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

Foresight regarding drug candidates acting on the succinate-GPR91 signalling pathway for non-alcoholic steatohepatitis (NASH) treatment

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and it is a liver manifestation of metabolic syndrome, with a histological spectrum from simple steatosis to non-alcoholic steatohepatitis (NASH). NASH can evolve into progressive liver fibrosis and eventually lead to liver cirrhosis. The pathological mechanism of NASH is multifactorial, involving a series of metabolic disorders and changes that trigger low-level inflammation in the liver and other organs. In the pathogenesis of NASH, the signal transduction pathway involving succinate and the succinate receptor (G-protein-coupled receptor 91, GPR91) regulates inflammatory cell activation and liver fibrosis. This review describes the mechanism of the succinate-GPR91 signalling pathway in NASH and summarizes the drugs that act on this pathway, with the aim of providing a new approach to NASH treatment.

Dietary phytochemicals that influence gut microbiota: Roles and actions as anti-Alzheimer agents

The last decide has witnessed a growing research interest in the role of dietary phytochemicals in influencing the gut microbiota. On the other hand, recent evidence reveals that dietary phytochemicals exhibit properties of preventing and tackling symptoms of Alzheimer's disease, which is a neurodegenerative disease that has also been linked with the status of the gut microbiota over the last decade. Till now, little serious discussions, however, have been made to link recent understanding of Alzheimer's disease, dietary phytochemicals and the gut microbiota together and to review the roles played by phytochemicals in gut dysbiosis induced pathologies of Alzheimer's disease. Deciphering these connections can provide insights into the development and future use of dietary phytochemicals as anti-Alzheimer drug candidates. This review aims at presenting latest evidence in the modulating role of phytochemicals in the gut microbiota and its relevance to Alzheimer's disease and summarizing the mechanisms behind the modulative activities. Limitations of current research in this field and potential directions will also be discussed for future research on dietary phytochemicals as anti-Alzheimer agents.

Activation of hypoxia-inducible factor 1 (Hif-1) enhanced bactericidal effects of macrophages to Mycobacterium tuberculosis

BACKGROUND

Tuberculosis is chronic infection caused by Mycobacterium tuberculosis (M.tb), which infects specifically macrophages. Hif-1, hypoxia-inducible factor-1, was reported to act as master regulator of killing functions in macrophages.

AIM

To investigate whether Hif-1 activation would enhance bactericidal effect of macrophages and anti-tuberculosis effect of chemical reagent.

METHODS

Hif-1 and LC3B were detected in tissues from pulmonary tuberculosis. U937, human monocytic leukemia cell line, was stimulated with PMA and differentiated into macrophages. Cells were pretreated with Hif-1 chemical inhibitor YC-1, stimulated with CoCl₂ (Hif-1 activator), to detect LC3B with Western blot and confocal microscopy. Cells were infected with M. tb H37Rv strain, stimulated with CoCl₂, following rifampine treatment. Expression of autophagy markers was detected using Western blot. IL-6 and TNF-α were detected in cell supernatant with ELISA. Acid-fast staining and CFU assay were performed to evaluate intracellular bacterial load.

RESULTS AND CONCLUSIONS

Hif-1 and LC3B increased in tissues of pulmonary tuberculosis. Hif-1 activation enhanced autophagy in M. tb infected U937 cells and production of IL-6 and TNF-α. Data from acid-fast staining and CFU indicated that Hif-1 activation enhanced anti-tuberculosis effect of rifampine in macrophages. Conclusively, to activate Hif-1 would strengthen bactericidal effect of macrophages, to further enhance anti-tuberculosis effect of chemical reagent.

Identification of Potential COX-2 Inhibitors for the Treatment of Inflammatory Diseases Using Molecular Modeling Approaches

Non-steroidal anti-inflammatory drugs are inhibitors of cyclooxygenase-2 (COX-2) that were developed in order to avoid the side effects of non-selective inhibitors of COX-1. Thus, the present study aims to identify new selective chemical entities for the COX-2 enzyme via molecular modeling approaches. The best pharmacophore model was used to identify compounds within the ZINC database. The molecular properties were determined and selected with Pearson’s correlation for the construction of quantitative structure–activity relationship (QSAR) models to predict the biological activities of the compounds obtained with virtual screening. The pharmacokinetic/toxicological profiles of the compounds were determined, as well as the binding modes through molecular docking compared to commercial compounds (rofecoxib and celecoxib). The QSAR analysis showed a fit with R = 0.9617, R² = 0.9250, standard error of estimate (SEE) = 0.2238, and F = 46.2739, with the tetra-parametric regression model. After the analysis, only three promising inhibitors were selected, Z-964, Z-627, and Z-814, with their predicted pIC₅₀ (−log IC₅₀) values, Z-814 = 7.9484, Z-627 = 9.3458, and Z-964 = 9.5272. All candidates inhibitors complied with Lipinski’s rule of five, which predicts a good oral availability and can be used in in vitro and in vivo tests in the zebrafish model in order to confirm the obtained in silico data.

Isoprenylcysteine Carboxyl Methyltransferase and Its Substrate Ras Are Critical Players Regulating TLR-Mediated Inflammatory Responses

In this study, we investigated the functional role of isoprenylcysteine carboxyl methyltransferase (ICMT) and its methylatable substrate Ras in Toll-like receptor (TLR)-activated macrophages and in mouse inflammatory disease conditions. ICMT and RAS expressions were strongly increased in macrophages under the activation conditions of TLRs by lipopolysaccharide (LPS, a TLR4 ligand), pam3CSK (TLR2), or poly(I:C) (TLR3) and in the colons, stomachs, and livers of mice with colitis, gastritis, and hepatitis. The inhibition and activation of ICMT and Ras through genetic and pharmacological approaches significantly affected the activation of interleukin-1 receptor-associated kinase (IRAK)s, tumor necrosis factor receptor associated factor 6 (TRAF6), transforming growth factor-β-activated kinase 1 (TAK1), mitogen-activated protein kinase (MAPK), and MAPK kinases (MAPKKs); translocation of the AP-1 family; and the expressions of inflammation-related genes that depend on both MyD88 and TRIF. Interestingly, the Ras/ICMT-mediated inflammatory reaction critically depends on the TIR domains of myeloid differentiation primary response 88 (MyD88) and TIR-domain-containing adapter-inducing interferon-β (TRIF). Taken together, these results suggest that ICMT and its methylated Ras play important roles in the regulation of inflammatory responses through cooperation with the TIR domain of adaptor molecules.

Alternative & complementary treatment for pediatric inflammatory bowel disease

Alternative medicine includes treatments that are not considered mainstream and is suggested to replace the accepted treatment, while complementary treatment is added to the conventional treatment. The estimated prevalence of their use in patients with inflammatory bowel disease (IBD) is high, ranging between 21-60%. This review summarizes the data on these treatments and their efficacy in the setting of IBD.

A novel benzamide derivative protects ligature-induced alveolar bone erosion by inhibiting NFATc1-mediated osteoclastogenesis

Since elevated osteoclast formation and/or activity by inhibitory responses against pathogens leads to diverse osteolytic bone diseases including periodontitis, inhibition of osteoclast differentiation and bone resorption has been a primary therapeutic strategy. In this study, we investigated the therapeutic potential of a novel benzamide-linked molecule, OCLI-070, for preventing alveolar bone loss in mice with ligature-induced experimental periodontitis. OCLI-070 inhibited osteoclast formation by acting on both early and late stages of differentiation, and attenuated the induction of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) and the expression of osteoclast-specific genes. In addition, OCLI-070 significantly suppressed the formation of actin rings and resorption pits. Analysis of the inhibitory action of OCLI-070 showed that it markedly suppressed receptor activator of nuclear factor-κB ligand (RANKL)-induced extracellular signal-regulated kinase (ERK) and NF-κB signaling cascades. Moreover, OCLI-070 prevented ligature-induced alveolar bone erosion in mice by suppressing osteoclast formation. These findings demonstrate that OCLI-070 attenuated osteoclast differentiation and function as well as ligature-induced bone erosion by inhibiting RANKL-mediated ERK and NF-κB signaling pathways.

Resveratrol suppresses hyperglycemia-induced activation of NF-κB and AP-1 via c-Jun and RelA gene regulation

Background: Resveratrol (RSV) provides several important biological functions in wide variety of cells. In this study, we investigated the molecular mechanisms underlying anti-inflammatory effect of RSV on HepG2 cells by assessing the gene expression of RelA and c-Jun- subunits of NF-κB and AP-1 transcription factors.

Methods: HepG2 cells were settled in a serum- free medium with high concentrations of glucose (30 mM) and insulin (1 µM) overnight and were then incubated with RSV (5, 10, and 20 µM) for 24 and 48 hours. Real time quantitative polymerase chain reaction (qRT-PCR) was used to determine RelA and c-Jun expression.

Results: RSV diminished hyperglycemia/hyperinsulinemia stimulated expression of c-Jun dose- dependently after 24 and 48 hours (p<0.05). In addition, RelA gene expression was decreased dose-dependently in all RSV doses after 48-hour incubation (p<0.05). Our results indicated that RSV may reduce NF-κB and AP-1 activity via RelA and c-Jun gene regulation.

Conclusion: The findings of the present study demonstrated that RSV may be considered as a preventative and therapeutic agent for antagonizing inflammation in Hepatocellular carcinoma (HCC).

IRAK-M alters the polarity of macrophages to facilitate the survival of Mycobacterium tuberculosis

Background

Intracellular bacterium, Mycobacterium tuberculosis (M. tb), infects specifically macrophages as host cells. IRAK-M, a member of IRAK family, is a negative regulator in TLR signaling and specifically expresses in monocytes and macrophages. The role of IRAK-M in intracellular growth of M. tb and macrophage polarization was explored, for deeply understanding the pathogenesis of M. tb, the significance of IRAK-M to innate immunity and pathogen-host interaction.

Methods

IRAK-M expression was detected in M. tb infected macrophages and in human lung tissue of pulmonary tuberculosis with immunofluorescence staining, Western blot and immunohistochemistry. IRAK-M knock-down and over-expressing cell strains were constructed and intracellular survival of M. tb was investigated by acid-fast staining and colony forming units. Molecular markers of M1-type (pSTAT1 and iNOS) and M2-type (pSTAT6 and Arg-1) macrophages were detected using Western blot in IRAK-M knockdown U937 cells infected with M. tb H37Rv. U937 cells were stimulated with immunostimulant CpG7909 into M1 status and then infected with M. tb H37Rv. Expression of IRAK-M, IRAK-4 and iNOS was detected with immunofluorescence staining and Western blot, to evaluate the effect of IRAK-M to CpG directed M1-type polarization of macrophages during M. tb infection. Molecules related with macrophage’s bactericidal ability such as Hif-1 and phosphorylated ERK1/2 were detected with immunohistochemistry and Western blot.

Results

IRAK-M increased in M. tb infected macrophage cells and also in human lung tissue of pulmonary tuberculosis. IRAK-M over-expression resulted in higher bacterial load, while IRAK-M interference resulted in lower bacterial load in M. tb infected cells. During M. tb infection, IRAK-M knockdown induced M1-type, while inhibited M2-type polarization of macrophage. M1-type polarization of U937 cells induced by CpG7909 was inhibited by M. tb infection, which was reversed by IRAK-M knockdown in U937 cells. IRAK-M affected Hif-1 and MAPK signaling cascade during M. tb infection.

Conclusions

Conclusively, IRAK-M might alter the polarity of macrophages, to facilitate intracellular survival of M. tb and affect Th1-type immunity of the host, which is helpful to understanding the pathogenesis of M. tb.

Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation

Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD.

Anti-Inflammation of N-Benzyl-4-Bromobenzamide in Lipopolysaccharide-Induced Human Gingival Fibroblasts

OBJECTIVE

To evaluate the effect of N-benzyl-4-bromobenzamide (NBBA) on lipopolysaccharide (LPS)-induced IL-6 and prostaglandin E2 (PGE2) production in human gingival fibroblasts (HGFs).

MATERIAL AND METHODS

The benzamide compound was synthesized. The condition for IL-6 production of HGFs after induction with LPS was optimized. The HGFs were incubated with NBBA (10 µg/ml) for 30 min before LPS (1 μg/ml) was added. After 24 h of incubation time, the culture media were harvested and their IL-6 and PGE2 contents were determined using an enzyme-linked immunosorbent assay. Prednisolone (PDS) and NS-398 were used as positive controls. Statistical analysis of the IL-6 and PGE2 contents was performed using the ANOVA test followed by the Tukey multiple-comparisons test to compare replicate means. p < 0.001 was considered statistically significant.

RESULTS

The maximum IL-6 production was achieved when HGFs were exposed to 1 μg/ml of LPS for 24 h, which was inhibited by the IL-6 immunosuppressant PDS. The benzamide compound, NBBA, exhibited a potent anti-IL-6 activity with inhibition of 35.6 ± 0.5%, significantly different from in the LPS-induced HGFs (p < 0.001). In addition, it inhibited 75.6 ± 0.52% PGE2 production. Cell viability was not significantly affected by treatment with NBBA at a concentration <10 µg/ml (p < 0.001).

CONCLUSIONS

NBBA exhibited an inhibitory effect on the production of IL-6 and PGE2 in LPS-induced HGFs. It could serve as a compound with inhibiting inflammatory activity in periodontal disease.

Soyasaponin Ab inhibits lipopolysaccharide-induced acute lung injury in mice

Soyasaponin Ab (SA) has been reported to have anti-inflammatory effect. However, the effects of SA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) have not been reported. The aim of this study was to investigate the anti-inflammatory effects of SA on LPS-induced ALI and clarify the possible mechanism. The mice were stimulated with LPS to induce ALI. SA was given 1h after LPS treatment. 12h later, lung tissues were collected to assess pathological changes and edema. Bronchoalveolar lavage fluid (BALF) was collected to assess inflammatory cytokines and nitric oxide (NO) production. In vitro, mice alveolar macrophages were used to investigate the anti-inflammatory mechanism of SA. Our results showed that SA attenuated LPS-induced lung pathological changes, edema, the expression of cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissues, as well as TNF-α, IL-6, IL-1β, and NO production in mice. Meanwhile, SA up-regulated the activities of superoxide dismutase (SOD) and catalase decreased by LPS in mice. SA also inhibited LPS-induced TNF-α, IL-6 and IL-1β production as well as NF-κB activation in alveolar macrophages. Furthermore, SA could activate Liver X Receptor Alpha (LXRα) and knockdown of LXRα by RNAi abrogated the anti-inflammatory effects of SA. In conclusion, the current study demonstrated that SA exhibited protective effects against LPS-induced acute lung injury and the possible mechanism was involved in activating LXRα, thereby inhibiting LPS-induced inflammatory response.

Phytochemicals and their potential usefulness in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with unclear etiology, namely ulcerative colitis and Crohn's disease. Various drug therapies including aminosalicylates and immunomodulators have been approved for use; they have shown to produce diverse side effects. To overcome these limitations of the current therapeutics for IBD, extensive research is underway to identify drugs that are effective and free of undesirable side effects. Recently, various naturally occurring phytochemicals that cover a wide range of chemical entities such as polyphenols, terpeniods, flavonoids, and alkaloids have received attention as alternative candidates for IBD therapy. These phytochemicals act by modulating the immune response, various transcription factors, or reduce cytokine secretion. This review summarizes the findings of recent studies on phytochemicals as therapeutic agents in the management of IBD.

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.

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.

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.

Resveratrol counteracts inflammation in human M1 and M2 macrophages upon challenge with 7-oxo-cholesterol: potential therapeutic implications in atherosclerosis

Macrophages consist of two main subsets: the proinflammatory M1 subset and the anti-inflammatory M2 one. 7-oxo-cholesterol, the most abundant cholesterol autoxidation product within atherosclerotic plaque, is able to skew the M1/M2 balance towards a proinflammatory profile. In the present study, we explored the ability of the polyphenolic compound resveratrol to counteract the 7-oxo-cholesterol-triggered proinflammatory signaling in macrophages. Resveratrol-pretreated human monocyte-derived M1 and M2 macrophages were challenged with 7-oxo-cholesterol and analyzed for phenotype and endocytic ability by flow cytometry, for metalloproteinase- (MMP-) 2 and MMP-9 by gelatin zymography, and for cytokine, chemokine, and growth factor secretome by a multiplex immunoassay. We also investigated the NF-κB signaling pathway. In the M1 subset, resveratrol prevented the downregulation of CD16 and the upregulation of MMP-2 in response to 7-oxo-cholesterol, whereas in M2 macrophages it prevented the upregulation of CD14, MMP-2, and MMP-9 and the downregulation of endocytosis. Resveratrol prevented the upregulation of several proinflammatory and proangiogenic molecules in both subsets. We identified modulation of NF-κB as a potential mechanism implicated in 7-oxo-cholesterol and resveratrol effects. Our results strengthen previous findings on the immunomodulatory ability of resveratrol and highlight its role as potential therapeutic or preventive compound, to counteract the proatherogenic oxysterol signaling within atherosclerotic plaque.

Anti-inflammatory activities and mechanisms of Artemisia asiatica ethanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia asiatica Nakai (Compositae) is a representative herbal plant used to treat infection and inflammatory diseases. Although Artemisia asiatica is reported to have immunopharmacological activities, the mechanisms of these activities and the effectiveness of Artemisia asiatica preparations in use are not known.

MATERIALS AND METHODS

To evaluate the anti-inflammatory activities of Artemisia asiatica ethanol extract (Aa-EE), we assayed nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E2 (PGE2) in macrophages and measured the extent of tissue injury in a model of gastric ulcer induced in mice by treatment with HCl in EtOH. Putative enzymatic mediators of Aa-EE activities were identified by nuclear fractionation, reporter gene assay, immunoprecipitation, immunoblotting, and kinase assay. Active compound in Aa-EE was identified using HPLC.

RESULTS

Treatment of RAW264.7 cells and peritoneal macrophages with Aa-EE suppressed the production of NO, PGE2, and TNF-α in response to lipopolysaccharide (LPS) and induced heme oxygenase-1 expression. The Aa-EE also ameliorated symptoms of gastric ulcer in HCl/EtOH-treated mice. These effects were associated with the inhibition of nuclear translocation of nuclear factor (NF)-κB and activator protein (AP)-1, implying that the anti-inflammatory action of the Aa-EE occurred through transcriptional inhibition. The upstream regulatory signals Syk and Src for translocation of NF-κB and TRAF6 for AP-1 were identified as targets of this effect. Analysis of Aa-EE by HPLC revealed the presence of luteolin, known to inhibit NO and PGE2 activity.

CONCLUSION

The anti-inflammatory activities attributed to Artemisia asiatica Nakai in traditional medicine may be mediated by luteolin through inhibition of Src/Syk/NF-κB and TRAF6/JNK/AP-1 signaling pathways.