory activity of APC might depend on its serine protease activity. These results would at least partly explain the mechanism(s) by which APC reduces the tissue injury seen in animal models of sepsis and in patients with sepsis.


2012 ◽  
Vol 90 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Li Wang ◽  
Yunxin Zhang ◽  
Zhiping Wang ◽  
Sijia Li ◽  
Guangning Min ◽  
...  

A previous study reported that ginsenoside-Rd reduced the production of tumor necrosis factor-α by inhibiting nuclear factor-κB in lipopolysaccharide-activated N9 microglia in vitro. The aim of the present study was to confirm the anti-inflammatory effects and mechanisms of ginsenoside-Rd in animal experiments involving acute inflammation. The results indicated that ginsenoside-Rd at doses ranging from 12.5 to 50 mg/kg i.m. significantly inhibited the swelling of hind paws in rats for 1–6 h after the carrageenan injection. The levels of proinflammatory cytokines and proinflammatory mediators were markedly reduced by ginsenoside-Rd. Ginsenoside-Rd, when administered intramuscularly at 12.5, 25, and 50 mg/kg doses, showed signicant inhibition of carrageenan-induced production of interleukin-1β (6.91%, 45.75%, and 55.18%, respectively), tumor necrosis factor-α (37.99%, 56.39%, and 47.38%, respectively), prostaglandin E2 (22.92%, 30.12%, and 36.36%, respectively), and nitric oxide (28.27%, 44.53%, and 53.42%, respectively). In addition, ginsenoside-Rd (12.5, 25, and 50 mg/kg i.m.) effectively decreased the levels of nuclear factor-κB (6.77%, 20.28%, and 41.03%, respectively) and phosphorylation of IκBα (13.23%, 26.92%, and 41.80%, respectively) in the carrageenan-inflamed paw tissues. These results suggest that ginsenoside-Rd has significant anti-inflammatory effects in vivo, which might be due to its blocking of the nuclear factor-κB signaling pathway. Thus, it may be possible to develop ginsenoside-Rd as a useful agent for inflammatory diseases.


1998 ◽  
Vol 275 (3) ◽  
pp. G387-G392 ◽  
Author(s):  
Cynthia A. Bradham ◽  
Jörg Plümpe ◽  
Michael P. Manns ◽  
David A. Brenner ◽  
Christian Trautwein

Tumor necrosis factor-α (TNF-α) functions as a two-edged sword in the liver. TNF-α is required for normal hepatocyte proliferation during liver regeneration. It functions both as a comitogen and to induce the transcription factor nuclear factor-κB, which has antiapoptotic effects. On the other hand, TNF-α is the mediator of hepatotoxicity in many animal models, including those involving the toxins concanavalin A and lipopolysaccharide. TNF-α has also been implicated as an important pathogenic mediator in patients with alcoholic liver disease and viral hepatitis.


2000 ◽  
Vol 279 (5) ◽  
pp. L958-L966 ◽  
Author(s):  
Guohua Zhao ◽  
Laszlo T. Vaszar ◽  
Daoming Qiu ◽  
Lingfang Shi ◽  
Peter N. Kao

Triptolide (PG490, 97% pure) is a diterpenoid triepoxide with potent anti-inflammatory and immunosuppressive effects in transformed human bronchial epithelial cells and T cells (Qiu D, Zhao G, Aoki Y, Shi L, Uyei A, Nazarian S, Ng JC-H, and Kao PN. J Biol Chem 274: 13443–13450, 1999). Triptolide, with an IC50of ∼20–50 ng/ml, inhibits normal and transformed human bronchial epithelial cell expression of interleukin (IL)-6 and IL-8 stimulated by phorbol 12-myristate 13-acetate (PMA), tumor necrosis factor-α, or IL-1β. Nuclear runoff and luciferase reporter gene assays demonstrate that triptolide inhibits IL-8 transcription. Triptolide also inhibits the transcriptional activation, but not the DNA binding, of nuclear factor-κB. A cDNA array and clustering algorithm analysis reveals that triptolide inhibits expression of the PMA-induced genes tumor necrosis factor-α, IL-8, macrophage inflammatory protein-2α, intercellular adhesion molecule-1, integrin β6, vascular endothelial growth factor, granulocyte-macrophage colony-stimulating factor, GATA-3, fra-1, and NF45. Triptolide also inhibits constitutively expressed cell cycle regulators and survival genes cyclins D1, B1, and A1, cdc-25, bcl-x, and c-jun. Thus anti-inflammatory, antiproliferative, and proapoptotic properties of triptolide are associated with inhibition of nuclear factor-κB signaling and inhibition of genes known to regulate cell cycle progression and survival.


2002 ◽  
Vol 283 (3) ◽  
pp. C831-C838 ◽  
Author(s):  
Bin Lu ◽  
Liying Wang ◽  
Djordje Medan ◽  
David Toledo ◽  
Chuanshu Huang ◽  
...  

The APO-1/Fas ligand (FasL) and tumor necrosis factor-α (TNF-α) are two functionally related molecules that induce apoptosis of susceptible cells. Although the two molecules have been reported to induce apoptosis via distinct signaling pathways, we have shown that FasL can also upregulate the expression of TNF-α, raising the possibility that TNF-α may be involved in FasL-induced apoptosis. Because TNF-α gene expression is under the control of nuclear factor-κB (NF-κB), we investigated whether FasL can induce NF-κB activation and whether such activation plays a role in FasL-mediated cell death in macrophages. Gene transfection studies using NF-κB-dependent reporter plasmid showed that FasL did activate NF-κB promoter activity. Gel shift studies also revealed that FasL mobilized the p50/p65 heterodimeric form of NF-κB. Inhibition of NF-κB by a specific NF-κB inhibitor, caffeic acid phenylethyl ester, or by dominant expression of the NF-κB inhibitory subunit IκB caused an increase in FasL-induced apoptosis and a reduction in TNF-α expression. However, neutralization of TNF-α by specific anti-TNF-α antibody had no effect on FasL-induced apoptosis. These results indicate that FasL-mediated cell death in macrophages is regulated through NF-κB and is independent of TNF-α activation, suggesting the antiapoptotic role of NF-κB and a separate death signaling pathway mediated by FasL.


Sign in / Sign up

Export Citation Format

Share Document