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Imperatorin has been known to exert many biological functions including anti-inflammatory activity. In this study, we investigated the inhibitory effects of imperatorin on the production of inflammatory mediators in mouse bone marrow-derived mast cells (BMMC). Imperatorin inhibited degranulation and the generation of eicosanoids (leukotriene C4 (LTC4) and prostaglandin D2 (PGD2)) in IgE/antigen (Ag)-stimulated BMMC. To elucidate the molecular mechanism involved in this process, we investigated the effect of imperatorin on intracellular signaling in BMMC. Biochemical analyses of the IgE/Ag-mediated signaling pathway demonstrated that imperatorin dramatically attenuated degranulation and the production of 5-lipoxygenase-dependent LTC4 and cyclooxygenase-2-dependent PGD2 through the inhibition of intracellular calcium influx/phospholipase Cγ1, cytosolic phospholipase A2/mitogen-activated protein kinases and/or nuclear factor-κB pathways in BMMC. These results suggest that the effects of imperatorin on inhibition of degranulation and eicosanoid generation through the suppression of multiple steps of IgE/Ag-mediated signaling pathways would be beneficial for the prevention of allergic inflammation.

Mast cells are central players in immediate-type hypersensitvity and inflammatory responses. In the present study, the effects of britanin on the passive cutaneous anaphylaxis (PCA) reaction in mice and on the phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-induced production of pro-inflammatory cytokines in human mast cell line (HMC-1) were evaluated. The oral administration of britanin (10–20 mg/kg) decreased the mast cell-mediated PCA reaction in IgE-sensitized mice. In the activity and mechanism of britanin in vitro assay, britanin suppressed the gene expression and secretion of pro-inflammatory cytokines in a dose-dependent manner in HMC-1. In addition, britanin attenuated PMACI-induced activation of NF-κB as indicated by the inhibition of the degradation of IκBα, nuclear translocation of NF-κB, NF-κB/DNA binding activity assay, and blocked the phosphorylation of p38 MAP kinase, in a dose-dependent manner. We conclude that britanin may have potential as a treatment for allergic-inflammatory diseases.

In this study, tomentosin, a sesquiterpene lactone was isolated from Inulae flos and its biological activities were investigated. The effects of tomentosin on the production of inflammatory mediators as well as on nuclear factor (NF)-κB and mitogen-activated protein (MAP) kinase activation were evaluated in RAW264.7 cells. Tomentosin decreased the production of nitric oxide (NO) and prostaglandin E2 (PGE2) by suppressing the protein expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, respectively. Additionally, tomentosin reduced the release of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Tomentosin not only attenuated lipopolysaccharide (LPS)-induced NF-κB activation via the abrogation of inhibitory (I)κBα degradation and caused a subsequent decrease in nuclear p65 level, but it also suppressed the phosphorylation of MAP kinases (p38 and c-Jun N terminal kinase (JNK)). These results indicate that tomentosin exerts anti-inflammatory activities through the inhibition of inflammatory mediators (NO, iNOS, PGE2, COX-2, TNF-α, and IL-6) by regulating NF-κB activation and phosphorylation of p38/JNK kinases in macrophages, thus suggesting that tomentosin could be a potential agent for the treatment of inflammatory diseases.

Background Biyeom-Tang, a medicine prescribed by oriental clinics, has been used for the treatment of the allergic rhinitis (AR). In the present study, an ethanol extract of Biyeom-Tang (EBT) was investigated for anti-allergic properties on bone-marrow derived mast cells (BMMC) and in vivo models. Methods The anti-allergic properties of EBT were evaluated by measuring β-Hex release and the production of prostaglandin D2 (PGD2) and leukotriene C4 (LTC4) on BMMC in vitro and PCA and OVA-induced AR models in vivo. Results EBT strongly inhibited a degranulation reaction in a dose dependent manner with an IC50 value of 35.6 μg/ml. In addition, the generation of PGD2 and LTC4 was inhibited in BMMC in a concentration-dependent manner with IC50 values of 7.0 μg/ml and 10.9 μg/ml, respectively. When administrated orally, EBT ameliorated the mast cell-mediated PCA reaction. In the OVA-induced AR model, the increased levels of IgE were reduced by EBT. The levels of cytokines, such as IL-4, IL-5, IL-10, and IL-13 decreased in the splenocytes of EBT-treated mice. The histological analysis shows that the infiltration of inflammatory cells increased by OVA-sensitization was also reduced. Conclusions Taken together, these results suggested that EBT has anti-allergic and anti-inflammatory effects in vitro and in vivo models.

Little is known about the biological properties of britanin, which is isolated from the flowers of Inula japonica (Inulae Flos). Based on our previous studies that Inulae Flos had anti-inflammation and anti-asthmatic activities, we tried to find the bioactive compounds from it. In this study, the anti-inflammatory effects of britanin on the inflammatory mediators as well as on nuclear factor (NF)-кB and mitogen-activated protein (MAP) kinase activation were evaluated in RAW 264.7 cells. Britanin inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) along with the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In addition, britanin reduced the release of pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6. Furthermore, the phosphorylations of MAP kinases (p38 and JNK) in LPS-stimulated RAW 264.7 cells were suppressed by britanin. Moreover, britanin inhibited the NF-κB activation induced by LPS, which was associated with the abrogation of IκBα degradation and subsequent decreases in nuclear p65 levels. This study suggests that the anti-inflammatory activities of britanin might be attributed to the inhibition of iNOS and COX-2 and cytokine expression at least in part, through the attenuation of the phosphorylations of MAP kinases and NF-κB activation via IκBα degradation in macrophages. We conclude that britanin may have potential for the treatment of inflammatory diseases through the down-regulation of MAP kinases and NF-κB mediated activation of macrophages.

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.

Background The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of inflammatory diseases. In the present study, we investigated the anti-inflammatory properties of Inulae Flos Extract (IFE). Methods The anti-inflammatory effects of IFE against nitric oxide (NO), PGE2, TNF-α, and IL-6 release, as well as NF-κB and MAP kinase activation were evaluated in RAW 264.7 cells. Results IFE inhibited the production of NO and the expression of inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. In addition, IFE reduced the release of pro-inflammatory cytokines, such as TNF-α and IL-6. Furthermore, IFE inhibited the NF-κB activation induced by LPS, which was associated with the abrogation of IκB-α degradation and subsequent decreases in nuclear p65 and p50 levels. Moreover, the phosphorylation of ERK, JNK, and p38 MAP kinases in LPS-stimulated RAW 264.7 cells was suppressed by IFE in a dose-dependent manner. Conclusion These results suggest that the anti-inflammation activities of IFE might be attributed to the inhibition of NO, iNOS and cytokine expression through the down-regulation of NF-κB activation via suppression of IκBα and MAP kinase phosphorylation in macrophages.