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

Immunomodulatory, Anti-Inflammatory, and Anti-Cancer Properties of Ginseng: A Pharmacological Update

Ginseng, a medicinal plant of the genus Panax, boasts a rich historical record of usage that dates back to the Paleolithic period. This botanical is extensively acknowledged and consumed in Eastern countries for its therapeutic properties, and, in Western countries, it is becoming increasingly popular as a remedy for fatigue and asthenia. This review provides an update on current research pertaining to ginseng and its isolated compounds, namely, ginsenosides and polysaccharides. The primary focus is on three crucial pharmacological activities, namely, immunomodulation, anti-inflammatory, and anti-cancer effects. The review encompasses studies on both isolated compounds and various ginseng extracts obtained from the root, leaves, and berries.

The protective role of ginsenoside compound K in porcine oocyte meiotic maturation failed caused by benzo(a)pyrene during in vitro maturation

Benzo(a)pyrene (BaP) is a pollutant and carcinogen derived from air pollution. It causes serious damage to reproductive system, especially ovary. Ginseng is always used in food and traditional medicine as a nutraceuticals or herbal medicine. Ginsenoside compound K (CK) is a major bioactive ingredient of ginseng, that shows very specific anti-apoptosis, anti-oxidant, and anti-inflammatory activities and thus, it protects cells from damage. The aim of this study was to investigate the effects of CK on the BaP-induced inhibition of the in vitro maturation of porcine oocytes and their subsequent embryonic development capacity. We found that supplementation with 10 μg mL^-1 CK during in vitro maturation significantly increased maturation rate (P < 0.05) and the expression level of related genes after damage induced by 40 μM BaP treatment. In addition, reactive oxygen species (ROS) levels significantly decreased and ATP content and mitochondrial membrane potential (MMP) increased after CK supplementation (P < 0.05). The competence for embryonic development was improved by the induction of pluripotency gene expression and the inhibition of apoptosis after CK supplementation of BaP-treated oocytes. Supplementation with 10 μg mL^-1 CK improved porcine oocyte maturation and subsequent embryonic development of parthenogenetic activation (33.01 vs. 20.92, P < 0.05) and in vitro fertilization (24.01 vs. 16.52, P < 0.05) by increasing antioxidant activity and improving mitochondrial function after BaP-induced damage.

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.

Functional mechanism of Ginsenosides on tumor growth and metastasis

Ginsengs, has long been used as one medicinal herb in China for more than two thousand years. Many studies have shown that ginsengs have preventive and therapeutic roles for cancer, and play a good complementary role in cancer treatment. Ginsenosides, as most important constituents of ginseng, have been extensively investigated and emphasized in cancer chemoprevention and therapeutics. However, the functional mechanism of Ginsenosides on cancer is not well known. This review will focus on introducing the functional mechanisms of ginsenosides and their metabolites, which regulate signaling pathways related with tumor growth and metastasis. Ginsenosides inhibit tumor growth via upregulating tumor apoptosis, inducing tumor cell differentiation and targeting cancer stem cells. In addition, Ginsenosides regulate tumor microenvironment via suppressing tumor angiogenesis-related proteins and pathways. Structural modification of ginsenosides and their administration alone or combinations with other Chinese medicines or chemical medicines have recently been developed to be a new therapeutic strategy for cancer.

ER stress and genomic instability induced by gamma radiation in mice primary cultured glial cells

Ionizing radiation induces various pathophysiological conditions by altering central nervous system (CNS) homeostasis, leading to neurodegenerative diseases. However, the potential effect of ionizing radiation response on cellular physiology in glial cells is unclear. In the present study, micronucleus test, comet assay, and RT-PCR were performed to investigate the potential effect of gamma radiation in cultured oligodendrocytes and astrocytes with respect to genomic instability, Endoplasmic Reticulum (ER) stress, and inflammation. Further, we studied the effect of alteration in ER stress specific gene expression in cortex post whole body radiation in mice. Results showed that exposure of gamma radiation of 2Gy in-vitro cultured astrocytes and oligodendrocytes and 7Gy in-vivo induced ER stress and Inflammation along with profuse DNA damage and Chromosomal abnormality. Additionally, we observed downregulation of myelin basic protein levels in cultured oligodendrocytes exposed to radiation. The present data suggests that ER stress and pro inflammatory cytokines serve as the major players in inducing glial cell dysfunction post gamma irradiation along with induction of genomic instability. Taken together, these results indicate that ER stress, DNA damage, and inflammatory pathways may be critical events leading to glial cell dysfunction and subsequent cell death following exposure to ionizing radiation.

AKT-targeted anti-inflammatory activity of Panax ginseng calyx ethanolic extract

Background

Korean ginseng (Panax ginseng) plays an anti-inflammatory role in a variety of inflammatory diseases such as gastritis, hepatitis, and colitis. However, inflammation-regulatory activity of the calyx of the P. ginseng berry has not been thoroughly evaluated. To understand whether the calyx portion of the P. ginseng berry is able to ameliorate inflammatory processes, an ethanolic extract of P. ginseng berry calyx (Pg-C-EE) was prepared, and lipopolysaccharide-activated macrophages and HEK293 cells transfected with inflammation-regulatory proteins were used to test the anti-inflammatory action of Pg-C-EE.

Methods

The ginsenoside contents of Pg-C-EE were analyzed by HPLC. Suppressive activity of Pg-C-EE on NO production, inflammatory gene expression, transcriptional activation, and inflammation signaling events were examined using the Griess assay, reverse transcription-polymerization chain reaction, luciferase activity reporter gene assay, and immunoblotting analysis.

Results

Pg-C-EE reduced NO production and diminished mRNA expression of inflammatory genes such as cyclooxygenase-2, inducible NO synthase, and tumor necrosis factor-α in a dose-dependent manner. This extract suppressed luciferase activity induced only by nuclear factor-κB. Interestingly, immunoblotting analysis results demonstrated that Pg-C-EE reduced the activities of protein kinase B (AKT)1 and AKT2.

Conclusion

These results suggest that Pg-C-EE may have nuclear-factor-κB-targeted anti-inflammatory properties through suppression of AKT. The calyx of the P. ginseng berry is an underused part of the ginseng plant, and development of calyx-derived extracts may be useful for treatment of inflammatory diseases.

Syk Plays a Critical Role in the Expression and Activation of IRAK1 in LPS-Treated Macrophages

To address how interleukin-1 receptor-associated kinase 1 (IRAK1) is controlled by other enzymes activated by toll-like receptor (TLR) 4, we investigated the possibility that spleen tyrosine kinase (Syk), a protein tyrosine kinase that is activated at an earlier stage during TLR4 activation, plays a central role in regulating the functional activation of IRAK1. Indeed, we found that overexpression of myeloid differentiation primary response gene 88 (MyD88), an adaptor molecule that drives TLR signaling, induced IRAK1 expression and that piceatannol, a Syk inhibitor, successfully suppressed the MyD88-dependent upregulation of IRAK1 under LPS treatment conditions. Interestingly, in Syk-knockout RAW264.7 cells, IRAK1 activity was almost completely blocked after LPS treatment, while providing a Syk-recovery gene to the knockout cells successfully restored IRAK1 expression. According to our measurements of IRAK1 mRNA levels, the transcriptional upregulation of IRAK1 was induced by LPS treatment between 4 and 60 min, and this can be suppressed in Syk knockout cells, providing an effect similar that that seen under piceatannol treatment. The overexpression of Syk reverses this effect and leads to a significantly higher IRAK1 mRNA level. Collectively, our results strongly suggest that Syk plays a critical role in regulating both the activity and transcriptional level of IRAK1.

Thymoquinone: An IRAK1 inhibitor with in vivo and in vitro anti-inflammatory activities

Thymoquinone (TQ) is a bioactive component of black seed (Nigella sativa) volatile oil and has been shown to have anti-oxidative, anti-inflammatory, and anti-cancer properties. In the present study, we explored the molecular mechanisms that underlie the anti-inflammatory effect of TQ and its target proteins using lipopolysaccharide (LPS)-stimulated murine macrophage-like RAW264.7 and human monocyte-like U937 cells, together with LPS/D-galactosamine (GalN)-induced acute hepatitis and HCl/EtOH-induced gastritis mouse models. TQ strongly inhibited the production of nitric oxide (NO) and repressed NO synthase (iNOS), tumor necrosis factor (TNF)-α, cyclooxygenase (COX)−2, interleukin (IL)−6, and IL-1β expression in LPS-activated RAW264.7 cells. Treatment of LPS/D-GalN–induced hepatitis and EtOH/HCl–induced gastritis mouse models with TQ significantly ameliorated disease symptoms. Using luciferase reporter gene assays, we also showed that the nuclear levels of transcription factors and phosphorylation patterns of signaling proteins, activator protein (AP)−1, and nuclear factor (NF)-κB pathways were all affected by TQ treatment. Finally, we used additional kinase and luciferase validation assays with interleukin-1 receptor-associated kinase 1 (IRAK1) to show that IRAK1 is directly suppressed by TQ treatment. Together, these findings strongly suggest that the anti-inflammatory actions of TQ are caused by suppression of IRAK-linked AP-1/NF-κB pathways.

Ginsenoside Re Attenuates Neuroinflammation in a Symptomatic ALS Animal Model

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive loss of upper and lower motor neurons, which cause paralysis and respiratory dysfunction. There is currently no permanently effective drug for patients with ALS. Ginsenoside Re (G-Re), one of the most active ingredients of ginseng, has pharmacological activities that affect a number of targets. To investigate the effects of G-Re on neuroinflammation, we used G-Re (2.5[Formula: see text][Formula: see text]g/g) at the Joksamni acupressure point (ST36) once every other day for one week. To evaluate G-Re function in symptomatic human-superoxide dismutase 1 (hSOD1[Formula: see text] transgenic mice, immunohistochemistry and Western blot analysis were performed with the spinal cord of symptomatic hSOD1(G93A) transgenic mice. Here, we report that G-Re exhibits potent neuroprotective effects against neuroinflammation in a murine model of ALS. G-Re treatment reduced the loss of motor neurons and active-microglia-related expression of Iba-1 in the spinal cord of symptomatic hSOD1(G93A) transgenic mice. In addition, compared with age-matched hSOD1(G93A) mice, G-Re-treated hSOD1(G93A) mice showed a significant reduction in expression of pro-inflammatory proteins such as CD14 and TNF-[Formula: see text] protein related to TLR4 signaling pathway. G-Re administration also led to a decrease in cell death-related phospho-p38 protein levels, and had an antioxidative effect by reducing HO1 expression. Together, our data suggest that G-Re could have potent anti-neuroinflammatory effects on ALS by inhibiting the TLR4 pathway.

PDK1 in NF-κB signaling is a target of Xanthium strumarium methanolic extract-mediated anti-inflammatory activities

ETHNOPHARMACOLOGICAL RELEVANCE

Xanthium strumarium L. (Asteraceae) has traditionally been used to treat bacterial infections, nasal sinusitis, urticaria, arthritis, chronic bronchitis and rhinitis, allergic rhinitis, edema, lumbago, and other ailments. However, the molecular mechanisms by which this plant exerts its anti-inflammatory effects are poorly characterized. Here we studied the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Xs-ME) and validated its pharmacological targets.

MATERIALS AND METHODS

To evaluate the anti-inflammatory activity of Xs-ME, we employed lipopolysaccharide (LPS)-treated macrophages and an HCl/EtOH-induced mouse model of gastritis. We also used HPLC to identify the potentially active anti-inflammatory components of this extract. The molecular mechanisms of its anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes.

RESULTS

The production of nitric oxide (NO) and prostaglandin E2 (PGE2) were both suppressed by Xs-ME. Moreover, orally administered Xs-ME ameliorated HCl/EtOH-induced gastric lesions. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signaling events upstream of NF-κB translocation, such as phosphorylation of AKT and the formation of PDK1-AKT signaling complexes, were also inhibited by Xs-ME. Moreover, Xs-ME suppressed the enzymatic activity of PDK1. Additionally, PDK1-induced luciferase activity and Akt phosphorylation were both inhibited by Xs-ME. We also identified the polyphenol resveratrol as a likely active anti-inflammatory component in Xs-ME that targets PDK1.

CONCLUSION

Xs-ME exerts anti-inflammatory activity in vitro and in vivo by inhibiting PDK1 kinase activity and blocking signaling to its downstream transcription factor, NF-κB.

Role of ginsenosides, the main active components of Panax ginseng, in inflammatory responses and diseases

Panax ginseng is one of the most universally used herbal medicines in Asian and Western countries. Most of the biological activities of ginseng are derived from its main constituents, ginsenosides. Interestingly, a number of studies have reported that ginsenosides and their metabolites/derivatives—including ginsenoside (G)-Rb1, compound K, G-Rb2, G-Rd, G-Re, G-Rg1, G-Rg3, G-Rg5, G-Rh1, G-Rh2, and G-Rp1—exert anti-inflammatory activities in inflammatory responses by suppressing the production of proinflammatory cytokines and regulating the activities of inflammatory signaling pathways, such as nuclear factor-κB and activator protein-1. This review discusses recent studies regarding molecular mechanisms by which ginsenosides play critical roles in inflammatory responses and diseases, and provides evidence showing their potential to prevent and treat inflammatory diseases.

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.

1-(2,3-Dibenzimidazol-2-ylpropyl)-2-methoxybenzene Is a Syk Inhibitor with Anti-Inflammatory Properties

Inflammation is the protective action of our bodies against external pathogens by recognition of pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs). Proper regulation of inflammatory responses is required to maintain our body’s homeostasis, as well as there are demands to develop proper acute or chronic inflammation. In this study, we elucidated the regulatory mechanism of NF-κB-mediated inflammatory responses by a novel compound, 1-(2,3-dibenzimidazol-2-ylpropyl)-2-methoxybenzene (DBMB). We found that DBMB suppressed inflammatory mediators, nitric oxide (NO) and prostaglandin E₂ (PGE₂), reacted to exposure to a number of toll like receptor (TLR) ligands. Such observations occurred following to decreased mRNA expression of several pro-inflammatory mediators, and such diminished mRNA levels were caused by inhibited transcriptional factor nuclear factor (NF)-κB, as evaluated by luciferase reporter assay and molecular biological approaches. To find the potential targets of DBMB, we screened phosphorylated forms of NF-κB signal molecules: inhibitor of κBα (IκBα), IκB kinase (IKK)α/β, Akt, 3-phosphoinositide dependent protein kinase-1 (PDK1), p85, and spleen tyrosine kinase (Syk). We found that DBMB treatment could suppress signal transduction through these molecules. Additionally, we conducted in vitro kinase assays using immunoprecipitated Syk and its substrate, p85. Consequently, we could say that DBMB clearly suppressed the kinase activity of Syk kinase activity. Together, our results demonstrate that synthetic DBMB has an effect on the inflammatory NF-κB signaling pathway and suggest the potential for clinical use in the treatment of inflammatory diseases.

Anti-Inflammatory and Antinociceptive Activities of Anthraquinone-2-Carboxylic Acid

Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, the in vivo anti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-) κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive components in vivo, thus contributing to the immune regulatory role of fruits and herbs.

(E)-3-(3-methoxyphenyl)-1-(2-pyrrolyl)-2-propenone displays suppression of inflammatory responses via inhibition of Src, Syk, and NF-κB

(E)-3-(3-methoxyphenyl)-1-(2-pyrrolyl)-2-propenone (MPP) is an aldol condensation product resulting from pyrrole-2-carbaldehyde and m- and p- substituted acetophenones. However, its biological activity has not yet been evaluated. Since it has been reported that some propenone-type compounds display anti-inflammatory activity, we investigated whether MPP could negatively modulate inflammatory responses. To do this, we employed lipopolysaccharide (LPS)-stimulated macrophage-like RAW264.7 cells and examined the inhibitory levels of nitric oxide (NO) production and transcriptional activation, as well as the target proteins involved in the inflammatory signaling cascade. Interestingly, MPP was found to reduce the production of NO in LPS-treated RAW264.7 cells, without causing cytotoxicity. Moreover, this compound suppressed the mRNA levels of inflammatory genes, such as inducible NO synthase (iNOS) and tumor necrosis factor (TNF)-α. Using luciferase reporter gene assays performed in HEK293 cells and immunoblotting analysis with nuclear protein fractions, we determined that MPP reduced the transcriptional activation of nuclear factor (NF)-κB. Furthermore, the activation of a series of upstream signals for NF-κB activation, composed of Src, Syk, Akt, and IκBα, were also blocked by this compound. It was confirmed that MPP was able to suppress autophosphorylation of overexpressed Src and Syk in HEK293 cells. Therefore, these results suggest that MPP can function as an anti-inflammatory drug with NF-κB inhibitory properties via the suppression of Src and Syk.

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.

Fisetin Suppresses Macrophage-Mediated Inflammatory Responses by Blockade of Src and Syk

Flavonoids, such as fisetin (3,7,3′,4′-tetrahydroxyflavone), are plant secondary metabolites. It has been reported that fisetin is able to perform numerous pharmacological roles including anti-inflammatory, anti-microbial, and anti-cancer activities; however, the exact anti-inflammatory mechanism of fisetin is not understood. In this study, the pharmacological action modes of fisetin in lipopolysaccharide (LPS)-stimulated macrophage-like cells were elucidated by using immunoblotting analysis, kinase assays, and an overexpression strategy. Fisetin diminished the release of nitric oxide (NO) and reduced the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in LPS-stimulated RAW264.7 cells without displaying cytotoxicity. This compound also blocked the nuclear translocation of p65/nuclear factor (NF)-κB. In agreement, the upstream phosphorylation events for NF-κB activation, composed of Src, Syk, and IκBα, were also reduced by fisetin. The phospho-Src level, triggered by overexpression of wild-type Src, was also inhibited by fisetin. Therefore, these results strongly suggest that fisetin can be considered a bioactive immunomodulatory compound with anti-inflammatory properties through suppression of Src and Syk activities.

Scutellarein Reduces Inflammatory Responses by Inhibiting Src Kinase Activity

Flavonoids are plant pigments that have been demonstrated to exert various pharmacological effects including anti-cancer, anti-diabetic, anti-atherosclerotic, anti-bacterial, and anti-inflammatory activities. However, the molecular mechanisms in terms of exact target proteins of flavonoids are not fully elucidated yet. In this study, we aimed to evaluate the anti-inflammatory mechanism of scutellarein (SCT), a flavonoid isolated from Erigeron breviscapus, Clerodendrum phlomidis and Oroxylum indicum Vent that have been traditionally used to treat various inflammatory diseases in China and Brazil. For this purpose, a nitric oxide (NO) assay, polymerase chain reaction (PCR), nuclear fractionation, immunoblot analysis, a kinase assay, and an overexpression strategy were employed. Scutellarein significantly inhibited NO production in a dose-dependent manner and reduced the mRNA expression levels of inducible NO synthase (iNOS) and tumor necrosis factor (TNF)-α in lipopolysaccharide (LPS)-activated RAW264.7 cells. In addition, SCT also dampened nuclear factor (NF)-κB-driven expression of a luciferase reporter gene upon transfection of a TIR-domain-containing adapter-inducing interferon-β (TRIF) construct into Human embryonic kidney 293 (HEK 293) cells; similarly, NF-κ B nuclear translocation was inhibited by SCT. Moreover, the phosphorylation levels of various upstream signaling enzymes involved in NF-κB activation were decreased by SCT treatment in LPS-treated RAW264.7 cells. Finally, SCT strongly inhibited Src kinase activity and also inhibited the autophosphorylation of overexpressed Src. Therefore, our data suggest that SCT can block the inflammatory response by directly inhibiting Src kinase activity linked to NF-κB activation.

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.

In vitro and in vivo anti-inflammatory activity of Phyllanthus acidus methanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus acidus (L.) Skeels (Phyllanthaceae) has traditionally been used to treat gastric trouble, rheumatism, bronchitis, asthma, respiratory disorders, and hepatitis. Despite this widespread use, the pharmacological activities of this plant and their molecular mechanisms are poorly understood. Therefore, we evaluated the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Pa-ME) and validated its pharmacological targets.

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-treated macrophages, an HCl/EtOH-induced gastritis model, and an acetic acid-injected capillary permeability mouse model were employed to evaluate the anti-inflammatory activity of Pa-ME. Potentially active anti-inflammatory components of this extract were identified by HPLC. The molecular mechanisms of the anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes.

RESULTS

Pa-ME suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and prevented morphological changes in LPS-treated RAW264.7 cells. Moreover, both HCl/EtOH-induced gastric damage and acetic acid-triggered vascular permeability were restored by orally administered Pa-ME. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signalling events upstream of NF-κB translocation, such as phosphorylation of Src and Syk and formation of Src/Syk signalling complexes, were also inhibited by Pa-ME. The enzymatic activities of Src and Syk were also suppressed by Pa-ME. Moreover, Src-induced and Syk-induced luciferase activity and p85/Akt phosphorylation were also inhibited by Pa-ME. Of the identified flavonoids, kaempferol and quercetin were revealed as partially active anti-inflammatory components in Pa-ME.

CONCLUSION

Pa-ME exerts anti-inflammatory activity in vitro and in vivo by suppressing Src, Syk, and their downstream transcription factor, NF-κB.

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.

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.

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.

Red ginseng extract ameliorates autoimmune arthritis via regulation of STAT3 pathway, Th17/Treg balance, and osteoclastogenesis in mice and human

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation. Red ginseng is a steamed and dried Panax ginseng C.A. Meyer, which has been used as alternative medicine for thousands of years. This study was undertaken to investigate the effects of red ginseng extracts (RGE) on autoimmune arthritis in mice and humans and to delineate the underlying mechanism. RGE was orally administered three times a week to mice with arthritis. Oral administration of RGE markedly ameliorated clinical arthritis score and histologically assessed joint inflammation in mice with CIA. A significant reduction in STAT3 phosphorylation and a decrease in the number of Th17 cells were observed with RGE treatment. There was also a marked reduction in RANKL-induced osteoclastogenesis with treatment of RGE. The inhibitory effect of RGE on Th17 differentiation and osteoclastogenesis observed in mice was also confirmed in the subsequent experiments performed using human peripheral blood mononuclear cells. Our findings provide the first evidence that RGE can regulate Th17 and reciprocally promote Treg cells by inhibiting the phosphorylation of STAT3. Therefore, RGE can ameliorate arthritis in mice with CIA by targeting pathogenic Th17 and osteoclast differentiation, suggesting a novel therapy for treatment of RA.

IKK β -Targeted Anti-Inflammatory Activities of a Butanol Fraction of Artificially Cultivated Cordyceps pruinosa Fruit Bodies

The inhibitory activities of the Cordyceps pruinosa butanol fraction (Cp-BF) were investigated by determining inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells and by evaluating HCl/ethanol (EtOH)-triggered gastric ulcers in mice. The molecular mechanisms of the inhibitory effects of Cp-BF were investigated by identifying target enzymes using biochemical and molecular biological approaches. Cp-BF strongly inhibited the production of NO and TNF-α, release of reactive oxygen species (ROS), phagocytic uptake of FITC-dextran, and mRNA expression levels of interleukin (IL)-6, inducible NO synthase (iNOS), and tumour necrosis factor-alpha (TNF)-α in activated RAW264.7 cells. Cp-BF also strongly downregulated the NF-κB pathway by suppressing IKKβ according to luciferase reporter assays and immunoblot analysis. Furthermore, Cp-BF blocked both increased levels of NF-κB-mediated luciferase activities and phosphorylation of p65/p50 observed by IKKβ overexpression. Finally, orally administered Cp-BF was found to attenuate gastric ulcer and block the phosphorylation of IκBα induced by HCl/EtOH. Therefore, these results suggest that the anti-inflammatory activity of Cp-BF may be mediated by suppression of IKKα and its downstream NF-κB activation. Since our group has established the mass cultivation conditions by developing culture conditions for Cordyceps pruinosa, the information presented in this study may be useful for developing new anti-inflammatory agents.

Ginsenoside-Rp1-induced apolipoprotein A-1 expression in the LoVo human colon cancer cell line

Background

Ginsenoside Rp1 (G-Rp1) is a novel ginsenoside derived from ginsenoside Rk1. This compound was reported to have anticancer, anti-platelet, and anti-inflammatory activities. In this study, we examined the molecular target of the antiproliferative and proapoptotic activities of G-Rp1.

Methods

To examine the effects of G-Rp1, cell proliferation assays, propidium iodine staining, proteomic analysis by two-dimensional gel electrophoresis, immunoblotting analysis, and a knockdown strategy were used.

Results

G-Rp1 dose-dependently suppressed the proliferation of colorectal cancer LoVo cells and increased their apoptosis. G-Rp1 markedly upregulated the protein level of apolipoprotein (Apo)-A1 in LoVo, SNU-407, DLD-1, SNU-638, AGS, KPL-4, and SK-BR-3 cells. The knockdown of Apo-A1 by its small-interfering RNA increased the levels of cleaved poly(ADP-ribose) polymerase and p53 and diminished the proliferation of LoVo cells.

Conclusion

These results suggest that G-Rp1 may act as an anticancer agent by strongly inhibiting cell proliferation and enhancing apoptosis through upregulation of Apo-A1.

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.

(5-Hydroxy-4-oxo-4H-pyran-2-yl)methyl 6-hydroxynaphthalene-2-carboxylate, a kojic acid derivative, inhibits inflammatory mediator production via the suppression of Syk/Src and NF-κB activation

Numerous derivatives of kojic acid have been synthesised to expand its immunopharmacological uses. Kojic acid is known to have anti-cancer, anti-inflammatory, and anti-melanogenesis effects. We found that (5-hydroxy-4-oxo-4H-pyran-2-yl)methyl 6-hydroxynaphthalene-2-carboxylate (MHNC) strongly suppressed the production of nitric oxide (NO) in an initial screening experiment. In this study, we explored the in vitro and in vivo anti-inflammatory activity of MHNC and its inhibitory mechanisms using lipopolysaccharide (LPS)-treated RAW264.7 cells and HCl/EtOH-treated ICR mice. MHNC dose-dependently diminished the secretion of nitric oxide (NO) and prostaglandin (PG)E2 in LPS-treated RAW264.7 cells. This compound also suppressed the upregulation of mRNA levels for the inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 genes. Additionally, the transcriptional activation of these genes was inhibited by MHNC through the suppression of the nuclear translocation of nuclear factor (NF)-κB subunits (p65 and p50), as determined by a luciferase reporter assay. Interestingly, MHNC treatment was found to suppress a series of upstream signalling cascades consisting of IκBα, AKT, PDK1, Src, and Syk for NF-κB activation. Furthermore, a direct enzyme assay with purified Src and Syk and luciferase assays using Src and Syk overexpression indicated that these enzymes were directly inhibited by MHNC. Finally, MHNC (20mg/kg) prevented inflammatory symptoms of the stomach in mice treated with HCl/EtOH by reducing phospho-IκBα levels. Taken together, our data suggest that MHNC may negatively modulate in vitro and in vivo inflammatory responses via the direct suppression of Syk/Src and NF-κB.

Syk and Src are major pharmacological targets of a Cerbera manghas methanol extract with kaempferol-based anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Cerbera manghas L. (Apocynaceae), a semi-mangrove medicinal plant distributed throughout tropical and subtropical countries, is traditionally known to possess analgesic, anti-inflammatory, anti-convulsant, cardiotonic, and hypotensive activity. In vitro and in vivo anti-inflammatory activities of a methanol extract of the leaves of Cerbera manghas and the underlying molecular mechanisms were investigated to validate the ethnopharmacological use of this plant.

MATERIALS AND METHODS

The effect of Cerbera manghas methanol extract (Cm-ME) on the production of inflammatory mediators and the induction of HCl/EtOH-treated gastritis was explored using macrophages, HEK293 cells, and ICR mice. The molecular targets of this extract and potential active components in Cm-ME were also investigated.

RESULTS

Cm-ME inhibited the production of nitric oxide (NO) in lipopolysaccharide (LPS)-treated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. This extract also suppressed the expression of NO synthase (iNOS) and cyclooxygenase (COX)-2. NF-κB-mediated enhancement of luciferase activity, nuclear translocation of p50 and p65, and phosphorylation of IκBα were markedly reduced by Cm-ME treatment. Direct enzyme assays, reporter gene assays, and immunoprecipitation analysis of kinases revealed Syk and Src as immunopharmacological targets of Cm-ME. Moreover, this extract strongly ameliorated the gastric symptoms induced by HCl/EtOH treatment of mice. Finally, HPLC analysis and pharmacological tests identified kaempferol as an active component of the extract with Src/Syk inhibitory activities.

CONCLUSION

Inhibition of Syk/Src and the NF-κB pathway by kaempferol could play a key role in the anti-inflammatory pharmacological action of Cerbera manghas.

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.

Korean Red Ginseng water extract inhibits COX-2 expression by suppressing p38 in acrolein-treated human endothelial cells

Cigarette smoke is considered a major risk factor for vascular diseases. There are many toxic compounds in cigarette smoke, including acrolein and other α,β-unsaturated aldehydes, which are regarded as mediators of inflammation and vascular dysfunction. Furthermore, recent studies have revealed that acrolein, an α,β-unsaturated aldehyde in cigarette smoke, induces inflammatory mediator expression, which is known to be related to vascular diseases. In this study, we investigated whether Korean Red Ginseng (KRG) water extract suppressed acrolein-induced cyclooxygenase (COX)-2 expression in human umbilical vein endothelial cells (HUVECs). Acrolein-induced COX-2 expression was accompanied by increased levels of phosphorylated p38 in HUVECs and KRG inhibited COX-2 expression in HUVECs. These results suggest that KRG suppresses acrolein-induced COX-2 expression via inhibition of the p38 mitogen-activated protein kinase signaling pathway. In addition, KRG exhibited an inhibitory effect on acrolein-induced apoptosis, as demonstrated by annexin V-propidium iodide staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. Consistent with these results, KRG may exert a vasculoprotective effect through inhibition of COX-2 expression in acrolein-stimulated human endothelial cells.

JAK2-targeted anti-inflammatory effect of a resveratrol derivative 2,4-dihydroxy-N-(4-hydroxyphenyl)benzamide

Chemical derivatization of resveratrol has been widely conducted in an effort to overcome its chemical instability and therapeutic potential. In the present study, we examined the anti-inflammatory effects of resveratrol derivatives containing an amide functionality using in vitro macrophage models that were stimulated by Toll-like receptor (TLR) ligands, and using several animal inflammatory disease models. Of the resveratrol derivatives tested, compound 8 (2,4-dihydroxy-N-(4-hydroxyphenyl)benzamide) most strongly inhibited the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E2 (PGE2), as well as the mRNA expression of inducible NO synthase (iNOS), TNF-α, and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-activated RAW264.7 cells, differentiated U937 cells, and peritoneal macrophages. The inhibitory activity of compound 8 was apparently mediated by suppressing the phosphorylation of signal transducer and activator of transcription (STAT)-1, STAT-3, STAT-5, and interferon regulatory factor (IRF)-3. The direct target of compound 8 was revealed to be Janus kinase 2 (JAK2) but not TANK-binding kinase (TBK) 1 using the direct kinase assay and analyses of complex formation with these molecules. Additionally, upstream kinase of TBK1 seems to be also inhibited by compound 8. This compound also strongly ameliorated mouse inflammatory symptoms seen in arachidonic acid-induced ear edema, dextran sodium sulfate (DSS)-treated colitis, EtOH/HCl-induced gastritis, collagen type II-triggered arthritis, and acetic acid-induced writhing. Therefore, of the resveratrol derivatives that we tested, compound 8 was determined to have the strongest anti-inflammatory activities in vitro and in vivo and may potentially be developed for use as a novel anti-inflammatory drug.

A ginseng metabolite, compound K, induces autophagy and apoptosis via generation of reactive oxygen species and activation of JNK in human colon cancer cells

Compound K (20-O-(β-D-glucopyranosyl)-20(S)-protopanaxadiol) is an active metabolite of ginsenosides and induces apoptosis in various types of cancer cells. This study investigated the role of autophagy in compound K-induced cell death of human HCT-116 colon cancer cells. Compound K activated an autophagy pathway characterized by the accumulation of vesicles, the increased positive acridine orange-stained cells, the accumulation of LC3-II, and the elevation of autophagic flux. Whereas blockade of compound K-induced autophagy by 3-methyladenein and bafilomycin A1 significantly increased cell viability. In addition, compound K augmented the time-dependent expression of the autophagy-related proteins Atg5, Atg6, and Atg7. However, knockdown of Atg5, Atg6, and Atg7 markedly inhibited the detrimental impact of compound K on LC3-II accumulation and cell vitality. Compound K-provoked autophagy was also linked to the generation of intracellular reactive oxygen species (ROS); both of these processes were mitigated by the pre-treatment of cells with the antioxidant N-acetylcysteine. Moreover, compound K activated the c-Jun NH2-terminal kinase (JNK) signaling pathway, whereas downregulation of JNK by its specific inhibitor SP600125 or by small interfering RNA against JNK attenuated autophagy-mediated cell death in response to compound K. Compound K also provoked apoptosis, as evidenced by an increased number of apoptotic bodies and sub-G1 hypodiploid cells, enhanced activation of caspase-3 and caspase-9, and modulation of Bcl-2 and Bcl-2-associated X protein expression. Notably, compound K-stimulated autophagy as well as apoptosis was induced by disrupting the interaction between Atg6 and Bcl-2. Taken together, these results indicate that the induction of autophagy and apoptosis by compound K is mediated through ROS generation and JNK activation in human colon cancer cells.

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.

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.

Inhibitory effects of total saponin from Korean red ginseng via vasodilator-stimulated phosphoprotein-Ser(157) phosphorylation on thrombin-induced platelet aggregation

In this study, we have investigated the effects of total saponin from Korean red ginseng (TSKRG) on thrombin-induced platelet aggregation. TSKRG dose-dependently inhibited thrombin-induced platelet aggregation with IC₅₀ value of about 81.1 μg/mL. In addition, TSKRG dose-dependently decreased thrombin-elevated the level of cytosolic-free Ca²⁺ ([Ca²⁺]_i), one of aggregation-inducing molecules. Of two Ca²⁺-antagonistic cyclic nucleotides as aggregation-inhibiting molecules, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), TSKRG significantly dose-dependently elevated intracellular level of cAMP, but not cGMP. In addition, TSKRG dose-dependently inhibited thrombin-elevated adenosine triphosphate (ATP) release from platelets. These results suggest that the suppression of [Ca²⁺]_i elevation, and of ATP release by TSKRG are associated with upregulation of cAMP. TSKRG elevated the phosphorylation of vasodilator-stimulated phosphoprotein (VASP)-Ser¹⁵⁷, a cAMP-dependent protein kinase (A-kinase) substrate, but not the phosphorylation of VASP-Ser²³⁹, a cGMPdependent protein kinase substrate, in thrombin-activated platelets. We demonstrate that TSKRG involves in increase of cAMP level and subsequent elevation of VASP-Ser¹⁵⁷ phosphorylation through A-kinase activation to inhibit [Ca²⁺]_i mobilization and ATP release in thrombin-induced platelet aggregation. These results strongly indicate that TSKRG is a beneficial herbal substance elevating cAMP level in thrombin-platelet interaction, which may result in preventing of platelet aggregation-mediated thrombotic diseases.

Protective Effect of Heat-processed Ginseng (Sun Ginseng) in the Adenine-induced Renal Failure Rats

The effect of orally administered sun ginseng (SG), which is a ginseng processed by steaming, was examined in adenine-induced chronic renal failure rat. SG significantly decreased both blood urea nitrogen and serum creatinine levels, indicating an improvement of renal function. Also, SG significantly increased the urinary excretion of both urea and creatinine. Furthermore it lowered the blood pressure, and inhibited adenine-induced kidney hypertrophy and edema. Based on these findings, SG may ameliorate chronic renal failures.

Ginsenoside Rp1 Exerts Anti-inflammatory Effects via Activation of Dendritic Cells and Regulatory T Cells

Ginsenoside Rp1 (G-Rp1) is a saponin derivate that provides anti-metastatic activities through inhibition of the NF-κB pathway. In this study, we examined the effects of G-Rp1 on regulatory T cell (Treg) activation. After treatment of splenocytes with G-Rp1, Tregs exhibited upregulation of IL-10 expression, and along with dendritic cells (DCs), these Tregs showed increased cell number compared to other cell populations. The effect of G-Rp1 on Treg number was augmented in the presence of lipopolysaccharide (LPS), which mimics pathological changes that occur during inflammation. However, depletion of DCs prevented the increase in Treg number in the presence of G-Rp1 and/or LPS. In addition, G-Rp1 promoted the differentiation of the memory types of CD4⁺Foxp3⁺CD62L^low Tregs rather than the generation of new Tregs. In vivo experiments also demonstrated that Tregs and DCs from mice that were fed G-Rp1 for 7 d and then injected with LPS exhibited increased activation compared with those from mice that were injected with LPS alone. Expression of TGF-β and CTLA4 in Tregs was increased, and upregulation of IL-2 and CD80/ CD86 expression by DCs affected the suppressive function of Tregs through IL-2 receptors and CTLA4. These data demonstrate that G-Rp1 exerts anti-inflammatory effects by activating Tregs in vitro and in vivo.

Oleanane-triterpenoids from Panax stipuleanatus inhibit NF-κB

In continuation of our research to find biological components from Panax stipuleanatus, four oleanane-type triterpenes (12 to 15) were isolated successively. Fifteen oleanane-type saponins (1 to 15) were evaluated for nuclear factor (NF)-κB activity using a luciferase reporter gene assay in HepG2 cells. Compounds 6 to 11 inhibited NF-κB, with IC₅₀ values between 3.1 to 18.9 μM. The effects on inducible nitric oxide synthase and cyclooxygenase-2 by compounds 8, 10, and 11 were also examined using reverse transcription-polymerase chain reaction. Three compounds (8, 10, and 11) inhibited NF-κB activity by reducing the concentration of inflammatory factors in HepG2 cells.

Ginsenoside Rd inhibits the expressions of iNOS and COX-2 by suppressing NF-κB in LPS-stimulated RAW264.7 cells and mouse liver

Ginsenoside Rd is a primary constituent of the ginseng rhizome and has been shown to participate in the regulation of diabetes and in tumor formation. Reports also show that ginsenoside Rd exerts anti-oxidative effects by activating anti-oxidant enzymes. Treatment with ginsenoside Rd decreased nitric oxide and prostaglandin E₂ (PGE₂) in lipopolysaccharides (LPS)-challenged RAW264.7 cells and in ICR mouse livers (5 mg/kg LPS; LPS + ginsenoside Rd [2, 10, and 50 mg/kg]). Furthermore, these decreases were associated with the down-regulations of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and of nuclear factor (NF)-κB activity in vitro and in vivo. Our results indicate that ginsenoside Rd treatment decreases; 1) nitric oxide production (40% inhibition); 2) PGE₂ synthesis (69% to 93% inhibition); 3) NF-κB activity; and 4) the NF-κB-regulated expressions of iNOS and COX-2. Taken together, our results suggest that the anti-inflammatory effects of ginsenoside Rd are due to the down-regulation of NF-κB and the consequent expressional suppressions of iNOS and COX-2.

A comprehensive review of the therapeutic and pharmacological effects of ginseng and ginsenosides in central nervous system

Ginseng is one of the most widely used herbal medicines in human. Central nervous system (CNS) diseases are most widely investigated diseases among all others in respect to the ginseng’s therapeutic effects. These include Alzheimer’s disease, Parkinson’s disease, cerebral ischemia, depression, and many other neurological disorders including neurodevelopmental disorders. Not only the various types of diseases but also the diverse array of target pathways or molecules ginseng exerts its effect on. These range, for example, from neuroprotection to the regulation of synaptic plasticity and from regulation of neuroinflammatory processes to the regulation of neurotransmitter release, too many to mention. In general, ginseng and even a single compound of ginsenoside produce its effects on multiple sites of action, which make it an ideal candidate to develop multi-target drugs. This is most important in CNS diseases where multiple of etiological and pathological targets working together to regulate the final pathophysiology of diseases. In this review, we tried to provide comprehensive information on the pharmacological and therapeutic effects of ginseng and ginsenosides on neurodegenerative and other neurological diseases. Side by side comparison of the therapeutic effects in various neurological disorders may widen our understanding of the therapeutic potential of ginseng in CNS diseases and the possibility to develop not only symptomatic drugs but also disease modifying reagents based on ginseng.

The bioavailability of red ginseng extract fermented by Phellinus linteus

For the improvement of ginsenoside bioavailability, the ginsenosides of fermented red ginseng by Phellinus linteus (FRG) were examined with respect to bioavailability and physiological activity. The polyphenol content of FRG (19.14±0.50 mg/g) was significantly higher (p<0.05) compared with that of non-fermented red ginseng (NFRG, 11.31±1.15 mg/g). The antioxidant activities in FRG, such as 2,2’-diphenyl-1-picrylhydrazyl, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, and ferric reducing antioxidant power, were significantly higher (p<0.05) than those in NFRG. The HPLC analysis results showed that the FRG had a high level of ginsenoside metabolites. The total ginsenoside contents in NFRG and FRG were 41.65±1.53 mg/g and 50.12±1.43 mg/g, respectively. However, FRG had a significantly higher content (33.90±0.97 mg/g) of ginsenoside metabolites (Rg3, Rg5, Rk1, compound K, Rh1, F2, and Rg2) compared with NFRG (14.75±0.46 mg/g). The skin permeability of FRG was higher than that of NFRG using Franz diffusion cell models. In particular, after 3 h, the skin permeability of FRG was significantly higher (p<0.05) than that of NFRG. Using a rat everted intestinal sac model, FRG showed a high transport level compared with NFRG after 1 h. FRG had dramatically improved bioavailability compared with NFRG as indicated by skin permeation and intestinal permeability. The significantly greater bioavailability of FRG may have been due to the transformation of its ginsenosides by fermentation to more easily absorbable forms (ginsenoside metabolites).

Dipterocarpus tuberculatus ethanol extract strongly suppresses in vitro macrophage-mediated inflammatory responses and in vivo acute gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Dipterocarpus tuberculatus Roxb. (Dipterocarpaceae) has been traditionally used to treat various inflammatory symptoms. However, no mechanistic studies on the anti-inflammatory actions of D. tuberculatus have been reported. This study is therefore aimed at exploring the anti-inflammatory effects of 95% ethanol extracts (Dt-EE) of this plant.

MATERIALS AND METHODS

The regulatory activity of Dt-EE and its molecular mechanism on the release of nitric oxide (NO) and prostaglandin (PG)E2 in lipopolysaccharide (LPS)-treated macrophage-like RAW264.7 cells were elucidated by evaluating the activation of transcription factors and their upstream signals and by analyzing the kinase activities of target enzymes. Furthermore, to confirm its availability for oral use, an EtOH/HCl-induced acute gastritis model was tested with this extract.

RESULTS

Dt-EE effectively suppressed LPS-mediated inflammatory responses such as the production of NO and PGE2 from macrophages in a dose-dependent manner. In particular, Dt-EE clearly blocked the activation of NF-κB by blocking the phosphorylation of its upstream enzymes IKK and Akt. Using a direct enzyme assay, Dt-EE was shown to block the enzyme activity of PDK1. Finally, this extract also remarkably ameliorated inflammatory lesions in the stomach induced by EtOH/HCl.

CONCLUSION

Our data strongly suggest that Dt-EE can be considered as a novel anti-inflammatory remedy with PDK1/NF-κB inhibitory properties and can also be used to treat gastritis symptoms. In addition, our findings can serve as a basis for further phytochemical and pharmacological studies in the future.

p38/AP-1 pathway in lipopolysaccharide-induced inflammatory responses is negatively modulated by electrical stimulation

Electrical stimulation with a weak current has been demonstrated to modulate various cellular and physiological responses, including the differentiation of mesenchymal stem cells and acute or chronic physical pain. Thus, a variety of investigations regarding the physiological role of nano- or microlevel currents at the cellular level are actively proceeding in the field of alternative medicine. In this study, we focused on the anti-inflammatory activity of aluminum-copper patches (ACPs) under macrophage-mediated inflammatory conditions. ACPs generated nanolevel currents ranging from 30 to 55 nA in solution conditions. Interestingly, the nanocurrent-generating aluminum-copper patches (NGACPs) were able to suppress both lipopolysaccharide-(LPS-) and pam3CSK-induced inflammatory responses such as NO and PGE2 production in both RAW264.7 cells and peritoneal macrophages at the transcriptional level. Through immunoblotting and immunoprecipitation analyses, we found that p38/AP-1 could be the major inhibitory pathway in the NGACP-mediated anti-inflammatory response. Indeed, inhibition of p38 by SB203580 showed similar inhibitory activity of the production of TNF- α and PGE2 and the expression of TNF- α and COX-2 mRNA. These results suggest that ACP-induced nanocurrents alter signal transduction pathways that are involved in the inflammatory response and could therefore be utilized in the treatment of various inflammatory diseases such as arthritis and colitis.

In vitro and in vivo anti-inflammatory effect of Rhodomyrtus tomentosa methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Rhodomyrtus tomentosa (Aiton) Hassk. is a representative Thai medicinal plant traditionally used in South Asian countries to relieve various inflammatory symptoms. However, no systematic studies on its anti-inflammatory activity and mechanisms have been reported.

MATERIALS AND METHODS

The effect of the methanol extract from the leaves of this plant (Rt-ME) on the production of inflammatory mediators [nitric oxide (NO) and prostaglandin E2 (PGE2)] and the molecular mechanism of Rt-ME-mediated inhibition, including target enzymes, were studied with RAW264.7, peritoneal macrophage, and HEK293 cells. Additionally, the in vivo anti-inflammatory activity of this extract was evaluated with mouse gastritis and colitis models.

RESULTS

Rt-ME clearly inhibited the production of NO and PGE2 in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. According to RT-PCR, immunoblotting and immunoprecipitation analyses and a kinase assay with mRNA, whole cell extract, and nucleus lysates from RAW264.7 cells and mice, it was revealed that Rt-ME was capable of suppressing the activation of both nuclear factor (NF)-κB and activator protein (AP)-1 pathways by directly targeting Syk/Src and IRAK1/IRAK4.

CONCLUSION

Rt-ME could have anti-inflammatory properties by suppressing Syk/Src/NF-kB and IRAK1/IRAK4/AP-1 pathways and will be further developed as a herbal remedy for preventive and/or curative purposes in various inflammatory diseases.

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.

Methanol extract of Hopea odorata suppresses inflammatory responses via the direct inhibition of multiple kinases

ETHNOPHARMACOLOGICAL RELEVANCE

Hopea odorata Roxb. (Dipterocarpaceae) is a representative Thai ethnopharmacological herbal plant used in the treatment of various inflammation-related diseases. In spite of its traditional use, systematic studies of its anti-inflammatory action have not been performed.

MATERIALS AND METHODS

The inhibitory activities of a Hopea odorata methanol extract (Ho-ME) on the production of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin E(2) (PGE(2)) in RAW264.7 cells and peritoneal macrophages were investigated. The effects of Ho-ME on the gastritis symptoms induced by HCl/EtOH and on ear oedemas induced by arachidonic acid were also examined. Furthermore, to identify the immunopharmacological targets of this extract, nuclear fractionation, a reporter gene assay, immunoprecipitation, immunoblot analysis, and a kinase assay were employed.

RESULTS

Ho-ME strongly inhibited the release of NO, PGE(2), and TNF-α in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ho-ME also clearly suppressed the gene expression of pro-inflammatory cytokines and chemokines, such as interferon (IFN)-β, interleukin (IL)-12, and monocyte chemotactic protein-1 (MCP-1). By analysing the inhibited target molecules, Syk and Src were found to be suppressed in the inhibition of nuclear factor (NF)-κB pathway. In addition, the observed downregulation of activator protein (AP)-1 and cAMP response element-binding (CREB) was due to the direct inhibition of interleukin-1 receptor-associated kinase (IRAK)1 and IRAK4, which was also linked to the suppression of c-Jun N-terminal kinase (JNK) and p38. In agreement with the in vitro observations, this extract also ameliorated the inflammatory symptoms in EtOH/HCl-induced gastritis and arachidonic acid-induced ear oedemas in mice.

CONCLUSION

Ho-ME has potential as a functional herbal remedy targeting Syk- and Src-mediated anti-inflammatory mechanisms. Future pre-clinical studies will be needed to investigate this possibility.