In order to identify the active anti-inflammatory ingredient(s) in Cirsium chanroenicum (Compositae), its methanol extract and several solvent fractions were prepared; the methanol extract and the ...ethylacetate fraction inhibited cyclooxygenase-2 (COX-2)-mediated prostaglandin E2 (PGE2) and 5-lipoxygenase (5-LOX)-mediated leukotriene (LT) production in lipopolysaccharide-treated RAW 264.7 cells and A23187-treated rat basophilic leukemia (RBL-1) cells, respectively. Further bioactivity-guided fractionation of the ethylacetate fraction using column chromatography led to the isolation of pectolinarigenin (5,7-dihydroxy-4′,6-dimethoxyflavone), along with pectolinarin pectolinarigenin 7-rhamnosyl-(1→6)-glucoside. Pectolinarigenin strongly inhibited COX-2-mediated PGE2 and 5-LOX-mediated LT production at >1 μM, indicating that it is a dual inhibitor of COX-2/5-LOX. However, pectolinarigenin did not affect COX-2 expression or nuclear transcription factor (NF-κB) activation. In addition, in vivo studies demonstrated that oral administration of these two compounds at 20—100 mg/kg resulted in similar inhibitory activities against several animal models of inflammation/allergy: arachidonic acid-induced mouse ear edema, carrageenan-induced mouse paw edema and passive cutaneous anaphylaxis. All of these results suggest that pectolinarigenin and pectolinarin possess anti-inflammatory activity and that they may inhibit eicosanoid formation in inflammatory lesions. These activities certainly contribute to the anti-inflammatory mechanism of C. chanroenicum.
Plant flavonoids show anti-inflammatory activity in vitro and in vivo. Although not fully understood, several action mechanisms are proposed to explain in vivo anti-inflammatory action. One of the ...important mechanisms is an inhibition of eicosanoid generating enzymes including phospholipase A2, cyclooxygenases, and lipoxygenases, thereby reducing the concentrations of prostanoids and leukotrienes. Recent studies have also shown that certain flavonoids, especially flavone derivatives, express their anti-inflammatory activity at least in part by modulation of proinflammatory gene expression such as cyclooxygenase-2, inducible nitric oxide synthase, and several pivotal cytokines. Due to these unique action mechanisms and significant in vivo activity, flavonoids are considered to be reasonable candidates for new anti-inflammatory drugs. To clearly establish the therapeutic value in inflammatory disorders, in vivo anti-inflammatory activity, and action mechanism of varieties of flavonoids need to be further elucidated. This review summarizes the effect of flavonoids on eicosanoid and nitric oxide generating enzymes and the effect on expression of proinflammatory genes. In vivo anti-inflammatory activity is also discussed. As natural modulators of proinflammatory gene expression, certain flavonoids have a potential for new anti-inflammatory agents.
Rutaecarpine is a pentacyclic indolopyridoquinazolinone alkaloid found in Evodia rutaecarpa and other related herbs. It has a variety of intriguing biological properties, which continue to attract ...the academic and industrial interest. Studies on rutaecarpine have included isolation from new natural sources, development of new synthetic methods for its total synthesis, the discovery of new biological activities, metabolism, toxicology, and establishment of analytical methods for determining rutaecarpine content. The present review focuses on the synthesis, biological activities, and structure-activity relationships of rutaecarpine derivatives, with respect to their antiplatelet, vasodilatory, cytotoxic, and anticholinesterase activities.
Fourteen compounds were isolated from the flowers of Inula japonica THUNB. (Asteraceae), including two new compounds, (1S,2S,4S,5S,8S,10R)-2-acetoxy-4,3-dihydroxy-pseudoguai-7(11)-en-12,8-olide (1) ...and (1S,2S,4S,5S,8S,10R)-2,4,13-trihydroxy-pseudoguai-7(11)-en-12,8-olide (2), and twelve known compounds, budlein B (3), 6β-hydroxytomentosin (4), 6-deacetoxybritanin (5), 4-epipulchellin (6), britanin (7), tomentosin (8), (+)-dihydroquercetin (9), (−)-syringaresinol (10), quercetagetin 3,4′-dimethyl ether (11), luteolin (12), britanin G (13) and inuchinenolide C (14). Structures of 1 and 2 were determined based on one and two dimensional (1D)- and (2D)-NMR data and Mosher’s esterification method. Compounds 9 and 12 showed inhibitory activities toward DNA topoisomerase I with IC50 values of 55.7 and 37.0 µM, respectively, compared to camptothecin (CPT) with an IC50 of 24.5 µM. Compounds 7–9 and 11–14 exhibited more potent inhibitory activity against topoisomerases II with IC50 values of 6.9, 3.8, 3.0, 6.9, 10.0, 14.7 and 13.8 µM, respectively, than that of etoposide (VP-16) with an IC50 of 26.9 µM. Compounds 4–7 and 10–14 exhibited weak cytotoxicities to the selected cancer cell lines.
Nur77 (NR4A1) plays an important role in various inflammatory responses. Nur77 is rapidly degraded in cells and its protein level is critically controlled. Although few E3 ligases regulating the ...Nur77 protein have been defined, the deubiquitinase (DUB) responsible for Nur77 stability has not been reported to date. We identified ovarian tumor domain-containing ubiquitin aldehyde binding protein 1 (OTUB1) as a DUB that stabilizes Nur77 by preventing its proteasomal degradation. We found that OTUB1 interacted with Nur77 to deubiquitinate it, thereby stabilizing Nur77 in an Asp88-dependent manner. This suggests that OTUB1 targets Nur77 for deubiquitination via a non-canonical mechanism. Functionally, OTUB1 inhibited TNFα-induced IL-6 production by promoting Nur77 protein stability. OTUB1 modulated the stability of Nur77 as a counterpart of tripartite motif 13 (Trim13). That is, OTUB1 reduced the ubiquitination and degradation of Nur77 potentiated by Trim13. In addition, this DUB also inhibited IL-6 production, which was further amplified by Trim13 in TNFα-induced responses. These findings suggest that OTUB1 is an important regulator of Nur77 stability and plays a role in controlling the inflammatory response.
•OTUB1 stabilizes the transcription factor Nur77 by deubiquitination.•OTUB1 interacts with Nur77 and promotes its deubiquitination by a non-canonical pathway.•OTUB1 inhibits TNFα-induced IL-6 production through the stability of Nur77.•OTUB1 acts as a partner of Trim13, E3 ligase, to regulate the stability of Nur77.
Isothiocyanates, which are present as glucosinolate precursors in cruciferous vegetables, have strong activity against various cancers. Here, we compared the anti-metastatic effects of ...isothiocyanates (benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC), and sulforaphane (SFN)) by examining how they regulate MMP-9 expression. Isothiocyanates, particularly PEITC, suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP-9 activity and invasion in various cancer cell lines. By contrast, N-methyl phenethylamine, a PEITC analog without an isothiocyanate functional group, had no effect. A reporter gene assay demonstrated that BITC, PEITC, and SFN suppressed TAP-induced MMP-9 expression by inhibiting AP-1 and NF-κB in U20S osteosarcoma cells. All three compounds reduced phosphorylation of FAK, ERK1/2, and Akt. In addition, MMP-9 expression was downregulated by inhibiting FAK, ERK1/2, and Akt. Isothiocyanates-mediated inhibition of FAK phosphorylation suppressed phosphorylation of ERK1/2 and Akt in U2OS and A549 cells, along with the translocation of p65 and c-Fos, suggesting that isothiocyanates inhibit MMP-9 expression and cell invasion by blocking phosphorylation of FAK. Furthermore, isothiocyanates, abolished MMP-9 expression and tumor metastasis
with the following efficacy: PEITC>BITC>SFN. Thus, isothiocyanates act as anti-metastatic compounds that suppress MMP-9 activity/expression by inhibiting NF-κB and AP-1 via suppression of the FAK/ERK and FAK/Akt signaling pathways.
Nur77 is a member of the NR4A subfamily of nuclear receptors and has been shown to regulate various biological processes such as apoptosis and inflammation. Here, we show that Nur77 ubiquitination is ...mediated by the tripartite motif 13 (Trim13), a RING-type E3 ubiquitin ligase. The interaction between Nur77 and Trim13 was confirmed by co-immunoprecipitation. Moreover, we found that Lys539 in Nur77 ubiquitination is targeted for Trim13, which leads to Nur77 degradation. The Trim13-mediated ubiquitination of Nur77 was optimal in the presence of the E2 enzyme UbcH5. Importantly, in addition to Trim13-mediated ubiquitination, the stability of Nur77 was also regulated by casein kinase 2α (CK2α). Pharmacological inhibition of CK2 markedly increased Nur77 levels, whereas overexpression of CK2α, but not its inactive mutant, dramatically decreased Nur77 levels by promoting Nur77 ubiquitination. CK2α phosphorylated Ser154 in Nur77 and thereby regulated Nur77 protein levels by promoting its ubiquitin-mediated degradation. Importantly, we also show that degradation of Nur77 is involved in TNFα-mediated IL-6 production via CK2α and Trim13. Taken together, these results suggest that the sequential phosphorylation and ubiquitination of Nur77 controls its degradation, and provide a therapeutic approach for regulating Nur77 activity through the CK2α-Trim13 axis as a mechanism to control the inflammatory response.
•Melittin inhibits EGF-induced cell motility and invasion in breast cancer cells.•MMP-9 and FAK are key factors on the inhibition of EGF-induced cell invasion by melittin.•Melittin suppresses ...EGF-induced cell invasion by reducing the PI3K/Akt/mTOR signaling pathway in breast cancer cells.
Bee venom is a natural compound produced by the honey bee (Apis mellifera), and has been reported as having the biological and pharmacological activities, including anti-bacterial, anti-viral and anti-inflammation. In the present study, the inhibitory effects of bee venom and its major peptide components on the tumor invasion were demonstrated. It was confirmed the inhibitory effects of bee venom, melittin, and apamin on the EGF-induced invasion of breast cancer cells. Transwell invasion and wound-healing assays showed that bee venom and melittin significantly inhibits the EGF-induced invasion and migration of breast cancer cells. Also, bee venom and melittin reduced the EGF-stimulated F-actin reorganization at the leading edge, but apamin did not affect. Particularly, melittin inhibited the EGF-induced MMP-9 expression via blocking the NF-κB and PI3K/Akt/mTOR pathway. In addition, melittin significantly suppressed the EGF-induced FAK phosphorylation through inhibition of mTOR/p70S6K/4E-BP1 pathway. These results suggest that inhibitory effects of melittin on breast cancer cell motility and migration may be related to the inhibition of mTOR pathway.
The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for treating inflammatory diseases. The effects on OVA-induced asthmatic mice of an Inulae Flos extract (IFE) ...were evaluated in this study. The anti-asthmatic effects of IFE were determined by observing eosinophil recruitment, airway hyper-responsiveness (AHR), Th2 cytokine and IgE levels, and lung histopathology. The IFE treatment effectively reduced the percentage of eosinophils and Th2 cytokines in the bronchoalveolar lavage fluid (BALF) when compared to the levels in OVA-induced mice. IFE also suppressed AHR induced by aerosolized methacholine in OVA-induced mice. The results of the histopathological studies indicate that inflammatory cell infiltration and mucus hypersecretion were both inhibited by the IFE administration when compared to the effect on OVA-induced mice. The IFE treatment also suppressed the serum IgE levels and decreased Th2 cytokines in the supernatant of cultured splenocytes. These results suggest that IFE may have therapeutic potential against asthma.
Sirt1, a key regulator of metabolism and longevity, has recently been implicated in the regulation of allergic reactions, although the underlying mechanism remains unclear. Here we show that Sirt1 ...negatively regulates FcεRI-stimulated mast cell activation and anaphylaxis through two mutually regulated pathways involving AMP-activated protein kinase (AMPK) and protein tyrosine phosphatase 1B (PTP1B). Mast cell-specific knockout of Sirt1 dampened AMPK-dependent suppression of FcεRI signaling, thereby augmenting mast cell activation both in vitro and in vivo. Sirt1 inhibition of FcεRI signaling also involved an alternative component, PTP1B, which attenuated the inhibitory AMPK pathway and conversely enhanced the stimulatory Syk pathway, uncovering a novel role of this phosphatase. Moreover, a Sirt1 activator resveratrol stimulated the inhibitory AMPK axis, with reciprocal suppression of the stimulatory PTP1B/Syk axis, thus potently inhibiting anaphylaxis. Overall, our results provide a molecular explanation for the beneficial role of Sirt1 in allergy and underscore a potential application of Sirt1 activators as a new class of anti-allergic agents.
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