Beneficial Effects of Astragalus membranaceus (Fisch.) Bunge Extract in Controlling Inflammatory Response and Preventing Asthma Features.

Astragalus membranaceus (Fisch.) Bunge root is used as herbal medicine for its immunomodulating activities in Chinese medicine. Recently, beneficial properties of A. membranaceus on allergic diseases have been proposed. Here we investigated the role of a commercial extract of A. membranaceus, standardized to 16% polysaccharides, in regulating the immune-inflammatory response in vitro and in vivo and its therapeutic application in asthma. A. membranaceus extract inhibited prostaglandin E2 and leukotriene C4 production in stimulated J774 and peritoneal macrophages, respectively. The extract also reduced interlukin-1ß, tumor necrosis factor-α, and nitrite production, affecting inducible nitric oxide synthase expression. In vivo experiments confirmed the anti-inflammatory properties of A. membranaceus, as evident by a reduction in zymosan-induced peritoneal cellular infiltration and pro-inflammatory mediator production. The efficacy of A. membranaceus extract in modulating the immune response was confirmed in a model of allergic airway inflammation. Extracts improve lung function by inhibiting airway hyperresponsiveness, airway remodeling, and fibrosis. Its anti-asthmatic effects were further sustained by inhibition of the sensitization process, as indicated by a reduction of ovalbumin-induced IgE levels and the mounting of a Th2 immune response. In conclusion, our data demonstrate the anti-inflammatory properties of the commercial extract of A. membranaceus and its beneficial effects on asthma feature development.

A vitamin E long-chain metabolite and the inspired drug candidate α-amplexichromanol relieve asthma features in an experimental model of allergen sensitization.

Benefits for vitamin E intake in diseases with inflammatory components have been described and related in part, to endogenously formed metabolites (long-chain metabolites, LCM). Here, we have evaluated the role of LCM in relieving asthma features. To this aim, the endogenous vitamin E metabolite α-13'-carboxychromanol (α-T-13'-COOH) that acts as potent 5-lipoxygenase inhibitor has been administered either intraperitoneally or by oral gavage to BALB/c mice sensitized by subcutaneous injection of ovalbumin (OVA). We also have taken advantage of the metabolically stable α-T-13'-COOH derivative α-amplexichromanol (α-AC). Intraperitoneal treatment with α-T-13'-COOH reduced OVA-induced airway hyperreactivity (AHR) as well as peri-bronchial inflammatory cell infiltration. α-AC was more efficacious than α-T-13'-COOH, as demonstrated by better control of AHR and in reducing subepithelial. Both compounds exerted their protective function by reducing pulmonary leukotriene C4 levels. Beneficial effects of α-AC were coupled to inhibition of the sensitization process, as indicated by a reduction of IgE plasma levels, lung mast cell infiltration and Th2 immune response. Metabololipidomics analysis revealed that α-AC raises the pulmonary levels of prostanoids, their degradation products, and 12/15-lipoxygenase metabolites. Following oral administration, the pharmacodynamically different profile in α-T-13'-COOH and α-AC was abrogated as demonstrated by a similar and improved efficacy in controlling asthma features as well as by metabololipidomics analysis. In conclusion, this study highlights a role for LCM and of vitamin E derivatives as pharmacologically active compounds that ameliorate asthmatic features and defines an important role for endogenous vitamin E metabolites in regulating immune response underlying the sensitization process.

Enhanced efficacy of formoterol-montelukast salt in relieving asthma features and in preserving ß2-agonists rescue therapy.

Adrenergic ß2-agonists represent a mainstay in asthma management. Their chronic use has been associated with decreased bronchoprotection and rebound hyperresponsiveness. Here we investigate on the possible therapeutic advantage of a pharmacological association of ß2-agonists with montelukast, a highly selective leukotriene receptor antagonist, in modulating bronchial reactivity and controlling asthma features. The study has been conducted in vitro and in vivo and also takes advantage of the synthesis of a salt that gave us the possibility to simultaneously administer in vivo formoterol and montelukast (MFS). In vitro studies demonstrate that montelukast (1) preserves ß2-agonist response in isolated bronchi by preventing homologous ß2-adrenoceptor desensitization; (2) reduces desensitization by modulating ß2-receptor translocation in bronchial epithelial cells. In vivo studies demonstrate that sensitized mice receiving formoterol or montelukast display a significant reduction in airway hyperresponsiveness, but the ß2-agonist relaxing response is still impaired. Allergen challenge causes ß2 heterologous desensitization that is further increased by treatment in vivo with formoterol. Conversely MFS not only inhibits airway hyperresponsiveness but it rescues the ß2-agonist response. Histological analysis confirms the functional data, demonstrating an enhanced therapeutic efficiency of MSF in controlling also pulmonary metaplasia and lung inflammation. MFS is efficacious also when sensitized mice received the drug by local administration. In conclusion, the data obtained evidenced a therapeutic advantage in the association of ß2-agonists with montelukast in the control of asthma-like features and a better rescue bronchodilation response to ß2-agonists.

Antagonizing S1P3 Receptor with Cell-Penetrating Pepducins in Skeletal Muscle Fibrosis.

S1P is the final product of sphingolipid metabolism, which interacts with five widely expressed GPCRs (S1P1-5). Increasing numbers of studies have indicated the importance of S1P3 in various pathophysiological processes. Recently, we have identified a pepducin (compound KRX-725-II) acting as an S1P3 receptor antagonist. Here, aiming to optimize the activity and selectivity profile of the described compound, we have synthesized a series of derivatives in which Tyr, in position 4, has been substituted with several natural aromatic and unnatural aromatic and non-aromatic amino acids. All the compounds were evaluated for their ability to inhibit vascular relaxation induced by KRX-725 (as S1P3 selective pepducin agonist) and KRX-722 (an S1P1-selective pepducin agonist). Those selective towards S1P3 (compounds V and VII) were also evaluated for their ability to inhibit skeletal muscle fibrosis. Finally, molecular dynamics simulations were performed to derive information on the preferred conformations of selective and unselective antagonists.

Prednisone-hydrogen sulfide releasing hybrid shows improved therapeutic profile in asthma.

Introduction: Hydrogen sulfide (H2S) is emerging as an important potential therapeutic option for respiratory inflammatory diseases. In this study, we investigated the effectiveness of a novel corticosteroid derivative, that is chemically linked to an H2S donor, in managing asthma features. Methods: The effects of prednisone (PS), H2S donor (4-hydroxybenzamide; TBZ), and their combination (PS-TBZ) have been evaluated in vitro and in vivo. The in vitro experiments were conducted using lipopolysaccharidestimulated J774 macrophages, while the in vivo experiments utilizing an experimental asthma model. Results: In the in vitro study we found that PS-TBZ exhibited an increased effect compared to the individual parent compounds in modulating the production of inflammatory mediators. TBZ also significantly reduced bronchial contractility and enhanced bronchial relaxation. In the in vivo experiments, where we administered PS, TBZ, or PS-TBZ to ovalbumin-sensitized BALB/c mice, we confirmed that PS-TBZ had a significantly better action in controlling airway hyperreactivity as compared to TBZ or PS alone. Moreover, PS-TBZ was more effective in restoring salbutamol-induced relaxation. The immunohistochemistry analysis demonstrated a significant reduction in the production of α-SMA and procollagen III, indicating the efficacy of PS-TBZ in controlling airway remodeling. Moreover, PS-TBZ also promoted epithelial repair, recovery of the bronchial and parenchyma structure and inhibited mucin production. Discussion: In conclusion, PS-TBZ offers an important opportunity to optimize the beneficial impact of corticosteroids on asthma features.

Circulating MicroRNAs Expression Profile in Lung Inflammation: A Preliminary Study.

BACKGROUND: Bronchial asthma is an inflammatory airway disease with an ever-increasing incidence. Therefore, innovative management strategies are urgently needed. MicroRNAs are small molecules that play a key role in lungs cellular functions and are involved in chronic inflammatory diseases, such as bronchial asthma. This study aims to compare microRNA serum expression between subjects with asthma, obesity, the most common co-morbidity in asthma, and healthy controls to obtain a specific expression profile specifically related to lung inflammation. METHODS: We collected serum samples from a prospective cohort of 25 sex-matched subjects to determine circulating miRNAs through a quantitative RT-PCR. Moreover, we performed an in silico prediction of microRNA target genes linked to lung inflammation. RESULTS: Asthmatic patients had a significant lower expression of hsa-miR-34a-5p, 181a-5p and 146a-5p compared to both obese and healthy ones suggesting microRNAs' specific involvement in the regulation of lungs inflammatory response. Indeed, using in silico analysis, we identified microRNAs novel target genes as GATA family, linked to the inflammatory-related pathway. CONCLUSIONS: This study identifies a novel circulating miRNAs expression profile with promising potentials for asthma clinical evaluations and management. Further and larger investigations will be needed to confirm the potential role of microRNA as a clinical marker of bronchial asthma and eventually of pharmacological treatment response.

Sphingosine-1-phosphate/TGF-ß axis drives epithelial mesenchymal transition in asthma-like disease.

BACKGROUND AND PURPOSE: Airway remodelling is a critical feature of chronic lung diseases. Epithelial-mesenchymal transition (EMT) represents an important source of myofibroblasts, contributing to airway remodelling. Here, we investigated the sphingosine-1-phosphate (S1P) role in EMT and its involvement in asthma-related airway dysfunction. EXPERIMENTAL APPROACH: A549 cells were used to assess the S1P effect on EMT and its interaction with TGF-ß signalling. To assess the S1P role in vivo and its impact on lung function, two experimental models of asthma were used by exposing BALB/c mice to subcutaneous administration of either S1P or ovalbumin (OVA). KEY RESULTS: Following incubation with TGF-ß or S1P, A549 acquire a fibroblast-like morphology associated with an increase of mesenchymal markers and down-regulation of the epithelial. These effects are reversed by treatment with the TGF-ß receptor antagonist LY2109761. Systemic administration of S1P to BALB/c mice induces asthma-like disease characterized by mucous cell metaplasia and increased levels of TGF-ß, IL-33 and FGF-2 within the lung. The bronchi harvested from S1P-treated mice display bronchial hyperresponsiveness associated with overexpression of the mesenchymal and fibrosis markers and reduction of the epithelial.The S1P-induced switch from the epithelial toward the mesenchymal pattern correlates to a significant increase of lung resistance and fibroblast activation. TGF-ß blockade, in S1P-treated mice, abrogates these effects. Finally, inhibition of sphingosine kinases by SK1-II in OVA-sensitized mice, abrogates EMT, pulmonary TGF-ß up-regulation, fibroblasts recruitment and airway hyperresponsiveness. CONCLUSION AND IMPLICATIONS: Targeting S1P/TGF-ß axis may hold promise as a feasible therapeutic target to control airway dysfunction in asthma.

Discovery and Optimization of Indoline-Based Compounds as Dual 5-LOX/sEH Inhibitors: In Vitro and In Vivo Anti-Inflammatory Characterization.

The design of multitarget drugs represents a promising strategy in medicinal chemistry and seems particularly suitable for the discovery of anti-inflammatory drugs. Here, we describe the identification of an indoline-based compound inhibiting both 5-lipoxygenase (5-LOX) and soluble epoxide hydrolase (sEH). In silico analysis of an in-house library identified nine compounds as potential 5-LOX inhibitors. Enzymatic and cellular assays revealed the indoline derivative 43 as a notable 5-LOX inhibitor, guiding the design of new analogues. These compounds underwent extensive in vitro investigation revealing dual 5-LOX/sEH inhibitors, with 73 showing the most promising activity (IC50s of 0.41 ± 0.01 and 0.43 ± 0.10 µM for 5-LOX and sEH, respectively). When challenged in vivo in zymosan-induced peritonitis and experimental asthma in mice, compound 73 showed remarkable anti-inflammatory efficacy. These results pave the way for the rational design of 5-LOX/sEH dual inhibitors and for further investigation of their potential use as anti-inflammatory agents.