Inhibition of Asthma in OVA Sensitized Mice Model by a Traditional Uygur Herb Nepeta bracteata Benth

Stigmasterol alleviates allergic airway inflammation and airway hyperresponsiveness in asthma mice through inhibiting substance-P receptor

CONTEXT

Stigmasterol has significant anti-arthritis and anti-inflammatory effects, but its role in immune and inflammatory diseases is still unclear.

OBJECTIVE

The potential advantages of stigmasterol in asthma were explored in IL-13-induced BEAS-2B cells and asthmatic mice.

MATERIALS AND METHODS

The optimal target of stigmasterol was confirmed in asthma. After detecting the cytotoxicity of stigmasterol in BEAS-2B cells, 10 μg/mL and 20 μg/mL stigmasterol were incubated with the BEAS-2B cell model for 48 h, and anti-inflammation and antioxidative stress were verified. Asthmatic mice were induced by OVA and received 100 mg/kg stigmasterol for 7 consecutive days. After 28 days, lung tissues and BAL fluid were collected for the following study. To further verify the role of NK1-R, 0.1 μM WIN62577 (NK1-R specific antagonist), and 1 μM recombinant human NK1-R protein were applied.

RESULTS

NK1-R was the potential target of stigmasterol. When the concentration of stigmasterol is 20 μg/mL, the survival rate of BEAS-2B cells is about 98.4%, which is non-toxic. Stigmasterol exerted anti-inflammation and antioxidant stress in a dose-dependent manner and decreased NK1-R expression in IL-13-induced BEAS-2B. Meanwhile, in vivo assay also indicated the anti-inflammation and antioxidant stress of stigmasterol after OVA challenge. Stigmasterol inhibited inflammation infiltration and mucus hypersecretion, and NK1-R expression.

DISCUSSION AND CONCLUSIONS

The protective effect of stigmaterol on asthma and its underlying mechanism have been discussed in depth, providing a theoretical basis and more possibilities for its treatment of asthma.

Quercetin Alleviates Asthma-Induced Airway Inflammation and Remodeling through Downregulating Periostin via Blocking TGF-β1/Smad Pathway

INTRODUCTION

The aim of the study was to discuss whether the anti-asthmatic effect of quercetin is related to periostin and the downstream molecular pathway of quercetin's anti-asthmatic effect.

METHODS

We constructed asthmatic mice, sensitized by ovalbumin, and administrated different treatments into mice according to the experimental design. In this study, we mainly observed the inflammatory response, airway fibrosis, and airway hyperresponsiveness in asthmatic mice. Pathological stains (H&E, PAS, and Masson) were performed. We also detected the inflammation factors and fibrosis-related cytokines by enzyme-linked immunosorbent serologic assay. In addition, we also explored the level of periostin by enzyme-linked immunosorbent serologic assay and Western blot. At the same time, TGF-β1/Smad pathway was also determined by Western blot.

RESULTS

A high expression of periostin was found in asthmatic mice, and quercetin decreases periostin content in bronchoalveolar lavage fluid. Quercetin and OC-20 inhibit airway inflammation response, airway fibrosis, and airway hyperreactivity. Quercetin downregulated TGF-β1/Smad pathway in the lung tissues of asthmatic mice. Anti-asthma role of quercetin is related to periostin. Then deeper mechanical study revealed that inhibiting TGF-β1 could improve asthmatic symptoms, and quercetin exerted the protective effect on asthmatic mice through inhibition of TGF-β1/Smad pathway.

CONCLUSION

Quercetin provided a protective role against asthma via periostin, manifested by mild inflammatory infiltration, reduced goblet cell proliferation, and reduced airway fibrosis. TGF-β1/Smad pathway is an important transduction system, participating in the protective effect of quercetin on asthma.

Abietane-Type Diterpenoids From Nepeta bracteata Benth. and Their Anti-Inflammatory Activity

Terpenes possess a wide range of structural features and pharmaceutical activities and are promising for drug candidates. With the aim to find bioactive terpene molecules, eight new compounds were isolated from the medicinal plant Nepeta bracteata Benth., including seven new abietane-type diterpenoids (1–7), along with a new ursane-type triterpenoid(8). The structures of compounds 1–8 were elucidated through the detailed spectroscopic analyses of their 1D and 2D NMR and MS data, and the absolute configurations of compounds 1–7 were determined by comparing their experimental and calculated ECD spectra. Compound 1 was a novel degraded carbon diterpene with the disappearing of methyl signal at C-19, while compound 7 possessed a new norabietane-type diterpenoid carbon skeleton with the presence of five-membered lactone arising from ring rearrangement. The anti-inflammatory of all obtained isolates were evaluated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the results of anti-inflammatory activity screening showed that compared with the LPS model group, all compounds were significantly down-regulation the TNF-α inflammatory factor at the specific concentration, except for compound 6.

Inflammatory and Cytotoxic Activities of Abietane Terpenoids from Nepeta bracteata Benth

Nepeta bracteata Benth. is used clinically to treat tracheal inflammation, coughs, asthma, colds, fevers, adverse urination, and other symptoms, along with functions in clearing heat and removing dampness. However, there have been few studies characterizing the material basis of its efficacy. Therefore, the aim of this study was to screen for compounds with anti-inflammatory activities in N. bracteata Benth. Using silica gel, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC, 10 compounds were separated from N. bracteata Benth. extract, including four new diterpenoids (1–4), one amide alkaloid (5), and five known diterpenoids (6–10). The structures of all the isolates were elucidated by HR-ESI-MS, NMR, and CD analyses. Using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, we investigated the anti-inflammatory activities of compounds 1–10. It is worth noting that all were able to inhibit nitric oxide (NO) production with IC₅₀ values < 50 μM and little effect on RAW 264.7 macrophage viability. Compounds 2 and 4 displayed remarkable inhibition with IC₅₀ values of 19.2 and 18.8 μM, respectively. Meanwhile, screening on HCT-8 cells demonstrated that compounds 2 and 4 also had moderate cytotoxic activities with IC₅₀ values of 36.3 and 41.4 μM, respectively, which is related to their anti-inflammatory effects.

Perilla Leaf Extract Attenuates Asthma Airway Inflammation by Blocking the Syk Pathway

Perilla frutescens (L.) Britton is a classic herbal plant used widely against asthma in China. But its mechanism of beneficial effect remains undermined. In the study, the antiallergic asthma effects of Perilla leaf extract (PLE) were investigated, and the underlying mechanism was also explored. Results showed that PLE treatment significantly attenuated airway inflammation in OVA-induced asthma mice, by ameliorating lung pathological changes, inhibiting recruitment of inflammatory cells in lung tissues and bronchoalveolar lavage fluid (BALF), decreasing the production of inflammatory cytokines in the BALF, and reducing the level of immunoglobulin in serum. PLE treatment suppressed inflammatory response in antigen-induced rat basophilic leukemia 2H3 (RBL-2H3) cells as well as in OVA-induced human peripheral blood mononuclear cells (PBMCs). Furthermore, PLE markedly inhibited the expression and phosphorylation of Syk, NF-κB, PKC, and cPLA₂ both in vivo and in vitro. By cotreating with inhibitors (BAY61-3606, Rottlerin, BAY11-7082, and arachidonyl trifluoromethyl ketone) in vitro, results revealed that PLE's antiallergic inflammatory effects were associated with the inhibition of Syk and its downstream signals NF-κB, PKC, and cPLA₂. Collectively, the present results suggested that PLE could attenuate allergic inflammation, and its mechanism might be partly mediated through inhibiting the Syk pathway.

Tespa1 plays a role in the modulation of airway hyperreactivity through the IL-4/STAT6 pathway

BACKGROUND

Thymocyte-expressed, positive selection-associated 1 (Tespa1) is a critical signaling molecule in thymocyte development. This study aimed to investigate the regulatory effect of Tespa1 on mast cells in the pathogenesis of asthma and its relationship with the interleukin (IL)-4/signal transducers and activators of transcription 6 (STAT6) signaling pathway.

METHODS

Tespa1 mRNA expression analysis and IgE levels were carried out using the induced sputum of 33 adults with stable asthma and 36 healthy controls. Tespa1-knockout mice (Tespa1-/-, KO) and C57BL/6 background (wild-type, WT) mice were sensitized and treated with ovalbumin (OVA) to establish an asthma model. Pathological changes, number and activity of mast cells, and changes in activation of the IL-4/STAT6 pathway in lung tissue were detected. The changes of tryptase expression and STAT6 activation after mast cell gene knockout were analyzed in vitro. The changes of enzyme expression and STAT6 activation after mast cell gene knockout were analyzed in vitro. The association between the Tespa1 and p-STAT6 was analyzed by co-immunoprecipitation method.

RESULTS

Compared with the healthy controls, Tespa1 expression was decreased, and IgE levels were elevated in the sputum of asthmatic patients. Animal experiments showed that Tespa1-/- mice exhibited more severe inflammation, higher quantity of goblet cells and mast cells in the bronchium, and greater expression of mast cell tryptase, which is induced by ovalbumin, than WT mice. And IL-4, IL-13, phospho-Janus kinase 1, and p-STAT6 expressions presented a higher increase in the Tespa1-/- mouse model than in the WT mouse model. Further in vitro studies confirmed that IL-4 could more significantly promote tryptase and p-STAT6 activities in Tespa1-/- mast cells than their WT counterparts. Correlation analysis results showed a negative correlation between Tespa1 and p-STAT6. Co-immunoprecipitation results demonstrated an association between Tespa1 and p-STAT6.

CONCLUSIONS

Altogether, our results indicate that Tespa1 can negatively regulate mast cell activity, and this event is related to the mast cell IL-4/STAT6 signaling pathway and could be therapeutically exploited to treat asthma attacks.

Multiple Components Rapidly Screened from Perilla Leaves Attenuate Asthma Airway Inflammation by Synergistic Targeting on Syk

Background

Perilla frutescens (L.) Britt., a classic medicinal plant, has been demonstrated to have anti-inflammatory and anti-allergic effects in asthma. Perilla leaves extract (PLE) exerted significant therapeutic effect against allergic asthma inflammation through Syk inhibition. But the active chemical ingredients from PLE are complex and unclear, it is difficult to fully elucidate its pharmacological mechanisms.

Methods

A method was established for rapid screening and characterization of active ingredients from PLE that targeted Syk, with which three potential active ingredients were identified. By using OVA-induced allergic asthma mouse model in vivo, OVA-induced human PBMCs inflammation model and DNP-IgE/BSA-induced RBL-2H3 cells model in vitro, the effects and mechanisms of PLE and its active components were evaluated.

Results

Using Syk-affinity screening method, roseoside (RosS), vicenin-2 (Vic-2) and rosmarinic acid (RosA) were identified from PLE. In vitro, PLE and its ingredients showed significant inhibitory activities against Syk, with their mixture (Mix, prepared by RosS, Vic-2 and RosA in accordance with their ratio in Syk-conjugated beads bound fraction) showing a stronger inhibitory activity. RosS, Vic-2 and RosA also showed significant effects on allergic asthma, and a synergistic effect of Mix was observed. Moreover, treatment with PLE, RosS, Vic-2, RosA, and Mix significantly inhibited the expression and phosphorylation of Syk, PKC, NF-κB p65, and cPLA₂ in allergic mice lung tissue and in RBL-2H3 cells.

Conclusion

PLE may alleviate allergic airway inflammation partly through the multiple components synergistic targeting on Syk and its downstream inflammatory pathway.

miR-30a-3p participates in the development of asthma by targeting CCR3

This study aimed to investigate the role and relevant mechanism of miR-30a-3p action in asthma. The results of this study revealed that the expression levels of miR-30a-3p were significantly decreased in the peripheral blood of asthmatic patients. In addition, we found that the CC chemokine receptor (CCR3) was a target of miR-30a-3p. Subsequently, an asthma mouse model was established using ovalbumin (OVA). The results showed that the expression of miR-30a-3p and CCR3 was downregulated and upregulated, respectively, in the peripheral blood of asthmatic mice. Enzyme-linked immunosorbent assay (ELISA) in asthmatic mouse serum demonstrated that miR-30a-3p mimic treatment significantly decreased the secretion of OVA-specific IgE, eotaxin-1, interleukin (IL)-5, and IL-4. These results suggested that miR-30a-3p inhibited CCR3 signaling pathway and relieved the inflammatory response against asthma in vivo. Eosinophils have also been implicated in the asthmatic inflammatory response. Therefore, the in vitro effects of miR-30a-3p on eosinophil activity were determined. Findings suggested that miR-30a-3p mimic significantly reduced eosinophil viability and migration and induced apoptosis. In addition, CCR3 and eotaxin-1 downregulation were observed. The aforementioned results were significantly reversed following CCR3 overexpression. This study suggested that miR-30a-3p was involved in asthma by regulating eosinophil activity and targeting CCR3.

Lamiaceae: An Insight on Their Anti-Allergic Potential and Its Mechanisms of Action

The prevalence of allergic diseases such as asthma, allergic rhinitis, food allergy and atopic dermatitis has increased dramatically in recent decades. Conventional therapies for allergy can induce undesirable effects and hence patients tend to seek alternative therapies like natural compounds. Considering the fact above, there is an urgency to discover potential medicinal plants as future candidates in the development of novel anti-allergic therapeutic agents. The Lamiaceae family, or mint family, is a diverse plant family which encompasses more than 7,000 species and with a cosmopolitan distribution. A number of species from this family has been widely employed as ethnomedicine against allergic inflammatory skin diseases and allergic asthma in traditional practices. Phytochemical analysis of the Lamiaceae family has reported the presence of flavonoids, flavones, flavanones, flavonoid glycosides, monoterpenes, diterpenes, triterpenoids, essential oil and fatty acids. Numerous investigations have highlighted the anti-allergic activities of Lamiaceae species with their active principles and crude extracts. Henceforth, this review has the ultimate aim of compiling the up-to-date (2018) findings of published scientific information about the anti-allergic activities of Lamiaceae species. In addition, the botanical features, medicinal uses, chemical constituents and toxicological studies of Lamiaceae species were also documented. The method employed for data collection in this review was mainly the exploration of the PubMed, Ovid and Scopus databases. Additional research studies were obtained from the reference lists of retrieved articles. This comprehensive summarization serves as a useful resource for a better understanding of Lamiaceae species. The anti-allergic mechanisms related to Lamiaceae species are also reviewed extensively which aids in future exploration of the anti-allergic potential of Lamiaceae species.

[Mechanism of action of BET bromodomain inhibitor JQ1 in treating airway remodeling in asthmatic mice]

OBJECTIVE

To investigate the molecular mechanism of action of BET bromodomain inhibitor JQ1 in treating airway remodeling in asthmatic mice.

METHODS

A total of 24 mice were randomly divided into control group, ovalbumin (OVA)-induced asthma group (OVA group), and JQ1 intervention group (JQ1+OVA group), with 8 mice in each group. OVA sensitization/challenge was performed to establish a mouse model of asthma. At 1 hour before challenge, the mice in the JQ1+OVA group were given intraperitoneal injection of JQ1 solution (50 μg/g). Bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at 24 hours after the last challenge, and the total number of cells and percentage of eosinophils in BALF were calculated. Pathological staining was performed to observe histopathological changes in lung tissue. RT-PCR and Western blot were used to measure the mRNA and protein expression of E-cadherin and vimentin during epithelial-mesenchymal transition (EMT).

RESULTS

Compared with the control group, the OVA group had marked infiltration of inflammatory cells in the airway, thickening of the airway wall, increased secretion of mucus, and increases in the total number of cells and percentage of eosinophils in BALF (P<0.01). Compared with the OVA group, the JQ1+OVA group had significantly alleviated airway inflammatory response and significant reductions in the total number of cells and percentage of eosinophils in BALF (P<0.01). Compared with the control group, the OVA group had significant reductions in the mRNA and protein expression of E-cadherin and significant increases in the mRNA and protein expression of vimentin (P<0.01); compared with the OVA group, the JQ1+OVA group had significant increases in the mRNA and protein expression of E-cadherin and significant reductions in the mRNA and protein expression of vimentin (P<0.01); there were no significant differences in these indices between the JQ1+OVA group and the control group (P>0.05).

CONCLUSIONS

Mice with OVA-induced asthma have airway remodeling during EMT. BET bromodomain inhibitor JQ1 can reduce airway inflammation, inhibit EMT, and alleviate airway remodeling, which provides a new direction for the treatment of asthma.

Effect of Nepeta bracteata Benth. on allergic rhinitis symptoms: A randomized double-blind clinical trial

Background:

Allergic rhinitis (AR) is one of the health problems in the world. It is necessary to develop new treatment procedure for control of this disease. The aim of this study was to assess the effect of Zofa (Nepeta bracteata Benth) on AR patients.

Materials and Methods:

In this double-blind randomized clinical trial study, 71 patients (37 patients in treatment and 34 in placebo group) participated. In treatment group, N. bracteata syrup (NBS) was used for 4 weeks as three times a day. The efficacy of the drug regarding AR symptoms (rhinorrhea, sneezing, nasal obstruction, itchy nose, and ocular symptoms) were evaluated through a visual analog scale (VAS) by 0–10 before administration and at the end of the whole treatment period. The collected information was entered in the SPSS software (version 18) and was analyzed using the Fisher's exact test, Chi-square test, independent sample t-test, and paired sample test.

Results:

The improvement of AR symptoms in the group receiving NBS was significantly higher compared to control group (4.73 ± 1.84 vs. 0.38 ± 2.06; P < 0.0001). Furthermore, the mean of total VAS before and after the treatment (in case group) was 7.10 ± 1.92 and 2.37 ± 1.76, respectively (P < 0.001).

Conclusion:

The results of this study indicate that N. bracteata has significant effects on improving the symptoms of AR. Hence, it can be a good alternative to AR symptoms relief.

Anti-asthmatic effect of pitavastatin through aerosol inhalation is associated with CD4+ CD25+ Foxp3+ T cells in an asthma mouse model

Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl-CoA (HMG-A) reductase, and studies have shown that statins also have anti-inflammatory and immunomodulatory properties. The purpose of this study was to investigate the anti-asthmatic effects of pitavastatin, a type of statin, in an asthma mouse model. Mice were sensitized and challenged with ovalbumin (OVA) to establish the asthma model. These mice were then treated with inhaled pitavastatin (5 mg/kg) or dexamethasone (2 mg/kg), the latter of which served as a positive control. The results of the study showed that pitavastatin reduced allergen-induced increases in airway resistance and alleviated bronchial tube thickness and goblet cell hyperplasia in lung tissues. In addition, the results showed that pitavastatin inhibited OVA-induced increases in eosinophil counts and total inflammatory cell counts in bronchoalveolar lavage fluid (BALF) and increased the percentage of CD4+ CD25+ Foxp3+ Treg in the BALF of asthmatic mice. IL-4 and IL-17 levels were decreased, whereas IFN-γ levels were significantly increased in the BALF of pitavastatin-treated mice compared with the BALF of OVA-challenged mice. These results suggest that pitavastatin has potential as a therapy for allergic airway disease and that its effects are associated with its ability to regulate CD4+ CD25+ Foxp3+ T cell counts.

Spectrophotometric determination of the total phenolic content, spectral and fluorescence study of the herbal Unani drug Gul-e-Zoofa (Nepeta bracteata Benth)

Objectives

This study quantitatively determined the total phenolic contents in ethanolic and aqueous extracts of Gul-e-Zoofa (flowers of Nepeta bracteata Benth) using a spectrophotometric method. We also performed a spectral study (UV and IR) of the ethanolic extract and a fluorescence study of the powdered drug and successive extracts to identify and characterize the genuine herbal drug, which has not been previously performed.

Methods

The total phenolic content was determined quantitatively using the Folin Ciocalteu reagent, with Gallic acid as the standard. The fluorescence characteristics of the powdered drug and successive extracts with and without chemical treatment during the day and under a UV light were recorded. The UV and IR spectra of the alcoholic extract of Gul-e-Zoofa were recorded using a spectrometer.

Results

The total phenolic contents of the alcoholic and aqueous extracts were found to be 326.28 and 319.14 mg/g of the Gallic acid equivalent (GAE), respectively. The wavelength of the maximum absorption in the UV spectrum was 320 nm, and the characteristic frequencies in the IR spectrum were 3465.31, 3220.07, 2927.3, 2856.1, 1709.07, 1610.19, 1404.5, 1250.2, 1056.42, 823.04, 775.58, 577.81, and 463.10 cm⁻¹. The fluorescence characteristics of the powdered drug were also observed.

Conclusion

This spectral and fluorescence study of the drug will be helpful for confirming the identity and purity of the genuine drug. The total phenolic content will be helpful for developing new drugs and standardizing the drug. The presence of a high total phenolic content shows that the flowers of N. bracteata Benth may possess antioxidant properties, which could lead to a new field of research in the future.