Suppressive effects of T-412, a flavone on interleukin-4 production in T cells

N-Farnesyloxy-norcantharimide inhibits progression of human leukemic Jurkat T cells through regulation of mitogen-activated protein kinase and interleukin-2 production

This study investigated the anticancer effects of N-farnesyloxy-norcantharimide (NOC15), a newly synthesized norcantharidin (NCTD) analogue, on human leukemic Jurkat T cells and the signaling pathway underlying its effects. We found that the half maximal inhibitory concentration (IC50) of NOC15 on Jurkat T cells is 1.4 μmol/l, which is 11.14-fold (=15.6÷1.4) smaller than the 15.6 μmol/l of NCTD on Jurkat T cells, whereas the IC50 of NOC15 on human normal lymphoblast (HNL) is 207.9 μmol/l, which is 8.17-fold (=1698.0÷207.8) smaller than the 1698.0 μmol/l of NCTD on HNL cells. These results indicated that NOC15 exerts a higher anticancer effect on Jurkat T cells and has higher toxicity toward HNL cells than NCTD. Thus, NOC15 is 1.36-fold (=11.14÷8.17) beneficial as an anticancer agent toward Jurkat T cells compared with NCTD. Moreover, NOC15 can increase the percentage of cells in the sub-G1 phase and reduce the cell viability of Jurkat T cells, stimulate p38 and extracellular signal-regulated protein kinase 1/2 (ERK1/2) of mitogen-activated protein kinases (MAPKs) signaling pathway, and inhibit calcineurin expression and interleukin-2 (IL-2) production. However, NOC15 exerted no effects on the Jun-N-terminal kinase 1/2 (JNK1/2) signaling pathway, the production of IL-8, and tumor necrosis factor-α. We conclude that the anticancer activity of the newly synthesized NOC15 is 1.36-fold beneficial than NCTD as an anticancer agent and that NOC15 can increase the percentage of cells in the sub-G1 phase through the stimulation of p38 and ERK1/2 of the MAPK signaling pathway and the inhibition of calcineurin expression and IL-2 production. The NOC15 may have the potential of being developed into an anticancer agent in the future.

Myrsine seguinii ethanolic extract and its active component quercetin inhibit macrophage activation and peritonitis induced by LPS by targeting to Syk/Src/IRAK-1

ETHNOPHARMACOLOGICAL RELEVANCE

Myrsine seguinii H. LÉVEILLÉ (syn. Rapanea neriifolia) (Myrsinaceae) is a medicinal plants traditionally used in Myanmar to treat infectious and inflammatory diseases. Since none of reports have systematically demonstrated the anti-inflammatory activity of this plant, we aimed to mechanistically understand the regulatory roles of the plant in inflammatory responses using the ethanolic extract of Myrsine seguinii (Ms-EE).

MATERIALS AND METHODS

Activated macrophages and peritonitis symptoms induced by lipopolysaccharide (LPS) were employed. HPLC analysis was used to identify active components. To characterize direct target enzymes, kinase assay was established.

RESULTS

Ms-EE inhibited the production of nitric oxide (NO) and prostaglandin (PG)E2 in RAW264.7 cells and peritoneal macrophages stimulated by LPS. This extract suppressed the mRNA expression of the inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 genes by down-regulating the activation of nuclear factor (NF)-κB and activator protein (AP-1). Interestingly, it was found that Ms-EE can directly suppress the enzyme activities of Syk, Src, and interleukin-1 receptor-associated kinase-1 (IRAK-1). Similarly, orally administered Ms-EE inhibited the phosphorylation of Src and Syk in peritoneal exudate-derived cells prepared from peritonitis. Finally, HPLC analysis clearly demonstrated that quercetin is a major active component with suppressing activity on the release of inflammatory mediators (NO and PGE2), and the enzyme activities of Src, Syk, and IRAK-1.

CONCLUSION

Ms-EE containing quercetin negatively modulates macrophage-mediated in vitro inflammatory responses and LPS-induced peritonitis by blocking the Src/Syk/NF-κB and IRAK-1/AP-1 pathways, which contributes to its major ethnopharmacological use as an anti-inflammatory herbal medicine.

IRAK1/4-targeted anti-inflammatory action of caffeic acid

Caffeic acid (CA) is a phenolic compound that is frequently present in fruits, grains, and dietary supplements. Although CA has been reported to display various biological activities such as anti-inflammatory, anti-cancer, anti-viral, and anti-oxidative effects, the action mechanism of CA is not yet fully elucidated. In this study, the anti-inflammatory action mechanism of CA was examined in lipopolysaccharide (LPS) treated macrophages (RAW264.7 cells) and HCl/EtOH-induced gastritis. CA was found to diminish nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in LPS-stimulated RAW264.7 cells. Additionally, mRNA levels of tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and inducible NO synthase (iNOS) were downregulated by CA. CA also strongly suppressed the nuclear translocation of AP-1 family proteins and the related upstream signaling cascade composed of interleukin-1 receptor-associated kinase 1 (IRAK1), IRAK4, TGF-β-activated kinase 1 (TAK1), mitogen-activated protein kinase kinase 4/7 (MKK4/7), and c-Jun N-terminal kinase (JNK). In a direct kinase assay, CA was revealed to directly inhibit IRAK1 and IRAK4. CA also ameliorated HCl/EtOH-induced gastric symptoms via the suppression of JNK, IRAK1, and IRAK4. Therefore, our data strongly suggest that CA acts as an anti-inflammatory drug by directly suppressing IRAK1 and IRAK4.

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.

Antiallergic asthma properties of brazilin through inhibition of TH2 responses in T cells and in a murine model of asthma

This study aimed to determine whether brazilin exhibits anti-inflammatory effects that inhibit T helper cell type II (T(H)2) responses and whether it suppresses allergic inflammation reactions in a murine model of asthma. We found that brazilin inhibited the mRNA and protein expression of interleukin (IL)-4 and IL-5 induced by phorbol myristate acetate (PMA) and cAMP in EL-4 T cells in a dose-dependent manner. Following the intratracheal instillation of brazilin in ovalbumin (OVA)-immunized mice, we found that brazilin-treated mice exhibited decreases in the release of IL-4, IL-5, IL-13, eotaxin-1, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF); inhibited T(H)2 functioning via a decrease in IL-4 production; and exhibited attenuation of OVA-induced lung eosinophilia, airway hyperresponsiveness, and airway remodeling. These results suggest that brazilin exhibits anti-T(H)2 effects both in vitro and in vivo and may possess therapeutic potential for allergic diseases.

8-(Tosylamino)quinoline inhibits macrophage-mediated inflammation by suppressing NF-κB signaling

AIM

The macrophage-mediated inflammatory response may contribute to the development of cancer, diabetes, atherosclerosis and septic shock. This study was to characterize several new compounds to suppress macrophage-mediated inflammation.

METHODS

Peritoneal macrophages from C57BL/6 male mice and RAW264.7 cells were examined. Anti-inflammatory activity was evaluated in the cells exposed to lipopolysaccharide (LPS). The mechanisms of the anti-inflammatory activity were investigated via measuring transcription factor activation in response to specific signals and via assaying the activities of the target kinases.

RESULTS

Of 7 candidate compounds tested, 8-(tosylamino)quinoline (8-TQ, compound 7) exhibited the strongest activities in suppressing the production of NO, TNF-α, and PGE(2) in LPS-activated RAW264.7 cells and peritoneal macrophages (the IC(50) values=1-5 μmol/L). This compound (1.25-20 μmol/L) dose-dependently suppressed the expression of the pro-inflammatory genes for iNOS, COX-2, TNF-α, and the cytokines IL-1β and IL-6 at the level of transcription in LPS-activated RAW264.7 cells. 8-TQ (20 μmol/L) significantly suppressed the activation of NF-κB and its upstream signaling elements, including inhibitor of κB (IκBα), IκBα kinase (IKK) and Akt in LPS-activated RAW264.7 cells. In in vivo experiments, oral administration of 20 and 40 mg/kg 8-TQ for 3 d significantly alleviated the signs of LPS-induced hepatitis and HCl/EtOH-induced gastritis, respectively, in ICR mice.

CONCLUSION

8-TQ (compound 7) exerts significant anti-inflammatory activity through the inhibition of the Akt/NF-κB pathway, thus may be developed as a novel anti-inflammatory drug.

In vitro and in vivo anti-inflammatory activities of Polygonum hydropiper methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum hydropiper L. (Polygonaceae) has been traditionally used to treat various inflammatory diseases such as rheumatoid arthritis. However, no systematic studies on the anti-inflammatory actions of Polygonum hydropiper and its inhibitory mechanisms have been reported. This study is therefore aimed at exploring the anti-inflammatory effects of 99% methanol extracts (Ph-ME) of this plant.

MATERIALS AND METHODS

The effects of Ph-ME on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages were investigated. Molecular mechanisms underlying the effects, especially inhibitory effects, were elucidated by analyzing the activation of transcription factors and their upstream signalling, and by evaluating the kinase activities of target enzymes. Additionally, a dextran sulphate sodium (DSS)-induced colitis model was employed to see whether this extract can be used as an orally available drug.

RESULTS

Ph-ME dose-dependently suppressed the release of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin (PG)E(2), in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ph-ME inhibited mRNA expression of pro-inflammatory genes such as inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α by suppressing the activation of nuclear factor (NF)-κB, activator protein (AP-1), and cAMP responsive element binding protein (CREB), and simultaneously inhibited its upstream inflammatory signalling cascades, including cascades involving Syk, Src, and IRAK1. Consistent with these findings, the extract strongly suppressed the kinase activities of Src and Syk. Based on HPLC analysis, quercetin, which inhibits NO and PGE(2) activities, was found as one of the active ingredients in Ph-ME.

CONCLUSION

Ph-ME exerts strong anti-inflammatory activity by suppressing Src/Syk/NF-κB and IRAK/AP-1/CREB pathways, which contribute to its major ethno-pharmacological role as an anti-gastritis remedy.

The ability of an ethanol extract of Cinnamomum cassia to inhibit Src and spleen tyrosine kinase activity contributes to its anti-inflammatory action

ETHNOPHARMACOLOGICAL RELEVANCE

Cinnamomum cassia Blume (Aceraceae) has been traditionally used to treat various inflammatory diseases such as gastritis. However, the anti-inflammatory mechanism of Cinnamomum cassia has not been fully elucidated. This study examined the anti-inflammatory mechanism of 95% ethanol extract (Cc-EE) of Cinnamomum cassia.

MATERIALS AND METHODS

The effect of Cc-EE on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages was investigated. Molecular mechanisms underlying the effects, especially inhibitory effects, was elucidated by analyzing the activation of transcription factors and their upstream signaling, and by evaluating the kinase activity of target enzymes.

RESULTS

Cc-EE of Cinnamomum cassia diminished the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin (PG)E(2), in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. Cc-EE also blocked mRNA expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α by suppressing the activation of nuclear factor (NF)-κB, and simultaneously inhibited its upstream inflammatory signaling cascades, including spleen tyrosine kinase (Syk) and Src. Consistent with these findings, the extract directly blocked the kinase activities of Src and Syk.

CONCLUSION

Cc-EE exerts strong anti-inflammatory activity by suppressing Src/Syk-mediated NF-κB activation, which contributes to its major ethno-pharmacological role as an anti-gastritis remedy. Future work will be focused on determining whether the extract can be further developed as an anti-inflammatory drug.

Nanostructured, self-assembling peptide K5 blocks TNF-α and PGE₂ production by suppression of the AP-1/p38 pathway

Nanostructured, self-assembling peptides hold promise for a variety of regenerative medical applications such as 3D cell culture systems, accelerated wound healing, and nerve repair. The aim of this study was to determine whether the self-assembling peptide K5 can be applied as a carrier of anti-inflammatory drugs. First, we examined whether the K5 self-assembling peptide itself can modulate various cellular inflammatory responses. We found that peptide K5 significantly suppressed the release of tumor-necrosis-factor- (TNF-) α and prostaglandin E₂ (PGE₂) from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Similarly, there was inhibition of cyclooxygenase- (COX-) 2 mRNA expression assessed by real-time PCR, indicating that the inhibition is at the transcriptional level. In agreement with this finding, peptide K5 suppressed the translocation of the transcription factors activator protein (AP-1) and c-Jun and inhibited upstream inflammatory effectors including mitogen activated protein kinase (MAPK), p38, and mitogen-activated protein kinase kinase 3/6 (MKK 3/6). Whether this peptide exerts its effects via a transmembrane or cytoplasmic receptor is not clear. However, our data strongly suggest that the nanostructured, self-assembling peptide K5 may possess significant anti-inflammatory activity via suppression of the p38/AP-1 pathway.

Anti-inflammatory activity of ethanol extract derived from Phaseolus angularis beans

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Phaseolus angularis Wight (adzuki bean) is an ethnopharmacologically well-known folk medicine that is prescribed for infection, edema, and inflammation of the joints, appendix, kidney and bladder in Korea, China and Japan.

AIM OF STUDY

The anti-inflammatory effect of this plant and its associated molecular mechanisms will be investigated.

MATERIALS AND METHODS

The immunomodulatory activity of Phaseolus angularis ethanol extract (Pa-EE) in toll like receptor (TLR)-activated macrophages induced by ligands such as lipopolysaccharide (LPS), Poly (I:C), and pam3CSK was investigated by assessing nitric oxide (NO) and prostaglandin (PG)E(2) levels. To identify which transcription factors such as nuclear factor (NF)-κB and their signaling enzymes can be targeted to Pa-EE, biochemical approaches including reporter gene assays, immunoprecipitation, kinase assays, and immunoblot analyses were also employed. Finally, whether Pa-EE was orally available, ethanol (EtOH)/hydrochloric acid (HCl)-induced gastritis model in mice was used.

RESULTS

Pa-EE dose-dependently suppressed the release of PGE(2) and NO in LPS-, Poly(I:C)-, and pam3CSK-activated macrophages. Pa-EE strongly down-regulated LPS-induced mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2. Interestingly, Pa-EE markedly inhibited NF-κB, activator protein (AP)-1, and cAMP response element binding protein (CREB) activation; further, according to direct kinase assays and immunoblot analyses, Pa-EE blocked the activation of the upstream signaling molecules spleen tyrosine kinase (Syk), p38, and transforming growth factor β-activated kinase 1 (TAK1). Finally, orally administered Pa-EE clearly ameliorated EtOH/HCl-induced gastritis in mice.

CONCLUSION

Our results suggest that Pa-EE can be further developed as a promising anti-inflammatory remedy because it targets multiple inflammatory signaling enzymes and transcription factors.