Protective Effects of Maclurin against Benzo[a]pyrene via Aryl Hydrocarbon Receptor and Nuclear Factor Erythroid 2-Related Factor 2 Targeting

Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon formed during the incomplete combustion of organic matter, has harmful effects. Therefore, much research is ongoing to develop agents that can mitigate the effects of B[a]P. The aim of this study was to examine the effect of maclurin, one component of the branches of Morus alba L., on the B[a]P-induced effects in HaCaT cells, a human keratinocyte cell line. Maclurin treatment inhibited aryl hydrocarbon receptor (AHR) signaling as evidenced by reduced xenobiotic response element (XRE) reporter activity, decreased expression of cytochrome P450 1A1 (CYP1A1), and reduced nuclear translocation of AHR. The B[a]P-induced dissociation of AHR from AHR-interacting protein (AIP) was suppressed by maclurin. Maclurin also inhibited the production of intracellular reactive oxygen species (ROS) induced by B[a]P. In addition, the antioxidant property of maclurin itself was demonstrated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Furthermore, maclurin activated antioxidant response element (ARE) signaling through enhancement of ARE luciferase reporter activity and the expression of ARE-dependent genes including nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1). Nrf2 activation and its nuclear translocation were promoted by maclurin through p38 MAPK activation. These data indicate that maclurin had antagonistic activity against B[a]P effects through activation of Nrf2-mediated signaling and inhibition of AHR signaling and, suggesting its potential in protecting from harmful B[a]P-containing pollutants.

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Antagonizing Effects of Clematis apiifolia DC. Extract against Benzo[a]pyrene-Induced Damage to Human Keratinocytes

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/2386163 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Seung Eun Lee ◽

See-Hyoung Park ◽

Ju Ah Yoo ◽

Kitae Kwon ◽

Ji Woong Kim ◽

...

Keyword(s):

Nuclear Translocation ◽

Human Keratinocytes ◽

Antioxidant Response ◽

Luciferase Reporter ◽

Heme Oxygenase 1 ◽

Protective Effects ◽

Cytochrome P450 1A1 ◽

Independent Manner ◽

Reporter Activity ◽

Aryl Hydrocarbon

Background. Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon present in the atmosphere, has cytotoxic and carcinogenic effects. There have been no reports to demonstrate involvement of Clematis apiifolia DC. extract (CAE) in B[a]P-induced effects. This study was conducted to investigate the effect of CAE on B[a]P-induced effects and to elucidate its mechanism of action in HaCaT human keratinocytes. CAE inhibited aryl hydrocarbon receptor (AhR) signaling by decreasing both XRE reporter activity and expression of cytochrome P450 1A1 (CYP1A1) induced by B[a]P treatment in HaCaT cells. We also found that B[a]P-induced nuclear translocation of AhR and production of reactive oxygen species (ROS) and proinflammatory cytokines were attenuated by CAE treatment. CAE treatment suppressed B[a]P-induced phosphorylation of Src (Tyr416). In addition, dasatinib, a Src inhibitor, also inhibited B[a]P-induced nuclear translocation of AhR, similar to CAE treatment. In addition, CAE activated antioxidant response element (ARE) signaling by increasing ARE luciferase reporter activity and expression of ARE-dependent genes such as nuclear factor (erythroid-derived 2)-like 2 (Nrf2), NAD(P)H dehydrogenase [quinone] 1 (NQO1), and heme oxygenase-1 (HO-1). Nuclear translocation of Nrf2 by CAE was demonstrated by Western blot analysis and immunocytochemistry. The effects of CAE on ARE signaling were attenuated by knockdown of the Nrf2 gene. Inhibition of AhR signaling and activation of antioxidant activity by CAE operated in a reciprocally independent manner as evidenced by AhR and Nrf2 siRNA experiments. These findings indicate that CAE exerts protective effects against B[a]P by inhibiting AhR signaling and activating Nrf2-mediated signaling, suggesting its potential in protection from harmful B[a]P-containing pollutants.

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Synthetic Ruthenium Complex TQ-6 Potently Recovers Cerebral Ischemic Stroke: Attenuation of Microglia and Platelet Activation

Journal of Clinical Medicine ◽

10.3390/jcm9040996 ◽

2020 ◽

Vol 9 (4) ◽

pp. 996

Author(s):

Chih-Hsuan Hsia ◽

Thanasekaran Jayakumar ◽

Joen-Rong Sheu ◽

Chih-Wei Hsia ◽

Wei-Chieh Huang ◽

...

Keyword(s):

Nitric Oxide ◽

Ischemic Stroke ◽

Platelet Activation ◽

Nuclear Translocation ◽

Radical Scavenging ◽

Microglia Activation ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Nuclear Factor ◽

Cox 2

Activated microglia are crucial in the regulation of neuronal homeostasis and neuroinflammation. They also contribute to neuropathological processes after ischemic stroke. Thus, finding new approaches for reducing neuroinflammation has gained considerable attention. The metal ruthenium has gained notable attention because of its ability to form new complexes that can be used in disease treatment. [Ru(η6-cymene)2-(1H-benzoimidazol-2-yl)-quinoline Cl]BF4 (TQ-6), a potent ruthenium (II)-derived compound, was used in this study to investigate its neuroprotective action against microglia activation, middle cerebral artery occlusion (MCAO)-induced embolic stroke, and platelet activation, respectively. TQ-6 (2 μM) potently diminished inflammatory mediators (nitric oxide/inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2)) expression, nuclear factor kappa B (NF-κB) p65 phosphorylation, nuclear translocation, and hydroxyl radical (OH•) formation in LPS-stimulated microglia. Conversely, TQ-6 increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Moreover, it significantly reduced brain infarct volume and edema in MCAO mice. Additionally, it drastically inhibited platelet aggregation and OH• production in mice platelets. This study confirmed that TQ-6 exerts an anti-neuroinflammatory effect on microglia activation through neuroprotection, antiplatelet activation, and free radical scavenging. The authors propose that TQ-6 might mitigate neurodegenerative pathology by inhibiting the NF-κB-mediated downstream pathway (iNOS and COX-2) and enhancing Nrf2/HO-1 signaling molecules in microglia.

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Aryl hydrocarbon receptor and NF-E2-related factor 2 are key regulators of human MRP4 expression

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00522.2010 ◽

2010 ◽

Vol 299 (1) ◽

pp. G126-G135 ◽

Cited By ~ 59

Author(s):

Shuhua Xu ◽

Jittima Weerachayaphorn ◽

Shi-Ying Cai ◽

Carol J. Soroka ◽

James L. Boyer

Keyword(s):

Aryl Hydrocarbon Receptor ◽

Program Analysis ◽

Promoter Activity ◽

Therapeutic Benefit ◽

Proximal Promoter ◽

Luciferase Reporter ◽

Related Factor ◽

Response Element ◽

Aryl Hydrocarbon ◽

Reporter Assays

Multidrug resistance protein 4 (MRP4; ABCC4) is an ATP binding cassette transporter that facilitates the excretion of bile salt conjugates and other conjugated steroids in hepatocytes and renal proximal tubule epithelium. MRP4/Mrp4 undergoes adaptive upregulation in response to oxidative and cholestatic liver injury in human and animal models of cholestasis. However, the molecular mechanism of this regulation remains to be determined. The aryl hydrocarbon receptor (AhR) and NF-E2-related factor 2 (Nrf2) play important roles in protecting cells from oxidative stress. Here we examine the role of these two nuclear factors in the regulation of the expression of human MRP4. HepG2 cells and human hepatocytes were treated with the AhR and Nrf2 activators, 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD), 3-methylcholanthrene (3-MC), or oltipraz and other nuclear receptor agonists. TCDD, 3-MC, and oltipraz significantly increased MRP4 expression at mRNA and protein levels. Computer program analysis revealed three Xenobiotic response element (XRE) and one Maf response element sites within the first 500 bp of the MRP4 proximal promoter. Luciferase reporter assay detected strong promoter activity (53-fold higher than vector control) in this region. TCDD and 3-MC also induced promoter activity in the reporter assays. Mutation of any of these XRE sites significantly decreased MRP4 promoter activity in reporter assays, although XRE2 demonstrated the strongest effects on both basal and TCDD-inducible activity. EMSA and chromatin immunoprecipitation assays further confirmed that both AhR and Nrf2 bind to the proximal promoter of MRP4. Our findings indicate that AhR and Nrf2 play important roles in regulating MRP4 expression and suggest that agents that activate their activity may be of therapeutic benefit for cholestasis.

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(10Z)-Debromohymenialdisine from Marine Sponge Stylissa sp. Regulates Intestinal Inflammatory Responses in Co-Culture Model of Epithelial Caco-2 Cells and THP-1 Macrophage Cells

Molecules ◽

10.3390/molecules24183394 ◽

2019 ◽

Vol 24 (18) ◽

pp. 3394 ◽

Cited By ~ 2

Author(s):

Seon Min Lee ◽

Na-Hyun Kim ◽

Sangbum Lee ◽

Yun Na Kim ◽

Jeong-Doo Heo ◽

...

Keyword(s):

Marine Sponge ◽

Nuclear Translocation ◽

Inflammatory Responses ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Nuclear Factor ◽

Subsequent Increase ◽

Vitro Model ◽

Factor Α

Crohn’s disease (CD) and ulcerative colitis (UC), collectively referred to as inflammatory bowel disease (IBD), are autoimmune diseases characterized by chronic inflammation within the gastrointestinal tract. Debromohymenialdisine is an active pyrrole alkaloid that is well known to serve as a stable and effective inhibitor of Chk2. In the present study, we attempted to investigate the anti-inflammatory properties of (10Z)-debromohymenialdisine (1) isolated from marine sponge Stylissa species using an intestinal in vitro model with a transwell co-culture system. The treatment with 1 attenuated the production and gene expression of lipopolysaccharide (LPS)-induced Interleukin (IL)-6, IL-1β, prostaglandin E2 (PGE2), and tumor necrosis factor-α in co-cultured THP-1 macrophages at a concentration range of 1–5 μM. The protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 were down-regulated in response to the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) translocation into the nucleus in cells. In addition, we observed that 1 markedly promoted the nuclear translocation of nuclear factor erythroid 2 related factor 2 (Nrf2) and subsequent increase of heme oxygenase-1 (HO-1) expression. These findings suggest the potential use of 1 as a pharmaceutical lead in the treatment of inflammation-related diseases including IBD.

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In Vivo Anti-Inflammatory Potential of Viscozyme®-Treated Jujube Fruit

Foods ◽

10.3390/foods9081033 ◽

2020 ◽

Vol 9 (8) ◽

pp. 1033 ◽

Cited By ~ 2

Author(s):

Yoonsu Kim ◽

Jisun Oh ◽

Chan Ho Jang ◽

Ji Sun Lim ◽

Jeong Soon Lee ◽

...

Keyword(s):

Lung Inflammation ◽

Radical Scavenging ◽

Lung Epithelial Cells ◽

Lung Damage ◽

Antioxidant Defenses ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Nuclear Factor ◽

Jujube Fruit

The fruit of Ziziphus jujuba, commonly called jujube, has long been consumed for its health benefits. The aim of this study was to examine the protective effect of dietary supplementation of enzymatically hydrolyzed jujube against lung inflammation in mice. The macerated flesh of jujube was extracted with aqueous ethanol before and after Viscozyme treatment. The extract of enzyme-treated jujube, called herein hydrolyzed jujube extract (HJE), contained higher levels of quercetin, total phenolics, and flavonoids, and exhibited more effective radical-scavenging abilities in comparison to non-hydrolyzed jujube extract (NHJE). HJE treatment decreased production of inflammation-associated molecules, including nitric oxide and pro-inflammatory cytokines from activated Raw 264.7 or differentiated THP-1 cells. HJE treatment also reduced expression of nuclear factor-κB and its downstream proteins in A549 human lung epithelial cells. Moreover, oral supplementation of 1.5 g of HJE per kg of body weight (BW) attenuated histological lung damage, decreased plasma cytokines, and inhibited expression of inflammatory proteins and oxidative stress mediators in the lungs of mice exposed to benzo(a)pyrene at 50 mg/kg BW. Expression levels of antioxidant and cytoprotective factors, such as nuclear factor erythroid-derived 2-related factor 2 and heme oxygenase-1, were increased in lung and liver tissues from mice treated with HJE, compared to mice fed NHJE. These findings indicate that dietary HJE can reduce benzo(a)pyrene-induced lung inflammation by inhibiting cytokine release from macrophages and promoting antioxidant defenses in vivo.

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Regulation of heme oxygenase-1 expression by demethoxy curcuminoids through Nrf2 by a PI3-kinase/Akt-mediated pathway in mouse β-cells

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00111.2007 ◽

2007 ◽

Vol 293 (3) ◽

pp. E645-E655 ◽

Cited By ~ 75

Author(s):

Subbiah Pugazhenthi ◽

Leonid Akhov ◽

Gopalan Selvaraj ◽

Maorong Wang ◽

Jawed Alam

Keyword(s):

Signaling Pathways ◽

Heme Oxygenase ◽

Nuclear Translocation ◽

Regulatory Subunit ◽

Luciferase Reporter ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Mrna Levels ◽

Phase 2 ◽

Β Cells

Curcumin (diferuloylmethane), a component of turmeric, has been shown to have therapeutic properties. Induction of phase 2 detoxifying enzymes is a potential mechanism through which some of the actions of curcumin could proceed. Heme oxygenase-1 (HO-1), an antioxidant phase 2 enzyme, has been reported to have cytoprotective effects in pancreatic β-cells. Curcumin on further purification yields demethoxy curcumin (DMC) and bisdemethoxy curcumin (BDMC). The objective of the present study was to determine the mechanism by which these purified curcuminoids induce HO-1 in MIN6 cells, a mouse β-cell line. Demethoxy curcuminoids induced HO-1 promoter linked to the luciferase reporter gene more effectively than curcumin. The induction was dependent on the presence of antioxidant response element (ARE) sites containing enhancer regions (E1 and E2) in HO-1 promoter and nuclear translocation of nuclear factor-E2-related factor (Nrf2), the transcription factor that binds to ARE. Curcuminoids stimulated multiple signaling pathways that are known to induce HO-1. Inhibition of specific signaling pathways with pharmacological inhibitors and cotransfection experiments suggested the involvement of phosphotidylinositol 3-kinase and Akt. Real-time quantitative RT-PCR analysis showed significant elevation in the mRNA levels of HO-1 and two other phase 2 enzymes, the regulatory subunit of glutamyl cysteine ligase, which is needed for the synthesis of glutathione, and NAD(P)H:quinone oxidoreductase, which detoxifies quinones. DMC and BDMC induced the expression of HO-1 and translocated Nrf2 to nucleus in β-cells of mouse islets. Our observations suggest that demethoxy curcuminoids could be used to induce a cellular defense mechanism in β-cells under conditions of stress as seen in diabetes.

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