scholarly journals Extracts of Thai Perilla frutescens nutlets attenuate tumour necrosis factor-α-activated generation of microparticles, ICAM-1 and IL-6 in human endothelial cells

2020 ◽  
Vol 40 (5) ◽  
Author(s):  
Narisara Paradee ◽  
Niramon Utama-ang ◽  
Chairat Uthaipibull ◽  
John B. Porter ◽  
Maciej W. Garbowski ◽  
...  

Abstract Elevation of endothelial microparticles (EMPs) play an important role in the progression of inflammation-related vascular diseases such as cardiovascular diseases (CVDs). Thai perilla (Perilla frutescens) nutlets are rich in phenolic compounds and flavonoids that exert potent antioxidant and anti-inflammatory effects. We found that the ethyl acetate (EA) and ethanol (Eth) extracts of Thai perilla nutlets contain phenolic compounds such as luteolin, apigenin, chryseoriol and their glycosides, which exhibit antioxidant activity. The goal of the present study was to investigate the effects of the extracts on endothelial activation and EMPs generation in tumour necrosis factor-α (TNF-α)-induced EA.hy926 cells. We found that TNF-α (10 ng/ml) activated EA.hy926 cells and subsequently generated EMPs. Pre-treatment with the extracts significantly attenuated endothelial activation by decreasing the expression of the intracellular adhesion molecule-1 (ICAM-1) in a dose-dependent manner. Only the Eth extract showed protective effects against overproduction of interleukin-6 (IL-6) in the activated cells. Furthermore, the extracts significantly reduced TNF-α-enhanced EMPs generation in a dose-dependent manner. In conclusion, Thai perilla nutlet extracts, especially the Eth extract, may have potential to protect endothelium against vascular inflammation through the inhibition of endothelial activation and the generation of endothelial microparticles (EMPs).

2005 ◽  
Vol 2 (3) ◽  
pp. 149-153
Author(s):  
Lin Ya-Qiu ◽  
Li Rui-Wen ◽  
Sun Chao ◽  
Chen Guo-Zhu ◽  
Yang Yong-Qing ◽  
...  

AbstractThe effects of different concentrations of tumour necrosis factor-α (TNF-α) on rat adipocyte apoptosis were detected by optical microscopy, agarose gel electrophoresis and flow cytometry methods. The morphological changes of rat adipocyte apoptosis induced by TNF-α correlated linearly with the concentration of TNF-α, ranging from 5 to 20 ng/ml. High concentrations of TNF-α induced more obvious apoptosis. Significant morphological changes of rat adipocytes treated with 5 ng/ml TNF-α were noticed, but DNA ladders did not appear in the DNA electrophoresis analysis, i.e. morphological changes occurred earlier than the biochemical changes. TNF-α induced apoptosis in the rat adipocyte in a dose-dependent manner. The induced apoptotic effect of 5, 10, 15 and 20 ng/ml TNF-α was significantly different (P0.01), but the effect among 10, 15 and 20 ng/ml TNF-α treatments was not significantly different (P0.05). Thus the optimum concentration of TNF-α for inducing apoptosis was 10 ng/ml.


2000 ◽  
Vol 98 (4) ◽  
pp. 461-470 ◽  
Author(s):  
Thomas NEUHAUS ◽  
Gudrun TOTZKE ◽  
Elisabeth GRUENEWALD ◽  
Hans-Peter JUESTEN ◽  
Agapios SACHINIDIS ◽  
...  

Endothelial cells act as an interface between the blood and tissues, and are known to be involved in inflammatory processes. These cells are responsive to and produce different cytokines. Tumour necrosis factor-α (TNF-α) not only is one of the most important inflammatory peptides, but also can be induced by lipopolysaccharide (LPS). The focus of the present study was on TNF-α gene expression and production in human umbilical arterial endothelial cells (HUAEC), including the kinetics of this process. Interleukin-1α (IL-1α), LPS and TNF-α, which are all known to be elevated in septic shock, were used as stimulators at concentrations commonly found in patients with sepsis. Through the use of reverse transcriptase/PCR, immunohistochemical reactions and ELISA techniques, we showed that, in HUAEC, all three stimuli were able to induce gene expression and production of TNF-α. Furthermore, this induction by IL-1α, LPS and TNF-α occurred in a time- and concentration-dependent manner in these cells. TNF-α expression and production was induced by all three agents at concentrations commonly found in patients with sepsis. TNF-α mRNA was observed within 30 min regardless of the stimulus used, but the levels peaked at different times. Since it is well established that TNF-α is able to induce the synthesis of IL-1α in endothelial cells and, as shown in the present study, TNF-α and IL-1α are themselves able to induce the synthesis of TNF-α in endothelial cells, an autocrine potentiation of cytokine release in sepsis can be proposed. This situation could lead to a locally acting ‘vicious cycle’ which, when considered in addition to the known ability of TNF-α to induce apoptosis, could mean that various organs will be damaged, a condition associated with sepsis. Thus these results provide further evidence for the important role played by the endothelium in inflammation.


1995 ◽  
Vol 144 (3) ◽  
pp. 457-462 ◽  
Author(s):  
G Haskó ◽  
I J Elenkov ◽  
V Kvetan ◽  
E S Vizi

Abstract The effect of selective block of α2-adrenoreceptors on plasma levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and corticosterone induced by bacterial lipopolysaccharide (LPS) was investigated in mice using ELISA and RIA. It was found that the LPS-induced TNF-α response was significantly blunted in mice pretreated with CH-38083, a novel and highly selective α2-adrenoreceptor antagonist (the α2/α1 ratio is >2000). In contrast, LPS-induced increases in both corticosterone and IL-6 plasma levels were further increased by CH-38083. Since it has recently been shown that the selective block of α2-adrenoreceptors located on noradrenergic axon terminals resulted in an increase in the release of noradrenaline (NA), both in the central and peripheral nervous systems, and, in our experiments, that propranolol prevented the effect of α2-adrenoreceptor blockade on TNF-α plasma levels induced by LPS, it seems likely that the excessive stimulation by NA of β-adrenoreceptors located on cytokine-secreting immune cells is responsible for this action. Since it is generally accepted that increased production of TNF-α is involved in the pathogenesis of inflammation and endotoxin shock on the one hand, and corticosterone and even IL-6 are known to possess anti-inflammatory properties on the other hand, it is suggested that the selective block of α2-adrenoreceptors might be beneficial in the treatment of inflammation and/or endotoxin shock. Journal of Endocrinology (1995) 144, 457–462


2016 ◽  
Vol 36 (1) ◽  
Author(s):  
Abbas Jawad Al-Shabany ◽  
Alan John Moody ◽  
Andrew David Foey ◽  
Richard Andrew Billington

Bacterial lipopolysaccharide induces changes in intracellular NAD+ levels in a pro-inflammatory, but not an anti-inflammatory, macrophage model that are correlated with the release of the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α).


2005 ◽  
Vol 230 (9) ◽  
pp. 645-651 ◽  
Author(s):  
James Rogers ◽  
Izabella Perkins ◽  
Alberto van Olphen ◽  
Nicholas Burdash ◽  
Thomas W. Klein ◽  
...  

The primary polyphenol in green tea extract is the catechin epigallocatechin gallate (EGCG). Various studies have shown significant suppressive effects of catechin on mammalian cells, either tumor or normal cells, including lymphoid cells. Previous studies from this laboratory reported that EGCG has marked suppressive activity on murine macrophages infected with the intracellular bacterium Legionella pneumophila (Lp), an effect mediated by enhanced production of both tumor necrosis factor-α (TNF-α) and γ-interferon (IFN-γ). In the present study, primary murine bone marrow (BM)-derived dendritic cells (DCs), a phagocytic monocytic cell essential for innate immunity to intracellular microorganisms, such as Lp, were stimulated in vitro with the microbial stimulant lipopolysaccharide (LPS) from gram-negative bacteria, the cell wall component from gram-positive bacteria muramyldipeptide (MDP) or infected with Lp. Production of the T helper cell (Th1)-activating cytokine, interleukin-12 (IL-12) and the proinflammatory cytokine, tumor necrosis factor-α (TNF-α), produced mainly by phagocytic cells and important for antimicrobial immunity, was determined in cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). Treatment of the cells with EGCG inhibited, in a dose-dependent manner, production of IL-12. In contrast, enhanced production of TNF-α occurred in a dose-dependent manner in the DC cultures stimulated with either soluble bacterial product or infected with Lp. Thus, the results of this study show that the EGCG catechin has a marked effect in modulating production of these immunoregulatory cytokines in stimulated DCs, which are important for antimicrobial immunity, especially innate immunity. Further studies are necessary to characterize the physiologic function of the effect of EGCG on TNF-α and IL-12 during Lp infection, and the mechanisms involved.


1999 ◽  
Vol 342 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Walter H. WATSON ◽  
Yanming ZHAO ◽  
Rajender K. CHAWLA

Intracellular deficiency of S-adenosylmethionine (AdoMet) and elevated serum concentrations of tumour necrosis factor α (TNF) are hallmarks of toxin-induced liver injury. In these models, the administration of either exogenous AdoMet or antibody/soluble receptor for TNF attenuates the injury. We have demonstrated previously that the administration of exogenous AdoMet to AdoMet-deficient rats attenuated lipopolysaccharide (LPS)-induced liver injury and serum TNF concentrations. Here we report that AdoMet lowered the amount of TNF secreted by LPS-stimulated murine macrophage cells (RAW 264.7) in a dose-dependent manner. The inhibition of TNF release was correlated with changes in the steady-state TNF mRNA concentrations. Changes in TNF mRNA were not due to its altered stability and might have been due to an attenuation of the transcription rate of the TNF gene. The inhibition of TNF release in RAW cells was not mediated by GSH because treatment with AdoMet did not increase intracellular GSH. In addition, N-acetylcysteine, whereas it did increase GSH concentration, had no effect on LPS-stimulated TNF release in these cells. Exogenous AdoMet also attenuated LPS-induced serum TNF levels in normal rats sensitized with lead. Thus AdoMet administration might exert its hepatoprotective effects at least in part by its inhibitory effect on expression of the gene for TNF.


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