Dietary acacetin reduces airway hyperresponsiveness and eosinophil infiltration by modulating eotaxin-1 and th2 cytokines in a mouse model of asthma

Gleditsiae Sinensis Fructus ingredients and mechanism in anti-asthmatic bronchitis research

BACKGROUND

Gleditsiae Sinensis Fructus (GSF) is commonly used in traditional medicine to treat respiratory diseases such as bronchial asthma. However, there is a lack of research on the chemical composition of GSF and the pharmacological substance and mechanism of action for GSF in treating bronchial asthma.

PURPOSE

The chemical constituents of GSF were analyzed using ultrahigh-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). In this study, we combined network pharmacology, molecular docking techniques, and experimental validation to explore the therapeutic efficacy and underlying mechanism of GSF in the treatment of bronchial asthma.

METHODS

Characterization of the chemical constituents of GSF was conducted using UHPLC-Q-Orbitrap HRMS. The identified chemical components were subjected to screening for active ingredients in the Swiss Absorption, Distribution, Metabolism, and Excretion (ADME) database. Relevant databases were utilized to retrieve target proteins for the active ingredients and targets associated with bronchial asthma disease, and the common targets between the two were selected. Subsequently, the protein-protein interaction (PPI) network was constructed using the String database and Cytoscape software to identify key targets. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the Metascape database. The "component-common target" network was constructed using Cytoscape to identify the primary active ingredients. Molecular docking validation was conducted using AutoDock software. The bronchial asthma mouse model was established using ovalbumin (OVA), and the lung organ index of the mice was measured. Lung tissue pathological changes were observed using hematoxylin and eosin (HE), Periodic Acid-Schiff (PAS), and Masson staining. The respiratory resistance (Penh) of the mice was assessed using a pulmonary function test instrument. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of IgE, IL-4, IL-5, and IL-13 in the mouse serum. Immunofluorescence staining was performed to detect the protein expression levels of AKT and PI3K in the lung tissues. An in vitro experiment was performed to observe the effects of echinocystic acid (EA) on IL-4 stimulated Human ASMCs (hASMCs). Cell viability was measured using a CCK-8 assay to calculate the IC50 value of the EA. A wound healing test was conducted to observe the effect of EA on degree of healing. RT-qPCR was performed to detect the influence of EA on the mRNA expression levels of ALB, SRC, TNF-α, AKT1, and IL6 in the cells.

RESULTS

A total of 95 chemical constituents were identified from the GSF. Of these, 37 were identified as active ingredients. There were 169 overlapping targets between the active ingredients and the disease targets. A topological analysis of the protein-protein interaction (PPI) network identified the core targets as IL6, TNF, ALB, AKT1, and SRC. An enrichment analysis revealed that the treatment of bronchial asthma with GSF primarily involved the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway, among others. The primary active ingredients included 13(s)-HOTRE, linolenic acid, and acacetin. The molecular docking results demonstrated a favorable binding activity between the critical components of GSF and the core targets. Animal experimental studies indicated that GSF effectively improved symptoms, lung function, and lung tissue pathological changes in the OVA-induced asthmatic mice, while alleviating inflammatory responses. GSF decreased the fluorescent intensity of the AKT and PI3K proteins. The IC50 value of EA was 30.02μg/ml. EA (30) significantly promoted the proliferation of IL4-stimulated hASMCs cells. EA (30) significantly increased the expression of ALB and SRC mRNA and decreased the expressions of TNF-α, AKT, and IL6 mRNA.

CONCLUSION

The multiple active ingredients found in GSF exerted their anti-inflammatory effects through multiple targets and pathways. This preliminary study revealed the core target and the mechanism of action underlying its treatment of bronchial asthma. These findings provided valuable insights for further research on the pharmacological substances and quality control of GSF.

Network pharmacology-based study on the mechanism of action of Trollius chinensis capsule in the treatment of upper respiratory tract infection

BACKGROUND

Upper respiratory tract infection (URTI), one of the most common respiratory diseases, has a high annual incidence. Trollius chinensis capsule has been used to treat URTI in China. However, the underlying-mechanisms remain unclear.

METHODS

Network pharmacology was used to explore the potential mechanism of action of Trollius chinensis capsule in URTI treatment. The active compounds in Trollius chinensis were obtained from the TCMSP, SymMap, and ETCM databases. The TCMSP, PubChem, and SwissTargetPrediction databases were used to predict potential targets of Trollius chinensis. URTI-associated targets were gathered from GeneCards and DisGeNET databases. The key targets and signaling pathways associated with URTI were selected by network topology, GO, and KEGG pathway enrichment analysis. Molecular docking was used to verify the binding activity between active compounds and key targets.

RESULTS

Quercetin, pectolinarigenin, beta-sitosterol, acacetin and cirsimaritin are major active compounds in Trollius chinensis capsule. Eighty one candidate therapeutic targets were confirmed to be involved in protection of Trollius chinensis capsule against URTI. Among them, 7 key targets (TP53, IL6, AKT1, CASP3, CXCL8, MMP9, and EGFR) were verified to have good binding affinities to the main active compounds. Furthermore, enrichment analyses suggested that inflammatory response, virus infection and oxidative stress related biological processes and pathways were possibly the potential mechanism.

CONCLUSION

Overall, the present study clarified that quercetin, pectolinarigenin, beta-sitosterol, acacetin and cirsimaritin are proved to be the main effective compounds of Trollius chinensis capsule treating URTI, possibly by acting on the targets of IL6, AKT1, CASP3, CXCL8, MMP9 and EGFR to play anti-infectious, anti-viral, and anti-oxidative effects. This study provides a new understanding of the active compounds and mechanisms of Trollius chinensis capsule in URTI treatment from the perspective of network pharmacology.

The effect of apigenin, an aryl hydrocarbon receptor antagonist, in Phthalate-Exacerbated eosinophilic asthma model

Endocrine disrupting chemicals have been known to contribute to the aggravation of inflammatory diseases including asthma. We aimed to investigate the effects of mono-n-butyl phthalate (MnBP) which is one of the representing phthalates, and its antagonist in an eosinophilic asthma mouse model. BALB/c mice were sensitized by intraperitoneal injection of ovalbumin (OVA) with alum and followed by three nebulized OVA challenges. MnBP was administered through drinking water administration throughout the study period, and its antagonist, apigenin, was orally treated for 14 days before OVA challenges. Mice were assessed for airway hyperresponsiveness (AHR), differential cell count and type 2 cytokines in bronchoalveolar lavage fluid were measured in vivo. The expression of the aryl hydrocarbon receptor was markedly increased when MnBP was administered. MnBP treatment increased AHR, airway inflammatory cells (including eosinophils), and type 2 cytokines following OVA challenge compared to vehicle-treated mice. However, apigenin treatment reduced all asthma features, such as AHR, airway inflammation, type 2 cytokines, and the expression of the aryl hydrocarbon receptor in MnBP-augmented eosinophilic asthma. Our study suggests that MnBP exposure may increase the risk of eosinophilic inflammation, and apigenin treatment may be a potential therapy for asthma exacerbated by endocrine-disrupting chemicals.

Therapeutic Potential of Leaves from Fridericia chica (Bonpl.) L. G. Lohmann: Botanical Aspects, Phytochemical and Biological, Anti-Inflammatory, Antioxidant and Healing Action

Plants of the species Fridericia chica (Bonpl.) L. G. Lohmann (Bignoniaceae), which are widely distributed in Brazil and named crajiru in the state of Amazonas, are known in folk medicine as a traditional medicine in the form of a tea for the treatment of intestinal colic, diarrhea, and anemia, among other diseases. The chemical analysis of extracts of the leaves has identified phenolic compounds, a class of secondary metabolites that provide defense for plants and benefits to the health of humans. Several studies have shown the therapeutic efficacy of F. chica extracts, with antitumor, antiviral, wound healing, anti-inflammatory, and antioxidant activities being among the therapeutic applications already proven. The healing action of F. chica leaf extract has been demonstrated in several experimental models, and shows the ability to favor the proliferation of fibroblasts, which is essential for tissue repair. The anti-inflammatory activity of F. chica has been clearly demonstrated by several authors, who suggest that it is related to the presence of 3-deoxyanthocyanidins, which is capable of inhibiting pro-inflammatory pathways such as the kappa B (NF-kB) nuclear transcription factor pathway. Another important effect attributed to this species is the antioxidant effect, attributed to phenolic compounds interrupting chain reactions caused by free radicals and donating hydrogen atoms or electrons. In conclusion, the species Fridericia chica has great therapeutic potential, which is detailed in this paper with the objective of encouraging new research and promoting the sum of efforts for the inclusion of herbal medicines in health systems around the world.

Acacetin Protects against Non-Alcoholic Fatty Liver Disease by Regulating Lipid Accumulation and Inflammation in Mice

We previously demonstrated that acacetin reduces adipogenesis in adipocytes, and decreases lipid accumulation in visceral adipocyte tissue. Here we investigated whether acacetin regulated the mechanisms of lipogenesis and inflammation in non-alcoholic fatty liver disease (NAFLD) in obese mice. Male C57BL/6 mice were fed a high-fat diet (HFD), and then administered acacetin by intraperitoneal injection. Acacetin reduced body weight and liver weight in obese mice. Acacetin-treated obese mice exhibited decreased lipid accumulation, increased glycogen accumulation, and improved hepatocyte steatosis. Acacetin regulated triglycerides and total cholesterol in the liver and serum. Acacetin decreased low-density lipoprotein and leptin concentrations, but increased high-density lipoprotein and adiponectin levels in obese mice. Acacetin effectively weakened the gene expressions of transcription factors related to lipogenesis, and promoted the expressions of genes related to lipolysis and fatty acid β-oxidation in liver. Acacetin also reduced expressions of inflammation-related cytokines in the serum and liver. Oleic acid induced lipid accumulation in murine FL83B hepatocytes, and the effects of acacetin treatment indicated that acacetin may regulate lipid metabolism through the AMPK pathway. Acacetin may protect against hepatic steatosis by modulating inflammation and AMPK expression.

Potential mechanism of action of Jing Fang Bai Du San in the treatment of COVID-19 using docking and network pharmacology

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), severely infects people and has rapidly spread worldwide. JingFangBaiDu San (JFBDS) has been used to treat prevalent epidemic pathogens, common cold, headache, cough due to lung-cold, and other symptoms; however, its treatment for COVID-19 is unknown. Molecular docking and network pharmacology were applied to obtain ingredient-protein structures and the herb-ingredient-disease target network model, respectively, to explore the potential mechanism of JFBDS in COVID-19 treatment. Network pharmacology analysis showed that acacetin, wogonin, and isorhamnetin were the main active ingredients of JFBDS, and EGFR, PIK3CA, LCK, MAPK1, MAPK3, MAPK8, STAT3, TNF, IL2, and RELA were speculated to be crucial therapeutic targets. Moreover, the Toll-like receptors, HIF-1, PIK3K/AKT, MAPK, NF-κB and NOD-like receptor signaling pathways were important for JFBDS in COVID-19 treatment. Molecular docking analysis indicated that ingredients of JFBDS could bind to angiotensin converting enzyme II, spike protein, and chymotrypsin like protease (3CLpro), which inhibits virus entry and replication in host cells. This study provides a new perspective for understanding potential therapeutic effects and mechanisms of JFBDS in COVID-19 and may facilitate its clinical application.

Exploring the Potential Targets and Mechanisms of Huang Lian Jie Du Decoction in the Treatment of Coronavirus Disease 2019 Based on Network Pharmacology

Background

In December 2019, coronavirus disease 2019 (COVID-19) caused by a novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2; previously known as 2019-nCoV) emerged in Wuhan, China, and caused many infections and deaths. At present, there are no specific drugs for the etiology and treatment of COVID-19. A combination of traditional Chinese and western medicine is proposed to treat COVID-19, in which Huang Lian Jie Du decoction (HLJDD) is recommended for the treatment of COVID-19 in many provinces in China and has been widely used in the clinic. This study explored the potential targets of HLJDD in the treatment of COVID-19 based on network pharmacology.

Methods

First, the chemical composition and targets of HLJDD and COVID-19-related targets were obtained through the TCMSP, UniProt, GeneCards and OMIM databases. Second, HLJDD target and HLJDD-COVID-19 target networks were constructed via the STRING database and Cytoscape software. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the HLJDD-COVID-19 targets was applied via the DAVID database.

Results

Our study identified a total of 67 active ingredients of HLJDD and 204 targets of HLJDD. A total of 502 COVID-19-related targets were obtained, of which 47 were intersecting targets of HLJDD and COVID-19. A total of 179 GO terms and 77 KEGG terms, including the TNF signaling pathway, NF-κB signaling pathway and HIF-1 signaling pathway, were identified.

Conclusion

The present study explored the potential targets and signaling pathways of HLJDD during the treatment of COVID-19, which may provide a basis for the research and development of drugs for the treatment of COVID-19.

Network Pharmacology-Based Analysis of the Underlying Mechanism of Hyssopus cuspidatus Boriss. for Antiasthma: A Characteristic Medicinal Material in Xinjiang

Background

Hyssopus cuspidatus Boriss. (Shen Xiang Cao (SXC)), a traditional medicine herb in Xinjiang, has a long history of being used by minorities to treat asthma. However, its active antiasthmatic compounds and underlying mechanism of action are still unknown. The aim of this study was to investigate the bioactive compounds and explore the molecular mechanism of SCX in the treatment of asthma using network pharmacology.

Methods

The compounds of SCX were collected by a literature search, and Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and SwissTargetPrediction were used to predict targets and screen active compounds. Moreover, asthma-related targets were obtained based on DisGeNET, Herb, and GeneCards databases, and a protein-protein interaction (PPI) network was built by the STRING database. Furthermore, the topological analysis of the PPI and SXC-compound-target networks were analyzed and established by Cytoscape software. Finally, the RStudio software package was used for carrying out Gene Ontology (GO) function enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. AutoDock tools and AutoDock Vina were used to molecularly dock the active compounds and key targets.

Results

A total of 8 active compounds and 258 potential targets related to SXC were predicted, and PPI network screened out key targets, including IL-6, JUN, TNF, IL10, and CXCL8. GO enrichment analysis involved cell responses to reactive oxygen species, oxidative stress, chemical stress, etc. In addition, KEGG pathway analysis showed that SXC effectively treated asthma through regulation of mitogen-activated protein kinases (MAPK) signaling pathways, interleukin 17 (IL-17) signaling pathways, toll-like receptor (TLR) signaling pathways, and tumor necrosis factor (TNF) signaling pathways.

Conclusion

The preliminary study that was based on multiple compounds, multiple targets, and multiple pathways provides a scientific basis for further elucidating the molecules involved and the underlying antiasthma-related mechanisms of SXC.

Tilianin attenuates HDM-induced allergic asthma by suppressing Th2-immune responses via downregulation of IRF4 in dendritic cells

BACKGROUND

Acacetin 7-O-β-D-glucoside (tilianin) is a major constituent of Agastache rugosa, a traditional medicine that has long been used for the treatment of gastrointestinal disorders. Tilianin has a wide variety of pharmacological properties such as cardioprotective, neuroprotective, and anti-atherogenic activities. We recently discovered that tilianin has the ability to suppress MUC5AC expression in vitro. In addition, we have established an in vivo model of allergic asthma using house dust mite (HDM) that can be applied to tilianin.

PURPOSE

We investigated the effects of tilianin on airway inflammation in a HDM-induced asthma mouse model and associated mechanisms.

METHODS

Tilianin was treated in splenocytes cultured in Th0 condition and HDM-stimulated bone marrow-derived dendritic cells (BMDCs), and their mRNA expression and cytokines production were determined by quantitative real-time PCR and ELISA. To evaluate the effects of tilianin in an allergic asthma model, mice were sensitized and challenged with HDM. Tilianin was administered prior to challenge by oral gavage and airway hyper-reactivity (AHR) to methacholine, inflammatory cell infiltration, cytokine levels, and airway remodeling were assessed.

RESULTS

Tilianin inhibited the production of Th2-related cytokines in splenocytes, which play pivotal roles in allergic airway inflammation. When treated in HDM-stimulated BMDCs, tilianin decreased Th2-skewing cytokine IL-33 and transcription factor IRF4. On the contrary, tilianin increased Th1-skewing regulators, IL-12 and IRF1. In an HDM-induced asthmatic mouse model, tilianin attenuated AHR and airway inflammation. Tilianin suppressed the expression of Th2-related cytokines, IL-13 and IL-33 in lung tissues. As seen in HDM-stimulated BMDCs, tilianin also downregulated the expression of the transcription factor IRF4 but not IRF1.

CONCLUSION

Taken together, these results suggest that tilianin attenuates HDM-induced allergic airway inflammation by inhibiting Th2-mediated inflammation through the selective inhibition of the IRF4-IL-33 axis in dendritic cells.

Acacetin suppresses the electrocardiographic and arrhythmic manifestations of the J wave syndromes

Background

J wave syndromes (JWS), including Brugada (BrS) and early repolarization syndromes (ERS), are associated with increased risk for life-threatening ventricular arrhythmias. Pharmacologic approaches to therapy are currently very limited. Here, we evaluate the effects of the natural flavone acacetin.

Methods

The effects of acacetin on action potential (AP) morphology and transient outward current (I_to) were first studied in isolated canine RV epicardial myocytes using whole-cell patch clamp techniques. Acacetin’s effects on transmembrane APs, unipolar electrograms and transmural ECGs were then studied in isolated coronary-perfused canine RV and LV wedge preparations as well as in whole-heart, Langendorff-perfused preparations from which we recorded a 12 lead ECG and unipolar electrograms. Using floating glass microelectrodes we also recorded transmembrane APs from the RVOT of the whole-heart model. The I_to agonist NS5806, sodium channel blocker ajmaline, calcium channel blocker verapamil or hypothermia (32°C) were used to pharmacologically mimic the genetic defects and conditions associated with JWS, thus eliciting prominent J waves and provoking VT/VF.

Results

Acacetin (5–10 μM) reduced I_to density, AP notch and J wave area and totally suppressed the electrocardiographic and arrhythmic manifestation of both BrS and ERS, regardless of the experimental model used. In wedge and whole-heart models of JWS, increasing I_to with NS5806, decreasing I_Na or I_Ca (with ajmaline or verapamil) or hypothermia all resulted in accentuation of epicardial AP notch and ECG J waves, resulting in characteristic BrS and ERS phenotypes. Phase 2-reentrant extrasystoles originating from the RVOT triggered VT/VF. The J waves in leads V1 and V2 were never associated with a delay of RVOT activation and always coincided with the appearance of the AP notch recorded from RVOT epicardium. All repolarization defects giving rise to VT/VF in the BrS and ERS models were reversed by acacetin, resulting in total suppression of VT/VF.

Conclusions

We present experimental models of BrS and ERS capable of recapitulating all of the ECG and arrhythmic manifestations of the JWS. Our findings provide definitive support for the repolarization but not the depolarization hypothesis proposed to underlie BrS and point to acacetin as a promising new pharmacologic treatment for JWS.

Effects of catalpol on asthma by airway remodeling via inhibiting TGF-β1 and EGF in ovalbumin-induced asthmatic mice

Airway remodeling represents the healing and alteration in the airway that occur as a consequence of chronic inflammation. Extracellular matrix synthesis regulated by transforming growth factor (TGF-β1) and vascular remodeling regulated by epidermal growth factor (EGF) are important factors for the airway remodeling. This study aimed to probe the effect of catalpol, a major component of Radix Rehmanniae Preparata (Shudihuang), on airway remodeling and expression of TGF-β1 and EGF in asthmatic mice. A mice model of asthma was induced by ovalbumin (OVA) treatment. BALB/c mice were randomly divided into blank control group, asthma model group, dexamethasone (DEX) group (positive control), high, medium and low dose of catalpol intervention group. Changes in lung histology were observed using hematoxylin and eosin staining. The levels of TGF-β1 and EGF in mouse sera and bronchoalveolar lavage fluid (BALF) were examined by ELISA. The EGF mRNA and protein levels in mice tissues were determined. The results indicated that catalpol improved general conditions and reduced the damage of lung tissues in asthmatic mice. Moreover, results of ELISA revealed that catalpol significantly reduced the OVA-induced levels of TGF-β1 and EGF in sera and in bronchoalveolar lavage fluid (BALF). Additionally, results indicated that catalpol decreased the OVA-induced EGF mRNA and protein expression in lung tissues in asthmatic mice. Catalpol at a high dose was more efficient in decreasing the level of TGF-β1 in mice sera and BALF comparing the DEX group. Current study has demonstrated that catalpol might effectively prevent airway remodeling in asthma via inhibiting TGF-β1 and EGF.

Saussureae Involucratae Herba (Snow Lotus): Review of Chemical Compositions and Pharmacological Properties

Saussureae Involucratae Herba is the dried ground part of Saussurea involucrata (Kar. et Kir.) Sch.-Bip, which is also named as “Snow lotus” and being used in traditional Uyghur and/or Chinese medicine. This rare herb can be found at 4,000 m elevation in western part of Tianshan Mountain, Xinjiang China. According to China Pharmacopoeia (2015), the major pharmaceutical values of “Snow lotus” (Xuě liánhuā in Chinese) are alleviating rheumatoid arthritis, accelerating blood circulation and mitigating other “cold” syndromes. Traditionally, the clinical application of “Snow lotus” includes the treatments in inflammation-associated disorder, blood circulation acceleration and heat and dampness elimination. Recent studies suggested that “Snow lotus” possessed therapeutic effects associating with anti-cancer, anti-oxidation, adipogenesis suppression and neuroprotection activities, which were proposed to be related with its bioactive constitutes, i.e. acacetin, hispidulin, and rutin. In the present review, we aim to summarize pharmacological effects and underlying cell signaling pathways of “Snow lotus” in treating various medical problems.

Inhibitory effects of catalpol coordinated with budesonide and their relationship with cytokines and Interleukin-13 expression

In this study, the molecular mechanism for inhibitory effect of Catalpol coordinated with Budesonide (BUD) on allergic airway inflammation was investigated. A total of 30 adult SD rats were randomly divided into five groups, namely the positive control group, the model group, the Catalpol group, the BUD group, and the Catalpol+BUD group with 6 rats in each group, respectively. The pathologic changes of lung tissue were observed by HE stain method. The lung function of rats, the cell count, and the cytokine concentrations in bronchoalveolar lavage fluid (BALF) were detected. The levels of cytokines [interleukin-4 (IL-4), interleukin-5 (IL-5), and interferon gamma (IFN-γ)] in BALF were measured using enzyme-linked immunosorbent assay method. The expressions of Interleukin-13 (IL-13) and Eotaxin in lung tissue were measured by RT-PCR method. The total number of cells in the BALF of the group treated with Catalpol and BUD was significantly lower than the model group. The cytokines IL-5 and IL-4 exhibited a similar tendency: the concentrations of IL-4 and IL-5 for the Catalpol group were dramatically decreased compared with the model group. However, the IFN-γ concentration for the Catalpol and BUD groups were higher than the model group. After treatment with Catalpol+BUD, the eosinophils and neutrophils of the rats were further reduced, asthma-associated inflammation was obviously inhibited, IL-4 level was further decreased and IFN-γ level was further increased comparing the Catalpol group and the BUD group. Moreover, IL-13 expression was positively correlated with Eotaxin expression. The results indicated that Catapol could inhibit the expression of IL-13 and Eotaxin in the lung of asthmatic rats, which also exhibited a synergistically inhibitory effect with BUD on airway inflammation. It is suggested that Catalpol+BUD might be an effective and potential treatment for the clinical therapy of asthma.

Tomatidine Attenuates Airway Hyperresponsiveness and Inflammation by Suppressing Th2 Cytokines in a Mouse Model of Asthma

Tomatidine is isolated from the fruits of tomato plants and found to have anti-inflammatory effects in macrophages. In the present study, we investigated whether tomatidine suppresses airway hyperresponsiveness (AHR) and eosinophil infiltration in asthmatic mice. BALB/c mice were sensitized with ovalbumin and treated with tomatidine by intraperitoneal injection. Airway resistance was measured by intubation analysis as an indication of airway responsiveness, and histological studies were performed to evaluate eosinophil infiltration in lung tissue. Tomatidine reduced AHR and decreased eosinophil infiltration in the lungs of asthmatic mice. Tomatidine suppressed Th2 cytokine production in bronchoalveolar lavage fluid. Tomatidine also blocked the expression of inflammatory and Th2 cytokine genes in lung tissue. In vitro, tomatidine inhibited proinflammatory cytokines and CCL11 production in inflammatory BEAS-2B bronchial epithelial cells. These results indicate that tomatidine contributes to the amelioration of AHR and eosinophil infiltration by blocking the inflammatory response and Th2 cell activity in asthmatic mice.

Acacetin attenuates mice endotoxin-induced acute lung injury via augmentation of heme oxygenase-1 activity

Acacetin, a natural product, has a wide spectrum of biological activities such as antioxidant properties. In the present study, we examined whether Acacetin has any beneficial role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and, if so, whether its effect is mediated via heme oxygenase-1 (HO-1), an antioxidant enzyme playing an important role in ALI. Male BALB/c mice were stimulated with LPS intratracheal instillation to induce ALI. Acacetin was administrated 2 h after LPS challenge. Samples were harvested 10 h after LPS administration. We demonstrated that LPS challenge significantly induced lung histological alterations such as inflammation and edema. Acacetin administration notably attenuated these changes and reduced tumor necrosis factor-α and interleukin-1β in lung tissues. The LPS-induced reactive oxygen species generation was markedly suppressed by Acacetin. Furthermore, Acacetin treatment significantly elevated pulmonary HO-1 and nuclear factor erythroid-2-related factor 2 (Nrf2) activities. However, the beneficial action of Acacetin was markedly abolished when pretreated with zinc protoporphyrin, an inhibitor of HO-1. In in vitro studies, Acacetin notably increased the HO-1 expression in pulmonary microvascular endothelial cells. During knockdown of Nrf2 by siRNA, the effect of Acacetin on HO-1 expression was significantly reversed. Acacetin attenuates LPS-induced ALI in mice. This protective effect of Acacetin may be mediated, in part, through an HO-1-dependent pathway.

Acacetin from Traditionally Used Saussurea involucrata Kar. et Kir. Suppressed Adipogenesis in 3T3-L1 Adipocytes and Attenuated Lipid Accumulation in Obese Mice

Acacetin, a flavone that can be isolated from the Saussurea involucrata plant, has anti-tumor and anti-inflammatory properties that ameliorate airway hyperresponsiveness in asthmatic mice. This study investigated whether acacetin has anti-adipogenic effects in 3T3-L1 adipocytes and whether it regulates the inflammatory response in adipocytes and macrophages. It also investigated whether acacetin ameliorates lipid accumulation in high-fat diet- (HFD) induced obese mice. Differentiated 3T3-L1 cells were treated with acacetin. The glycerol levels in the culture medium were measured, and the expression of proteins and genes involved in adipogenesis and lipolysis were assayed by Western blot and real-time PCR, respectively. Inflammatory cytokine signaling pathway activity was assessed in macrophages that were treated with acacetin and cultured with differentiated medium from 3T3-L1 cells. Intraperitoneal injections of acacetin were administered to HFD-induced obese mice twice a week for 10 weeks. Acacetin significantly increased the levels of glycerol in the culture medium and significantly inhibited lipid accumulation in adipocytes. Acacetin reduced the expression of adipogenesis-related transcription factors, including the expression of the CCAAT/enhancer-binding protein; it also increased sirtuin 1 expression and AMPK phosphorylation in adipocytes. In macrophages cultured with differentiated media from 3T3-L1 adipocytes, acacetin reduced the levels of inflammatory mediators and the activity of the mitogen-activated protein kinase and NF-κB pathways. In obese mice, acacetin reduced both body weight and visceral adipose tissue weight. These results demonstrate that acacetin inhibited adipogenesis in adipocytes and in obese mice. Acacetin also reduced the inflammatory response of macrophages that were stimulated with differentiated media from 3T3-L1 cells.

Breast Cancer Resistance Protein and Multidrug Resistance Protein 2 Regulate the Disposition of Acacetin Glucuronides

PURPOSE

To determine the mechanism responsible for acacetin glucuronide transport and the bioavailability of acacetin.

METHODS

Area under the curve (AUC), clearance (CL), half-life (T1/2) and other pharmacokinetic parameters were determined by the pharmacokinetic model. The excretion of acacetin glucuronides was evaluated by the mouse intestinal perfusion model and the Caco-2 cell model.

RESULTS

In pharmacokinetic studies, the bioavailability of acacetin in FVB mice was 1.3%. Acacetin was mostly exposed as acacetin glucuronides in plasma. AUC of acacetin-7-glucuronide (Aca-7-Glu) was 2-fold and 6-fold higher in Bcrp1 (-/-) mice and Mrp2 (-/-) mice, respectively. AUC of acacetin-5-glucuronide (Aca-5-Glu) was 2-fold higher in Bcrp1 (-/-) mice. In mouse intestinal perfusion, the excretion of Aca-7-Glu was decreased by 1-fold and 2-fold in Bcrp1 (-/-) and Mrp2 (-/-) mice, respectively. In Caco-2 cells, the efflux rates of Aca-7-Glu and Aca-5-Glu were significantly decreased by breast cancer resistance protein (BCRP) inhibitor Ko143 and multidrug resistance protein 2 (MRP2) inhibitor LTC4. The use of these inhibitors markedly increased the intracellular acacetin glucuronide content.

CONCLUSIONS

BCRP and MRP2 regulated the in vivo disposition of acacetin glucuronides. The coupling of glucuronidation and efflux transport was probably the primary reason for the low bioavailability of acacetin.

Phloretin Attenuates Allergic Airway Inflammation and Oxidative Stress in Asthmatic Mice

Phloretin (PT), isolated from the apple tree, was previously demonstrated to have antioxidative and anti-inflammatory effects in macrophages and anti-adiposity effects in adipocytes. Inflammatory immune cells generate high levels of reactive oxygen species (ROS) for stimulated severe airway hyperresponsiveness (AHR) and airway inflammation. In this study, we investigated whether PT could reduce oxidative stress, airway inflammation, and eosinophil infiltration in asthmatic mice, and ameliorate oxidative and inflammatory responses in tracheal epithelial cells. BALB/c mice were sensitized with ovalbumin (OVA) to induce asthma symptoms. Mice were randomly assigned to the five experimental groups: normal controls; OVA-induced asthmatic mice; and OVA-induced mice injected intraperitoneally with one of the three PT doses (5, 10, or 20 mg/kg). In addition, we treated inflammatory human tracheal epithelial cells (BEAS-2B cells) with PT to assess oxidative responses and the levels of proinflammatory cytokines and chemokines. We found that PT significantly reduced goblet cell hyperplasia and eosinophil infiltration, which decreased AHR, inflammation, and oxidative responses in the lungs of OVA-sensitized mice. PT also decreased malondialdehyde levels in the lung and reduced Th2 cytokine production in bronchoalveolar lavage fluids. Furthermore, PT reduced ROS, proinflammatory cytokines, and eotaxin production in BEAS-2B cells. PT also suppressed monocyte cell adherence to inflammatory BEAS-2B cells. These findings suggested that PT alleviated pathological changes, inflammation, and oxidative stress by inhibiting Th2 cytokine production in asthmatic mice. PT showed therapeutic potential for ameliorating asthma symptoms in the future.

Catalpol alleviates ovalbumin-induced asthma in mice: Reduced eosinophil infiltration in the lung

BACKGROUND

Radix Rehmanniae Preparata is a traditional Chinese herbal medicine used to treat asthma, and catalpol is one of the main active ingredients in this herb. In the present study, the effects of catalpol on asthma and the underlying mechanism were explored.

METHODS

Mice with ovalbumin (OVA)-induced asthma were given 5 or 10mg/kg catalpol from Day 15 to Day 28 (intraperitoneal injection). Histopathologic changes were detected by Hematoxylin and Eosin staining and Periodic Acid Schiff staining. The levels of IgE, interleukin (IL)-4, IL-5 and eotaxin were measured by ELISA. The numbers of lymphocytes, monocytes, basophils and eosinophils in the bronchoalveolar lavage fluid were determined by Wright-Giemsa staining. The expression and distribution of eotaxin and C-C chemokine receptor 3 (CCR3) were detected by immunohistochemistry and immunofluorescence. The expression of interleukin-5 receptor α (IL-5Rα) was detected by Western blot assay.

RESULTS

Catalpol inhibited OVA-induced inflammation and IgE secretion in the lung. OVA-induced type 2 inflammation was suppressed by catalpol as evidenced by decreased levels of IL-4 and IL-5. Moreover, catalpol inhibited the aberrant eosinophil infiltration in the lungs, and also suppressed OVA-induced elevation of eosinophil chemokine eotaxin and its receptor CCR3. In addition, IL-5Rα expression in the bone marrow cells derived from catalpol-treated asthmatic mice was lower than that from the untreated asthmatic mice.

CONCLUSION

Our study demonstrated that catalpol attenuated OVA-induced asthma and inhibit the infiltration of inflammatory cells, especially eosinophils, into the lung. This study suggests that catalpol may become a promising drug for the treatment of asthma.

Water-soluble acacetin prodrug confers significant cardioprotection against ischemia/reperfusion injury

The morbidity and mortality of patients with ischemic cardiomyopathy resulted from ischemia/reperfusion injury are very high. The present study investigates whether our previously synthesized water-soluble phosphate prodrug of acacetin was cardioprotective against ischemia/reperfusion injury in an in vivo rat model. We found that intravenous administration of acacetin prodrug (10 mg/kg) decreased the ventricular arrhythmia score and duration, reduced ventricular fibrillation and infarct size, and improved the impaired heart function induced by myocardial ischemia/reperfusion injury in anesthetized rats. The cardioprotective effects were further confirmed with the parent compound acacetin in an ex vivo rat regional ischemia/reperfusion heart model. Molecular mechanism analysis revealed that acacetin prevented the ischemia/reperfusion-induced reduction of the anti-oxidative proteins SOD-2 and thioredoxin, suppressed the release of inflammation cytokines TLR4, IL-6 and TNFα, and decreased myocyte apoptosis induced by ischemia/reperfusion. Our results demonstrate the novel evidence that acacetin prodrug confer significant in vivo cardioprotective effect against ischemia/reperfusion injury by preventing the reduction of endogenous anti-oxidants and the release of inflammatory cytokines, thereby inhibiting cardiomyocytes apoptosis, which suggests that the water-soluble acacetin prodrug is likely useful in the future as a new drug candidate for treating patients with acute coronary syndrome.

Intranasal Administration of Recombinant Mycobacterium smegmatis Inducing IL-17A Autoantibody Attenuates Airway Inflammation in a Murine Model of Allergic Asthma

Asthma is a chronic inflammatory disorder, previous studies have shown that IL-17A contributes to the development of asthma, and there is a positive correlation between the level of IL-17A and the severity of disease. Here, we constructed recombinant Mycobacterium smegmatis expressing fusion protein Ag85A-IL-17A (rMS-Ag85a-IL-17a) and evaluated whether it could attenuate allergic airway inflammation, and further investigated the underlying mechanism. In this work, the murine model of asthma was established with ovalbumin, and mice were intranasally vaccinated with rMS-Ag85a-IL-17a. Autoantibody of IL-17A in sera was detected, and the airway inflammatory cells infiltration, the local cytokines and chemokines production and the histopathological changes of lung tissue were investigated. We found that the administration of rMS-Ag85a-IL-17a induced the autoantibody of IL-17A in sera. The vaccination of rMS-Ag85a-IL-17a remarkably reduced the infiltration of inflammatory cells and the secretion of mucus in lung tissue and significantly decreased the numbers of the total cells, eosinophils and neutrophils in BALF. Th1 cells count in spleen, Th1 cytokine levels in BALF and supernatant of splenocytes and mediastinal lymph nodes, and T-bet mRNA in lung tissue were significantly increased with rMS-Ag85a-IL-17a administration. Meanwhile, rMS-Ag85a-IL-17a vaccination markedly decreased Th2 cells count, Th2 cytokine and Th17 cytokine levels in BALF and supernatant of splenocytes and mediastinal lymph nodes, and chemokines mRNA expression in lung tissue. These data confirmed that recombinant Mycobacterium smegmatis in vivo could induce autoantibody of IL-17A, which attenuated asthmatic airway inflammation.

Matrine Attenuates COX-2 and ICAM-1 Expressions in Human Lung Epithelial Cells and Prevents Acute Lung Injury in LPS-Induced Mice

Matrine is isolated from Sophora flavescens and shows anti-inflammatory effects in macrophages. Here we evaluated matrine's suppressive effects on cyclooxygenase 2 (COX-2) and intercellular adhesion molecule-1 (ICAM-1) expressions in lipopolysaccharide- (LPS-) stimulated human lung epithelial A549 cells. Additionally, BALB/c mice were given various matrine doses by intraperitoneal injection, and then lung injury was induced via intratracheal instillation of LPS. In LPS-stimulated A549 cells, matrine inhibited the productions of interleukin-8 (IL-8), monocyte chemotactic protein-1, and IL-6 and decreased COX-2 expression. Matrine treatment also decreased ICAM-1 protein expression and suppressed the adhesion of neutrophil-like cells to inflammatory A549 cells. In vitro results demonstrated that matrine significantly inhibited mitogen-activated protein kinase phosphorylation and decreased nuclear transcription factor kappa-B subunit p65 protein translocation into the nucleus. In vivo data indicated that matrine significantly inhibited neutrophil infiltration and suppressed productions of tumor necrosis factor-α and IL-6 in mouse bronchoalveolar lavage fluid and serum. Analysis of lung tissue showed that matrine decreased the gene expression of proinflammatory cytokines, chemokines, COX-2, and ICAM-1. Our findings suggest that matrine improved lung injury in mice and decreased the inflammatory response in human lung epithelial cells.

Oral lovastatin attenuates airway inflammation and mucus secretion in ovalbumin-induced murine model of asthma

PURPOSE

Lovastatin is an effective inhibitor of cholesterol synthesis. A previous study demonstrated that lovastatin can also suppress airway hyperresponsiveness (AHR) in murine model of asthma. We aimed to investigate the effect of lovastatin on mucus secretion and inflammation-associated gene expression in the lungs of murine model of asthma.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) by intraperitoneal injection, and orally administered lovastatin from days 14 to 27 post-injection. Gene expression in lung tissues was analyzed using real-time polymerase chain reaction. AHR and goblet cell hyperplasia were also examined. BEAS-2B human bronchial epithelial cells were used to evaluate the effect of lovastatin on the expression of cell adhesion molecules, chemokines, and proinflammatory cytokines in vitro.

RESULTS

We showed that lovastatin inhibits the expression of Th2-associated genes, including eotaxins and adhesion molecules, in the lungs of murine model of asthma. Mucin 5AC expression, eosinophil infiltration and goblet cell hyperplasia were significantly decreased in the lung tissue of murine model of asthma treated with lovastatin. Furthermore, lovastatin inhibited AHR and expression of Th2-associated cytokines in bronchoalveolar lavage fluid. However, a high dose (40 mg/kg) of lovastatin was required to decrease specific IgE to OVA levels in serum, and suppress the expression of Th2-associated cytokines in splenocytes. Activated BEAS-2B cells treated with lovastatin exhibited reduced IL-6, eotaxins (CCL11 and CCL24), and intercellular adhesion molecule-1 protein expression. Consistent with this, lovastatin also suppressed the ability of HL-60 cells to adhere to inflammatory BEAS-2B cells.

CONCLUSIONS

These data suggest that lovastatin suppresses mucus secretion and airway inflammation by inhibiting the production of eotaxins and Th2 cytokines in murine model of asthma.

Matrine attenuates allergic airway inflammation and eosinophil infiltration by suppressing eotaxin and Th2 cytokine production in asthmatic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Matrine has been isolated from Sophora flavescens, and found to show anti-inflammatory effects in macrophages and anti-cachectic effects in hepatomas. The present study investigated whether matrine suppressed eosinophil infiltration and airway hyperresponsiveness (AHR) in mice, and decreased the inflammatory response of tracheal epithelial cells.

MATERIALS AND METHODS

BALB/c mice were sensitized and challenged with ovalbumin to induce allergic asthma in mice. These asthmatic mice were given various doses of matrine by intraperitoneal injection. Additionally, activated human tracheal epithelial cells (BEAS-2B cells) were treated with matrine, and evaluated for levels of proinflammatory cytokines and chemokines.

RESULTS

We found that matrine significantly decreased AHR, and suppressed goblet cell hyperplasia, eosinophil infiltration, and inflammatory response in the lung tissue of asthmatic mice. Matrine also reduced the levels of Th2 cytokines and chemokines in bronchoalveolar lavage fluid, and suppressed OVA-IgE production in serum. Furthermore, matrine treatment of activated BEAS-2B cells decreased production of proinflammatory cytokines and eotaxins, as well as suppressed ICAM-1 expression and thus adhesion of eosinophils to inflammatory BEAS-2B cells in vitro.

CONCLUSIONS

Our findings suggest that matrine can improve allergic asthma in mice, and therefore has potential therapeutic potential in humans.

Effect of dehydroepiandrosterone on atopic dermatitis-like skin lesions induced by 1-chloro-2,4-dinitrobenzene in mouse

BACKGROUND

Th2 cells are overexpressed in the skin and serum of atopic dermatitis (AD) patients. Previously, we found that dehydroepiandrosterone (DHEA) decreased eosinophil infiltration in asthmatic mice through the suppression of Th2-associated cytokines. Therefore, we hypothesized that DHEA might improve the symptoms of AD syndrome.

OBJECTIVE

In this study, we evaluated the symptom improvement and anti-inflammatory response that result from the modulation of immunity by DHEA modulated in AD-like mice.

METHODS

Female BALB/c mice were sensitized and challenged with 1-chloro-2,4-dinitrobenzene. On days 14-29 after sensitization, mice were treated with cutaneous (skin smear) or oral administration of DHEA. In addition, human keratinocyte (HaCat) cells were used to evaluate the effect of DHEA on the in vitro production of proinflammatory cytokines and chemokines.

RESULTS

Both cutaneous and oral DHEA were able to decrease ear swelling and skin inflammation in AD-like mice. DHEA also attenuated eosinophil and mast cell infiltration into ear and skin tissue. Additionally, Th2-associated cytokines were inhibited in splenocyte culture, and suppressed the levels of IgE and interleukin 4 in serum. Oral and cutaneous administration of DHEA reduced the inflammatory response, as evidenced by AD-like skin lesions, in a similar manner. DHEA significantly reduced inflammatory cytokines and chemokines through the nuclear factor-κB and mitogen-activated protein kinases pathways in tumor necrosis factor-α activated HaCat cells.

CONCLUSION

DHEA ameliorates AD-like mouse skin inflammation and reduces eosinophil and mast cell infiltration by reducing the production of Th2-associated cytokines and chemokines.

Graptopetalum paraguayense Ameliorates Airway Inflammation and Allergy in Ovalbumin- (OVA-) Sensitized BALB/C Mice by Inhibiting Th2 Signal

Role of inflammation-induced oxidative stress in the pathogenesis and progression of chronic inflammatory airways diseases has received increasing attention in recent years. Nuclear factor erythroid 2-related factor 2 is the primary transcription factor that regulates the expression of antioxidant and detoxifying enzymes. Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury through elevating antioxidation. Recently, we found that gallic acid is an active compound of Graptopetalum paraguayense E. Walther, which has been reported to inhibit T-helper 2 cytokines. Currently, we assumed that Graptopetalum paraguayense E. Walther may potentially protect against ovalbumin-induced allergy and airway inflammation. Results demonstrated that Graptopetalum paraguayense E. Walther ethanolic extracts (GPE) clearly inhibited airway inflammation, mucus cell hyperplasia, and eosinophilia in OVA-challenged mice. Additionally, GPE also prevented T-cell infiltration and Th2 cytokines, including interleukin- (IL-)4, IL-5, and IL-13 generations in bronchial alveolar lavage fluid. The adhesion molecules ICAM-1 and VCAM-1 were substantially reduced by GPE treatment mediated by Nrf2 activation. Moreover, GPE attenuated GATA3 expression and inhibited Th2 signals of the T cells. These findings suggested that GPE ameliorated the development of airway inflammation through immune regulation.

Flavonoids and asthma

Asthma is a chronic disease, characterized by airway inflammation, airflow limitation, hyper-reactivity and airway remodeling. It is believed that asthma is caused by the interaction between genetic and environmental factors. The prevalence of allergic diseases, including asthma, has increased worldwide during the past two decades. Although the precise reasons that have caused this increase remain unknown, dietary change is thought to be one of the environmental factors. Flavonoids, which are polyphenolic plant secondary metabolites ubiquitously present in vegetables, fruits and beverages, possess antioxidant and anti-allergic traits, as well as immune-modulating activities. Flavonoids are powerful antioxidants and anti-allergic nutrients that inhibit the release of chemical mediators, synthesis of Th2 type cytokines, such as interleukin (IL)-4 and IL-13, and CD40 ligand expression by high-affinity immunoglobulin E (IgE) receptor-expressing cells, such as mast cells and basophils. They also inhibit IL-4-induced signal transduction and affect the differentiation of naïve CD4+ T cells into effector T-cells through their inhibitory effect on the activation of the aryl hydrocarbon receptor. Various studies of flavonoids in asthmatic animal models have demonstrated their beneficial effects. The results of several epidemiological studies suggest that an increase in flavonoid intake is beneficial for asthma. Moreover, clinical trials of flavonoids have shown their ameliorative effects on symptoms related to asthma. However, these human studies are currently limited; further validation is required to clarify whether an appropriate intake of flavonoids may constitute dietary treatment and for part of a preventive strategy for asthma.