Akt Cys-310-targeted inhibition by hydroxylated benzene derivatives is tightly linked to their immunosuppressive effects

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1β and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

The Intracellular Interaction of Porcine β-Defensin 2 with VASH1 Alleviates Inflammation via Akt Signaling Pathway

Defensins are a major class of antimicrobial peptides that facilitate the immune system to resist pathogen infection. To date, only β-defensins have been identified in pigs. In our previous studies, porcine β-defensin 2 (PBD-2) was shown to have both bactericidal activity and modulatory roles on inflammation. PBD-2 can interact with the cell surface TLR4 and interfere with the NF-κB signaling pathway to suppress the inflammatory response. In this study, the intracellular functions of PBD-2 were investigated. The fluorescently labeled PBD-2 could actively enter mouse macrophage cells. Proteomic analysis indicated that 37 proteins potentially interacted with PBD-2, among which vasohibin-1 (VASH1) was further tested. LPS, an inflammation inducer, suppressed the expression of VASH1, whereas PBD-2 inhibited this effect. PBD-2 inhibited LPS-induced activation of Akt, expression and release of the inflammatory mediators vascular endothelial growth factor and NO, and cell damage. A follow-up VASH1 knockdown assay validated the specificity of the above observations. In addition, PBD-2 inhibited LPS-induced NF-κB activation via Akt. The inhibition effects of PBD-2 on LPS triggered suppression of VASH1 and activation of Akt, and NF-κB and inflammatory cytokines were also confirmed using pig alveolar macrophage 3D4/21 cells. Therefore, the data indicate that PBD-2 interacts with intracellular VASH1, which inhibits the LPS-induced Akt/NF-κB signaling pathway, resulting in suppression of inflammatory responses. Together with our previous findings, we conclude that PBD-2 interacts with both the cell surface receptor (TLR4) and also with the intracellular receptor (VASH1) to control inflammation, thereby providing insights into the immunomodulatory roles of defensins.

Compound C induces autophagy and apoptosis in parental and hydroquinone-selected malignant leukemia cells through the ROS/p38 MAPK/AMPK/TET2/FOXP3 axis

Hydroquinone (HQ), a major metabolic product of benzene, causes acute myeloid leukemia (AML) elicited by benzene exposure. Past studies found that continuous exposure of human AML U937 cells to HQ selectively produces malignant U937/HQ cells in which FOXP3 upregulation modulates malignant progression. Other studies revealed that AMPK promotes TET2 activity on DNA demethylation and that TET2 activity is crucial for upregulating FOXP3 expression. This study was conducted to elucidate whether compound C, an AMPK inhibitor, blocked the AMPK-TET2-FOXP3 axis in AML and in HQ-selected malignant cells. We found higher levels of AMPKα, TET2, and FOXP3 expression in U937/HQ cells compared to U937 cells. Treatment of parental Original Article and HQ-selected malignant U937 cells with compound C induced ROS-mediated p38 MAPK activation, leading to a suppression of AMPKα, TET2, and FOXP3 expression. Moreover, compound C induced apoptosis and mTOR-independent autophagy. The suppression of the autophagic flux inhibited the apoptosis of compound C-treated U937 and U937/HQ cells, whereas co-treatment with rapamycin, a mTOR inhibitor, sensitized the two cell lines to compound C cytotoxicity. Overexpression of AMPKα1 or pretreatment with autophagic inhibitors abrogated compound C-induced autophagy and suppression of TET2 and FOXP3 expression. Restoration of AMPKα1 or FOXP3 expression increased cell survival after treatment with compound C. In conclusion, our results show that compound C suppresses AMPK/TET2 axis-mediated FOXP3 expression and induces autophagy-dependent apoptosis in parental and HQ-selected malignant U937 cells, suggesting that the AMPK/TET2/FOXP3 axis is a promising target for improving AML therapy and attenuating benzene exposure-induced AML progression.

Anti-inflammatory functions of the CDC25 phosphatase inhibitor BN82002 via targeting AKT2

This study presents BN82002 as an anti-inflammatory drug candidate. It was found that BN82002 inhibited the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in RAW 264.7 cells and peritoneal macrophages that were activated by toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS). BN82002 dose-dependently down-regulated mRNA levels of nitric oxide synthase, tumor necrosis factor-α, and cyclooxygenase-2. The nuclear translocation of nuclear factor (NF)-κB (p65 and p50) was also blocked by BN82002 in RAW265.7 cells stimulated by LPS. According to reporter gene assay performed with NF-κB construct, BN82002 clearly reduced increased level of luciferase activity mediated by transcription factor NF-κB in LPS-treated RAW264.7 cells and in MyD88- and AKT2-overexpressing HEK293 cells. However, BN82002 did not inhibit NF-κB activity in AKT1- or IKKβ-overexpressing HEK293 cells. NF-κB upstream signaling events specifically targeted AKT2 but had no effect on AKT1. The specific target of BN82002 was Tyr-178 in AKT2. BN82002 bound to Tyr-178 and interrupted the kinase activity of AKT2, according to a cellular thermal shift assay analysis of the interaction of BN82002 with AKT2 and an AKT2 mutant (Tyr-178 mutated to Ala; AKT2 Y178A). These results suggest that BN82002 could reduce inflammatory pathway by controlling NF-κB pathway and specifically targeting AKT2.

Targeting allosteric site of AKT by 5,7-dimethoxy-1,4-phenanthrenequinone suppresses neutrophilic inflammation

BACKGROUND

Acute lung injury (ALI) is a severe life-threatening inflammatory disease. Neutrophil activation is a major pathogenic factor in ALI. Protein kinase B (PKB)/AKT regulates diverse cellular responses, but the significance in neutrophilic inflammation and ALI remains unknown.

METHODS

Human neutrophils and neutrophil-like differentiated HL-60 (dHL-60) cells were used to examine the anti-inflammatory effects of 5,7-dimethoxy-1,4-phenanthrenequinone (CLLV-1). The therapeutic potential of CLLV-1 was determined in a mouse model of lipopolysaccharide (LPS)-induced ALI.

FINDINGS

CLLV-1 inhibited respiratory burst, degranulation, adhesion, and chemotaxis in human neutrophils and dHL-60 cells. CLLV-1 inhibited the phosphorylation of AKT (Thr308 and Ser473), but not of ERK, JNK, or p38. Furthermore, CLLV-1 blocked AKT activity and covalently reacted with AKT Cys310 in vitro. The AKT_309-313 peptide-CLLV-1 adducts were determined by NMR or mass spectrometry assay. The alkylation agent-conjugated AKT (reduced form) level was also inhibited by CLLV-1. Significantly, CLLV-1 ameliorated LPS-induced ALI, neutrophil infiltration, and AKT activation in mice.

INTERPRETATION

Our results identify CLLV-1 as a covalent allosteric AKT inhibitor by targeting AKT Cys310. CLLV-1 shows potent anti-inflammatory activity in human neutrophils and LPS-induced mouse ALI. Our findings provide a mechanistic framework for redox modification of AKT that may serve as a novel pharmacological target to alleviate neutrophilic inflammation.

Hydroquinone Exhibits In Vitro and In Vivo Anti-Cancer Activity in Cancer Cells and Mice

Hydroquinone (HQ, 1,4-benzenediol) is a hydroxylated benzene metabolite with various biological activities, including anti-oxidative, neuroprotective, immunomodulatory, and anti-inflammatory functions. However, the anti-cancer activity of HQ is not well understood. In this study, the in vitro and in vivo anti-cancer activity of HQ was investigated in various cancer cells and tumor-bearing mouse models. HQ significantly induced the death of A431, SYF, B16F10, and MDA-MB-231 cells and also showed a synergistic effect on A431 cell death with other anti-cancer agents, such as adenosine-2′,3′-dialdehyde and buthionine sulfoximine. In addition, HQ suppressed angiogenesis in fertilized chicken embryos. Moreover, HQ prevented lung metastasis of melanoma cells in mice in a dose-dependent manner without toxicity and adverse effects. HQ (10 mg/kg) also suppressed the generation of colon and reduced the thickness of colon tissues in azoxymethane/dextran sodium sulfate-injected mice. This study strongly suggests that HQ possesses in vitro and in vivo anti-cancer activity and provides evidence that HQ could be developed as an effective and safe anti-cancer drug.

Momordica charantia Inhibits Inflammatory Responses in Murine Macrophages via Suppression of TAK1

Momordica charantia known as bitter melon is a representative medicinal plant reported to exhibit numerous pharmacological activities such as antibacterial, antidiabetic, anti-inflammatory, anti-oxidant, antitumor, and hypoglycemic actions. Although this plant has high ethnopharmacological value for treating inflammatory diseases, the molecular mechanisms by which it inhibits the inflammatory response are not fully understood. In this study, we aim to identify the anti-inflammatory mechanism of this plant. To this end, we studied the effects of its methanol extract (Mc-ME) on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Specifically, we evaluated nitric oxide (NO) production, mRNA expression of inflammatory genes, luciferase reporter gene activity, and putative molecular targets. Mc-ME blocked NO production in a dose-dependent manner in RAW264.7 cells; importantly, no cytotoxicity was observed. Moreover, the mRNA expression levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 were decreased by Mc-ME treatment in a dose-dependent manner. Luciferase assays and nuclear lysate immunoblotting analyses strongly indicated that Mc-ME decreases the levels of p65 [a nuclear factor (NF)-[Formula: see text]B subunit] and c-Fos [an activator protein (AP)-1 subunit]. Whole lysate immunoblotting assays, luciferase assays, and overexpression experiments suggested that transforming growth factor [Formula: see text]-activated kinase 1 (TAK1) is targeted by Mc-ME, thereby suppressing NF-[Formula: see text]B and AP-1 activity via downregulation of extracellular signal-regulated kinases (ERKs) and AKT. These results strongly suggest that Mc-ME exerts its anti-inflammatory activity by reducing the action of TAK1, which also affects the activation of NF-[Formula: see text]B and AP-1.

Hydroquinone suppresses IFN-β expression by targeting AKT/IRF3 pathway

Previous studies have demonstrated the role of hydroquinone (HQ), a hydroxylated benzene metabolite, in modulating various immune responses; however, its role in macrophage-mediated inflammatory responses is not fully understood. In this study, the role of HQ in inflammatory responses and the underlying molecular mechanism were explored in macrophages. HQ down-regulated the expression of interferon (IFN)-β mRNA in LPS-stimulated RAW264.7 cells without any cytotoxicity and suppressed interferon regulatory factor (IRF)-3-mediated luciferase activity induced by TIR-domain-containing adapter-inducing interferon-β (TRIF) and TANK-binding kinase 1 (TBK1). A mechanism study revealed that HQ inhibited IRF-3 phosphorylation induced by lipopolysaccharide (LPS), TRIF, and AKT by suppressing phosphorylation of AKT, an upstream kinase of the IRF-3 signaling pathway. IRF-3 phosphorylation is highly induced by wild-type AKT and poorly induced by an AKT mutant, AKT C310A, which is mutated at an inhibitory target site of HQ. We also showed that HQ inhibited IRF-3 phosphorylation by targeting all three AKT isoforms (AKT1, AKT2, and AKT3) in RAW264.7 cells and suppressed IRF-3-mediated luciferase activities induced by AKT in HEK293 cells. Taken together, these results strongly suggest that HQ inhibits the production of a type I IFN, IFN-β, by targeting AKTs in the IRF-3 signaling pathway during macrophage-mediated inflammation.

Beauvericin, a cyclic peptide, inhibits inflammatory responses in macrophages by inhibiting the NF-κB pathway

Beauvericin (BEA), a cyclic hexadepsipeptide produced by the fungus Beauveria bassiana, is known to have anti-cancer, anti-inflammatory, and anti-microbial actions. However, how BEA suppresses macrophage-induced inflammatory responses has not been fully elucidated. In this study, we explored the anti-inflammatory properties of BEA and the underlying molecular mechanisms using lipopolysaccharide (LPS)-treated macrophage-like RAW264.7 cells. Levels of nitric oxide (NO), mRNA levels of transcription factors and the inflammatory genes inducible NO synthase (iNOS) and interleukin (IL)-1, and protein levels of activated intracellular signaling molecules were determined by Griess assay, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), luciferase reporter gene assay, and immunoblotting analysis. BEA dose-dependently blocked the production of NO in LPS-treated RAW264.7 cells without inducing cell cytotoxicity. BEA also prevented LPS-triggered morphological changes. This compound significantly inhibited nuclear translocation of the NF-κB subunits p65 and p50. Luciferase reporter gene assays demonstrated that BEA suppresses MyD88-dependent NF-κB activation. By analyzing upstream signaling events for NF-κB activation and overexpressing Src and Syk, these two enzymes were revealed to be targets of BEA. Together, these results suggest that BEA suppresses NF-κB-dependent inflammatory responses by suppressing both Src and Syk.

JS-III-49, a hydroquinone derivative, exerts anti-inflammatory activity by targeting Akt and p38

Since previous studies have reported that hydroquinone (HQ) exerted immunosuppressive and anti-inflammatory activity, various HQ derivatives have been synthesized and their biological activities investigated. In this study, we explored the anti-inflammatory activity of JS-III-49, a novel HQ derivative, in macrophage-mediated inflammatory responses. JS-III-49 suppressed the production of the inflammatory mediators nitric oxide (NO) and prostaglandin E₂ (PGE₂) and down-regulated the mRNA expression of the inflammatory enzymes cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-1b without cytotoxicity in LPS-stimulated RAW264.7 cells. JS-III-49 inhibited nuclear translocation of the NF-kB transcription factors p65 and p50 by directly targeting Akt, an upstream kinase of the NF-kB pathway, in LPS-stimulated RAW264.7 cells. However, JS-III-49 did not directly inhibit the kinase activities of Src and Syk, which are upstream kinases of Akt, in LPS-stimulated RAW264.7 cells. Moreover, JS-III-49 suppressed the nuclear translocation of c-Fos, one of the components of AP-1, by specifically targeting p38, an upstream mitogen-activated protein kinase (MAPK) in the AP-1 pathway in LPS-stimulated RAW264.7 cells. These results suggest that JS-III-49 plays an anti-inflammatory role in LPS-stimulated macrophages by targeting Akt and p38 in the NF-kB and AP-1 pathways, respectively.

Src/Syk-Targeted Anti-Inflammatory Actions of Triterpenoidal Saponins from Gac (Momordica cochinchinensis) Seeds

Momordica cochinchinensis Spreng (family Cucurbitaceae), also known as gac, or red melon, is an edible Southeast Asian fruit valued for its nutritional and medicinal properties. Specifically, Momordicae Semen, the seeds of the gac fruit, is used in traditional Chinese medicine to treat boils, rheumatic pain, muscle spasm, hemorrhoids, and hemangiomas. In this study, a chemical investigation into a gac seed ethanol (EtOH) extract resulted in the identification of three triterpenoidal saponins (1-3), which were investigated for their anti-inflammatory effects. Among the saponins, momordica saponin I (compound 3) reduced the production of nitric oxide (NO) in LPS-activated RAW264.7 cells without inducing cytotoxicity. The mRNA levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 were decreased by momordica saponin I. Additionally, the translocation of p65 and p50 (subunits of the transcription factor NF-[Formula: see text]B) into the nucleus was remarkably inhibited. Furthermore, the phosphorylation levels of inflammatory signaling proteins (I[Formula: see text]B[Formula: see text], Src, and Syk) known to be upstream regulatory molecules of p65 were decreased under momordica saponin I-treated conditions. The molecular targets of momordica saponin I were confirmed in overexpression experiments and through immunoblot analyses with Src and Syk. This study provides evidence that momordica saponin I could be beneficial in treating inflammatory diseases, and should be considered a bioactive immunomodulatory agent with anti-inflammatory properties.

Hydroquinone-induced FOXP3-ADAM17-Lyn-Akt-p21 signaling axis promotes malignant progression of human leukemia U937 cells

Hydroquinone (1,4-benzenediol; HQ), a major marrow metabolite of the leukemogen benzene, has been proven to evoke benzene-related hematological disorders and myelotoxicity in vitro and in vivo. The goal of the present study was to explore the role of FOXP3 in HQ-induced malignant progression of U937 human leukemia cells. U937 cells were treated with 5 μM HQ for 24 h, and the cells were re-suspended in serum-containing medium without HQ for 2 days. The same procedure was repeated three times, and the resulting U937/HQ cells were maintained in cultured medium containing 5 μM HQ. Proliferation and colony formation of U937/HQ cells were notably higher than those of U937 cells. Ten-eleven translocation methylcytosine dioxygenase-mediated demethylation of the Treg-specific demethylated region in FOXP3 gene resulted in higher FOXP3 expression in U937/HQ cells than in U937 cells. FOXP3-induced miR-183 expression reduced β-TrCP mRNA stability and suppressed β-TrCP-mediated Sp1 degradation, leading to up-regulation of Sp1 expression in U937/HQ cells. Sp1 up-regulation further increased ADAM17 and Lyn expression, and ADAM17 up-regulation stimulated Lyn activation in U937/HQ cells. Moreover, U937/HQ cells showed higher Lyn-mediated Akt activation and cytoplasmic p21 expression than U937 cells did. Abolishment of Akt activation decreased cytoplasmic p21 expression in U937/HQ cells. Suppression of FOXP3, ADAM17, and Lyn expression, as well as Akt inactivation, repressed proliferation and clonogenicity of U937/HQ cells. Together with the finding that cytoplasmic p21 shows anti-apoptotic and oncogenic activities in cancer cells, the present data suggest a role of FOXP3/ADAM17/Lyn/Akt/p21 signaling axis in HQ-induced hematological disorders.

Neuroprotection and reduced gliosis by pre- and post-treatments of hydroquinone in a gerbil model of transient cerebral ischemia

Hydroquinone (HQ), a major metabolite of benzene, exists in many plant-derived food and products. Although many studies have addressed biological properties of HQ including the regulation of immune responses and antioxidant activity, neuroprotective effects of HQ following ischemic insults have not yet been considered. Therefore, in this study, we examined neuroprotective effects of HQ against ischemic damage in the gerbil hippocampal cornu ammonis 1 (CA1) region following 5 min of transient cerebral ischemia. We found that pre- and post-treatments with 50 and 100 mg/kg of HQ protected CA1 pyramidal neurons from ischemic insult. Especially, pre- and post-treatments with 100 mg/kg of HQ showed strong neuroprotective effects against ischemic damage. In addition, pre- and post-treatments with 100 mg/kg of HQ significantly attenuated activations of astrocytes and microglia in the ischemic CA1 region compared to the vehicle-treated-ischemia-operated group. Briefly, these results show that pre- and post-treatments with HQ can protect neurons from transient cerebral ischemia and strongly attenuate ischemia-induced glial activation in the hippocampal CA1 region, and indicate that HQ can be used for both prevention and therapy of ischemic injury.

Src/Syk/IRAK1-targeted anti-inflammatory action of Torreya nucifera butanol fraction in lipopolysaccharide-activated RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Seed of Torreya nucifera (L.) Siebold & Zucc is used to treat several diseases in Asia. Reports document that T. nucifera has anti-cancer, anti-inflammatory, anti-oxidative activities. In spite of numerous findings on its pharmacological effects, the understanding of the molecular inhibitory mechanisms of the plant remains to be studied. Therefore, we aimed to explore in vitro anti-inflammatory mechanisms of ethyl acetate fraction (Tn-EE-BF) prepared from the seed of T. nucifera in LPS-stimulated macrophage inflammatory responses.

MATERIALS AND METHODS

For this purpose, we measured nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated macrophages. Additionally, using RT-PCR, luciferase reporter gene assay, immunoblotting analysis, and kinase assay, the levels of inflammatory genes, transcription factors, and inflammatory signal-regulatory proteins were investigated. Finally, the constituent of Tn-EE-BF was identified using HPLC.

RESULTS

Tn-EE-BF inhibits NO and PGE2 production and also blocks mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in a dose dependent manner. Tn-EE-BF reduces nuclear levels of the transcriptional factors NF-κB (p65) and AP-1 (c-Jun and FRA-1). Surprisingly, we found that Tn-EE-BF inhibits phosphorylation levels of Src and Syk in the NF-κB pathway, as well as, IRAK1 at the protein level, part of the AP-1 pathway. By kinase assay, we confirmed that Src, Syk, and IRAK1 are suppressed directly. HPLC analysis indicates that arctigenin, amentoflavone, and quercetin may be active components with anti-inflammatory activities.

CONCLUSION

Tn-EE-BF exhibits anti-inflammatory activities by direct inhibition of Src/Syk/NF-κB and IRAK1/AP-1.

Glycosylation enables aesculin to activate Nrf2

Since aesculin, 6,7-dihydroxycoumarin-6-O-β-glucopyranoside, suppresses inflammation, we asked whether its anti-inflammatory activity is associated with the activation of nuclear factor-E2-related factor 2 (Nrf2), a key anti-inflammatory factor. Our results, however, show that aesculin marginally activated Nrf2. Since glycosylation can enhance the function of a compound, we then asked whether adding a glucose makes aesculin activate Nrf2. Our results show that the glycosylated aesculin, 3-O-β-d-glycosyl aesculin, robustly activated Nrf2, inducing the expression of Nrf2-dependent genes, such as heme oxygenase-1, glutamate-cysteine ligase catalytic subunit, and NAD(P)H quinone oxidoreductase 1 in macrophages. Mechanistically, 3-O-β-d-glycosyl aesculin suppressed ubiquitination of Nrf2, retarding degradation of Nrf2. Unlike aesculin, 3-O-β-d-glycosyl aesculin significantly suppressed neutrophilic lung inflammation, a hallmark of acute lung injury (ALI), in mice, which was not recapitulated in Nrf2 knockout mice, suggesting that the anti-inflammatory function of the compound largely acts through Nrf2. In a mouse model of sepsis, a major cause of ALI, 3-O-β-d-glycosyl aesculin significantly enhanced the survival of mice, compared with aesculin. Together, these results show that glycosylation could confer the ability to activate Nrf2 on aesculin, enhancing the anti-inflammatory function of aesculin. These results suggest that glycosylation can be a way to improve or alter the function of aesculin.

Therapeutic effect of ent-kaur-16-en-19-oic acid on neutrophilic lung inflammation and sepsis is mediated by Nrf2

Kaurenoic acid (ent-kaur-16-en-19-oic acid: KA) is a key constituent found in the roots of Aralia continentalis Kitagawa (Araliaceae), a remedy to treat patients with inflammatory diseases in traditional Asian medicine. Since KA activates Nrf2, a key anti-inflammatory factor, at the cellular level, we explored a possible therapeutic usage of KA against neutrophilic inflammatory lung disease such as acute lung injury (ALI). Intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) to C57BL/6 mice induced lung inflammation as in ALI. 2 h after i.p. LPS, intratracheal (i.t.) delivery of KA (0.3, 3, or 30 μg/kg body weight) improved lung structure and significantly suppressed neutrophil infiltrations to mouse lungs, with concomitant reduction of myeloperoxidase activity and of the expression of pro-inflammatory cytokine genes. While activating Nrf2 and expressing Nrf2-dependent genes in mouse lungs, KA did not significantly suppress neutrophil lung inflammation in Nrf2 KO mice. In a mouse model of sepsis, a major cause of ALI, single i.t. KA (3 μg/kg) 2 h after the onset of sepsis significantly decreased the mortality of mice. Together, these results suggest that KA has a therapeutic potential against inflammatory lung disease, the effect of which is associated with Nrf2 activation.

Anticancer effect of joboksansam, Korean wild ginseng germinated from bird feces

BACKGROUND

Joboksansam, Korean bird wild ginseng, is an artificially cultivated wild ginseng germinated from bird feces. Although numerous pharmacologic activities of wild ginsengs have been reported, the beneficial effect of joboksansam in cancer has not been elucidated. In this study, we investigated the in vivo and in vitro anticancer activities of joboksansam powder.

METHODS

To evaluate the in vivo anticancer activity of joboksansam, we established a xenograft mouse model bearing RMA cell-derived cancer. Direct cytotoxicity induced by joboksansam powder was also investigated in vitro using (3-4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide (MTT) assay. The inhibitory activity of this powder on the activation of cell survival signaling involving Akt and Src was examined with immunoblot analysis.

RESULTS

Joboksansam powder displayed strong inhibitory activity against the increased tumor size, increased weight of total body and cancer tissues, and mortality of tumor-bearing mice. Joboksansam powder also suppressed the activation of survival regulatory enzymes Akt and Src, as assessed by phosphorylation levels in the immunoblot analysis of tumor tissues. Interestingly, the viability of RMA cells in vitro was directly decreased by joboksansam treatment.

CONCLUSION

Overall, our results strongly suggest that joboksansam powder has the potential to protect against cancer generation by direct cytotoxic effects on cancer cells resulting from suppression of cell survival signaling.

In vitro antioxidative and anti-inflammatory effects of the compound K-rich fraction BIOGF1K, prepared from Panax ginseng

Background

BIOGF1K, a compound K-rich fraction prepared from the root of Panax ginseng, is widely used for cosmetic purposes in Korea. We investigated the functional mechanisms of the anti-inflammatory and antioxidative activities of BIOGF1K by discovering target enzymes through various molecular studies.

Methods

We explored the inhibitory mechanisms of BIOGF1K using lipopolysaccharide-mediated inflammatory responses, reporter gene assays involving overexpression of toll-like receptor adaptor molecules, and immunoblotting analysis. We used the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to measure the antioxidative activity. We cotransfected adaptor molecules, including the myeloid differentiation primary response gene 88 (MyD88) and Toll/interleukin-receptor domain containing adaptor molecule-inducing interferon-β (TRIF), to measure the activation of nuclear factor (NF)-κB and interferon regulatory factor 3 (IRF3).

Results

BIOGF1K suppressed lipopolysaccharide-triggered NO release in macrophages as well as DPPH-induced electron-donating activity. It also blocked lipopolysaccharide-induced mRNA levels of interferon-β and inducible nitric oxide synthase. Moreover, BIOGF1K diminished the translocation and activation of IRF3 and NF-κB (p50 and p65). This extract inhibited the upregulation of NF-κB-linked luciferase activity provoked by phorbal-12-myristate-13 acetate as well as MyD88, TRIF, and inhibitor of κB (IκBα) kinase (IKKβ), and IRF3-mediated luciferase activity induced by TRIF and TANK-binding kinase 1 (TBK1). Finally, BIOGF1K downregulated the NF-κB pathway by blocking IKKβ and the IRF3 pathway by inhibiting TBK1, according to reporter gene assays, immunoblotting analysis, and an AKT/IKKβ/TBK1 overexpression strategy.

Conclusion

Overall, our data suggest that the suppression of IKKβ and TBK1, which mediate transcriptional regulation of NF-κB and IRF3, respectively, may contribute to the broad-spectrum inhibitory activity of BIOGF1K.

Tetrachlorobenzoquinone exhibits neurotoxicity by inducing inflammatory responses through ROS-mediated IKK/IκB/NF-κB signaling

Tetrachlorobenzoquinone (TCBQ) is a joint metabolite of persistent organic pollutants (POPs), hexachlorobenzene (HCB) and pentachlorophenol (PCP). Previous studies have been reported that TCBQ contributes to acute hepatic damage due to its pro-oxidative nature. In the current study, TCBQ showed the highest capacity on the cytotoxicity, ROS formation and inflammatory cytokines release among four compounds, i.e., HCB, PCP, tetrachlorohydroquinone (TCHQ, reduced form of TCBQ) and TCBQ, in PC 12 cells. Further mechanistic study illustrated TCBQ activates nuclear factor-kappa B (NF-κB) signaling. The activation of NF-κB was identified by measuring the protein expressions of inhibitor of nuclear factor kappa-B kinase (IKK) α/β, p-IKKα/β, an inhibitor of NF-κB (IκB) α, p-IκBα, NF-κB (p65) and p-p65. The translocation of NF-κB was assessed by Western blotting of p65 in nuclear/cytosolic fractions, electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. In addition, TCBQ significantly induced protein and mRNA expressions of inflammatory cytokines and mediators, such as interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and the production of nitric oxide (NO) and prostaglandin E2 (PGE2). Pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor inhibited these effects efficiently, further suggested TCBQ-induced inflammatory responses involve NF-κB signaling. Moreover, antioxidants, i.e., N-acetyl-l-cysteine (NAC), Vitamin E and curcumin, ameliorated TCBQ-induced ROS generation as well as the activation of NF-κB, which implied that ROS serve as the upstream molecule of NF-κB signaling. In summary, TCBQ exhibits a neurotoxic effect by inducing oxidative stress-mediated inflammatory responses via the activation of IKK/IκB/NF-κB pathway in PC12 cells.

4-Isopropyl-2,6-bis(1-phenylethyl)aniline 1, an Analogue of KTH-13 Isolated from Cordyceps bassiana, Inhibits the NF-κB-Mediated Inflammatory Response

The Cordyceps species has been a good source of compounds with anticancer and anti-inflammatory activities. Recently, we reported a novel compound (4-isopropyl-2,6-bis(1-phenylethyl)phenol, KTH-13) with anticancer activity isolated from Cordyceps bassiana and created several derivatives to increase its pharmacological activity. In this study, we tested one of the KTH-013 derivatives, 4-isopropyl-2,6-bis(1-phenylethyl)aniline 1 (KTH-13-AD1), with regard to anti-inflammatory activity under macrophage-mediated inflammatory conditions. KTH-13-AD1 clearly suppressed the production of nitric oxide (NO) and reactive oxygen species (ROS) in lipopolysaccharide (LPS) and sodium nitroprusside- (SNP-) treated macrophage-like cells (RAW264.7 cells). Similarly, this compound also reduced mRNA expression of inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α), as analyzed by RT-PCR and real-time PCR. Interestingly, KTH-13-AD1 strongly diminished NF-κB-mediated luciferase activities and nuclear translocation of NF-κB family proteins. In accordance, KTH-13-AD1 suppressed the upstream signaling pathway of NF-κB activation, including IκBα, IKKα/β, AKT, p85/PI3K, and Src in a time- and dose-dependent manner. The autophosphorylation of Src and NF-κB observed during the overexpression of Src was also suppressed by KTH-13-AD1. These results strongly suggest that KTH-13-AD1 has strong anti-inflammatory features mediated by suppression of the Src/NF-κB regulatory loop.

A direct protein kinase B-targeted anti-inflammatory activity of cordycepin from artificially cultured fruit body of Cordyceps militaris

Background:

Cordyceps militaris is one of well-known medicinal mushrooms with anti-inflammatory, anti-cancer, anti-diabetic, and anti-obesity activities.

Objective:

The objective of the following study is to isolate chemical components from the ethanol extract (Cm-EE) from Cordyceps militaris and to evaluate their anti-inflammatory activities.

Materials and Methods:

Column chromatographic separation was performed and anti-inflammatory roles of these compounds were also examined by using NO production and protein kinase B (AKT) activity assays.

Results:

From Cm-EE, 13 constituents, including trehalose (1), cordycepin (2), 6-hydroxyethyladenosine (3), nicotinic amide (4), butyric acid (5), β-dimorphecolic acid (6), α-dimorphecolic acid (7), palmitic acid (8), linoleic acid (9), cordycepeptide A (10), 4-(2-hydroxy-3-((9E,12E)-octadeca-9,12-dienoyloxy)propoxy)-2-(trimethylammonio)butanoate (11), 4-(2-hydroxy-3-(palmitoyloxy)propoxy)-2-(trimethylammonio)butanoate (12), and linoleic acid methyl ester (13) were isolated. Of these components, compound 2 displayed a significant inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. Furthermore, this compound strongly and directly suppressed the kinase activity of AKT, an essential signalling enzyme in LPS-induced NO production, by interacting with its ATP binding site.

Conclusion:

C. militaris could have anti-inflammatory activity mediated by cordycepin-induced suppression of AKT.

ATP-Binding Pocket-Targeted Suppression of Src and Syk by Luteolin Contributes to Its Anti-Inflammatory Action

Luteolin is a flavonoid identified as a major anti-inflammatory component of Artemisia asiatica. Numerous reports have demonstrated the ability of luteolin to suppress inflammation in a variety of inflammatory conditions. However, its exact anti-inflammatory mechanism has not been fully elucidated. In the present study, the anti-inflammatory mode of action in activated macrophages of luteolin from Artemisia asiatica was examined by employing immunoblotting analysis, a luciferase reporter gene assay, enzyme assays, and an overexpression strategy. Luteolin dose-dependently inhibited the secretion of nitric oxide (NO) and prostaglandin E₂ (PGE₂) and diminished the levels of mRNA transcripts of inducible NO synthase (iNOS), tumor necrosis factor- (TNF-) α, and cyclooxygenase-2 (COX-2) in lipopolysaccharide- (LPS-) and pam3CSK-treated macrophage-like RAW264.7 cells without displaying cytotoxicity. Luteolin displayed potent NO-inhibitory activity and also suppressed the nuclear translocation of NF-κB (p65 and p50) via blockade of Src and Syk, but not other mitogen-activated kinases. Overexpression of wild type Src and point mutants thereof, and molecular modelling studies, suggest that the ATP-binding pocket may be the luteolin-binding site in Src. These results strongly suggest that luteolin may exert its anti-inflammatory action by suppressing the NF-κB signaling cascade via blockade of ATP binding in Src and Syk.

The dietary flavonoid Kaempferol mediates anti-inflammatory responses via the Src, Syk, IRAK1, and IRAK4 molecular targets

Even though a lot of reports have suggested the anti-inflammatory activity of kaempferol (KF) in macrophages, little is known about its exact anti-inflammatory mode of action and its immunopharmacological target molecules. In this study, we explored anti-inflammatory activity of KF in LPS-treated macrophages. In particular, molecular targets for KF action were identified by using biochemical and molecular biological analyses. KF suppressed the release of nitric oxide (NO) and prostaglandin E2 (PGE2), downregulated the cellular adhesion of U937 cells to fibronectin (FN), neutralized the generation of radicals, and diminished mRNA expression levels of inflammatory genes encoding inducible NO synthase (iNOS), TNF-α, and cyclooxygenase- (COX-) 2 in lipopolysaccharide- (LPS-) and sodium nitroprusside- (SNP-) treated RAW264.7 cells and peritoneal macrophages. KF reduced NF-κB (p65 and p50) and AP-1 (c-Jun and c-Fos) levels in the nucleus and their transcriptional activity. Interestingly, it was found that Src, Syk, IRAK1, and IRAK4 responsible for NF-κB and AP-1 activation were identified as the direct molecular targets of KF by kinase enzyme assays and by measuring their phosphorylation patterns. KF was revealed to have in vitro and in vivo anti-inflammatory activity by the direct suppression of Src, Syk, IRAK1, and IRAK4, involved in the activation of NF-κB and AP-1.

Cathelicidin-BF, a Novel Antimicrobial Peptide from Bungarus fasciatus, Attenuates Disease in a Dextran Sulfate Sodium Model of Colitis

Antimicrobial peptides are molecules of innate immunity. Cathelicidin-BF is the first cathelicidin peptide found in reptiles. However, the immunoregulatory and epithelial barrier protective properties of C-BF have not been reported. Inflammatory bowel diseases, including ulcerative colitis and Crohn's disease, can lead to colon cancer, the third most common malignant tumor. The objective is to develop the new found cathelicidin-BF as a therapeutic to patients of ulcerative colitis. The morphology of the colon epithelium was observed by H&E staining; apoptosis index and infiltration of inflammatory cells in colonic epithelium were measured by TUNEL and immunohistochemistry; the expression level of endogenous mCRAMP was analyzed by immunofluorescence; and phosphorylation of the transcription factors c-jun and NF-κB in colon were analyzed by Western blot. Our results showed that the morphology of the colon epithelium in the C-BF+DSS group was improved compared with the DSS group. Apoptosis and infiltration of inflammatory cells in colonic epithelium were also significantly attenuated in the C-BF+DSS group compared with the DSS group, and the expression level of endogenous mCRAMP in the DSS group was significantly higher than other groups. DSS-induced phosphorylation level of c-jun and NF-κB while C-BF effectively inhibited phosphorylation of NF-κB (p65). The barrier protective effect of C-BF was still excellent. In conclusion, C-BF effectively attenuated inflammation and improved disrupted barrier function. Notably, this is the first report to demonstrate that C-BF attenuates DSS-induced UC both through the regulation of intestinal immune and retention of barrier function, and the exact pathway was through NF-κB.

21-O-angeloyltheasapogenol E3, a novel triterpenoid saponin from the seeds of tea plants, inhibits macrophage-mediated inflammatory responses in a NF-κB-dependent manner

21-O-Angeloyltheasapogenol E3 (ATS-E3) is a triterpenoid saponin recently isolated from the seeds of the tea tree Camellia sinensis (L.) O. Kuntze. ATS-E3 has several beneficial properties including anti-inflammatory, antidiabetic, antiatherosclerotic, and anticancer effects. Unlike other phenolic compounds isolated from tea plants, there are no studies reporting the pharmacological action of ATS-E3. In this study, we therefore aimed to explore the cellular and molecular inhibitory activities of ATS-E3 in macrophage-mediated inflammatory responses. ATS-E3 remarkably diminished cellular responses of macrophages such as FITC-dextran-induced phagocytic uptake, sodium nitroprusside- (SNP-) induced radical generation, and LPS-induced nitric oxide (NO) production. Analysis of its molecular activity showed that this compound significantly suppressed the expression of inducible NO synthase (iNOS), nuclear translocation of nuclear factor- (NF-) κB subunits (p50 and p65), phosphorylation of inhibitor of κB kinase (IKK), and the enzyme activity of AKT1. Taken together, the novel triterpenoid saponin compound ATS-E3 contributes to the beneficial effects of tea plants by exerting anti-inflammatory and antioxidative activities in an AKT/IKK/NF-κB-dependent manner.

Anti-inflammatory activity of AP-SF, a ginsenoside-enriched fraction, from Korean ginseng

BACKGROUND

Korean ginseng is an ethnopharmacologically valuable herbal plant with various biological properties including anticancer, antiatherosclerosis, antidiabetic, and anti-inflammatory activities. Since there is currently no drug or therapeutic remedy derived from Korean ginseng, we developed a ginsenoside-enriched fraction (AP-SF) for prevention of various inflammatory symptoms.

METHODS

The anti-inflammatory efficacy of AP-SF was tested under in vitro inflammatory conditions including nitric oxide (NO) production and inflammatory gene expression. The molecular events of inflammatory responses were explored by immunoblot analysis.

RESULTS

AP-SF led to a significant suppression of NO production compared with a conventional Korean ginseng saponin fraction, induced by both lipopolysaccharide and zymosan A. Interestingly, AP-SF strongly downregulated the mRNA levels of genes for inducible NO synthase, tumor necrosis factor-α, and cyclooxygenase) without affecting cell viability. In agreement with these observations, AP-SF blocked the nuclear translocation of c-Jun at 2 h and also reduced phosphorylation of p38, c-Jun N-terminal kinase, and TAK-1, all of which are important for c-Jun translocation.

CONCLUSION

Our results suggest that AP-SF inhibits activation of c-Jun-dependent inflammatory events. Thus, AP-SF may be useful as a novel anti-inflammatory remedy.

p47phox and reactive oxygen species production modulate expression of microRNA-451 in macrophages

The production of microRNAs (miRNA) is influenced by various stimuli, including environmental stresses. We hypothesized that reactive oxygen species (ROS)-associated stress could regulate macrophage miRNA synthesis. miRNAs undergo unique steps of maturation processing through either one of two pathways of cytoplasmic processing. Unlike the canonical pathway, the regulation of alternative cytoplasmic processing of miRNA has not been fully elucidated yet. We cultured bone marrow derived macrophages (BMDM) from wild type (WT) and p47(phox-/-) mice and profiled miRNA expression using microarrays. We analyzed 375 miRNAs including four endogenous controls to normalize the data. At resting state, p47(phox-/-) BMDM has the markedly reduced expression of miR-451 compared to WT BMDM, without other significant differences. Unlike majority of miRNAs, miR-451 goes through the unique alternative processing pathway, in which Ago2 plays a key role. In spite of significant reduction of mature miR-451, however, its precursor form, pre-mir-451, was similar in both BMDMs, suggesting that the processing of pre-mir-451 is impaired in p47(phox-/-) BMDM. Moreover, p47(phox-/-) BMDM expressed significantly reduced level of Ago2. In contrast, Ago2 mRNA levels were similar in WT and p47(phox-/-) BMDM, suggesting a post-transcriptional defect of Ago2 production in p47(phox-/-) macrophages, which resulted in impaired processing of pre-miR-451. In order to examine the functional significance of miR-451 in macrophages, we cultured BMDMs from miR-451 knock-out mice. Of interest, miR-451-deficient BMDM exhibited reduced ROS generation upon zymosan stimulation, compared to WT BMDM. Our studies suggest functional crosstalk between ROS and miR-451 in the regulation of macrophage oxidant stress.

NF-κB/AP-1-targeted inhibition of macrophage-mediated inflammatory responses by depigmenting compound AP736 derived from natural 1,3-diphenylpropane skeleton

AP736 was identified as an antimelanogenic drug that can be used for the prevention of melasma, freckles, and dark spots in skin by acting as a suppressor of melanin synthesis and tyrosinase expression. Since macrophage-mediated inflammatory responses are critical for skin health, here we investigated the potential anti-inflammatory activity of AP736. The effects of AP736 on various inflammatory events such as nitric oxide (NO)/prostaglandin (PG) E₂ production, inflammatory gene expression, phagocytic uptake, and morphological changes were examined in RAW264.7 cells. AP736 was found to strongly inhibit the production of both NO and PGE₂ in lipopolysaccharide- (LPS-) treated RAW264.7 cells. In addition, AP736 strongly inhibited both LPS-induced morphological changes and FITC-dextran-induced phagocytic uptake. Furthermore, AP736 also downregulated the expression of multiple inflammatory genes, such as inducible NO synthase (iNOS), cyclooxygenase- (COX-) 2, and interleukin- (IL-) 1β in LPS-treated RAW264.7 cells. Transcription factor analysis, including upstream signalling events, revealed that both NF-κB and AP-1 were targeted by AP736 via inhibition of the IKK/IκBα and IRAK1/TAK1 pathways. Therefore, our results strongly suggest that AP736 is a potential anti-inflammatory drug due to its suppression of NF-κB-IKK/IκBα and AP-1-IRAK1/TAK1 signalling, which may make AP736 useful for the treatment of macrophage-mediated skin inflammation.

Molecular mechanism of protopanaxadiol saponin fraction-mediated anti-inflammatory actions

Background

Korean Red Ginseng (KRG) is a representative traditional herbal medicine with many different pharmacological properties including anticancer, anti-atherosclerosis, anti-diabetes, and anti-inflammatory activities. Only a few studies have explored the molecular mechanism of KRG-mediated anti-inflammatory activity.

Methods

We investigated the anti-inflammatory mechanisms of the protopanaxadiol saponin fraction (PPD-SF) of KRG using in vitro and in vivo inflammatory models.

Results

PPD-SF dose-dependently diminished the release of inflammatory mediators [nitric oxide (NO), tumor necrosis factor-α, and prostaglandin E₂], and downregulated the mRNA expression of their corresponding genes (inducible NO synthase, tumor necrosis factor-α, and cyclooxygenase-2), without altering cell viability. The PPD-SF-mediated suppression of these events appeared to be regulated by a blockade of p38, c-Jun N-terminal kinase (JNK), and TANK (TRAF family member-associated NF-kappa-B activator)-binding kinase 1 (TBK1), which are linked to the activation of activating transcription factor 2 (ATF2) and interferon regulatory transcription factor 3 (IRF3). Moreover, this fraction also ameliorated HCl/ethanol/-induced gastritis via suppression of phospho-JNK2 levels.

Conclusion

These results strongly suggest that the anti-inflammatory action of PPD-SF could be mediated by a reduction in the activation of p38-, JNK2-, and TANK-binding-kinase-1-linked pathways and their corresponding transcription factors (ATF2 and IRF3).

ATF-2/CREB/IRF-3-targeted anti-inflammatory activity of Korean red ginseng water extract

ETHNOPHARMACOLOGICAL RELEVANCE

Korean Red Ginseng (KRG) is one of the representative traditional herbal medicines prepared from Panax ginseng Meyer (Araliaceae) in Korea. It has been reported that KRG exhibits a lot of different biological actions such as anti-aging, anti-fatigue, anti-stress, anti-atherosclerosis, anti-diabetic, anti-cancer, and anti-inflammatory activities. Although systematic studies have investigated how KRG is able to ameliorate various inflammatory diseases, its molecular inhibitory mechanisms had not been carried out prior to this study.

MATERIALS AND METHODS

In order to investigate these mechanisms, we evaluated the effects of a water extract of Korean Red Ginseng (KRG-WE) on the in vitro inflammatory responses of activated RAW264.7 cells, and on in vivo gastritis and peritonitis models by analyzing the activation events of inflammation-inducing transcription factors and their upstream kinases.

RESULTS

KRG-WE reduced the production of nitric oxide (NO), protected cells against NO-induced apoptosis, suppressed mRNA levels of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and interferon (IFN)-β, ameliorated EtOH/HCl-induced gastritis, and downregulated peritoneal exudate-derived NO production from lipopolysaccharide (LPS)-injected mice. The inhibition of these inflammatory responses by KRG-WE was regulated through the suppression of p38, c-Jun N-terminal kinase (JNK), and TANK-binding kinase 1 (TBK1) and by subsequent inhibition of activating transcription factor (ATF)-2, cAMP response element-binding protein (CREB), and IRF-3 activation. Of ginsensides included in this extract, interestingly, G-Rc showed the highest inhibitory potency on IRF-3-mediated luciferase activity.

CONCLUSION

These results strongly suggest that the anti-inflammatory activities of KRG-WE could be due to its inhibition of the p38/JNK/TBK1 activation pathway.

Lancemaside A from Codonopsis lanceolata modulates the inflammatory responses mediated by monocytes and macrophages

In this study, we aimed to examine the cellular and molecular mechanisms of lancemaside A from Codonopsis lanceolata (Campanulaceae) in the inflammatory responses of monocytes (U937 cells) and macrophages (RAW264.7 cells). Lancemaside A significantly suppressed the inflammatory functions of lipopolysaccharide- (LPS-) treated RAW264.7 cells by suppressing the production of nitric oxide (NO), the expression of the NO-producing enzyme inducible NO synthase (iNOS), the upregulation of the costimulatory molecule CD80, and the morphological changes induced by LPS exposure. In addition, lancemaside A diminished the phagocytic activity of RAW264.7 cells and boosted the neutralizing capacity of these cells when treated with the radical generator sodium nitroprusside (SNP). Interestingly, lancemaside A strongly blocked the adhesion activity of RAW264.7 cells to plastic culture plates, inhibited the cell-cell and cell-fibronectin (FN) adhesion of U937 cells that was triggered by treatment with an anti-β1-integrin (CD29) antibody and immobilized FN, respectively. By evaluating the activation of various intracellular signaling pathways and the levels of related nuclear transcription factors, lancemaside A was found to block the activation of inhibitor of κB kinase (IKK) and p65/nuclear factor- (NF-) κB. Taken together, our findings strongly suggest that the anti-inflammatory function of lancemaside A is the result of its strong antioxidative and IKK/NF-κB inhibitory activities.

Novel anti-inflammatory function of NSC95397 by the suppression of multiple kinases

NSC95397 (2,3-bis-[(2-hydroxyethyl)thio]-1,4-naphthoquinone) is a CDC25 inhibitor with anti-cancer properties. Since the anti-inflammatory activity of this compound has not yet been explored, the aim of this study was to examine whether this compound is able to modulate the inflammatory process. Toll like receptor (TLR)-mediated inflammatory responses were induced by lipopolysaccharide (LPS), a TLR4 ligand, and pam3CSK, a TLR2 ligand, in peritoneal macrophages and RAW264.7. The molecular mechanism of NSC95397's anti-inflammatory activity was studied using immunoblotting analysis, nuclear fractionation, immunoprecipitation, overexpression strategies, luciferase reporter gene assays, and kinase assays. NSC95397 dose-dependently suppressed the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin (PG)E2, and diminished the mRNA expression of inflammatory genes such as inducible NO synthase (iNOS), cyclooxygenase (COX)-2, interferon (IFN)-β, and TNF-α in peritoneal macrophages and RAW264.7 cells that were stimulated by LPS and pam3CSK. This compound also clearly blocked the activation of NF-κB (p65), AP-1 (c-Fos/c-Jun), and IRF-3 in LPS-treated RAW264.7 cells and TRIF- and MyD88-overexpressing HEK293 cells. In addition, biochemical and molecular approaches revealed that this compound targeted AKT, IKKα/β, MKK7, and TBK1. Therefore, these results suggest that the anti-inflammatory function of NSC95397 can be attributed to its inhibition of multiple targets such as AKT, IKKα/β, MKK7, and TBK1.

Cysteine-reactive chemical probes based on a modular 4-aminopiperidine scaffold

Tri-substituted 4-aminopiperidine provides a modular and versatile scaffold for the generation of cysteine-reactive probes for diverse proteins.

Influence of acetylsalicylic acid on hematotoxicity of benzene

OBJECTIVES

The aim of the study was to evaluate the influence of acetylsalicylic acid (ASA) on benzene hematotoxicity in rats.

MATERIALS AND METHODS

The study was carried out on rats exposed for 2, 4 and 8 weeks to benzene vapour at a concentration of 1.5 or 4.5 mmol/m(3) of air (5 days per week, 6 hours per day) alone or together with ASA at the doses of 5, 150 or 300 mg/kg body weight (per os).

RESULTS

Benzene at a concentration of 4.5 mmol/m(3) caused a slight lymphopenia, granulocytosis and reticulocytosis in blood. In bone marrow traits of megaloblastic renewal, presence of undifferentiated cells and giant forms of granulocytes as well as an increase in myeloperoxidase and decrease in chloroacetate esterase activity and lipids content were noted. ASA (150 and 300 mg/kg b.w.) influenced some of hematological parameters, altered by benzene intoxication. ASA limited the solvent-induced alteration in blood reticulocyte count and in the case of bone marrow in the erythroblasts count. Traits of megaloblastic renewal in bone marrow were less pronounced. Besides, higher activity of myeloperoxidase and the decrease in the level of lipids in granulocytes were noted.

CONCLUSION

Our results suggest that ASA limited the benzene-induced hematotoxicity.

Methanol extract of Evodia lepta displays Syk/Src-targeted anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Evodia lepta (Spreng.) Merr., in the Rutaceae family, is a medicinal plant traditionally used to treat inflammatory symptoms such as in meningitis and hepatitis. However, no study has systematically investigated its anti-inflammatory activities including its molecular mechanism.

MATERIALS AND METHODS

The effects of a methanol extract from the roots Evodia lepta (El-ME) were evaluated using lipopolysaccharide (LPS)-treated RAW264.7 cells producing nitric oxide (NO) and prostaglandin E2 (PGE2), and an HCl/ethanol-induced mouse gastritis model. Target molecules were identified by analyzing the activation of transcription factors and their upstream kinases.

RESULTS

El-ME reduced the production of NO and PGE2 from LPS-activated RAW264.7 cells in a dose-dependent manner. El-ME also ameliorated the gastritis symptoms of EtOH/HCl-treated mice. The extract suppressed production of mRNA for the inducible NO synthase (iNOS) and cyclooxygenase (COX)-2; the nuclear translocation of nuclear factor (NF)-κB; the phosphorylation of upstream kinases that activate NF-κB; and the kinase activities of Syk and Src.

CONCLUSION

The anti-inflammatory effects of El-ME might be due to its suppression of Syk/Src and NF-κB. Considering the in vitro and in vivo efficacy of El-ME, Evodia lepta could be developed into an anti-inflammatory herbal remedy.

Therapeutic Effect of the Tuber of Alisma orientale on Lipopolysaccharide-Induced Acute Lung Injury

Although Alisma orientale, an ethnic herb, has been prescribed for treating various diseases in Asian traditional medicine, experimental evidence to support its therapeutic effects is lacking. Here, we sought to determine whether A. orientale has a therapeutic effect on acute lung injury (ALI). Ethanol extract of the tuber of A. orientale (EEAO) was prepared and fingerprinted by HPLC for its constituents. Mice received an intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) for the induction of ALI. At 2 h after LPS treatment, mice received an intratracheal (i.t.) spraying of various amounts of EEAO to the lung. Bioluminescence imaging of transgenic NF- κ B/luciferase reporter mice shows that i.t. EEAO posttreatment suppressed lung inflammation. In similar experiments with C57BL/6 mice, EEAO posttreatment significantly improved lung inflammation, as assessed by H&E staining of lung sections, counting of neutrophils in bronchoalveolar lavage fluid, and semiquantitative RT-PCR analyses of proinflammatory cytokines and Nrf2-dependent genes in the inflamed lungs. Furthermore, EEAO posttreatment enhanced the survival of mice that received a lethal dose of LPS. Together, our results provide evidence that A. orientale has a therapeutic effect on ALI induced by sepsis.

Extracellular signal-regulated kinase is a direct target of the anti-inflammatory compound amentoflavone derived from Torreya nucifera

Amentoflavone is a biflavonoid compound with antioxidant, anticancer, antibacterial, antiviral, anti-inflammatory, and UV-blocking activities that can be isolated from Torreya nucifera, Biophytum sensitivum, and Selaginella tamariscina. In this study, the molecular mechanism underlying amentoflavone's anti-inflammatory activity was investigated. Amentoflavone dose dependently suppressed the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in RAW264.7 cells stimulated with the TLR4 ligand lipopolysaccharide (LPS; derived from Gram-negative bacteria). Amentoflavone suppressed the nuclear translocation of c-Fos, a subunit of activator protein (AP)-1, at 60 min after LPS stimulation and inhibited the activity of purified and immunoprecipitated extracellular signal-regulated kinase (ERK), which mediates c-Fos translocation. In agreement with these results, amentoflavone also suppressed the formation of a molecular complex including ERK and c-Fos. Therefore, our data strongly suggest that amentoflavone's immunopharmacological activities are due to its direct effect on ERK.

Ginsenoside Rp1, a Ginsenoside Derivative, Blocks Promoter Activation of iNOS and COX-2 Genes by Suppression of an IKKβ-mediated NF-кB Pathway in HEK293 Cells

Ginsenoside (G) Rp₁ is a ginseng saponin derivative with anti-cancer and anti-inflammatory activities. In this study, we examined the mechanism by which G-Rp₁ inhibits inflammatory responses of cells. We did this using a strategy in which DNA constructs containing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) promoters were transfected into HEK293 cells. G-Rp₁ strongly inhibited the promoter activities of COX-2 and iNOS; it also inhibited lipopolysaccharide induced upregulation of COX-2 and iNOS mRNA levels in RAW264.7 cells. In HEK293 cells G-Rp₁ did not suppress TANK binding kinase 1-, Toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β (TRIF)-, TRIFrelated adaptor molecule (TRAM)-, or activation of interferon regulatory factor (IRF)-3 and nuclear factor (NF)-кB by the myeloid differentiation primary response gene (MyD88)-induced. However, G-Rp₁ strongly suppressed NF-кB activation induced by IкB kinase (IKK)β in HEK293 cells. Consistent with these results, G-Rp₁ substantially inhibited IKKβ-induced phosphorylation of IкBɑ and p65. These results suggest that G-Rp₁ is a novel anti-inflammatory ginsenoside analog that can be used to treat IKKβ/NF-кB-mediated inflammatory diseases.

Hydroquinone regulates hemeoxygenase-1 expression via modulation of Src kinase activity through thiolation of cysteine residues

The hydroxylated benzene metabolite hydroquinone (HQ) is mainly generated from benzene, an important industrial chemical, and is also a common dietary component. Although numerous papers have addressed the potential role of HQ in tumorigenic responses, the immunosuppressive and anti-inflammatory effects of hydroquinone have also been considered. In this study, we characterized the mechanism of the induction of hemeoxygenase (HO)-1 and other phase 2 enzymes by HQ and its derivatives. HQ upregulated the mRNA and protein levels of HO-1 by increasing the antioxidant-response element-dependent transcriptional activation of Nrf-2. Src knockdown or deficiency induced via siRNA treatment and infection with a retrovirus expressing shRNA targeting Src, as well as exposure to PP2, a Src kinase inhibitor, strongly abrogated HO-1 expression. Interestingly, HQ directly targeted and bound to the sulfhydryl group of cysteine-483 (C483) and C400 residues of Src, potentially leading to disruption of intracellular disulfide bonds. Src kinase activity was dramatically enhanced by mutation of these cysteine sites, implying that these sites may play an important role in the regulation of Src kinase activity. Therefore, our data suggest that Src and, particularly, its C483 target site can be considered as prime molecular targets of the HQ-mediated induction of phase 2 enzymes, which is potentially linked to HO-1-mediated cellular responses such as immunosuppressive and anti-inflammatory actions.

AP-1 pathway-targeted inhibition of inflammatory responses in LPS-treated macrophages and EtOH/HCl-treated stomach by Archidendron clypearia methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Archidendron clypearia Jack. (Fabaceae) is a representative ethnomedicinal herbal plant prescribed for various inflammatory diseases such as pharyngolaryngitis and tonsillitis. However, the pharmacology behind this plant's anti-inflammatory properties has not been fully understood. Therefore, in this study, the anti-inflammatory mechanism of a 95% methanol extract (Ac-ME) was explored.

MATERIALS AND METHODS

The anti-inflammatory mechanism of Ac-ME on the AP-1 activation pathway, which plays a critical role in the production of prostaglandin (PG)E2 in RAW264.7 cells and peritoneal macrophages and in induction of acute gastritis caused by HCl/EtOH, was investigated using immunoblotting, immunoprecipitation analyses, and reporter gene activity assays. In particular, enzyme assays and HPLC analysis were employed to identify direct target enzymes of Ac-ME and to detect active chemical components from the plant extract.

RESULTS

Ac-ME clearly reduced the nuclear levels of total and phospho-forms of c-Jun, FRA-1, and ATF-2. Consequently, this extract suppressed both the production of PGE2 in lipopolysaccharide (LPS)-activated RAW264.7 and peritoneal macrophage cells and PGE2-dependent induction of gastritis lesion in stomach under EtOH/HCl exposure. Analysis of AP-1 upstream signalling revealed that the AP-1 activation pathway consisting of IRAK1, TRAF6, TAK1, MKK3/6, and p38 was predominantly inhibited by Ac-ME. Similarly, this extract directly blocked the enzyme activity of IRAK1, indicating that this enzyme is an inhibitory target of Ac-ME and is involved in the suppression of the AP-1 pathway. HPLC analysis showed that quercetin, which inhibits PGE2 production, is an active component in Ac-ME.

CONCLUSION

Ac-ME is an ethnomedicinal remedy with an IRAK1/p38/AP-1-targeted inhibitory property. Since AP-1 is a major inflammation-inducing transcription factor, the therapeutic potential of Ac-ME in other AP-1-mediated inflammatory symptoms will be further tested.

Radical scavenging activity-based and AP-1-targeted anti-inflammatory effects of lutein in macrophage-like and skin keratinocytic cells

Lutein is a naturally occurring carotenoid with antioxidative, antitumorigenic, antiangiogenic, photoprotective, hepatoprotective, and neuroprotective properties. Although the anti-inflammatory effects of lutein have previously been described, the mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, in the present study, we aimed to investigate the regulatory activity of lutein in the inflammatory responses of skin-derived keratinocytes or macrophages and to elucidate the mechanism of its inhibitory action. Lutein significantly reduced several skin inflammatory responses, including increased expression of interleukin-(IL-) 6 from LPS-treated macrophages, upregulation of cyclooxygenase-(COX-) 2 from interferon-γ/tumor necrosis-factor-(TNF-) α-treated HaCaT cells, and the enhancement of matrix-metallopeptidase-(MMP-) 9 level in UV-irradiated keratinocytes. By evaluating the intracellular signaling pathway and the nuclear transcription factor levels, we determined that lutein inhibited the activation of redox-sensitive AP-1 pathway by suppressing the activation of p38 and c-Jun-N-terminal kinase (JNK). Evaluation of the radical and ROS scavenging activities further revealed that lutein was able to act as a strong anti-oxidant. Taken together, our findings strongly suggest that lutein-mediated AP-1 suppression and anti-inflammatory activity are the result of its strong antioxidative and p38/JNK inhibitory activities. These findings can be applied for the preparation of anti-inflammatory and cosmetic remedies for inflammatory diseases of the skin.

p38 MAPK/PP2Acα/TTP pathway on the connection of TNF-α and caspases activation on hydroquinone-induced apoptosis

This study investigated tumor necrosis factor-α (TNF-α)-mediated death pathway contribution to hydroquinone (HQ) cytotoxicity in human leukemia U937 cells. HQ-induced apoptosis of human leukemia U937 cells was characterized by the increase in mitochondrial membrane depolarization, procaspase-8 degradation and tBid production. Downregulation of Fas-associated death domain protein (FADD) blocked HQ-induced procaspase-8 degradation and rescued the viability of HQ-treated cells, suggesting the involvement of a death receptor-mediated pathway in HQ-induced cell death. HQ induced increased TNF-α mRNA stability led to TNF-α protein expression upregulation, whereas HQ suppressed TNF-α-mediated NFκB pathway activation. HQ elicited protein phosphatase 2A catalytic subunit α (PP2Acα) upregulation via p38 mitogen-activated protein kinase (MAPK)-mediated CREB/c-Jun/ATF-2 phosphorylation, and PP2Acα upregulation was found to promote tristetraprolin (TTP) degradation. Suppression of p38 MAPK activation and protein phosphatase 2A (PP2A) activity abrogated TNF-α upregulation and procaspase degradation in HQ-treated cells. Overexpression of TTP suppressed HQ-induced TNF-α upregulation and restored the viability of HQ-treated cells. Moreover, TTP overexpression increased TNF-α mRNA decay in HQ-treated cells. Taken together, our data indicate that HQ elicits TNF-α upregulation via p38 MAPK/PP2A-mediated TTP downregulation, and suggest that the TNF-α-mediated death pathway is involved in HQ-induced U937 cell death. The same pathway was also proven to be involved in the HQ-induced death of human leukemia HL-60 and Jurkat cells.

Src and Syk are targeted to an anti-inflammatory ethanol extract of Aralia continentalis

ETHNOPHARMACOLOGICAL RELEVANCE

Aralia continentalis Kitagawa (Araliaceae) is a representative ethnomedicinal herbal plant traditionally prescribed in Korea to relieve various inflammatory symptoms. However, the exact molecular mechanism of its anti-inflammatory activity has not been fully investigated.

MATERIALS AND METHODS

The effect of the ethanol extract from the roots of this plant (Ac-EE) on the production of the inflammatory mediator nitric oxide (NO) was studied in RAW264.7 cells. Its effect on inflammatory symptoms (gastritis and hepatitis) in mice was also examined. In particular, the molecular inhibitory mechanism was analysed by measuring the activation of transcription factors and their upstream signalling and the kinase activity of target enzymes.

RESULTS

Ac-EE dose-dependently suppressed NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. This extract also displayed curative activity against EtOH/HCl-induced gastritis and LPS-induced hepatitis in mice. Ac-EE-mediated anti-inflammatory activity was found to be at the transcriptional level, as it blocked the activation of the nuclear factor (NF)-κB pathway composed of Syk and Src, according to immunoblotting and immunoprecipitation analyses and a kinase assay with whole and nucleus lysates from RAW264.7 cells and mice.

CONCLUSION

Ac-EE may be developed as a functional herbal remedy targeting Syk- and Src-mediated anti-inflammatory mechanisms. Future work using pre-clinical studies will be needed to investigate this possibility.

Src/NF-κB-targeted inhibition of LPS-induced macrophage activation and dextran sodium sulphate-induced colitis by Archidendron clypearia methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Archidendron clypearia Jack. (Fabaceae) has been traditionally used to treat various inflammatory diseases such as pain in the eyes. However, the antiinflammatory mechanism of A. clypearia has not been fully elucidated. This study examined the anti-inflammatory mechanism of a 95% methanol extract (Ac-ME) of A. clypearia in vitro and in vivo.

MATERIALS AND METHODS

The effect of Ac-ME on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages and on symptoms of colitis in mouse induced by dextran sodium sulphate (DSS) was investigated. Molecular mechanisms underlying the inhibitory effects were elucidated by analyzing the activation of transcription factors and their upstream signaling as well as by evaluating the kinase activity of target enzymes in vitro and in vivo.

RESULTS

Ac-ME dose-dependently suppressed the secretion of nitric oxide (NO) and prostaglandin (PG)E₂ from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ac-ME clearly reduced mRNA expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and tumor necrosis factor (TNF)-α by the blockade of nuclear factor (NF)-κB activation and its upstream signaling events containing protein tyrosine kinase such as Syk and Src. In agreement with this, Ac-ME directly reduced the kinase activities of Src and Syk as well as the formation of molecular signaling complex including p85. DSS-induced colitis was also remarkably inhibited by this extract through the suppression of Src and IκBα phosphorylation.

CONCLUSION

Ac-ME displays strong anti-inflammatory activity in vivo by suppressing Src/Syk-mediated NF-κB activation which is linked to its ethno-pharmacological uses as an anti-gastritis remedy. Through preclinical studies, the potential therapeutic application will be tested further.

BAY 11-7082 is a broad-spectrum inhibitor with anti-inflammatory activity against multiple targets

BAY 11-7082 (BAY) is an inhibitor of κB kinase (IKK) that has pharmacological activities that include anticancer, neuroprotective, and anti-inflammatory effects. In this study, BAY-pharmacological target pathways were further characterized to determine how this compound simultaneously suppresses various responses. Primary and cancerous (RAW264.7 cells) macrophages were activated by lipopolysaccharide, a ligand of toll-like receptor 4. As reported previously, BAY strongly suppressed the production of nitric oxide, prostaglandin E₂, and tumor necrosis factor-α and reduced the translocation of p65, major subunit of nuclear factor-κB, and its upstream signaling events such as phosphorylation of IκBα, IKK, and Akt. In addition, BAY also suppressed the translocation and activation of activator protein-1, interferon regulatory factor-3, and signal transducer and activator of transcription-1 by inhibiting the phosphorylation or activation of extracellular signal-related kinase, p38, TANK-binding protein, and Janus kinase-2. These data strongly suggest that BAY is an inhibitor with multiple targets and could serve as a lead compound in developing strong anti-inflammatory drugs with multiple targets in inflammatory responses.

Syk/Src pathway-targeted inhibition of skin inflammatory responses by carnosic acid

Carnosic acid (CA) is a diterpene compound exhibiting antioxidative, anticancer, anti-angiogenic, anti-inflammatory, anti-metabolic disorder, and hepatoprotective and neuroprotective activities. In this study, the effect of CA on various skin inflammatory responses and its inhibitory mechanism were examined. CA strongly suppressed the production of IL-6, IL-8, and MCP-1 from keratinocyte HaCaT cells stimulated with sodium lauryl sulfate (SLS) and retinoic acid (RA). In addition, CA blocked the release of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E₂ (PGE₂) from RAW264.7 cells activated by the toll-like receptor (TLR)-2 ligands, Gram-positive bacterium-derived peptidoglycan (PGN) and pam3CSK, and the TLR4 ligand, Gram-negative bacterium-derived lipopolysaccharide (LPS). CA arrested the growth of dermatitis-inducing Gram-positive and Gram-negative microorganisms such Propionibacterium acnes, Pseudomonas aeruginosa, and Staphylococcus aureus. CA also blocked the nuclear translocation of nuclear factor (NF)-κB and its upstream signaling including Syk/Src, phosphoinositide 3-kinase (PI3K), Akt, inhibitor of κBα (IκBα) kinase (IKK), and IκBα for NF-κB activation. Kinase assays revealed that Syk could be direct enzymatic target of CA in its anti-inflammatory action. Therefore, our data strongly suggest the potential of CA as an anti-inflammatory drug against skin inflammatory responses with Src/NF-κB inhibitory properties.