Quantification of major compounds from Ixeris dentata, Ixeris dentata Var. albiflora, and Ixeris sonchifolia and their comparative anti-inflammatory activity in lipopolysaccharide-stimulated RAW 264.7 cells

The mechanism and experimental verification of Ixeris sonchifolia promoting apoptosis of hepatocellular carcinoma based on network pharmacology: Ixeris sonchifolia Induces Hepatocellular Carcinoma Apoptosis via the PI3K/AKT Pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ixeris sonchifolia alias Kudiezi, it was named Ixeris sonchifolia (Bunge) Hance, a synonym for Crepidiastrum sonchifolium (Bunge) Pak & Kawano in the https://www.iplant.cn/. And it was first published in J. Linn. Soc., Bot. 13: 108 (1873), which was named Ixeris sonchifolia (Maxim.) Hance in the MPNS (http://mpns.kew.org). As a widely distributed medicinal and edible wild plant, it possesses unique bitter-cold characteristics and constituents with various pharmacological activities. Its main antitumor substances, same as artemisinin and paclitaxel, are classified as terpenoids and have become research foci in recent years. However, its specific biological activity and role in antitumor treatment remain largely unclear.

AIM OF THE STUDY

This study aimed to elucidate the molecular targets and potential mechanisms of hepatocellular carcinoma apoptosis induced by Ixeris sonchifolia.

MATERIALS AND METHODS

We used network pharmacology methods to analyze and screen the active ingredients and possible underlying mechanisms of Ixeris sonchifolia in treating liver cancer and employed integrative time- and dose-dependent toxicity, transcriptomics, and molecular biology approaches to comprehensively verify the function of Ixeris sonchifolia extract (IsE) in human hepatoblastoma cell (HepG2) apoptosis and its potential mechanism.

RESULTS

A total of 169 common targets were screened by network pharmacology, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that IsE inhibited HepG2 cell activity in a time- and dose-dependent manner. Western blot analysis confirmed that IsE promoted HepG2 cell apoptosis by inhibiting the PI3K/AKT signaling pathway and that the PI3K/AKT inhibitor LY294002 also substantially enhanced IsE-induced apoptosis. The PI3K/AKT signaling pathway exhibited significant differences compared to that in the control group.

CONCLUSION

Combining network pharmacology with experimental verification, IsE inhibited mitochondrial function and the PI3K/AKT pathway while inducing hepatoma cell apoptosis. IsE may have promising potential for liver cancer treatment and chemoprevention.

Luteolin-7-O-β-d-glucuronide Ameliorates Cerebral Ischemic Injury: Involvement of RIP3/MLKL Signaling Pathway

Luteolin-7-O-β-d-glucuronide (LGU) is a major active flavonoid glycoside compound that is extracted from Ixeris sonchifolia (Bge.) Hance, and it is a Chinese medicinal herb mainly used for the treatment of coronary heart disease, angina pectoris, cerebral infarction, etc. In the present study, the neuroprotective effect of LGU was investigated in an oxygen glucose deprivation (OGD) model and a middle cerebral artery occlusion (MCAO) rat model. In vitro, LGU was found to effectively improve the OGD-induced decrease in neuronal viability and increase in neuronal death by a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) leakage rate assay, respectively. LGU was also found to inhibit OGD-induced intracellular Ca2+ overload, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) decrease. By Western blotting analysis, LGU significantly inhibited the OGD-induced increase in expressions of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). Moreover, molecular docking analysis showed that LGU might bind to RIP3 more stably and firmly than the RIP3 inhibitor GSK872. Immunofluorescence combined with confocal laser analyses disclosed that LGU inhibited the aggregation of MLKL to the nucleus. Our results suggest that LGU ameliorates OGD-induced rat primary cortical neuronal injury via the regulation of the RIP3/MLKL signaling pathway in vitro. In vivo, LGU was proven, for the first time, to protect the cerebral ischemia in a rat middle cerebral artery occlusion (MCAO) model, as shown by improved neurological deficit scores, infarction volume rate, and brain water content rate. The present study provides new insights into the therapeutic potential of LGU in cerebral ischemia.

Chemico-biological interaction unraveled the potential mechanistic pathway of Ixeridium dentatum compounds against atopic dermatitis

This study aims to investigate the potential therapeutic application of Ixeridium dentatum (ID) in treating atopic dermatitis (AD) through network pharmacology, molecular docking, and molecular dynamic simulation. We employed GC-MS techniques and identified 40 bioactive compounds present in the ID and determined their targets by accessing public databases. The convergence of compounds and dermatitis related targets led to the identification of 32 common genes. Among them, IL1B, PTGS2, IL6, IL2, and RELA, were found to be significant targets which were analyzed using Cytoscape network topology. The KEGG pathway evaluation revealed that these targets were significantly enriched in the C-type lectin receptor signaling pathway. The therapeutic efficacy of Stigmasta-5,22-dien-3-ol, Urea, n-Heptyl-, and 3-Epimoretenol was demonstrated in molecular docking assay, as evidenced by their presence in the core compounds of the compound-target network. Furthermore, these compounds exhibited significant kinetic stability and chemical reactivity in DFT quantum analysis when compared to their co-crystallized ligands and reference drug, indicating their potential as key targets for future research. Among the top three docking complexes, namely IL6-3-Epimoretenol, and IL2- Stigmasta-5,22-dien-3-ol, both demonstrated exceptional dynamic characteristics in molecular dynamics simulations at 100 ns. The feasibility of these compounds could be attributed to the prior traditional interrelationship between ID and AD. Overall, this research elucidates the interplay between AD-associated signaling pathways and target receptors with the bioactive ID. The proposal posits the utilization of antecedent compounds as a substitute for the customary pharmaceutical intervention that obstructs the discharge of cytokines, which incite dermal inflammation in the C-type lectin receptor signaling pathway of atopic dermatitis.

Ixeris dentata and Lactobacillus gasseri media protect against periodontitis through Nrf2-HO-1 signalling pathway

Periodontitis is an infectious inflammation in the gums characterized by loss of periodontal ligaments and alveolar bone. Its persistent inflammation could result in tooth loss and other health issues. Ixeris dentata (IXD) and Lactobacillus gasseri media (LGM) demonstrated strong antioxidant activity, which may prevent oxidative and inflammatory periodontitis. Here, IXD and LGM extracts were investigated for antioxidative activity against oral discomfort and evaluated for their synergistic effect against oxidative and inflammatory periodontitis in a mouse model. IXD/LGM suppressed pro-inflammatory cytokines like interleukin (IL)-1β, IL-6, and TNF-α. Additionally, it reduced pro-inflammatory mediators, nitric oxide, iNOS (inducible nitric oxide synthase), and COX-2 (cyclooxygenase-2) and enhanced AKT, Nrf2, and HO-1 activation. Similarly, IXD/LGM treatment elevated osteogenic proteins and mRNAs; alkaline phosphatase, collagen type 1 (COL1), osteopontin (OPN), and runt-related transcription factor 2 (RUNX2). Hematoxylin and Eosin (H&E) staining and micro-CT analysis confirm the positive impact of IXD/LGM on the periodontal structure and its associated inflammation. These findings demonstrate that IXD/LGM inhibits oxidative stress, periodontal inflammation, and its resultant alveolar bone loss in which Akt (also known as protein kinase B)-nuclear factor-erythroid 2-related factor 2 (Nrf2)-hemoxygenase-1 (HO-1) signaling is involved. Thus, IXD/LGM is a potential candidate against oxidative/inflammatory stress-associated periodontitis.

Three new sesquiterpenes from Ixeris sonchifolia

Two new guaiacene-type sesquiterpenes 13α-dihydroixerin acid, ixerin acid and one new secoguaiacene-type sesquiterpene secoixerin Z, along with four known compounds, were separated from ethanol extract of Ixeris sonchifolia. The structures were determined based on the detailed spectroscopic and physicochemical methods. The cytotoxic activity of the isolates was tested against A549 cells. Among them, compound 3 exhibited potent cytotoxicity against A549 cells with the IC₅₀ of 5.6 ± 0.9 µM.

Luteolin-7-O-Glucuronide Improves Depression-like and Stress Coping Behaviors in Sleep Deprivation Stress Model by Activation of the BDNF Signaling

Stress exposure is a major risk factor for mental disorders such as depression. Because of the limitations of classical antidepressants such as side effects, low efficacy, and difficulty in long-term use, new natural medicines and bioactive molecules from plants with greater safety and efficacy have recently attracted attention. Luteolin-7-O-glucuronide (L7Gn), a bioactive molecule present in Perilla frutescens, is known to alleviate severe inflammatory responses and oxidative stress in macrophages. However, its antistress and antidepressant effects have not been elucidated. The present study aims to explore the antidepressant the effect of L7Gn on stress-induced behaviors and the underlying mechanism in a mouse sleep deprivation (SD) model. L7Gn treatment improved depression-like and stress coping behaviors induced by SD stress, as confirmed by the tail suspension test and forced swimming test. Furthermore, L7Gn treatment reduced the blood corticosterone and hippocampal proinflammatory cytokine levels which were increased by SD stress, and L7Gn also increased the mRNA and protein levels of hippocampal brain-derived neurotrophic factor (BDNF) which were reduced by SD stress. Additionally, treatment with L7Gn resulted in increases in the phosphorylation of tropomyosin-related kinase B (TrkB), extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB), which are downstream molecules of BDNF signaling. These findings suggest that L7Gn have therapeutic potential for SD-induced stress, via activating the BDNF signaling.

Recent research progress of Cirsium medicinal plants in China

ETHNOPHARMACOLOGICAL RELEVANCE

The species of the genus Cirsium have been used as traditional Chinese medicine for hundreds of years. It is believed that Cirsium has the efficacies of cooling blood and stopping bleeding, dispelling blood stasis, detoxifying and eliminating carbuncle. At present, they are mainly used in treatment of the hemoptysis, hematemesis, hemoptysis, hematuria, traumatic bleeding and Henoch-Schonlein purpura. They are widely used in traditional Chinese medicine.

AIM

This paper systematically collated the classification, traditional use, pharmacological action, phytochemistry and clinical application of Cirsium plants in the past ten years, intending to provide a critical appraisal of current knowledge for future in-depth study and rational development and utilization of Cirsium plants.

MATERIAL AND METHODS

This paper searched various databases (SciFinder, Science Direct, CNKI, Wiley online library, Spring Link, Web of Science, PubMed, Wanfang Data, Weipu Data), Chinese Pharmacopoeia 2020 Edition, Chinese Flora, Chinese Materia Medica and some local books on ethnopharmacology.

RESULTS

More than ten species of Cirsium have been used as folk medicine, and modern pharmacological studies have shown that Cirsium has the effects of protecting liver, antioxidation, anti-tumor, anti-inflammation, antibacterial, etc. More than 200 chemical constituents such as flavonoids, triterpenes, sterols, phenylpropanoids have been isolated from Cirsium. Some ingredients show a wide variety of bioactivities including hepatoprotective, anti-inflammatory, antioxidant, anti-tumor and other activities. At present, Cirsium medicinal plants, as traditional Chinese medicine, were mainly used to treat nephritis, Henoch-Schonlein purpura and hemorrhage, although some species used in folk lack of quality control systems.

CONCLUSION

Cirsium plants are a safe and effective medicine for cooling blood and hemostasis. Recent studies on pharmacology and phytochemistry also provide solid scientific evidences for the traditional application of this genus. It also shows significant hepatoprotective activity and may be a potential clinical candidate for the treatment of liver disease. However, the qualitative and quantitative analysis, pharmacokinetics-pharmacodynamics and mechanism of action also need in-depth study.

α‑rhamnrtin‑3‑α‑rhamnoside exerts anti‑inflammatory effects on lipopolysaccharide‑stimulated RAW264.7 cells by abrogating NF‑κB and activating the Nrf2 signaling pathway

α-rhamnrtin-3-α-rhamnoside (ARR) is the principal compound extracted from Loranthus tanakae Franch. & Sav. However, its underlying pharmacological properties remain undetermined. Inflammation is a defense mechanism of the body; however, the excessive activation of the inflammatory response can result in physical injury. The present study aimed to investigate the effects of ARR on lipopolysaccharide (LPS)-induced RAW264.7 macrophages and to determine the underlying molecular mechanism. A Cell Counting Kit-8 assay was performed to assess cytotoxicity. Nitric oxide (NO) production was measured via a NO colorimetric kit. Levels of prostaglandin E2 (PGE₂) and proinflammatory cytokines, IL-1β and IL-6, were detected using ELISAs. Reverse transcription-quantitative (RT-q)PCR analysis was performed to detect the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and IL-1β in LPS-induced RAW246.7 cells. Western blotting, immunofluorescence and immunohistochemistry analyses were performed to measure the expression levels of NF-κB and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins to elucidate the molecular mechanisms of the inflammatory response. The results of the cytotoxicity assay revealed that doses of ARR ≤200 µg/ml exhibited no significant effect on the viability of RAW264.7 cells. The results of the Griess assay demonstrated that ARR inhibited the production of NO. In addition, the results of the ELISAs and RT-qPCR analysis discovered that ARR reduced the production of the proinflammatory cytokines, IL-1β and IL-6, as well as the proinflammatory mediators, PGE₂, iNOS and COX-2, in LPS-induced RAW264.7 cells. Immunohistochemical analysis demonstrated that ARR inhibited LPS-induced activation of TNF-associated factor 6 (TRAF6) and NF-κB p65 signaling molecules, while reversing the downregulation of the NOD-like receptor family CARD domain containing 3 (NLRC3) signaling molecule, which was consistent with the results of the western blotting analysis. Immunofluorescence results indicated that ARR reduced the increase of NF-κB p65 nuclear expression induced by LPS. Furthermore, the results of the western blotting experiments also revealed that ARR upregulated heme oxygenase-1, NAD(P)H quinone dehydrogenase 1 and Nrf2 pathway molecules. In conclusion, the results of the present study suggested that ARR may exert anti-inflammatory effects by downregulating NF-κB and activating Nrf2-mediated inflammatory responses, suggesting that ARR may be an attractive anti-inflammatory candidate drug.

Protective effect of total flavonoids from Ixeris Sonchifolia on herpes simplex virus keratitis in mice

Background

To investigate the protective effect of Ixeris Sonchifolia (Bae.) Hance (ISH) extract on herpes simplex virus keratitis (HSK) in mice.

Methods

A mouse model of HSK was established by inoculating 60 mice (60 right eyes) with herpes simplex virus type 1 (HSV-1) by corneal scratch. The other 15 mice as blank control only received corneal scratch but without HSV-1. From the 2nd day after the successful modeling, the experimental group was fed with ISH total flavonoids (50, 100 and 200 mg/kg) orally, twice a day for 14 days. The model group and control group were given the same amount of normal saline. The pathological changes of cornea were observed once a day by slit lamp microscopy combined with fluorescein staining. The corneal histopathological examination, the survival status and the serum levels of interleukin-2 (IL-2), IL-4 and interferon-gama (INF-γ) were performed at the end of the experiment.

Results

The result showed that ISH could significantly improve the corneal lesion degree, increase mice survival rate, and markedly increase the levels of IL-2 and INF-γ, reduce the levels of IL-4 in serum of mice.

Conclusions

ISH could increase the anti-virus ability, promote the healing of corneal inflammation and alleviate the pathological damage of cornea, which suggested that ISH has a potential and valuable therapeutic effect on the HSK.

Anti-Inflammatory and Anti-Oxidative Effects of luteolin-7-O-glucuronide in LPS-Stimulated Murine Macrophages through TAK1 Inhibition and Nrf2 Activation

Various herbal extracts containing luteolin-7-O-glucuronide (L7Gn) have been traditionally used to treat inflammatory diseases. However, systemic studies aimed at elucidating the anti-inflammatory and anti-oxidative mechanisms of L7Gn in macrophages are insufficient. Herein, the anti-inflammatory and anti-oxidative effects of L7Gn and their underlying mechanisms of action in macrophages were explored. L7Gn inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by transcriptional regulation of inducible NO synthase (iNOS) in a dose-dependent manner. The mRNA expression of inflammatory mediators, including cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α), was inhibited by L7Gn treatment. This suppression was mediated through transforming growth factor beta-activated kinase 1 (TAK1) inhibition that leads to reduced activation of nuclear factor-κB (NF-κB), p38, and c-Jun N-terminal kinase (JNK). L7Gn also enhanced the radical scavenging effect and increased the expression of anti-oxidative regulators, including heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and NAD(P)H quinone oxidoreductase 1 (NQO1), by nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) activation. These results indicate that L7Gn exhibits anti-inflammatory and anti-oxidative properties in LPS-stimulated murine macrophages, suggesting that L7Gn may be a suitable candidate to treat severe inflammation and oxidative stress.

Characterization and immunological activity of polysaccharides from Ixeris polycephala

A water-soluble polysaccharide, named KMCP, was isolated and purified from edible plant Ixeris polycephala by using DEAE-52 cellulose chromatography. Its structure was determined by chemical analysis, methylation analysis, and NMR analysis, coupled with characterization by scanning electron spectroscopy (SEM). The resulting data indicated that KMCP was an arabinogalactan, with an average molecular weight of 1.95×10⁶Da, which was mainly composed of arabinose and galactose in a relative molar ratio of 28.1% and 70.3%, respectively. The structure of KMPC was characterized as 72.5% of (1→4)-β-Galp residues interspersed with 27.5% of (1→4,6)-β-Galp residues in the main chain, and the branches were composed of (1→5)-α-Araf moieties or α-Araf (1→5) α-Araf (1→disaccharide moieties attached at O-6 of the (1→4,6)-β-Galp residues. KMCP was revealed to be capable of exhibiting macrophage-mediated innate immune responses via enhancing phagocytosis of macrophages and increasing production of NO, activating NF-κB signaling pathway and promoting the mice spleen cells proliferation in a dose-dependent manner within the test concentrations (10.0-200.0μg/mL). These results suggested that KMCP could potentially be an effective and safe immunomodulator valuable to be utilized in pharmacological fields or in the development of functional foods.

Anticancer effects of Ixeris dentata (Thunb. ex Thunb.) nakai extract on human melanoma cells A375P and A375SM

ETHNOPHARMACOLOGICAL RELEVANCE

The plant species Taraxacum coreanum (TC), Youngia sonchifolia (YS), and Ixeris dentata (ID) belong to the family Compositae and are used for medicinal purposes in traditional medicine. However, the anticancer effects of TC, YS, and ID extracts and the underlying molecular mechanisms in melanoma cells have not been elucidated.

AIM OF THE STUDY

To investigate the potential anticancer effects of TC, YS, and ID extracts on human melanoma cells and explore the potential pharmacological mechanisms in vitro and in vivo.

MATERIALS AND METHODS

In this comparative study, we investigated the effects of TC, YS, and ID extracts on cell proliferation in human melanoma A375P and A375SM cells using MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays. Apoptotic cells were detected by 4',6-diamidino-2-phenylinodole (DAPI) staining. We also investigated whether the growth-inhibitory effects were associated with the induction of apoptosis and whether the mechanisms of cell death were the result of signaling molecules such as p53, Bax, Bcl-2, caspase-9, Poly-ADP ribose polymerase (PARP), and Erk (Extracellular signal-regulated protein kinase) 1/2. The in vivo antitumor effects were evaluated by measuring the tumor volume and weight and performing Terminal deoxynucleotidyl transferase (TdT) dUTP Nick End Labeling (TUNEL) assay and immunohistochemistry (IHC) in tumor xenograft models.

RESULTS

TC, YS, and ID extracts effectively inhibited the growth of A375P and A375SM cells. In addition, several apoptotic events were observed following treatment, including DNA fragmentation and chromatin condensation by DAPI staining. The extracts increased p53, Bax, cleaved-caspase-9 and cleaved-PARP expression, whereas the expression of Bcl-2 was decreased in both cell lines. Furthermore, ID extract significantly inhibited the activation of Erk1/2 in both cell lines. Among the three extracts, ID had the strongest apoptotic effects. The administration of ID extract to mice inhibited tumor growth without any toxicity following 4 weeks of treatment. This extract increased the expression of apoptotic cells and p53 protein and decreased phospho-Erk1/2 protein.

CONCLUSION

TC, YS, and ID extracts suppress the growth of human melanoma cells through apoptosis. Among these extracts, ID has the strongest anticancer and apoptotic effects. It induces apoptosis through the inhibition of Erk1/2 in A375P and A375SM human melanoma cells and in tumor xenograft models and may be a potential chemotherapeutic agent against melanoma.

Investigation of the interactions between Chrysanthemum morifolium flowers extract and intestinal bacteria from human and rat

Flos Chrysanthemi, dried flower of Chrysanthemum morifolium Ramat, has drawn much attention recently owing to its potential beneficial health effects for human. Flos Chrysanthemi products are usually taken orally and metabolized by intestinal microflora. However, there has been no investigation of the comprehensive metabolic profile of the Flos Chrysanthemi extract by intestinal flora owing to its chemical complexity and the limitations of analytical methods. In this paper, a rapid, sensitive and automated analysis method, ultra-performance liquid chromatography/quadrupole time of flight mass spectrometry including MS^E technology and automated data processing Metabolynx™ software, was developed and successfully applied for the biotransformation and metabolic profile of flavonoids in the Flos Chrysanthemi extract by intestinal flora from human and rat. A total of 32 metabolites were detected and tentatively identified in human and rat intestinal bacterial samples. These metabolites indicated that hydrolysis, hydroxylation, acetylation, methylation, hydrogenation and deoxygenation were the major conversion pathways of flavonoids in the Flos Chrysanthemi extract in vitro. Furthermore, the effects of the Flos Chrysanthemi extract on the growth of different intestinal bacteria were detected using an Emax precision microplate reader. Certain pathogenic bacteria such as Enterobacter, Enterococcus, Clostridium and Bacteroides were significantly inhibited by Flos Chrysanthemi, while commensal probiotics such as Lactobacillus and Bifidobacterium were moderately promoted. Our observation provided further evidence for the importance of intestinal bacteria in the metabolism and potential activity of the Flos Chrysanthemi extract. The results will also be helpful for the further pharmacokinetic study of Flos Chrysanthemi and to unravel how it works in vivo.

Effect of Ixeris dentata Nakai Extract on Nitric Oxide Production and Prostaglandin E2 Generation in LPS-stimulated RAW264.7 Cells

Inflammation is the basis of severe acute and chronic diseases. This study investigated the anti-inflammatory property of a crude methanol extract (MeOH-ex) and the solvent fractions of Ixeris dentata Nakai (IDN) in LPS-stimulated murine macrophage-like cell line RAW264.7. Here, we showed that the ethyl acetate fraction (EtOAc-fr) had the most potent inhibitory activity on LPS-induced nitric oxide (NO) production among the tested samples, i.e., IDN MeOH-ex and the three different solvent fractions (chloroform, n-hexane, and EtOAc). We further found that the EtOAc-fr significantly inhibited LPS-induced prostaglandin PGE2 (PGE₂) generation in RAW264.7 cells. Furthermore, the treatment with EtOAc-fr effectively suppressed the expression of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2). These results suggest that the EtOAc-fr of IDN MeOH-ex exhibits an anti-inflammatory activity in vitro by inhibiting LPS-induced NO production and PGE₂ generation via suppression of iNOS and COX-2 expression.

Isolation of two new bioactive sesquiterpene lactone glycosides from the roots of Ixeris dentata

Two new sesquiterpene lactone glycosides, 3-O-β-d-glucopyranosyl-8-hydroxy-(1,5,6,7,11)-guaia-3,10(14)-dien-12,6-olide (1) and 3-O-β-d-glucopyranosyl-8-(4-hydroxyphenylacetyloxy)-(1.5.6,7)-guaia-3,10(14),11(13)-trien-12,6-olide (2), and 12 known sesquiterpene lactone derivatives (3-14) were isolated from the roots of Ixeris dentata. Their structures were determined by extensive spectroscopic methods including 1D and 2D NMR and MS spectra data. All compounds were tested for their ability to inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglial cell. 3-O-β-d-Glucopyranosyl-8-(4-hydroxyphenylacetyloxy)-(1.5.6,7)-guaia-3,10(14),11(13)-trien-12,6-olide (2) showed the most potent inhibitory activity at a concentration of 20μM.

Effects of Ixeris dentata water extract and caffeic acid on allergic inflammation in vivo and in vitro

Background

Ixeris dentata Nakai has been used for the treatment of mithridatism, calculous, indigestion, pneumonia, hepatitis, and tumors in Korea, China, and Japan. However, the effect of a water extract of Ixeris dentata (ID) and its molecular mechanism on allergic inflammation has not been elucidated. In this study, we attempted to evaluate the effects of ID and its major compound caffeic acid on allergic inflammation in vivo and in vitro.

Methods

ID was applied to 2, 4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis (AD)-like skin lesion mice and immune cell infiltration, cytokine production, and the activation of mitogen-activated protein kinases (MAPKs) were investigated. Moreover, the effect of ID on compound 48/80-induced anaphylactic shock was investigated in a mouse model. The human keratinocyte cell line (HaCaT cells) and human mast cells (HMC-1) were treated with ID or caffeic acid to investigate the effects on the production of chemokines and proinflammatory cytokines and on the activation of MAPKs.

Results

ID inhibited the serum levels of IgE and interleukin (IL)-1β in DNFB-induced AD-like skin lesion mouse models and suppressed anaphylactic shock in the mouse models. ID and caffeic acid inhibited the production of chemokines and adhesion molecules in HaCaT cells. In addition, ID reduced the release of tumor necrosis factor-α and IL-8 via the inhibition of MAPKs phosphorylation in HMC-1 cells.

Conclusions

These results suggest that ID is a potential therapeutic agent for allergic inflammatory diseases, including dermatitis.