Ulva prolifera Extract Alleviates Intestinal Oxidative Stress via Nrf2 Signaling in Weaned Piglets Challenged With Hydrogen Peroxide.

Background: Ulva prolifera extract contains a variety of functional active substances. Whether these substances had any beneficial effects on the small intestine of weaned piglets under oxidative stress remained unknown. Method: We explored the effects of U. prolifera extract on oxidative stress and related mechanisms in weaned piglets and intestinal porcine epithelial cells (IPEC-J2) challenged with hydrogen peroxide. Results: U. prolifera extract was found to mainly consist of polyphenols and unsaturated fatty acids. U. prolifera extract increased total antioxidant capacity and superoxide dismutase (SOD) activity, while it decreased malondialdehyde content, in the serum of weaned piglets challenged with hydrogen peroxide. Moreover, U. prolifera extract increased mRNA expression of SOD and catalase, as well as the intestinal expression of nuclear NF-E2-related factor 2 (Nrf2), both in vitro and in vivo. Furthermore, U. prolifera extract decreased reactive oxygen species and improved mitochondrial respiration in IPEC-J2 cells treated with hydrogen peroxide. However, AMPK inhibition did not affect nuclear Nrf2 expression and only partially affected the effects of U. prolifera extract on oxidative stress. Conclusion: We suggest that U. prolifera extract alleviates oxidative stress via Nrf2 signaling, but independent of AMPK pathway in weaned piglets challenged with hydrogen peroxide. These results shed new insight into the potential applications of U. prolifera extract as a therapeutic agent for the prevention and treatment of oxidative stress-induced intestinal diseases.

Pyrocatechol, a component of coffee, suppresses LPS-induced inflammatory responses by inhibiting NF-κB and activating Nrf2.

Coffee is a complex mixture of many bioactive compounds possessing anti-inflammatory properties. However, the mechanisms by which coffee exerts anti-inflammatory effects remains unclear and the active ingredients have not yet been identified. In this study, we found that coffee extract at more than 2.5%(v/v) significantly inhibited LPS-induced inflammatory responses in RAW264.7 cells and that anti-inflammatory activity of coffee required the roasting process. Interestingly, we identified pyrocatechol, a degradation product derived from chlorogenic acid during roasting, as the active ingredient exhibiting anti-inflammatory activity in coffee. HPLC analysis showed that 124 µM pyrocatechol was included in 100% (v/v) roasted coffee. A treatment with 5%(v/v) coffee extract and more than 2.5 µM pyrocatechol inhibited the LPS-induced activation of NF-κB and also significantly activated Nrf2, which acts as a negative regulator in LPS-induced inflammation. Furthermore, intake of 60% (v/v) coffee extract and 74.4 µM pyrocatechol, which is the concentration equal to contained in 60% (v/v) coffee, markedly inhibited the LPS-induced inflammatory responses in mice. Collectively, these results demonstrated that pyrocatechol, which was formed by the roasting of coffee green beans, is one of the ingredients contributing to the anti-inflammatory activity of coffee.

Optimal dietary curcumin improved growth performance, and modulated innate immunity, antioxidant capacity and related genes expression of NF-κB and Nrf2 signaling pathways in grass carp (Ctenopharyngodon idella) after infection with Aeromonas hydrophila.

This study investigated the effects of dietary curcumin on growth performance, non-specific immunity, antioxidant capacity and related genes expression of NF-κB and Nrf2 signaling pathways in grass carp (Ctenopharyngodon idella). A total of 525 juvenile grass carps with mean initial body weight of (5.30 ± 0.10) g were randomly distributed into five groups with three replicates each, fed five diets containing graded levels of curcumin (0, 196.11, 393.67, 591.46 and 788.52 mg/kg diet) for 60 days. After feeding trial, fifteen fish per tank were challenged with Aeromonas hydrophila and the mortalities were recorded for 7 days. The results showed that optimal dietary curcumin (393.67 mg/kg diet) improved the weight gain (WG) and specific growth rate (SGR) of juvenile grass carp, reduced feed conversion ratio (FCR) and the mortalities after challenge (P < 0.05). Moreover, optimal dietary curcumin increased the activities of lysozyme (LYZ) and acid phosphatase (ACP), and complement 3 (C3) and C4 levels, decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum of grass carp after injection with A. hydrophila (P < 0.05). Meanwhile, optimal dietary curcumin up-regulated the mRNA levels of LYZ, C3 and antimicrobial peptides [hepcidin, liver-expressed antimicrobial peptide-2 (LEAP-2), ß-defensin], and anti-inflammatory cytokines of interleukin-10 (IL-10) and transforming growth factor ß1 (TGF-ß1), and inhibitor of κBα (IκBα), whereas down-regulated pro-inflammatory cytokines of tumor necrosis factor-α (TNF-α), IL-1ß, IL-6 and IL-8, and nuclear factor kappa B p65 (NF-κB p65), IκB kinases (IKKα, IKKß and IKKγ) mRNA levels in the liver and blood of grass carp after injection with A. hydrophila (P < 0.05). In addition, optimal dietary curcumin increased the reduced glutathione (GSH) content and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR), reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels in the liver of grass carp after injection with A. hydrophila (P < 0.05). Meanwhile, optimal dietary curcumin up-regulated the mRNA levels of these antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2), whereas down-regulated Kelch-like ECH-associated protein (Keap) 1a and Keap 1b mRNA levels (P < 0.05) in the liver and blood of grass carp after injection with A. hydrophila. Thus, optimal dietary curcumin supplementation could promote growth of juvenile grass carp, reduce FCR, and enhance disease resistance, innate immunity and antioxidant capacity of fish, attenuating inflammatory response. However, dietary excessive curcumin had negative effect on fish. Based on second-order regression analysis between dietary curcumin contents and weight gain, the optimum requirement of dietary curcumin in juvenile grass carp was determined to be 438.20 mg/kg diet.

The protective effect of Sargassum horneri against particulate matter-induced inflammation in lung tissues of an in vivo mouse asthma model.

Sargassum horneri is an edible brown seaweed with potential anti-inflammatory properties. The present study was designed to evaluate the anti-inflammatory properties of S. horneri using an in vivo mouse asthma model following exposure to particulate matter (PM). 7-8 week old BALB/c mice (20-25 g) were randomly divided into seven groups (n = 4) as follows: 1: no treatment, 2: OVA (ovalbumin) + PM, 3: OVA + PM + SHE (S. horneri ethanol extract) 200 mg kg-1, 4: OVA + PM + SHE 400 mg kg-1, 5: OVA + PM + prednisone 5 mg kg-1, 6: OVA only, and 7: PM only. All mice (except healthy controls) were sensitized on the first day by intraperitoneal injection of 10 µg OVA and 2 mg Al(OH)3 in 200 µL of saline. Starting from day 15, mice (except groups 1 and 6) were exposed to sonicated PM (5 mg m-3, 30 min day-1) through a nebulizer daily for 7 consecutive days. Mice exposed to PM and OVA showed up-regulated expression of MAPKs and pro-inflammatory cytokine production in the lungs. Furthermore, PM-exposed lungs had significantly reduced expression of Nrf2 and HO-1 genes. However, oral administration of the SHE reduced the phosphorylation levels of MAPKs, iNOS and COX2 expression levels, and mRNA expression levels of pro-inflammatory cytokines. In addition, SHE treated group mice had up-regulated anti-oxidant gene expression levels in the lungs compared to group 2. These findings demonstrate that oral administration of the SHE re-establishes PM-induced inflammation and oxidative stress in the lungs. Taken together, the SHE has therapeutic potential in preventing PM-induced inflammation and oxidative stress.

Heracleum moellendorffii roots inhibit the production of pro-inflammatory mediators through the inhibition of NF-κB and MAPK signaling, and activation of ROS/Nrf2/HO-1 signaling in LPS-stimulated RAW264.7 cells.

BACKGROUND: Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R. METHODS: The cytotoxicity of HM-R against RAW264.7 cells was evaluated using MTT assay. The inhibition of NO and PGE2 production by HM-R was evaluated using Griess reagent and Prostaglandin E2 ELISA Kit, respectively. The changes in mRNA or protein level following HM-R treatment were assessed by RT-PCR and Western blot analysis, respectively. RESULTS: HM-R dose-dependently blocked LPS-induced NO and PGE2 production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, IL-1ß and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound. CONCLUSIONS: These results indicate that HM-R may exert anti-inflammatory activity by inhibiting NF-κB and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. These findings suggest that HM-R has a potential as a natural material for the development of anti-inflammatory drugs.

Antcamphin M Inhibits TLR4-Mediated Inflammatory Responses by Upregulating the Nrf2/HO-1 Pathway and Suppressing the NLRP3 Inflammasome Pathway in Macrophages.

The medicinal mushroom Antrodia cinnamomea has been demonstrated to have anti-inflammatory properties. However, the bioactive compounds in A. cinnamomea need further investigation. The present study aimed to understand the mechanism of action of antcamphin M, an ergostanoid isolated from A. cinnamomea mycelium and to clarify its underlying mechanisms of action. RAW264.7 cells were pretreated with the indicated concentrations of antcamphin M, prior to stimulation with lipopolysaccharide (LPS). Cell viability, production of nitric oxide (NO), prostaglandin E2 (PGE2), cytokines, and chemokines, as well as the inflammation-related signaling pathways were investigated. The study revealed that antcamphin M significantly decreased the LPS-induced production of NO, PGE2, pro-inflammatory cytokines, and keratinocyte chemoattractant CXCL1 (KC), along with the levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins without significant cytotoxicity, indicating it had a better anti-inflammatory activity than that of gisenoside Rb1 and Rg1. Additionally, antcamphin M significantly inhibited the activation of MAPKs (p38, ERK, and JNK), NFκB, and components of the NLRP3 inflammasome (NLRP3, ASC, and caspase-1) signaling pathways and also increased the levels of nuclear factor erythroid-2-related factor (Nrf2) and heme oxygenase-1 (HO-1). These findings suggest that antcamphin M possesses potent anti-inflammatory activities and could be a potential candidate for the development of anti-inflammatory drugs.

p-Coumaric-Acid-Containing Adenostemma lavenia Ameliorates Acute Lung Injury by Activating AMPK/Nrf2/HO-1 Signaling and Improving the Anti-oxidant Response.

Adenostemma lavenia is a perennial herb belonging to the Compositae family and is widely distributed in the tropical parts of Asia. It has been widely used as medicine in Taiwan with the whole plant used to treat pulmonary congestion, pneumonia, bacterial infections of the respiratory tract, edema, and inflammation. This study sought to investigate the anti-inflammatory effects of A. lavenia in vitro and in animal models. The anti-inflammatory effects of ethyl acetate fractions of A. lavenia (EAAL) were stimulated with lipopolysaccharide (LPS) murine macrophages (RAW 264.7) and lung injury in mice. EAAL reduced proinflammatory cytokine responses. Preoral EAAL alleviated LPS-induced histological alterations in lung tissue and inhibited the infiltration of inflammatory cells and protein concentrations in bronchoalveolar lavage fluid (BALF). EAAL prevented protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2); phosphorylation of IκB-α, MAPKs, and AMP-activated protein kinase (AMPK); and activated anti-oxidant enzymes (catalase, SOD, and GPx), heme oxygenase-1 (HO-1), and nuclear factor E2-related factor 2 (Nrf2) in LPS-stimulated cells and lung tissues. Fingerprinting of EAAL was performed with HPLC to control its quality, and p-coumaric acid was found to be a major constituent. This study suggests that EAAL is a potential therapeutic agent to treat inflammatory disorders.

Soybean ß-conglycinin caused intestinal inflammation and oxidative damage in association with NF-κB, TOR and Nrf2 in juvenile grass carp (Ctenopharyngodon idella): varying among different intestinal segments.

The current study aimed to investigate the effects and mechanisms of dietary soybean ß-conglycinin in immune function and oxidative damage among different intestinal segments of juvenile grass carp (Ctenopharyngodon idella). 240 fish (13.77 ±â€¯0.10 g) were fed control or 8% ß-conglycinin diet for 7 weeks. Dietary ß-conglycinin caused inconsistent suppression effects on the innate immune by decreasing complement component, lysozyme, antimicrobial peptide and acid phosphatase among different intestinal segments. Meanwhile, dietary ß-conglycinin caused inflammation in the mid and distal intestine by raising pro-inflammatory cytokines and declining anti-inflammatory cytokines mRNA levels, while more serious in the distal intestine than in the mid intestine. Furthermore, dietary ß-conglycinin regulating inflammatory cytokines might be associated with transcription factors nuclear factor-κB P65 (NF-κB P65) nucleus translocation and target of rapamycin (TOR) phosphorylation in the distal intestine but only related to TOR phosphorylation in the mid intestine. Interestingly, in the proximal intestine, dietary ß-conglycinin decreased both pro-inflammatory and anti-inflammatory cytokines mRNA level, and did not affect NF-κB P65 nucleus translocation and TOR phosphorylation. For oxidative damage, dietary ß-conglycinin exposure elevated both malondialdehyde (MDA) and protein carbonyl (PC) contents in the distal intestine, which might be attributed to the suppression of the Mn-SOD, catalase (CAT) and glutathione peroxidase (GPx) activities. In the mid intestine, dietary ß-conglycinin only increased PC content in association with the low activities of CAT, GPx and glutathione peroxidase (GR). Unexpectedly, in the proximal intestine, dietary ß-conglycinin did not significantly change MDA and PC contents while decreased antioxidant enzyme activities. Furtherly, dietary ß-conglycinin affect the antioxidant enzyme activity might be regulated by the varying pattern of nuclear factor-erythroid 2-related factor 2 (Nrf2) nucleus translocation among these three intestinal segments. In summary, dietary ß-conglycinin caused intestinal inflammation and oxidative damage in association with NF-κB, TOR and Nrf2 signaling molecules, which were varying among the three intestinal segments of grass carp.

Toosendanin alleviates dextran sulfate sodium-induced colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling.

Toosendanin (TSN), a triterpenoid extracted from the bark of fruit of Melia toosendan Sieb et Zucc, has been proven to have various biological activities including anti-inflammatory activity. But its effects on experimental colitis remain unreported. Herein, we investigated the role and potential mechanisms of TSN in dextran sulfate sodium (DSS) induced colitis in mice. The results showed that, TSN reduced colitis-associated disease activity index (DAI), shortened colon length, and weakened the pathological damage of the colon tissues in murine colitis models. Further studies disclosed that, TSN inhibited the secretion of proinflammatory cytokines and oxidative stress, and suppressed M1 macrophage polarization and the activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome, but upregulated HO-1/Nrf2 expression in murine colitis. In addition, TSN maintained intestinal barrier by regulating zonula occludens-1 (ZO-1) and occludin expression. In conclusion, our findings demonstrated that, TSN alleviates DSS-induced experimental colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling, and may provide a novel Chinese patent medicine for the treatment of murine colitis.

Protective Effect of Schisandra chinensis Polysaccharides Against the Immunological Liver Injury in Mice Based on Nrf2/ARE and TLR4/NF-κB Signaling Pathway.

We have previously demonstrated the hepatoprotective effect of Schisandra chinensis polysaccharides (SCP) against the liver injury induced by alcohol, high-fat diet, and carbon tetrachloride in mice. In this study, we investigated the effect of SCP against the immunological liver injury induced by concanavalin A (Con A) in mice. The results showed that SCP could significantly reduce the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in the serum of mice with immunological liver injury. SCP could significantly decrease the content of malondialdehyde (MDA) and nitric oxide (NO) and increase the activity of superoxide dismutase (SOD) and glutathione (GSH) in the liver tissue. SCP could significantly increase the number of CD4+ and decrease the number of CD8+ in the peripheral blood, and elevate the ratio of CD4+/CD8+. SCP could significantly downregulate the expression of Kelch-like ECH-associated protein 1 (Keap1) and upregulate the expression of nuclear factor-erythroid 2-related factor2 (Nrf2) and downstream gene heme oxygenase-1 (HO-1), and downregulate the expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), and nuclear factor-kappa B (NF-κB) proteins. This study indicates that SCP can reduce the release of a large number of inflammatory factors to inhibit the oxidative stress in mice with the immunological liver injury induced by Con A, and its mechanism is closely related to the regulation of Nrf2/antioxidant response element and TLR4/NF-κB signaling pathways.

Inhibition of p300/CBP-Associated Factor Attenuates Renal Tubulointerstitial Fibrosis through Modulation of NF-kB and Nrf2.

p300/CBP-associated factor (PCAF), a histone acetyltransferase, is involved in many cellular processes such as differentiation, proliferation, apoptosis, and reaction to cell damage by modulating the activities of several genes and proteins through the acetylation of either the histones or transcription factors. Here, we examined a pathogenic role of PCAF and its potential as a novel therapeutic target in the progression of renal tubulointerstitial fibrosis induced by non-diabetic unilateral ureteral obstruction (UUO) in male C57BL/6 mice. Administration of garcinol, a PCAF inhibitor, reversed a UUO-induced increase in the renal expression of total PCAF and histone 3 lysine 9 acetylation and reduced positive areas of trichrome and α-smooth muscle actin and collagen content. Treatment with garcinol also decreased mRNA levels of transforming growth factor-ß, matrix metalloproteinase (MMP)-2, MMP-9, and fibronectin. Furthermore, garcinol suppressed nuclear factor-κB (NF-κB) and pro-inflammatory cytokines such as tumor necrosis factor-α and IL-6, whereas it preserved the nuclear expression of nuclear factor erythroid-derived 2-like factor 2 (Nrf2) and levels of Nrf2-dependent antioxidants including heme oxygense-1, catalase, superoxide dismutase 1, and NAD(P)H:quinone oxidoreductase 1. These results suggest that the inhibition of inordinately enhanced PCAF could mitigate renal fibrosis by redressing aberrant balance between inflammatory signaling and antioxidant response through the modulation of NF-κB and Nrf2.

Electroacupuncture at ST-36 ameliorates DSS-induced acute colitis via regulating macrophage polarization induced by suppressing NLRP3/IL-1ß and promoting Nrf2/HO-1.

BACKGROUND: Electroacupuncture (EA) at ST-36 can attenuate acute experimental colitis, but the mechanisms are unclear. We investigated the role of macrophages in the anti-inflammatory effects of EA and its molecular mechanisms. METHODS: Male C57BL/6 mice were randomized into five groups: normal control, dextran sulfate sodium (DSS)-induced acute colitis (DSS), DSS with sham EA (SEA), DSS with high-frequency EA (HEA) and DSS with low-frequency EA (LEA). Body weight, colon length, DAI score and histological score were evaluated during colitis progression. Serum and colonic levels of pro- and anti-inflammatory cytokines were detected with ELISA, cytometric beads array, RT-PCR and western blotting analysis. Colonic macrophage subsets were determined using flow cytometry. Magnetic-activated cell sorting was applied to isolate colonic macrophages, and molecular mechanisms were explored with western blotting, RT-PCR and immunofluorescence. RESULTS: (1) Compared with the DSS group, HEA and LEA attenuated body weight loss and decreased DAI and histological scores. (2) Serum levels and colonic protein and mRNA levels of IL-1ß, TNFα, IL-6, IL-12 and IL17 were markedly decreased with HEA and LEA. IL-10 level was increased with HEA. (3) M1 macrophage percentage increased, while M2 macrophage percentage decreased in the DSS group; HEA and LEA reversed these proportions. (4) NLRP3/IL-1ß protein and mRNA levels in isolated macrophages decreased with HEA and LEA compared with the DSS treatment group; (5) HEA increased Nrf2/HO-1 levels compared with levels in DSS mice. CONCLUSION: The anti-inflammatory effects of EA on DSS-induced acute colitis may rely on regulating macrophage polarization, NLRP3/IL-1ß suppression and Nrf2/HO-1 promotion.

Suppression of lung inflammation by the ethanol extract of Chung-Sang and the possible role of Nrf2.

BACKGROUND: Asian traditional herbal remedies are typically a concoction of a major and several complementary herbs. While balancing out any adverse effect of the major herb, the complementary herbs could dilute the efficacy of the major herb, resulting in a suboptimal therapeutic effect of an herbal remedy. Here, we formulated Chung-Sang (CS) by collating five major herbs, which are used against inflammatory diseases, and tested whether an experimental formula composed of only major herbs is effective in suppressing inflammation without significant side effects. METHODS: The 50% ethanol extract of CS (eCS) was fingerprinted by HPLC. Cytotoxicity to RAW 264.7 cells was determined by an MTT assay and a flow cytometer. Nuclear NF-κB and Nrf2 were analyzed by western blot. Ubiquitinated Nrf2 was similarly analyzed following immunoprecipitation of Nrf2. Acute lung inflammation and sepsis were induced in C57BL/6 mice. The effects of eCS on lung disease were measured by HE staining of lung sections, a differential cell counting of bronchoalveolar lavage fluid, a myeloperoxidase (MPO) assay, a real-time qPCR, and Kaplan-Meier survival of mice. RESULTS: eCS neither elicited cytotoxicity nor reactive oxygen species. While not suppressing NF-κB, eCS activated Nrf2, reduced the ubiquitination of Nrf2, and consequently induced the expression of Nrf2-dependent genes. In an acute lung inflammation mouse model, an intratracheal (i.t.) eCS suppressed neutrophil infiltration, the expression of inflammatory cytokine genes, and MPO activity. In a sepsis mouse model, a single i.t. eCS was sufficient to significantly decrease mouse mortality. CONCLUSIONS: eCS could suppress severe lung inflammation in mice. This effect seemed to associate with eCS activating Nrf2. Our findings suggest that herbal remedies consisting of only major herbs are worth considering.

Polydatin prevents fructose-induced liver inflammation and lipid deposition through increasing miR-200a to regulate Keap1/Nrf2 pathway.

Oxidative stress is a critical factor in nonalcoholic fatty liver disease pathogenesis. MicroRNA-200a (miR-200a) is reported to target Kelch-like ECH-associated protein 1 (Keap1), which regulates nuclear factor erythroid 2-related factor 2 (Nrf2) anti-oxidant pathway. Polydatin (3,4',5-trihydroxy-stilbene-3-ß-D-glucoside), a polyphenol found in the rhizome of Polygonum cuspidatum, have anti-oxidative, anti-inflammatory and anti-hyperlipidemic effects. However, whether miR-200a controls Keap1/Nrf2 pathway in fructose-induced liver inflammation and lipid deposition and the blockade of polydatin are still not clear. Here, we detected miR-200a down-regulation, Keap1 up-regulation, Nrf2 antioxidant pathway inactivation, ROS-driven thioredoxin-interacting protein (TXNIP) over-expression, NOD-like receptor (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome activation and dysregulation of peroxisome proliferator activated receptor-α (PPAR-α), carnitine palmitoyl transferase-1 (CPT-1), sterol regulatory element binging protein 1 (SREBP-1) and stearoyl-CoA desaturase-1 (SCD-1) in rat livers, BRL-3A and HepG2 cells under high fructose induction. Furthermore, the data from the treatment or transfection of miR-200a minic, Keap1 and TXNIP siRNA, Nrf2 activator and ROS inhibitor demonstrated that fructose-induced miR-200a low-expression increased Keap1 to block Nrf2 antioxidant pathway, and then enhanced ROS-driven TXNIP to activate NLRP3 inflammasome and disturb lipid metabolism-related proteins, causing inflammation and lipid deposition in BRL-3A cells. We also found that polydatin up-regulated miR-200a to inhibit Keap1 and activate Nrf2 antioxidant pathway, resulting in attenuation of these disturbances in these animal and cell models. These findings provide a novel pathological mechanism of fructose-induced redox status imbalance and suggest that the enhancement of miR-200a to control Keap1/Nrf2 pathway by polydatin is a therapeutic strategy for fructose-associated liver inflammation and lipid deposition.

Neuroprotective Effect of Alpha-Linolenic Acid against Aß-Mediated Inflammatory Responses in C6 Glial Cell.

Therapeutic approaches for neurodegeneration, such as Alzheimer's disease (AD), have been widely studied. One of the critical hallmarks of AD is accumulation of amyloid beta (Aß). Aß induces neurotoxicity and releases inflammatory mediators or cytokines through activation of glial cell, and these pathological features are observed in AD patient's brain. The purpose of this study is to investigate the protective effect of alpha-linolenic acid (ALA) on Aß25-35-induced neurotoxicity in C6 glial cells. Exposure of C6 glial cells to 50 µM Aß25-35 caused cell death, overproduction of nitric oxide (NO), and pro-inflammatory cytokines release [interleukin (IL)-6 and tumor necrosis factor-α], while treatment of ALA increased cell viability and markedly attenuated Aß25-35-induced excessive production of NO and those inflammatory cytokines. Inhibitory effect of ALA on generation of NO and cytokines was mediated by down-regulation of inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions. In addition, ALA treatment inhibited reactive oxygen species generation induced by Aß25-35 through the enhancement of the nuclear factor-erythroid 2-related factor-2 (Nrf-2) protein levels and subsequent induction of heme-oxygenase-1 (HO-1) expression in C6 glial cells dose- and time-dependently. Furthermore, the levels of neprilysin and insulin-degrading enzyme protein expressions, which contribute to degradation of Aß, were also increased by treatment of ALA compared to Aß25-35-treated control group. In conclusion, effects of ALA on Aß degradation were shown to be mediated through inhibition of inflammatory responses and activation of antioxidative system, Nrf-2/HO-1 signaling pathway, in C6 glial cells. Our findings suggest that ALA might have the potential for therapeutics of AD.

Anti-Inflammatory Activity of Epimedium brevicornu Maxim Ethanol Extract.

Epimedium brevicornu Maxim has been used as a traditional herbal drug in China. In this study, the anti-inflammatory effects of E. brevicornu Maxim ethanol extract (EBME) were investigated in RAW264.7 macrophages and mice challenged with lipopolysaccharide (LPS). Results showed that EBME attenuated inflammation by decreasing the production of several proinflammatory mediators, such as nitric oxide (NO), prostaglandin (PG) E2, inducible nitric oxide synthase, and cyclooxygenase-2, in LPS-stimulated RAW264.7 macrophages. EBME increased the expression of heme oxygenase-1 (HO-1) and promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2. The inhibitory effects of EBME on LPS-stimulated NO and PGE2 expression were partially reversed by HO-1 inhibitor. EBME also elicited an anti-inflammatory effect by inhibiting the production of tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 in LPS-induced peritonitis. Therefore, EBME exhibited anti-inflammatory effects in vitro and in vivo.

Involvement of heme oxygenase-1 induction in anti-vascular inflammation effects of Xanthoceras sorbifolia in human umbilical vein endothelial cells.

OBJECTIVE: To define the effects of Xanthoceras sorbifolia (EXS) on vascular inflammation and the mechanisms in endothelial cells. METHODS: Vascular protective effects of an ethanol extract of seeds from EXS (1-50 µg/mL) against tumor necrosis factor-α (TNF-α)-induced vascular inflammation were examined in human umbilical vein endothelial cells (HUVECs). RESULTS: EXS significantly decreased TNF-α-induced expression of cell adhesion molecules, such as intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and endothelial cell selectin, in a dose-dependent manner. Pre-treatment with EXS significantly inhibited translocation and transcriptional activity of nuclear factor-κB (NF-κB) increased by TNF-α. EXS also significantly inhibited formation of intracellular reactive oxygen species (ROS). Moreover, the vascular protective effects of EXS were linked to up-regulation of heme oxygenase-1 (HO-1) and nuclear factor E2-related factor-2 (Nrf-2) expression. EXS-induced HO-1 expression was significantly decreased in SnPP (HO-1 inhibitor)- and HO-1 siRNA-treated cells, whereas an increase was found in cobalt protoporphyrin IX (CoPP) (HO-1 inducer)-treated cells. In addition, pretreatment with EXS increased HO-1 and Nrf-2 expression under TNF-α stimulation with or without N-acetyl-L-cysteine. Furthermore, the inhibitory effects of EXS on TNF-α-induced vascular inflammation were partially reversed in SnPP- and of HO-1 siRNA-treated cells but increased by CoPP. CONCLUSION: These results suggest that EXS may have important implications for prevention of vascular complications associated with vascular inflammation by inhibition of the NF-¦ÊB/ROS pathway and activation of the Nrf-2/HO-1 pathway.

RA-XII exerts anti-oxidant and anti-inflammatory activities on lipopolysaccharide-induced acute renal injury by suppressing NF-κB and MAPKs regulated by HO-1/Nrf2 pathway.

Acute kidney injury (AKI) is an abrupt loss of kidney function and severe AKI needs renal replacement therapeutic strategy and has high mortality. RA-XII is a natural cyclopeptide, isolated from the traditional Chinese medicine Rubia yunnanensis, exerting anti-inflammatory and anti-tumor activities. The present study aimed to explore the effects of RA-XII on LPS-induced ACI and the underlying molecular mechanism in TCMK-1 cells in vitro. The results indicated that RA-XII delayed the animal death caused by LPS in mice. The kidney histological changes were markedly attenuated by RA-XII. RA-XII also reduced the serum uric acid, creatinine, BUN and renal 8-OHdG. In addition, RA-XII suppressed LPS-induced oxidative stress in kidney, as evidenced by the up-regulation of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, and the down-regulation of malondialdehyde (MDA) levels. Additionally, RA-XII enhanced heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expressions in renal tissue sections. Further, RA-XII reduced the release of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), IL-6 and IL-18, in renal, which was linked to the inhibition of inhibitor of alpha/nuclear factor kappa B (IκBα/NF-κB) and mitogen-activated protein kinases (MAPKs) pathways. The in vitro study illustrated that the anti-inflammatory effects of RA-XII were partially reversed following Nrf2 and HO-1 inhibition. Together, these findings strongly suggested that RA-XII is a potential agent against acute kidney injury.

Piceatannol inhibits the IL-1ß-induced inflammatory response in human osteoarthritic chondrocytes and ameliorates osteoarthritis in mice by activating Nrf2.

Osteoarthritis (OA) is a complex process, to which an inflammatory environment contributes markedly. Piceatannol exerts anti-inflammatory effects on several diseases. In the current study, we explored the protective effects of piceatannol on the progression of OA and investigated its molecular target. In vitro, piceatannol not only attenuated the over-production of inflammatory mediators and cytokines-such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6)-but also suppressed the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) at both the mRNA and protein levels. Piceatannol also decreased the expression of metalloproteinase 13 (MMP13) and thrombospondin motifs 5 (ADAMTS5), which mediate extracellular matrix degradation. Mechanistically, we found that piceatannol inhibited IL-1ß-induced nuclear factor kappa B (NF-κB) activation by activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. Furthermore, piceatannol exerted protective effects in a mouse model of OA. Taken together, these findings indicate that piceatannol may be a potential therapeutic agent for OA.

Nrf2-Mediated HO-1 Induction and Antineuroinflammatory Activities of Halleridone.

Nuclear factor E2-related factor 2 (Nrf2) is the master regulator of antioxidant enzymes and is known to act on the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. Few studies have examined the bioactivity of halleridone. Herein, we investigated whether halleridone, which was isolated from the stems of the plant Cornus walteri, could regulate Nrf2-mediated heme oxygenase (HO)-1 expression and prevent intramicroglial inflammation induced by amyloid beta (Aß)1-42 overexpression. Biochemical and molecular experiments, such as real-time polymerase chain reaction, Western blot analysis, immunocytochemistry, immunofluorescence, and luciferase reporter gene assays, were performed. The results demonstrated that halleridone promoted the upregulation of Nrf2 expression and its translocation to the nucleus, thereby activating antioxidant response element gene transcription and HO-1 expression in murine hippocampal HT22 cells. Additionally, halleridone removed intramicroglial Aß1-42 and suppressed the production of inflammatory mediators such as interleukin (IL)-1ß, IL-6, prostaglandin E2, and nitric oxide (NO) induced by artificially overexpressed Aß1-42 and decreased pNF-κB accumulation in the nucleus and the expression of inducible NO synthase and cyclooxygenase II in BV-2 cells. In conclusion, halleridone activated Nrf2-mediated HO-1 expression and inhibited Aß1-42-overexpressed microglial BV-2 cell activation. These observations suggest that halleridone may have therapeutic potential for targeting neurodegeneration through neuroinflammation.