1,2,3,6‐tetra‐O‐galloyl‐β‐D‐allopyranose gallotannin isolated,from Euphorbia jolkini,attenuates LPS‐induced nitric oxide production in macrophages

Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including vasodilatation and macrophage‐mediated immunity. Macrophages express inducible NO synthase (iNOS) and produce NO after lipopolysaccharide (LPS) stimulation. Gallotannins are water‐soluble polyphenols with wide‐ranging biological activities. Various chemical structures of gallotannins occurring in medicinal and food plants that are used worldwide showed several remarkable biological and pharmacological activities. In the present study, we examined the inhibitory effects of gallotannin 1,2,3,6‐tetra‐O‐galloyl‐β‐D‐allopyranose (GT24) isolated from Euphorbia jolkini on the LPS‐induced NO production and underlying mechanisms of action. GT24 dose‐dependently decreased LPS‐induced NO production and iNOS expression in J774A.1 macrophages. In addition, GT24 inhibited LPS‐induced activation of nuclear factor (NF)‐κB as indicated by inhibition of degradation of I‐κBα, nuclear translocation of NF‐κB, and NF‐κB dependent gene reporter assay. Our results suggest that GT24 possesses an inhibitory effect on the LPS‐induced inflammatory reaction. Copyright © 2010 John Wiley & Sons, Ltd.     

Myrislignan Attenuates Lipopolysaccharide‐induced Inflammation Reaction in Murine Macrophage Cells Through Inhibition of NF‐κB Signalling Pathway Activation

Myrislignan is a new kind of lignan isolated from Myristica fragrans Houtt. Its antiinflammatory effects have not yet been reported. In the present study, the antiinflammatory effects and the underlying mechanisms of myrislignan in lipopolysaccharide (LPS)‐induced inflammation in murine RAW 264.7 macrophage cells were investigated. Myrislignan significantly inhibited LPS‐induced production of nitric oxide (NO) in a dose‐dependent manner. It inhibited mRNA expression and release of interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α). This compound significantly inhibited mRNA and protein expressions of inducible NO synthase (iNOS) and cyclooxygenase‐2 (COX‐2) dose‐dependently in LPS‐stimulated macrophage cells. Further study showed that myrislignan decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and the translocation of NF‐κB from cytoplasm to the nucleus. Our results suggest that myrislignan may exert its antiinflammatory effects in LPS‐stimulated macrophages cells by inhibiting the NF‐κB signalling pathway activation. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of crocin and saffron aqueous extract on gene expression of SIRT1, AMPK,LOX1, NF‐κB,and MCP‐1 in patients with coronary artery disease: A randomized placebo‐controlled clinical trial

This trial evaluated the potential impacts of saffron aqueous extract (SAE) and its main carotenoid on some of the atherosclerosis‐related gene expression and serum levels of oxidized low‐density cholesterol (ox‐LDL) and Monocyte chemoattractant protein 1 (MCP‐1) in patients with coronary artery disease (CAD). Participants of this randomized controlled trial included 84 CAD patients who categorized into three groups: Group 1 received crocin (30 mg/day), Group 2 SAE (30 mg/day), and Group 3 placebo for 8 weeks. Gene expression of Sirtuin 1 (SIRT1), 5'‐adenosine monophosphate‐activated protein kinase (AMPK), Lectin‐like oxidized LDL receptor 1 (LOX1), nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB), and MCP‐1 in peripheral blood mononuclear cells assessed by real‐time PCR. Furthermore, serum ox‐LDL and MCP‐1 levels measured at the beginning and end of the intervention. Compared with the placebo group, gene expression of SIRT1 and AMPK increased significantly in the crocin group (p = .001), and the expression of LOX1 and NF‐κB decreased significantly (p = .016 and .004, respectively). Serum ox‐LDL levels decreased significantly in the crocin group after the intervention (p = .002) while MCP‐1 levels decreased both in crocin and SAE groups (p = .001). Crocin may have beneficial effects on CAD patients by increasing the gene expression of SIRT1 and AMPK and decreasing the expression of LOX1 and NF‐κB.     

Mogroside IIIE Attenuates LPS‐Induced Acute Lung Injury in Mice Partly Through Regulation of the TLR4/MAPK/NF‐κB Axis via AMPK Activation

Acute lung injury (ALI) often leads to high mortality, and there is as yet no effective drug treatment. The present study aimed to investigate protective effects of mogroside IIIE (MGIIIE, a cucurbitane‐type triterpenoid from Siraitia grosvenorii Fruits) in experimental ALI and its underlying mechanism. MGIIIE (1, 10 0r 20 mg/kg) was orally administered for 1 h before a single intratracheal administration of lipopolysaccharide (LPS, 5 mg/kg). MGIIIE treatment dose‐dependently suppressed pulmonary oedema, pro‐inflammatory mediators (IL‐1β, IL‐6, TNF‐α and HMGB1) release and higher MPO activity in lung tissues induced by LPS challenge. Molecular researches showed that mogroside IIIE (20 mg/kg) not only increased the phosphorylation of adenosine 5′‐monophosphate‐activated protein kinase (AMPK) but suppressed the over‐expression of toll‐like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). In addition, MGIIIE also inhibited the activation of MAPKs and nuclear factor κB (NF‐κB) signalling in lung tissues from LPS‐challenged mice. Similar antiinflammatory effects of MGIIIE were obtained in LPS‐treated macrophages. Compound C (a pharmacological AMPK inhibitor) obviously reversed the antiinflammatory effect of MGIIIE in LPS‐induced ALI mice. Taken together, AMPK activation plays a crucial role in the antiinflammatory effects of MGIIIE in LPS‐induced ALI by down‐regulating TLR4/MAPK/NF‐κB signalling pathways. Copyright © 2017 John Wiley & Sons, Ltd.     

Quercetin protects against cisplatin‐induced acute kidney injury by inhibiting Mincle/Syk/NF‐κB signaling maintained macrophage inflammation

Acute kidney injury (AKI) with high incidence and mortality is the main cause of chronic kidney disease. Previous studies have indicated that quercetin, an abundant flavonoid in plants, exhibited renoprotective role in AKI. However, the underlying mechanism is largely unknown. In this study, we try to explore whether quercetin protects against AKI by inhibiting macrophage inflammation via regulation of Mincle/Syk/NF‐κB signaling. The results demonstrated that quercetin can significantly inhibit expression and secretion of IL‐1β, IL‐6, and TNF‐α in LPS‐induced bone marrow‐derived macrophages (BMDMs) and reduce activity of Mincle/Syk/NF‐κB signaling in vitro. We also found that quercetin can strongly reduce the concentration of serum creatinine, BUN, IL‐1β, IL‐6, and TNF‐α in cisplatin‐induced AKI model. Furthermore, quercetin down‐regulated protein levels of Mincle, phosphorylated Syk and NF‐κB in kidney macrophages of AKI, as well as inhibited M1, up‐regulated M2 macrophage activity. Notably, the down‐regulation of LPS‐induced inflammation by quercetin was reversed after adding TDB (an agonist of Mincle) in BMDMs, suggesting that quercetin suppresses macrophage inflammation may mainly through inhibiting Mincle and its downstream signaling. In summary, these findings clarified a new mechanism of quercetin improving AKI‐induced kidney inflammation and injury, which provides a new drug option for the clinical treatment of AKI.     

Inhibition of TNF‐α‐mediated endothelial cell–monocyte cell adhesion and adhesion molecules expression by the resveratrol derivative,trans‐3,5,4′‐trimethoxystilbene

Resveratrol (RSV) has been shown to have anti‐inflammatory activity and to have a protective role against atherosclerosis. Here it is shown, for the first time, that its derivative trans‐3,5,4′‐trimethoxystilbene (TMS) may be a more potent anti‐inflammatory agent than resveratrol. A comparative analysis of the inhibitory activities of related stilbenes, resveratrol, TMS and polydatin (PD), on monocyte adhesion to TNF‐α‐activated endothelial cells showed TMS to be the most effective, with PD being the least effective. RSV and its analogues inhibited, albeit differentially, the protein and mRNA expression levels of inducible cell adhesion molecules, ICAM‐1 and VCAM‐1, in cultured endothelial cells. The mechanism of the inhibitory effects of these stilbenes on endothelial cell–monocyte cell adhesion can be attributed mainly to inhibition of NF‐κB pathway activation. The results demonstrate that all three investigated stilbene compounds, especially TMS, exhibit a potent inhibitory effect on inflammation‐induced cell–cell adhesion, expression of adhesion molecules and activation of the NF‐κB pathway. Copyright © 2010 John Wiley & Sons, Ltd.     

Praeruptorin a inhibits lipopolysaccharide‐induced inflammatory response in murine macrophages through inhibition of NF‐κB pathway activation

Praeruptorin A (PA) is a pyranocoumarin compound isolated from the dried root of Peucedanum praeruptorum Dunn (Umbelliferae). However, the antiinflammatory effect of PA has not been reported. The present study investigated the antiinflammatory effect of PA in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells. PA significantly inhibited the LPS‐induced production of nitric oxide (NO), interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α). The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), IL‐1β and TNF‐α were also suppressed by this compound. Further study showed that PA decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and inhibited the translocation of NF‐κB from cytoplasm to nucleus. Taken together, the results suggest that PA may exert antiinflammatory effects in vitro in LPS‐stimulated RAW 264.7 macrophages through inhibition of NF‐κB signal pathway activation. Copyright © 2010 John Wiley & Sons, Ltd.     

Tectorigenin protects against experimental fulminant hepatic failure by regulating the TLR4/mitogen‐activated protein kinase and TLR4/nuclear factor‐κB pathways and autophagy

Tectorigenin has received attention due to its antiproliferation, anti‐inflammatory, and antioxidant activities. In this study, we investigated the effects of tectorigenin on lipopolysaccharide (LPS)/D‐galactosamine(D‐GalN)‐induced fulminant hepatic failure (FHF) in mice and LPS‐stimulated macrophages (RAW 264.7 cells). Pretreatment with tectorigenin significantly reduced the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), histological injury, apoptosis, and the mortality of FHF mice, by suppressing the production of inflammatory cytokines such as TNF‐α and IL‐6. Tectorigenin also suppressed the activation of the inflammatory response in LPS‐stimulated RAW 264.7 cells. Tectorigenin‐induced protection is mediated through its mitigation of TLR4 expression, inhibition of mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB (NF‐κB) pathway activation, and promotion of autophagy in FHF mice and LPS‐stimulated RAW 264.7 cells. Therefore, tectorigenin has therapeutic potential for FHF in mice via the regulation of TLR4/MAPK and TLR4/NF‐κB pathways and autophagy.     

Apoptosis Induction by 13‐Acetoxyrolandrolide through the Mitochondrial Intrinsic Pathway

The aim of this study was to evaluate the mechanisms of cytotoxicity of the sesquiterpene lactone 13‐acetoxyrolandrolide, a nuclear factor kappa B (NF‐κB) inhibitor that was previously isolated from Rolandra fruticosa. The effects associated with the inhibition of the NF‐κB pathway included dose‐dependent inhibition of the NF‐κB subunit p65 (RelA) and inhibition of upstream mediators IKKβ and oncogenic Kirsten rat sarcoma (K‐Ras). The inhibitory concentration of 13‐acetoxyrolandrolide on K‐Ras was 7.7 µm . The downstream effects of the inhibition of NF‐κB activation were also investigated in vitro. After 24 h of treatment with 13‐acetoxyrolandrolide, the mitochondrial transmembrane potential was depolarized in human colon cancer (HT‐29) cells. The mitochondrial oxidative phosphorylation was also negatively affected, and reduced levels of nicotinamine adenine dinucleotide phosphate (NAD(P)H) were detected after 2 h of 13‐acetoxyrolandrolide exposure. Furthermore, the expression of the pro‐apoptotic protein caspase‐3 increased in a concentration‐dependent manner. Cell flow cytometry showed that 13‐acetoxyrolandrolide induced cell cycle arrest at G₁, indicating that the treated cells had undergone caspase‐3‐mediated apoptosis, indicating negative effects on cancer cell proliferation. These results suggest that 13‐acetoxyrolandrolide inhibits NF‐κB and K‐Ras and promotes cell death mediated through the mitochondrial apoptotic pathway. Copyright © 2013 John Wiley & Sons, Ltd.     

Chelidonine inhibits TNF‐α‐induced inflammation by suppressing the NF‐κB pathways in HCT116 cells

Nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) is a complex that regulates several hundreds of genes, including those involved in immunity and inflammation, survival, proliferation, and the negative feedback of NF‐κB signaling. Chelidonine, a major bioactive, isoquinoline alkaloid ingredient in Chelidonium majus, exhibits antiinflammatory pharmacological properties. However, its antiinflammatory molecular mechanisms remain unclear. In this work, we explored the effect of chelidonine on TNF‐induced NF‐κB activation in HCT116 cells. We found chelidonine inhibited the phosphorylation and degradation of the inhibitor of NF‐κB alpha and nuclear translocation of RELA. Furthermore, by inhibiting the activation of NF‐κB, chelidonine downregulated target genes involved in inflammation, proliferation, and apoptosis. Chelidonine also inhibited mitogen‐activated protein kinase pathway activation by blocking c‐Jun N‐terminal kinase and p38 phosphorylation. These results suggest that chelidonine may be a potential therapeutic agent against inflammatory diseases in which inhibition of NF‐κB activity plays an important role.     

Astragaloside IV inhibits TGF‐β1‐induced epithelial‐mesenchymal transition through inhibition of the PI3K/Akt/NF‐κB pathway in gastric cancer cells

Astragaloside IV (AS‐IV) has been reported to possess anti‐metastasis activity in cancer cells. However, it is unknown whether AS‐IV could inhibit epithelial‐mesenchymal transition (EMT), a cellular de‐differentiation program that promotes metastasis, in cancer cells. The aim of this study was to study the effect and mechanism of AS‐IV on EMT in gastric cancer (GC) cells. The results showed that AS‐IV significantly inhibited cell viability, invasion, and migration of GC cells. The E‐cadherin to N‐cadherin switch and expression of Vimentin and metastasis‐related genes were induced by transforming growth factor β1 (TGF‐β1), whereas AS‐IV reversed the induction. In addition, AS‐IV inhibited TGF‐β1‐induced activation of PI3K/Akt/NF‐κB. Inhibition of the PI3K/Akt/NF‐κB pathway reversed TGF‐β1‐induced EMT. In conclusion, AS‐IV inhibited TGF‐β1‐induced EMT through inhibition of the PI3K/Akt/NF‐κB pathway in GC cells. AS‐IV might be an effective candidate for the treatment for GC.     

Synergistic anti‐inflammatory effects of quercetin and catechin via inhibiting activation of TLR4–MyD88‐mediated NF‐κB and MAPK signaling pathways

The synergistic anti‐inflammatory effect of quercetin and catechin was investigated using lipopolysaccharide (LPS)‐stimulated macrophage RAW 264.7 cells. Results showed that the combined treatment of quercetin with catechin synergistically attenuated LPS‐stimulated increase of some proinflammatory molecules, including nitric oxide, tumor necrosis factor α, interleukin‐1β, nitric oxide synthase, and cyclooxygenase‐2. Moreover, it exhibited significantly (p < 0.05) stronger inhibitory effect on nuclear translocation of nuclear factor‐κB (NF‐κB) by suppressing the phosphorylation of NF‐κB p65 and p50 submits and on the phosphorylation of ETS domain‐containing protein and c‐Jun N‐terminal kinase than any of quercetin or catechin alone. Besides, the cotreatment of quercetin with catechin significantly (p < 0.05) restored the impaired expression of toll‐like receptor 4, myeloid differentiation primary response gene 88, and some downstream effectors (IRAK1, TRAF6, and TAK1). These results suggest that quercetin and catechin possessed synergistic anti‐inflammatory effects, which may be attributed to their roles in suppressing the activation of TLR4–MyD88‐mediated NF‐κB and mitogen‐activated protein kinases signaling pathways.     

Artichoke Leaf Extract Inhibits AKR1B1 and Reduces NF‐κB Activity in Human Leukemic Cells

The human intracellular enzyme AKR1B1 belongs to the aldo‐keto reductase superfamily. The AKR1B1‐catalyzed reduction of aldehydes is part of the intracellular inflammatory pathway leading to the activation of NF‐κB and the expression of pro‐inflammatory genes. The present study is aimed at determining the inhibition of AKR1B1 brought about by an extract of artichoke leaves (bracts), and the effects of this extract and three participating compounds on the expression of AKR1B1, COX‐2, and MMP‐2 proteins in THP‐1 cells. It seeks to identify the ability of the test substances to modulate the lipopolysaccharide (LPS)‐induced activation of NF‐κB in cells and the intracellular oxidant effect of test substances after incubation with LPS. Low concentrations of the extract inhibit the enzyme AKR1B1. After stimulation by LPS, the extract attenuated the activity of NF‐κB in THP‐1 cells, but no changes in the expression of AKR1B1 were recorded. The extract diminished the expression of the inflammation‐related enzymes COX‐2 and MMP‐2, probably by inhibiting the activity of NF‐κB. The extract significantly diminished the intracellular reactive oxygen species after a brief LPS incubation, which may also have reduced intracellular inflammation. The diminished activity of NF‐κB in the cells could be linked to the inhibition of the activity of AKR1B1. Copyright © 2017 John Wiley & Sons, Ltd.     

Retracted: Lipopolysaccharides‐mediated injury to chondrogenic ATDC5 cells can be relieved by Sinomenine via downregulating microRNA‐192

Sinomenine (SIN) is an isoquinoline derived from Caulis Sinomenii that has been used to treat rheumatoid arthritis and osteoarthritis for several decades in China. This study aims to reveal the effects of SIN on mouse chondrogenic ATDC5 cells growth and inflammation. SIN was used to treat ATDC5 cells injured by lipopolysaccharides (LPS). The following parameters were determined for evaluating the treatment effects of SIN: cell viability, apoptosis, reactive oxygen species generation, and pro‐inflammatory cytokines release. Besides, the expression of LPS‐sensitive miRNA (miR‐192) and the activation of NF‐κB and MAPK signaling were studied to explain SIN's function. SIN with concentration of 30 μM significantly attenuated LPS‐induced cell damage via increasing cell viability, inhibiting apoptosis and reactive oxygen species generation, and declining IL‐6 and TNF‐α release. miR‐192 was downregulated by SIN treatment. Restoration of miR‐192 expression by miRNA transfection could significantly impede SIN's protective action. Besides, the inhibitory effects of SIN on the activation of NF‐κB and MAPK signaling were attenuated by miR‐192 overexpression. Furthermore, GDF11 was found to be a target gene of miR‐192. LPS‐mediated injury to chondrogenic ATDC5 cells can be relieved by SIN via downregulating miR‐192 and subsequently repressing the activation of NF‐κB and MAPK signaling.     

Inhibition of TNF‐α‐Induced MUC5AC Mucin Gene Expression and Production by Wogonin Through the Inactivation of NF‐κB Signaling in Airway Epithelial Cells

In this study, we investigated whether wogonin significantly affects MUC5AC mucin gene expression and production in human airway epithelial cells. Confluent NCI‐H292 cells were pretreated with wogonin for 30 min and then stimulated with tumor necrosis factor‐α (TNF‐α) for 24 h or the indicated periods. The MUC5AC mucin gene expression and mucin protein production were measured by RT‐PCR and ELISA, respectively. We found that incubation of NCI‐H292 cells with wogonin significantly inhibited mucin production and down‐regulated MUC5AC gene expression induced by TNF‐α in a dose‐dependent fashion. To elucidate the action mechanism of wogonin, effect of wogonin on TNF‐α‐induced NF‐κB signaling pathway was investigated by western blot analysis. Wogonin inhibited NF‐κB activation induced by TNF‐α. Inhibition of IKK by wogonin led to the suppression of IκB phosphorylation and degradation, p65 nuclear translocation and NF‐κB‐regulated gene expression. This, in turn, led to the down‐regulation of MUC5AC protein production in NCI‐H292 cells. Wogonin also inhibited the gene products involved in cell survival (Bcl‐2) and proliferation (cyclooxygenase‐2). These results suggest that wogonin inhibits the NF‐κB signaling pathway, which may explain its role in the inhibition of MUC5AC mucin gene expression and production. Copyright © 2013 John Wiley & Sons, Ltd.     

A Polyphenol‐rich Pomegranate Fruit Extract Suppresses NF‐κB and IL‐6 Expression by Blocking the Activation of IKKβ and NIK in Primary Human Chondrocytes

Pomegranate fruit extract (PE) rich in polyphenols has been shown to exert chondroprotective effects, but the mechanism is not established. Here, we used an in vitro model of inflammation in osteoarthritis (OA) to investigate the potential of PE to suppress interleukin 1 beta (IL‐1β)‐stimulated expression of inflammatory cytokine IL‐6, generation of reactive oxygen species (ROS) levels, and investigated the mechanism of NF‐κB inhibition by analyzing the activation of the kinases upstream of IκBα in primary human chondrocytes. Total and phosphorylated forms of kinases and expression of IL‐6 were determined at protein and mRNA levels by western immunoblotting and Taqman assay, respectively. Dihydrorhodamine 123 staining estimated ROS generation. Pomegranate fruit extract inhibited the mRNA and protein expression of IL‐6, generation of ROS, and inhibited the IL‐1β‐mediated phosphorylation of inhibitor of nuclear factor kappa‐B kinase subunit beta (IKKβ), expression of IKKβ mRNA, degradation of IκBα, and activation and nuclear translocation of NF‐κB/p65 in human chondrocytes. Importantly, phosphorylation of NF‐κB‐inducing kinase was blocked by PE in IL‐1β‐treated human OA chondrocytes. Taken together, these data suggest that PE exerts the chondroprotective effect(s) by suppressing the production of IL‐6 and ROS levels. Inhibition of NF‐κB activation by PE was blocked via modulation of activation of upstream kinases in human OA chondrocytes. Copyright © 2017 John Wiley & Sons, Ltd.