Cruciferous vegetable-derived indole-3-carbinol prevents coronavirus cell egression mechanisms in tracheal and intestinal 3D in vitro models

The potential antiviral effects of indole-3-carbinol (I3C), a phytochemical found in Cruciferous vegetables, were investigated. Fibroblasts and epithelial cells were co-cultured on Alvetex® scaffolds, to obtain ad hoc 3D in vitro platforms able to mimic the trachea and intestinal mucosae, which represent the primary structures involved in the coronavirus pathogenesis. The two barriers generated in vitro were treated with various concentrations of I3C for different incubation periods. A protective effect of I3C on both intestinal and trachea models was demonstrated. A significant reduction in the transcription of the two main genes belonging to the Homologous to E6AP C-terminus (HECT)-E3 ligase family members, namely NEDD4 E3 Ubiquitin Protein Ligase (NEDD4) and WW Domain Containing E3 Ubiquitin Protein Ligase 1 (WWP1), which promote virus matrix protein ubiquitination and inhibit viral egression, were detected. These findings indicate I3C potential effect in preventing coronavirus cell egression processes that inhibit viral production. Although further studies are needed to clarify the molecular mechanisms whereby HECT family members control virus life cycle, this work paves the way to the possible therapeutic use of new natural compounds that may reduce the clinical severity of future pandemics.

Altered gene expression levels of IL-17/TRAF6/MAPK/USP25 axis and pro-inflammatory cytokine levels in lung tissue of obese ovalbumin-sensitized rats

AIMS

The association between asthma and obesity has been shown but its accurate mechanism is unknown. In the current study, we sought to investigate the gene expression levels of IL-17/TRAF6/MAPK/USP25 axis and pro-inflammatory cytokine level (IL-6, IL-1β, and TNF-α) in obese Ovalbumin (OVA)-sensitized female and male Wistar rats lung tissue.

MAIN METHODS

Animals in both males and females were divided into eight groups (four groups in each sex) based on diet and OVA-sensitization: normal diet, a normal diet with OVA-sensitization, high-fat diet (HFD), and OVA-sensitization with an HFD.

KEY FINDINGS

In both sexes, obese OVA-sensitized rats, the methacholine concentration-response curve shifted to the left and EC50 methacholine decreased. Increased pro-inflammatory cytokines as well as elevated IL-17/TRAF6/MAPK axis genes and decreased USP25 gene expression were identified in obese OVA-sensitized groups.

SIGNIFICANCE

The results indicate that in obese OVA-sensitized rats, the IL-17 axis were involved in the pathogenesis of the disease and can be considered as a therapeutic target in subjects with obesity-related asthma.

In Silico and Ex Vivo Studies on the Spasmolytic Activities of Fenchone Using Isolated Guinea Pig Trachea

Fenchone is a bicyclic monoterpene found in a variety of aromatic plants, including Foeniculum vulgare and Peumus boldus, and is used in the management of airways disorders. This study aimed to explore the bronchodilator effect of fenchone using guinea pig tracheal muscles as an ex vivo model and in silico studies. A concentration-mediated tracheal relaxant effect of fenchone was evaluated using isolated guinea pig trachea mounted in an organ bath provided with physiological conditions. Sustained contractions were achieved using low K⁺ (25 mM), high K⁺ (80 mM), and carbamylcholine (CCh; 1 µM), and fenchone inhibitory concentration–response curves (CRCs) were obtained against these contractions. Fenchone selectively inhibited with higher potency contractions evoked by low K⁺ compared to high K⁺ with resultant EC₅₀ values of 0.62 mg/mL (0.58–0.72; n = 5) and 6.44 mg/mL (5.86–7.32; n = 5), respectively. Verapamil (VRP) inhibited both low and high K⁺ contractions at similar concentrations. Pre-incubation of the tracheal tissues with K⁺ channel blockers such as glibenclamide (Gb), 4-aminopyridine (4-AP), and tetraethylammonium (TEA) significantly shifted the inhibitory CRCs of fenchone to the right towards higher doses. Fenchone also inhibited CCh-mediated contractions at comparable potency to its effect against high K⁺ [6.28 mg/mL (5.88–6.42, n = 4); CCh] and [6.44 mg/mL (5.86–7.32; n = 5); high K⁺]. A similar pattern was obtained with papaverine (PPV), a phosphodiesterase (PDE), and Ca²⁺ inhibitor which inhibited both CCh and high K⁺ at similar concentrations [10.46 µM (9.82–11.22, n = 4); CCh] and [10.28 µM (9.18–11.36; n = 5); high K⁺]. However, verapamil, a standard Ca²⁺ channel blocker, showed selectively higher potency against high K⁺ compared to CCh-mediated contractions with respective EC₅₀ values of 0.84 mg/mL (0.82–0.96; n = 5) 14.46 mg/mL (12.24–16.38, n = 4). The PDE-inhibitory action of fenchone was further confirmed when its pre-incubation at 3 and 5 mg/mL potentiated and shifted the isoprenaline inhibitory CRCs towards the left, similar to papaverine, whereas the Ca²⁺ inhibitory-like action of fenchone pretreated tracheal tissues were authenticated by the rightward shift of Ca²⁺ CRCs with suppression of maximum response, similar to verapamil, a standard Ca²⁺ channel blocker. Fenchone showed a spasmolytic effect in isolated trachea mediated predominantly by K⁺ channel activation followed by dual inhibition of PDE and Ca²⁺ channels. Further in silico molecular docking studies provided the insight for binding of fenchone with Ca²⁺ channel (−5.3 kcal/mol) and K⁺ channel (−5.7), which also endorsed the idea of dual inhibition.

Role of nitric oxide, bradykinin B2 receptor, and TRPV1 in the airway alterations caused by simvastatin in rats

Dry cough has been reported in patients receiving statin therapy. However, the underlying mechanism or other possible alterations in the airways induced by statins remain unknown. Thus, the aim of this study was to evaluate whether simvastatin promotes alterations in airways, such as bronchoconstriction and plasma extravasation, as well as the mechanism involved in these events. Using methods to detect alterations in airway resistance and plasma extravasation, we demonstrated that simvastatin [20 mg/kg, intravenous (i.v.)] caused plasma extravasation in the trachea (79.8 + 14.8 μg/g/tissue) and bronchi (73.3 + 8.8 μg/g/tissue) of rats, compared to the vehicle (34.2 + 3.6 μg/g/tissue and 29.3 + 5.3 μg/g/tissue, respectively). NG-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg, intraperitoneal), a nitric oxide (NO) synthase inhibitor, Icatibant [HOE 140, 10 nmol/50 μl, intratracheal (i.t.)], a bradykinin B2 antagonist, and capsazepine (100 nmol/50 μl, i.t.), a TRPV1 antagonist, attenuated simvastatin-induced plasma extravasation. Simvastatin (5, 10 and 20 mg/kg) did not cause bronchoconstriction per se, but exacerbated the bronchoconstrictive response to bradykinin (30 nmol/kg, i.v.), a B2 agonist (0.7 + 0.1 ml/H2O), or capsaicin (30 nmol/kg, i.v.), a TRPV1 agonist (0.8 + 0.1 ml/H2O), compared to the vehicle (0.1 + 0.04 ml/H2O and 0.04 + 0.01 ml/H2O, respectively). The bronchoconstriction elicited by bradykinin (100 nmol/kg, i.v.) in simvastatin non-treated rats was inhibited by L-NAME. The exacerbation of bronchoconstriction induced by bradykinin or capsaicin in simvastatin-treated rats was inhibited by L-NAME, HOE 140 or capsazepine. These results suggest that treatment with simvastatin promotes the release of bradykinin, which, via B2 receptors, releases NO that can then activate the TRPV1 to promote plasma extravasation and bronchoconstriction.

Drosophila Trachea as a Novel Model of COPD

COPD, a chronic obstructive pulmonary disease, is one of the leading causes of death worldwide. Clinical studies and research in rodent models demonstrated that failure of repair mechanisms to cope with increased ROS and inflammation in the lung leads to COPD. Despite this progress, the molecular mechanisms underlying the development of COPD remain poorly understood, resulting in a lack of effective treatments. Thus, an informative, simple model is highly valued and desired. Recently, the cigarette smoke-induced Drosophila COPD model showed a complex set of pathological phenotypes that resemble those seen in human COPD patients. The Drosophila trachea has been used as a premier model to reveal the mechanisms of tube morphogenesis. The association of these mechanisms to structural changes in COPD can be analyzed by using Drosophila trachea. Additionally, the timeline of structural damage, ROS, and inflammation can be studied in live organisms using fluorescently-tagged proteins. The related function of human COPD genes identified by GWAS can be screened using respective fly homologs. Finally, the Drosophila trachea can be used as a high-throughput drug screening platform to identify novel treatments for COPD. Therefore, Drosophila trachea is an excellent model that is complementary to rodent COPD models.

Monomeric, Dimeric, and Trimeric Tropane Alkaloids from Pellacalyx saccardianus

Seven new tropane alkaloids, including five monomeric (1-5), one dimeric (6), and one trimeric (7) 3α-nortropane ester, along with two known monomeric nortropane alkaloids (8 and 9), were isolated from the leaves and bark of Pellacalyx saccardianus. Their structures, including the absolute configuration of the enantiomeric pair of (±)-6, were elucidated by comprehensive spectroscopic analyses. Alkaloids 6 and 7 showed cytotoxicity toward human pancreatic cancer cell lines (AsPC-1, BxPC3, PANC-1, and SW1990). Alkaloids 1, 4, and 9 induced a smooth muscle relaxation effect comparable to that of atropine (E_max 106.1 ± 7.5%, 97.0 ± 5.2%, 100.9 ± 1.4%, 111.7 ± 1.7%, respectively) on isolated rat tracheal rings.

In vitro and in vivo relaxation and anti-inflammation of natural flavonoids from Elaeagnus pungens leaf via L-type calcium channel and targeting MAPK signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM), the leaf of Elaeagnus pungens Thunb. (Family Elaeagnaceae) is a herb documented as an antiasthmatic remedy to treat the severe asthma, bronchitis and other respiratory diseases in the early material medica "Bencao Gangmu" (Ming dynasty, about 442 years ago).

AIM OF THE STUDY

This work is purposed to investigate the pharmacological effects and mechanism of total flavonoids from Elaeagnus pungens leaves (FLA) on asthma in vivo and vitro.

MATERIALS AND METHODS

Female BALB/c mice were sensitized by intraperitoneal injection of OVA with aluminum hydroxide and intranasal challenged with OVA. After treatment with FLA (10, 20 mg/kg p.o.), the behaviors of mice were observed by score evaluation. Enumeration of total cells and OVA-specific IgE assay in the blood were measured as well as enumeration of total cells and cytokines assay in the BALF. Furthermore, histopathological analysis was performed by HE staining. The in vitro relaxing action on muscle force of FLA (0.0316-10.0 mg/ml) was evaluated using isometric tension in tracheal rings, and VDLCC currents were recorded to explore the relaxation mechanism in the isolated tracheal rings and mouse ASM cells, respectively. In vitro anti-inflammatory actions were assessed with LPS-stimulated RAW 264.7 macrophages. The production of inflammatory mediators and MAPK signaling pathway was estimated using ELISA and Western blotting analysis, respectively.

RESULTS

The high dose of flavones from E. pungens leaf (20 mg/kg) can significantly improve the symptom of asthma breakout and relieve the lung swelling. FLA treatment decreased eosinophils and leukocytes numbers in blood and BLAF with a dosedependent manner. Furthermore, the inhibiting effect of FLA on the level of Ig E and inflammatory-related cytokines including TNF-α, IL-5 showed dose-independent. FLA relaxed high K + -induced contraction in a dose-dependent manner. The maximal relaxation produced by FLA was 99.7% (IC 50 = 0.46 mg/ml). The whole-cell VDLCC currents were abolished by FLA (3.16 mg/ml) and FLA significantly decreased the maximal amplitude of VDLCCs. No cytotoxic effect of FLA was observed in RAW264.7 cells under the tested concentrations (1-300 μg/mL). The increased IL-6 and NO by the stimulation of LPS in RAW264.7 cells were significantly inhibited by FLA in the dosedependent manner. Treatment with LPS in the presence of FLA, LPS-induced phosphorylation of ERK1/2 and JNK was inhibited in the macrophages.

CONCLUSION

FLA from Elaeagnus pungens leaf can alleviate the inflammation symptom via reducing the eosinophils and leukocytes numbers as well as the production of pro-inflammatory cytokines. This anti-inflammatory effect is related to the modulation of the MAPK signaling pathway. FLA can relax the precontracted TRs by blocking the VDLCCs, which interrupts extracellular Ca 2+ influx and inhibit the rise of [Ca 2+ ]i. It strongly suggests that these flavonoids components are the substances basis of Elaeagnus pungens leaves for allergic action, bronchospasm and inflammation in asthma.

Traffic-related PM2.5 and diverse constituents disturb the balance of Th17/Treg cells by STAT3/RORγt-STAT5/Foxp3 signaling pathway in a rat model of asthma

Water-soluble ions (WSI) and organic extract (OE) in traffic-related particulate matter with aerodynamic diameters ≤ 2.5 μm (TRPM2.5) are potential risk factors for asthma exacerbation. Although CD4+ T lymphocytes mediated immune response is involved in the pathogenesis of asthma, the effect of WSI-TRPM2.5 and OE-TRPM2.5 on the balance of Th17/Treg cells in asthma remains poorly understood. In this study, the ovalbumin (OVA)-sensitized rats were repeatedly exposure to TRPM2.5 (3 mg/kg·bw), WSI-TRPM2.5 (1.8 mg/kg·bw, 7.2 mg/kg·bw) and OE-TRPM2.5 (0.6 mg/kg·bw, 2.4 mg/kg·bw) every three days for five times. The inflammation response and hyperemia edema were observed in the lung and trachea tissues. DNA methylation levels of STAT3 and RORγt genes in rats with WSI-TRPM2.5 and OE-TRPM2.5 treatment were decreased. DNA methylation level in STAT5 gene tended to decrease, with no change observed on Foxp3 expression. WSI-TRPM2.5 and OE-TRPM2.5 enhanced the mRNA and protein expression of STAT3 and RORγt while inhibited the expression of STAT5 and Foxp3, which may contribute to the imbalance of Th17/Treg cells (P < 0.05). More importantly, recovered balance of Th17/Treg cell subsets, upregulated p-STAT5 and Foxp3 expression and reduced p-STAT3 and RORγt levels were observed after 5-Aza treatment. Our results demonstrate that the STAT3/RORγt-STAT5/Foxp3 signaling pathway is involved in asthma exacerbation induced by WSI-TRPM2.5 and OE-TRPM2.5 through disrupting the balance of Th17/Treg cells. The alteration of DNA methylation of STAT3, STAT5, and RORγt genes may be involved in asthma exacerbation as well.

Insulin-like growth factor 1 promotes the extension of Tracheal Epithelium in an in Vitro Tracheal organ culture model

OBJECTIVE

Rapid epithelialization is crucial to maintain tracheal patency and prevent potential graft failure in tracheal reconstruction after tracheal resection for cancer with tracheal infiltration or tracheal stenosis. Insulin-like growth factor 1 is a liver-secreted endocrine molecule that controls cell proliferation, differentiation, and apoptosis and has been reported to promote epithelialization in several organs. Here, we utilized mouse tracheal organ cultures to examine the effect of insulin-like growth factor 1 on tracheal epithelialization.

METHODS

The trachea was resected from thirteen-week-old female ICR mice, and cut into small plate-shaped tracheal sections. First, the expression of insulin-like growth factor 1 receptor was assessed by immunohistochemistry. Secondly, the tracheal sections were cultured for seven days in the culture medium, and the morphological change during the seven-day culture was assessed by immunohistochemistry, hematoxylin and eosin staining, and scanning electron microscopy. Moreover, the tracheal sections were cultured for 48 h with different concentration of insulin-like growth factor 1 (0, 0.1, 1 and 10 µg/mL) in the culture medium, and the extension length of the tracheal epithelium during culture was measured in order to assess the effect of topical IGF1 on tracheal epithelialization.

RESULTS

Immunohistochemistry showed that insulin-like growth factor 1 receptor was expressed in tracheal epithelium. Immunohistochemistry, hematoxylin and eosin staining, and scanning electron microscopy showed that the tracheal organ cultures were stable for at least seven days without apparent morphological damage. The effect of insulin-like growth factor 1 on tracheal epithelialization was examined in plate-shaped tracheal sections cultured in medium supplemented with or without insulin-like growth factor 1 for 48 h. We also found that the epithelial edge of plate-shaped tracheal sections extended further along the surface of the tracheal section in culture medium containing insulin-like growth factor 1 compared with that in culture medium without insulin-like growth factor 1.

CONCLUSION

The current study using an in vitro mouse tracheal organ culture model demonstrated that topical insulin-like growth factor 1 treatment promoted the extension of tracheal epithelium, suggesting the potential utility of insulin-like growth factor 1 in aiding rapid tracheal epithelialization in patients requiring tracheal reconstruction using tissue-engineered tracheas.

Cannabis roots: Pharmacological and toxicological studies in mice

ETHNOPHARMACOLOGICAL RELEVANCE

There are many studies and therapeutic properties attributed to the flowers and leaves of the Cannabis species, but even with few pharmacological studies, Cannabis sativa L. (Cannabaceae) roots presents several therapeutic indications in folk medicine.

AIM OF THE STUDY

This study aimed to evaluate the anti-inflammatory and spasmolytic effects as well as the toxicological profile of the aqueous extract of Cannabis sativa roots (CsAqEx) in mice.

MATERIALS AND METHODS

We assessed the anti-inflammatory effect with carrageenan-induced leukocyte migration assay, and carrageenan and histamine-induced paw edema methods; The spasmolytic effect was assessed through in vitro assays with isolated mice trachea. To assess motor coordination and mobility, mice went through the rotarod and open field tests, respectively. For the single-dose toxicity study, we administered CsAqEx at the dose of 1000 mg/kg by gavage. In a repeated dose toxicity study, animals received CsAqEx at doses of 25 mg or 100 mg/kg for 28 days.

RESULTS

The CsAqEx inhibited the migration of leukocytes at the doses of 25, 50, and 100 mg/kg. The CsAqEx showed anti-inflammatory activity after the intraplantar injection of carrageenan, presenting a reduction in edema formation at all tested doses (12.5, 25, 50 and 100 mg/kg). The dose of 12.5 mg/kg of CsAqEx prevented edema formation after intraplantar injection of histamine. In an organ bath, 729 μg/mL of CsAqEx did not promote spasmolytic effect on isolated mice tracheal rings contracted by carbachol (CCh) or potassium chloride (KCl). We did not observe clinical signs of toxicity in the animals after acute treatment with CsAqEx, which suggested that the median lethal dose (LD₅₀) is greater than 1000 mg/kg. Repeated dose exposure to the CsAqEx did not produce significant changes in hematological, biochemical, or organ histology parameters.

CONCLUSIONS

The results suggest that the anti-inflammatory effect of CsAqEx is related to the reduction of vascular extravasation and migration of inflammatory cells, without effects on the central nervous system. Moreover, there was no spasmolytic effect on airway smooth muscle and no toxicity was observed on mice.

Acute cigarette smoke or extract exposure rapidly activates TRPA1-mediated calcium influx in primary human airway smooth muscle cells

Tobacco smoking is the largest risk factor for developing chronic obstructive pulmonary disease (COPD), and is associated with hyperresponsiveness of airway smooth muscle (ASM). Chronic exposure to cigarette smoke (CS) leads to airway inflammation and remodelling. However, the direct effect of gaseous CS or CS extract (CSE) on human airway smooth muscle cell (hASMC) function remains poorly understood. This study investigated the acute effect of CS/CSE on calcium homeostasis, a key regulator of ASM physiology and pathophysiology. Primary hASMC were isolated from non-smoking donor lungs, and subjected to Ca2+ imaging studies. We found that both CS, and CSE, rapidly elevated cytosolic Ca2+ in hASMC through stimulation of plasmalemmal Ca2+ influx, but excluded store-operated and L-type Ca2+ channels as mediators of this effect. Using a specific pharmacological inhibitor, or shRNA-driven knockdown, we established that both CS and CSE stimulated Ca2+ influx in hASMC through the neurogenic pain receptor channel, transient receptor potential ankyrin 1 (TRPA1). CS/CSE-dependent, TRPA1-mediated Ca2+ influx led to myosin light-chain phosphorylation, a key process regulating ASM contractility. We conclude that TRPA1 is likely an important link between CS/CSE exposure and airway hyperresponsiveness, and speculate that acute CS/CSE-induced Ca2+ influx could lead to exacerbated ASM contraction and potentially initiate further chronic pathological effects of tobacco smoke.

Herb pair of Ephedrae Herba-Armeniacae Semen Amarum alleviates airway injury in asthmatic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ephedrae Herba (EH, Ephedra sinica Stapf.) and Armeniacae Semen Amarum (ASA, Prunus armeniaca L. var. ansu Maxim.) have been used to treat asthma, cold, fever, and cough in China for thousands of years.

AIM OF THE STUDY

In this study, we aimed to investigate the optimal ratio of EH and ASA compatibility (EAC) to reduce airway injury in asthmatic rats and its possible mechanism.

METHODS

Rats were sensitized with a mixture of acetylcholine chloride and histamine bisphosphate 1 h before sensitization by intragastric administration of EAC or dexamethasone or saline for 7 days. Subsequently, the ultrastructure of rat airway epithelial tissue changes, apoptosis of the airway epithelial cells, and the expression of mRNA and protein of EGRF and Bcl-2 were detected.

RESULTS

Transmission electron microscope: EAC (groups C and E) had the most prominent effect on repairing airway epithelial cells' ultrastructural changes in asthmatic rats. TUNEL: dexamethasone and EAC (groups B、C、E and F) inhibited the apoptosis of airway epithelial cells in asthmatic rats (P < 0.05). In situ hybridization: EAC (group E) inhibited the overexpression of EGFR and Bcl-2 mRNA (P < 0.05).Western Blotting: EAC (groups A、B、C、E and F) inhibited the upregulation of airway epithelial EGFR and Bcl-2 protein expression (P < 0.01).

CONCLUSIONS

Our findings indicate that EAC can inhibit abnormal changes in airway epithelial structure and apoptosis of airway epithelial cells, thereby alleviating airway injury. In this study, the best combination of EH and ASA to alleviate airway epithelial injury in asthmatic rats was group E (EH: ASA = 8: 4.5).

Ammonia exposure causes the disruption of the solute carrier family gene network in pigs

Ammonia is the main harmful gas in livestock houses. However, the toxic mechanism of ammonia is still unclear. Therefore, we examined the effects of ammonia exposure on different tissues of fattening pigs by histological analysis and transcriptome techniques in this study. The results showed that there were varying degrees of pathological changes in liver, kidney, hypothalamus, jejunum, lungs, spleen, heart and trachea of fattening pigs under ammonia exposure. Notably, the extent of damage in liver, kidney, jejunum, lungs, hypothalamus and trachea was more severe than that in heart and spleen. Transcriptome results showed that ammonia exposure caused changes in 349, 335, 340, 229, 120, 578, 407 and 115 differentially expressed genes in liver, kidney, spleen, lung, trachea, hypothalamus, jejunum and heart, respectively. Interestingly, the changes in solute vector (SLC) family genes were found in all 8 tissues, and the verified gene results (SLC11A1, SLC17A7, SLC17A6, SLC6A4, SLC22A7, SLC25A3, SLC28A3, SLC7A2, SLC6A6, SLC38A5, SLC22A12, SLC34A1, SLC26A1, SLC26A6, SLC27A5, SLC22A8 and SLC44A4) were consistent with qRT-PCR results. In conclusion, ammonia exposure can cause pathological changes in many tissues and organs of fattening pigs and changes in the SCL family gene network. Importantly, the SCL family is involved in the toxic mechanism of ammonia. Our findings will provide a new insight for better assessing the mechanism of ammonia toxicity.

Differentiation of Tarchonanthus camphoratus L. and Tarchonanthus parvicapitulatus P.P.J. Herman (Asteraceae) using electron microscopy, and comparison of their biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Tarchonanthus camphoratus L. complex has numerous medicinal uses amongst the sub-Saharan African populace, including treatment for bronchospasm. This study focused on providing scientific rationale for the traditional use of the extracts of T. camphoratus and T. parvicapitulatus. T. camphoratus L. complex has been published under diverse names by various taxonomists. Tarchonanthus parvicapitulatus was one of the newly described taxa, leaving Tarchonanthus camphoratus L. sens. strict. as a homogenous taxon. However, some of the morphological characters used tend to overlap, making it difficult to identify the different taxa.

AIMS

The aim of this study was to evaluate the bronchodilatory, antioxidant and toxicological properties of the leaves of T. camphoratus L. and T. parvicapitulatus. This study also aimed to use scanning electron microscopy (SEM) to assess the differences between T. camphoratus L. and T. parvicapitulatus.

MATERIALS AND METHODS

Thin layer chromatography (TLC) with vanillin as visualizing agent was used to qualitatively compare the phytoconstituents of the plant acetone extracts. The free radical scavenging antioxidant qualitative assay was done by spraying TLC plates with DPPH free radical. The bronchodilatory effects of the aqueous extracts were assessed using pre-contracted guinea pig trachea. The effects of the extracts of T. camphoratus L. and T. parvicapitulatus on superoxide and ATP production was also investigated on isolated human neutrophils. A micromorphology study was done using scanning electron microscopy to study the leaves.

RESULTS

Different compounds were visualized on the TLC plates with more than 40 compounds of intermediate polarity. The TLC plates sprayed with DPPH revealed the presence of 20 and 23 antioxidant compounds for T. camphoratus and T. parvicapitulatus respectively. Upon pre-contraction of the tracheal smooth muscles, the aqueous extracts of T. parvicapitulatus significantly relaxed the trachea while the relaxation observed for T. camphoratus was not significant. All the tested concentrations had a dose dependent inhibitory effect on superoxide production. The crude extract of T. parvicapitulatus at the highest concentration (10 mg/ml) significantly decreased ATP production while a non-significant increase in ATP production was observed for T. camphoratus at the highest concentration (10 mg/ml) when compared with the control. The micromorphology study was useful in revealing the presence of trichomes on the upper leaf surface of the studied taxa.

CONCLUSIONS

The results obtained from this study showed that the studied plant extracts had bronchodilatory effects on contracted guinea pig trachea and could also inhibit the production of free radicals including superoxide anions. To the best of our knowledge, this is the first report on the bronchodilatory activity of T. camphoratus and T. parvicapitulatus. The micromorphological studies were useful in distinguishing between the two species, confirming that T. camphoratus L. and T. parvicapitulatus are different taxa. This study provides evidence to support the traditional use of T. camphoratus and T. parvicapitulatus in managing bronchospasm.

More serious autophagy can be induced by ZnO nanoparticles than single-walled carbon nanotubes in rat tracheal epithelial cells

Metal oxide nanoparticles and carbon nanoparticles, as common nanoparticles (NPs), can cause autophagy in certain cells, which will lead to biohealth risk issues. This study determined the difference in autophagy induced by zinc oxide nanoparticles (ZnO NPs) and single-walled carbon nanotubes (SWCNTs) in respiratory epithelial cells. ICP-OES results showed that NPs uptake as well as the intercellular contents of particles affected cytotoxicity in a dose-dependent manner. ZnO NPs-30 nm had a distinct green dot structure representing autophagy, the SWCNTs exposure group had a few green light spots at a concentration of 10 μg/L. The ROS content of the ZnO NP-30 nm exposure group had the greatest increase at a concentration of 1000 μg/L, which was 2.5 times higher than that of the control, the SWCNTs exposure group showed a 2.2-fold increase. A slight downregulation of p-mTOR was detected, and the ZnO NPs-30 nm treatment group had the significant downregulation rate. The gene and protein expression levels of Beclin-1 and LC3B were upregulated as the exposure concentration increased. The protein expression of Beclin-1 and LC3B in the 1000 μg/L ZnO NPs-30 nm exposure group were 5.21 times and 4.12 times that of the control, respectively. The mRNA expression of Beclin-1 and LC3B in the 1000 μg/L ZnO NPs-30 nm exposure group were 5.04 times and 3.61 times that of the control, respectively. At any concentration, the effect of ZnO NPs-30 nm was greater than that of the SWCNTs. Interaction and crosstalk analysis showed that exposure to ZnO NPs-30 nm caused autophagy through the aggregation of undegraded autophagosomes, whereas SWCNTs exposure induced diminished intercellular oxidative stress to inhibit autophagy. Therefore, this study demonstrated that the effects of autophagy induced by ZnO NPs-30 nm and SWCNTs were different. The health risks of ZnO-30 nm NPs are higher than those of SWCNTs.

Biological effects of inhaled hydraulic fracturing sand dust. IV. Pulmonary effects

Hydraulic fracturing creates fissures in subterranean rock to increase the flow and retrieval of natural gas. Sand ("proppant") in fracking fluid injected into the well bore maintains fissure patency. Fracking sand dust (FSD) is generated during manipulation of sand to prepare the fracking fluid. Containing respirable crystalline silica, FSD could pose hazards similar to those found in work sites where silica inhalation induces lung disease such as silicosis. This study was performed to evaluate the possible toxic effects following inhalation of a FSD (FSD 8) in the lung and airways. Rats were exposed (6 h/d × 4 d) to 10 or 30 mg/m3 of a FSD collected at a gas well, and measurements were performed 1, 7, 27 and, in one series of experiments, 90 d post-exposure. The following ventilatory and non-ventilatory parameters were measured in vivo and/or in vitro: 1) lung mechanics (respiratory system resistance and elastance, tissue damping, tissue elastance, Newtonian resistance and hysteresivity); 2) airway reactivity to inhaled methacholine (MCh); airway epithelium integrity (isolated, perfused trachea); airway efferent motor nerve activity (electric field stimulation in vitro); airway smooth muscle contractility; ion transport in intact and cultured epithelium; airway effector and sensory nerves; tracheal particle deposition; and neurogenic inflammation/vascular permeability. FSD 8 was without large effect on most parameters, and was not pro-inflammatory, as judged histologically and in cultured epithelial cells, but increased reactivity to inhaled MCh at some post-exposure time points and affected Na+ transport in airway epithelial cells.

Calcium and potassium channels are involved in curcumin relaxant effect on tracheal smooth muscles

Context: Curcumin, the active component of Curcuma longa L. (Zingiberaceae), exhibits a wide variety of biological activities including vasodilation and anti-inflammation.Objective: The relaxant effect of curcumin in tracheal smooth muscle (TSM) was not examined so far, thus, this study was designed to assess the relaxant effect of curcumin on rat TSM and examine the underlying mechanism(s) responsible for this effect.Materials and methods: TSM was contracted by KCl (60 mM) or methacholine (10 μM), and cumulative concentrations of curcumin (12.5, 25, 50, and 100 mg/mL) or theophylline (0.2, 0.4, 0.6, and 0.8 mM, as positive control) were added to organ bath. The relaxant effect of curcumin was examined in non-incubated or incubated tissues with atropine (1 μM), chlorpheniramine (1 μM), indomethacin (1 μM), and papaverine (100 μM).Results: In non-incubated TSM, curcumin showed significant relaxant effects on KCl-induced contraction in a concentration-dependent manner (p < 0.001 for all concentrations). The relaxant effects of curcumin 12.5, 25, and 50 mg/mL were significantly lower in atropine-incubated tissue compared to non-incubated TSM (p < 0.05 to p < 0.001). A significant difference was observed in EC₅₀ between atropine-incubated (48.10 ± 2.55) and non-incubated (41.65 ± 1.81) tissues (p < 0.05). Theophylline showed a significant relaxant effect on both KCl and methacholine-induced contraction in a concentration-dependent manner (p < 0.001 for all cases).Conclusions: The results indicated a relatively potent relaxant effect of curcumin on TSM, which was less marked than the effect of theophylline. Calcium channel blocking and/or potassium channel opening properties of curcumin may be responsible for TSM relaxation.

Anesthetic effect and safety of sevoflurane combined with propofol in removing tracheobronchial foreign bodies in children

OBJECTIVE

To systematically evaluate the anesthetic effect and safety of sevoflurane combined with propofol in removing tracheal foreign bodies in children.

MATERIALS AND METHODS

PubMed, EMbase, The Cochrane Library, China Biomedicine Database, China National Knowledge Internet, WanFang Data, and VIP databases were searched. Randomized controlled trials (RCTs) of sevoflurane combined with propofol for anesthesia during tracheal foreign body extraction in children were collected. The retrieval time was from the establishment of the database to April 10, 2019. RevMan 5.3 software was used for meta-analysis after two researchers independently screened the literature, extracted data, and evaluated the risk bias included in the study.

RESULTS

Seven RCTs involving 473 patients were included. Meta-analysis showed that the time of loss of consciousness significantly reduced (MD=-38.27, 95% CI (-41.77, -34.77), p < 0.00001) and the recovery time significantly reduced (MD=-12.29, 95% CI (-2.77, -1.80), p < 0.00001) in the sevoflurane combined with propofol group compared with the control group. In terms of safety, the heart rate was slower [MD=-11.00, 95% CI (-21.64, -0.36), p=0.04 < 0.05] and the incidence of cough and breath holding was lower [MD=0.38, 95% CI (0.19, 0.78), p=0.008] in the sevoflurane combined with propofol group than in the control group. However, no significant difference in respiratory rate and SPO 2 < 90% was found between the two groups (p > 0.05).

CONCLUSIONS

Sevoflurane combined with propofol is worth popularizing because of its high anesthetic effect and safety in the removal of tracheal foreign bodies in children. However, given the limited quantity and quality of the included studies, the above conclusions need to be verified by high-quality studies.

Anti-Inflammatory Effects of a Cordyceps sinensis Mycelium Culture Extract (Cs-4) on Rodent Models of Allergic Rhinitis and Asthma

Allergic rhinitis and asthma are common chronic allergic diseases of the respiratory tract, which are accompanied by immunoglobulin E (IgE)-mediated inflammation and the involvement of type 2 T helper cells, mast cells, and eosinophils. Cordyceps sinensis (Berk.) Sacc is a fungal parasite on the larva of Lepidoptera. It has been considered to be a health-promoting food and, also, one of the best-known herbal remedies for the treatment of airway diseases, such as asthma and lung inflammation. In the present study, we demonstrated the antiallergic rhinitis effect of Cs-4, a water extract prepared from the mycelium culture of Cordyceps sinensis (Berk) Sacc, on ovalbumin (OVA)-induced allergic rhinitis in mice and the anti-asthmatic effect of Cs-4 in a rat model of asthma. Treatment with Cs-4 suppressed the nasal symptoms induced in OVA-sensitized and challenged mice. The inhibition was associated with a reduction in IgE/OVA-IgE and interleukin (IL)-4/IL-13 levels in the nasal fluid. Cs-4 treatment also decreased airway responsiveness and ameliorated the scratching behavior in capsaicin-challenged rats. It also reduced plasma IgE levels, as well as IgE and eosinophil peroxidase levels, in the bronchoalveolar fluid. Cs-4 treatment completely suppressed the increases in IL-4, IL-5, and IL-13 levels in rat lung tissue. In conclusion, our results suggest that Cs-4 has the potential to alleviate immune hypersensitivity reactions in allergic rhinitis and asthma.

A PPAR-α agonist protects the non-adrenergic, non-cholinergic inhibitory system of guinea pig trachea from the effect of inhaled ammonium persulphate: a pilot study

Aim of the study. Inhaled ammonium persulphate (AP) reduces non adrenergic, non cholinergic (NANC) relaxation in the guinea pig trachea, as a part of its inflammatory effects. Peroxisome Proliferator-Activated Receptor (PPAR) stimulation has shown anti-inflammatory properties. This study aimed at evaluating whether the PPAR-α agonist WY 14643 can prevent the reduction in NANC relaxation caused by inhaled AP in the guinea pig trachea. Materials and Methods. Four groups of ten male guinea pigs were treated for three weeks with inhaled AP (10 mg/m3, 30 min per day, group A), saline (group B), AP and WY 14643 (0.36 μM/die, per os, group C), and AP, WY 14643 and the PPAR-α antagonist GW 6471 (0.36 μM/die, per os, group D). NANC relaxations to electrical field stimulation (EFS) at 3 Hz were evaluated in whole tracheal segments as intraluminal pressure changes. Results. The tracheal NANC relaxations were reduced by 90.3% in group A, as compared to group B. In group C, they were reduced by only 22.2%. In group D, they were reduced by 92.6 %. PPAR-α receptors were detected in inhibitory nerve fibers within the trachea as shown by immonohistochemical analysis. Conclusions. The PPAR-α agonist WY 14643 protects the NANC inhibitory system of the guinea pig trachea from the effect of inhaled ammonium persulphate and its protective effect is antagonized by GW 6471. PPAR-α might be exploited.

Pharmacological investigation of activities pertaining to modulation of gastrointestinal, respiratory and cardiovascular parameters by Indigofera argentea in experimental models

Indigofera argentea is widely used for the management of gastrointestinal, respiratory and cardiac disorders. This study was done to explore scientific basis of its uses. Aqueous methanolic extract of Indigofera argentea and its fractions were studied on isolated tissues of rabbit's jejunum, trachea, aorta and atrium. Castor oil induced diarrheal model was used for the study of the antidiarrheal effect and pre-anesthetized rats were used for hypotensive study. Concentration dependent spasmolytic effect of the extract upon isolated jejunum, trachea and aorta was observed. Concentration response curves constructed upon isolated rabbit jejunum, revealed the presence of calcium channel blocker in the plant extract. Moreover, significant reduction (P<0.05) in atrial force of contraction but non-significant reduction in rate of contraction was seen by the application of plant extract. Protection (P<0.05) against diarrhea was observed by the administration of crude extract to rats which were pretreated with castor oil. When given to rats intravenously, the extract showed hypotensive effect. Experimental findings justified the traditional uses of Indigofera argentea on pharmacological basis for the management of disorders pertaining to gut, airway and hypertensive situation.

Rapid Ex-Vivo Ciliogenesis and Dose-Dependent Effect of Notch Inhibition on Ciliogenesis of Respiratory Epithelia

Background: Cilia are actin based cellular protrusions conserved from algae to complex multicellular organisms like Homo sapiens. Respiratory motile cilia line epithelial cells of the tracheobronchial tree, beat in a synchronous, metachronal wave, moving inhaled pollutants and pathogens cephalad. Their role in both congenital disorders like primary ciliary dyskinesia (PCD) to acquired disorders like chronic obstructive pulmonary disease (COPD) continues to evolve. In this current body of work we outline a protocol optimized to reciliate human nasal epithelial cells and mouse tracheal cells in vitro. Using this protocol, we knocked down known cilia genes, as well as use a small molecule inhibitor of Notch, N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl Ester (DAPT), to assess the effect of these on ciliogenesis in order to show the validity of our protocol. Methods: Tracheas were harvested from wild-type, adult C57B6 mice, pronase digested and sloughed off epithelial cells grown to confluence in stationary culture on rat-tail collagen coated wells. Upon reaching confluence, collagen was digested and cells placed suspension culture protocol to reciliate the cells. Using this suspension culture protocol, we employed siRNA gene knockdown to assay gene functions required for airway ciliogenesis. Knock down of Dynein axonemal heavy chain 5 (Dnah5), a ciliary structural protein, was confirmed using immunostaining. Mouse tracheal cells were treated in suspension with varying doses of DAPT, an inhibitor of Notch, with the purpose of evaluating its effect and dose response on ciliogenesis. The optimum dose was then used on reciliating human nasal epithelial cells. Results: siRNA knockdown of Foxj1 prevented ciliation, consistent with its role as a master regulator of motile cilia. Knockdown of Dnai1 and Dnah5 resulted in immotile cilia, and Cand1 knockdown, a centrosome protein known to regulate centrosome amplification, inhibited airway ciliogenesis. Dnah5 knockdown was confirmed with significantly decreased immunostaining of cilia for this protein. Inhibiting Notch signaling by inhibiting gamma secretase with DAPT enhanced the percentage of ciliation, and resulted in longer cilia that beat with higher frequency in both mouse and human airway epithelia. Conclusions: Modifying existing reciliation protocols to suit both human nasal epithelial and mouse tracheal tissue, we have shown that knockdown of known cilia-related genes have the expected effects. Additionally, we have demonstrated the optimal dosage for significantly improving reciliation of airway epithelia using DAPT. Given that cilia length and function are significantly compromised in COPD, these findings open up interesting avenues for further exploration.

A comparison of four different models of acute respiratory distress syndrome in sheep

BACKGROUND

Acute respiratory distress syndrome (ARDS) can have various causes. The study objective was to investigate whether different pathophysiologic models of ARDS would show different respiratory, cardiovascular and inflammatory outcomes.

METHODS

We performed a prospective, randomized study in 27 ventilated ewes inducing ARDS using three different techniques to mimic the pulmonary causes of ARDS (ARDSp): warm saline lavage (n = 6), intratracheal hydrochloric acid (HCl; n = 6), intratracheal albumin (n = 10), and one technique to mimic an extrapulmonary cause of ARDS (ARDSexp): intravenous lipopolysaccharide (LPS iv; n = 5). ARDS was defined when PaO2 was < 15 kPa (112 mmHg) when ventilated with PEEP 10 cm H2O and FiO2 = 1.0. The effects on gas exchange were investigated by calculating the oxygenation index (OI) and the ventilation efficacy index (VEI) every 30 min for a period of 4 h. Post mortem lung lavage was performed to obtain broncho-alveolar lavage fluid (BALF) to assess lung injury and inflammation. Lung injury and inflammation were assessed by measuring the total number and differentiation of leukocytes, the concentration of protein and disaturated phospholipids, and interleukine-6 and -8 in the BALF. Histology of the lung was evaluated by measuring the mean alveolar size, alveolar wall thickness and the lung injury score system by Matute-Bello et al., as markers of lung injury. The concentration of interleukin-6 was determined in plasma, as a marker of systematic inflammation.

RESULTS

The OI and VEI were most affected in the LPS iv group and thereafter the HCl group, after meeting the ARDS criteria. Diastolic blood pressure was lowest in the LPS iv group. There were no significant differences found in the total number and differentiation of leukocytes, the concentration of protein and disaturated phospholipids, or interleukin-8 in the BALF, histology of the lung and the lung injury score. IL-6 in BALF and plasma was highest in the LPS iv group, but no significant differences were found between the other groups. It took a significantly longer period of time to meet the ARDS criteria in the LPS iv group.

CONCLUSIONS

The LPS model caused the most severe pulmonary and cardiovascular insufficiency. Surprisingly, there were limited significant differences in lung injury and inflammatory markers, despite the different pathophysiological models, when the clinical definition of ARDS was applied.

Curcumin analogs (B2BrBC and C66) supplementation attenuates airway hyperreactivity and promote airway relaxation in neonatal rats exposed to hyperoxia

BACKGROUND

This study was undertaken to test the hypothesis that the newly synthesized curcuminoids B2BrBC and C66 supplementation will overcome hyperoxia-induced tracheal hyperreactivity and impairment of relaxation of tracheal smooth muscle (TSM).

MATERIALS AND METHODS

Rat pups (P5) were exposed to hyperoxia (>95% O2 ) or normoxia for 7 days. At P12, tracheal cylinders were used to study in vitro contractile responses induced by methacholine (10-8 -10-4 M) or relaxation induced by electrical field stimulation (5-60 V) in the presence/absence of B2BrBC or C66, or to study the direct relaxant effects elicited by both analogs.

RESULTS

Hyperoxia significantly increased contraction and decreased relaxation of TSM compared to normoxia controls. Presence of B2BrBC or C66 normalized both contractile and relaxant responses altered by hyperoxia. Both, curcuminoids directly induced dose-dependent relaxation of preconstricted TSM. Supplementation of hyperoxic animals with B2BrBC or C66, significantly increased catalase activity. Lung TNF-α was significantly increased in hyperoxia-exposed animals. Both curcumin analogs attenuated increases in TNF-α in hyperoxic animals.

CONCLUSION

We show that B2BrBC and C66 provide protection against adverse contractility and relaxant effect of hyperoxia on TSM, and whole lung inflammation. Both analogs induced direct relaxation of TSM. Through restoration of catalase activity in hyperoxia, we speculate that analogs are protective against hyperoxia-induced tracheal hyperreactivity by augmenting H2 O2 catabolism. Neonatal hyperoxia induces increased tracheal contractility, attenuates tracheal relaxation, diminishes lung antioxidant capacity, and increases lung inflammation, while monocarbonyl CUR analogs were protective of these adverse effects of hyperoxia. Analogs may be promising new therapies for neonatal hyperoxic airway and lung disease.

Randomised study of the immunomodulatory effects of azithromycin in severely asthmatic horses

Neutrophilic inflammation is believed to contribute to the airway obstruction and remodelling in equine asthma. Azithromycin, an antibiotic with immunomodulatory properties, reduces pulmonary neutrophilia and hyper-responsiveness in human asthmatics and decreases airway remodelling in rodent models of asthma. It was therefore hypothesised that azithromycin would improve lung function, mucus accumulation and central airway remodelling by decreasing luminal neutrophilia in severe equine asthma. The effects of a 10-day treatment with either azithromycin or ceftiofur, an antimicrobial without immune-modulating activity, were assessed using a blind, randomised, crossover design with six severe asthmatic horses in clinical exacerbation. Lung function, tracheal mucus accumulation, tracheal wash bacteriology, bronchial remodelling, airway neutrophilia and mRNA expression of proinflammatory cytokines (interleukin (IL)-8, IL-17A, IL-1β, tumour necrosis factor-α) in bronchoalveolar lavage fluid were evaluated. Azithromycin decreased the expression of IL-8 (P=0.03, one-tailed) and IL-1β (P=0.047, one-tailed) but failed to improve the other variables evaluated. Ceftiofur had no effect on any parameter. The reduction of neutrophilic chemoattractants (IL-8, IL-1β) justifies further efforts to investigate the effects of a prolonged treatment with macrolides on airway neutrophilia and remodelling. The lack of efficacy of ceftiofur suggests that severe equine asthma should not be treated with antibiotics at first-line therapy.

Testosterone augments β2 adrenergic receptor genomic transcription increasing salbutamol relaxation in airway smooth muscle

Androgens in asthmatic men may be linked to asthma severity, acting via nongenomic and genomic effects. This ailment affects boys more than girls during infancy, and this proportion reverses in puberty. Plasmatic androgen concentration in young men increases at this age and might be related to lower asthma symptoms. Nongenomic actions occur in a brief period and are independent of the androgen receptor (AR), while genomic effects depend on AR, take hours-days and are modified by transcription or protein synthesis inhibitors. Guinea pig tracheas chronic incubation with testosterone (TES, 40 nM, 48 h) potentiates salbutamol-induced relaxation, an effect that was reversed by flutamide, not observed when tissues were pre-incubated with TES-bovine serum albumin (TES-BSA) nor when tissues were preincubated with TES for 15-60 min. In tracheal myocytes, TES chronic incubation increases salbutamol-induced K⁺ currents (IK⁺), an effect that was also reversed by flutamide, actinomycin D and cycloheximide and not seen with TES-BSA. The increment in IK⁺ was blocked by 4-aminopyridine and iberiotoxin, indicating that delayed rectifier K⁺ and high-conductance Ca²⁺ activated K⁺ channels were involved in the TES potentiation effect. Immunofluorescence studies showed that chronic TES augmented the β₂ adrenergic receptor (β₂-AR) expression in ASM and this finding was corroborated by q-PCR and Western blot assays. β₂-AR affinity for salbutamol after TES incubation was increased. In conclusion, chronic exposure to physiological TES concentration of the guinea pig ASM promotes β₂-AR upregulation favoring β₂ adrenergic responses and probably limiting the severity of the asthmatic exacerbations in teenage boys and men.

PLK1 Inhibition alleviates transplant-associated obliterative bronchiolitis by suppressing myofibroblast differentiation

Chronic allograft dysfunction (CAD) resulting from fibrosis is the major limiting factor for long-term survival of lung transplant patients. Myofibroblasts promote fibrosis in multiple organs, including the lungs. In this study, we identified PLK1 as a promoter of myofibroblast differentiation and investigated the mechanism by which its inhibition alleviates transplant-associated obliterative bronchiolitis (OB) during CAD. High-throughput bioinformatic analyses and experiments using the murine heterotopic tracheal transplantation model revealed that PLK1 is upregulated in grafts undergoing CAD as compared with controls, and that inhibiting PLK1 alleviates OB in vivo. Inhibition of PLK1 in vitro reduced expression of the specific myofibroblast differentiation marker α-smooth muscle actin (α-SMA) and decreased phosphorylation of both MEK and ERK. Importantly, we observed a similar phenomenon in human primary fibroblasts. Our results thus highlight PLK1 as a promising therapeutic target for alleviating transplant-associated OB through suppression of TGF-β1-mediated myofibroblast differentiation.

Tracheal relaxation through calcium channel blockade of Achillea millefolium hexanic extract and its main bioactive compounds

ETHNOPHARMACOLOGICAL IMPORTANCE

Achillea millefolium L. (Asteraceae) is used for the treatment of respiratory diseases, diabetes, and hypertension.

AIM

to explore its tracheal relaxant properties and clarify its functional mechanism of action on smooth muscle cells, which allow us to propose it as a potential anti-asthmatic drug.

MATERIAL AND METHODS

organic and hydro-alcoholic extracts from A. millefolium were obtained by macerations, then their relaxing effect on ex vivo isolated rat trachea rings was determined. Most active extract (hexanic extract, EHAm) was studied to determine its functional mechanism of action using synergic, antagonist and inhibitor agents related with the contraction/relaxation process of the smooth muscle. Also, EHAm was subjected to bio-guided fractionation by open-column chromatography (on silica gel) using cyclohexane-EtOAc (80:20) in an isocratic way to isolate main bioactive compounds.

RESULTS

organic and hydro-alcoholic extracts showed relaxant effect in a concentration-response dependent manner, being EHAm the most active. The functional mechanism of action indicates that EHAm induced a non-competitive antagonism to the muscarinic receptors ; in addition, the NO/cGMP pathway is involved in the relaxation process of the tracheal smooth muscle. However, the most important mechanism of action showed by EHAm was related with the calcium channel blockade influx into the smooth muscle cells. On the other hand, epimeric sesquiterpene lactones leucodin (1) and achillin (2) were isolated and purified, which are responsible for the observed smooth muscle relaxant activity of the extract.

CONCLUSION

hexanic extract of A. millefollium induced a significant relaxant effect on tracheal rat rings by calcium channel blockade and NO release.

Metabolomic fingerprinting of Cissampelos sympodialis Eichler leaf extract and correlation with its spasmolytic activity

ETHNOPHARMACOLOGICAL RELEVANCE

Cissampelos sympodialis Eichler (Menispermaceae) is popularly used in northeastern Brazil for the treatment of respiratory diseases such as bronchitis and asthma. Despite many pre-clinical pharmacological studies, the compounds mediating the anti-asthma activity of polar extracts of Cissampelos sympodialis leaves have not been definitively identified.

AIM OF THE STUDY

Aim of the study: The aim of the study was to investigate the correlation between the bioactivity of polar extracts prepared from the leaves of C. sympodialis and the chemical composition using a ¹H-NMR-based metabolomics approach.

MATERIAL AND METHODS

The metabolic profile of the leaf polar extract during different phenological stages of the plant was investigated using ¹H NMR spectroscopy while simultaneously screening for spasmolytic activity using guinea-pig tracheal preparations. The content of the alkaloids previously implicated in the bioactivity of Cissampelos sympodialis was determined by HPLC.

RESULTS

PCA analysis of the ¹H NMR data discriminated the extracts from different plant phenological stages. The contents of the major alkaloids decrease (from 2 ± 0.32 μg/mL for warifteine and 1 ± 0.14 μg/mL for methylwarifteine) to undetectable levels from 90 (CsL₉₀ extract) and 120 (CsL₁₂₀) days onwards for warifteine and methylwarifteine, respectively. All six extracts relaxed the trachea pre-contracted with carbachol, but the CsF₂₁₀ extract was more potent (EC₅₀ = 74.6 ± 7.9 μg/mL) compared to both CsL₉₀ extracts and CsL₁₈₀ in the presence of functional epithelium. PLS regression analysis of ¹H-NMR spectral data demonstrated that the spasmolytic activity was better correlated with signals for flavonol derivatives.

CONCLUSIONS

Our data challenge the idea that warifteine and methylwarifteine mediate the spasmolytic activity of the polar extract of C. sympodialis leaves.

Quantitative comparison of three widely-used pulmonary administration methods in vivo with radiolabeled inhalable nanoparticles

Pulmonary formulations have been attracting much attention because of their direct effects on respiratory diseases, but also their non-invasive administration for the treatment of systemic diseases. When developing such formulations, they are typically first investigated in mice. As there are various pulmonary administration methods, the researcher has to decide on the best quantitative method for their preclinical investigations among candidate methods, both for total delivery and distribution within the lung lobes. In this study, we investigated the deposition and distribution of siRNA loaded PLGA nanoparticles (NPs) in the different lung lobes via three widely used pulmonary administration methods: intratracheal instillation, intratracheal spraying and intranasal instillation. The NPs were radiolabeled with ¹¹¹In, administered and a single photon emission computed tomography (SPECT/CT) whole body scan performed. Quantitative image volume of interest (VOI) analysis of all inhalation related organs was performed, plus sub-organ examinations using dissection and gamma counting. Intratracheal instillation and intratracheal spraying deposited >95% and >85% of radiolabeled NPs in the lung, respectively. However, the lung lobe distribution of the NPs was inhomogeneous. Intranasal instillation deposited only ~28% of the dose in the lungs, with even larger inhomogeneity and individual variation between animals. Furthermore, there was a high deposition of the NPs in the stomach. Intratracheal instillation and intratracheal spraying deposit a large number of NPs in the lungs, and are thus useful to test therapeutic effects in preclinical animal studies. However, the inhomogeneous distribution of formulation between lung lobes needs to be considered in the experimental design. Intranasal instillation should not be used as a means of pulmonary administration.

Upper-airway collapsibility and compensatory responses under moderate sedation with ketamine, dexmedetomidine, and propofol in healthy volunteers

BACKGROUND

Ketamine is a potent sedative drug that helps to maintain upper-airway patency, due to its higher upper-airway dilator muscular activity and higher level of duty cycle, as seen in rats. However, no clinical trials have tested passive upper-airway collapsibility and changes in the inspiratory duty cycle against partial upper-airway obstruction in humans. The present study evaluated both the passive mechanical upper-airway collapsibility and compensatory response against acute partial upper-airway obstruction using three different sedative drugs in a crossover trial.

METHODS

Eight male volunteers entered this nonblinded, randomized crossover study. Upper-airway collapsibility (passive critical closing pressure) and inspiratory duty cycle were measured under moderate sedation with ketamine, propofol, and dexmedetomidine. Propofol, dexmedetomidine, and ketamine anesthesia were induced to obtain adequate, same-level sedation, with a BIS value of 50-70 and the OAA/S score of 2-3 and RASS score of -3.

RESULTS

The median passive critical closing pressure of 0.08 [-5.51 to 1.20] cm H2 O was not significantly different compared to that of propofol sedation (-0.32 [-1.41 to -0.19] cm H2 O) and of dexmedetomidine sedation (-0.28 [-0.95 to -0.03] cm H2 O) (p = .045). The median passive RUS for ketamine 54.35 [32.00 to 117.50] cm H2 O/L/s was significantly higher than that for propofol 5.50 [2.475 to 19.60] cm H2 O/L/s; (mean difference, 27.50; 95% CI 9.17 to 45.83) (p = .009) and for dexmedetomidine 19.25 [4.125 to 22.05] cm H2 O/L/s; (mean difference, 22.88; 95% CI 4.67 to 41.09) (p = .021). The inspiratory duty cycle increased significantly as the inspiratory airflow decreased in passive conditions for each sedative drug, but behavior differed among the three sedative drugs.

CONCLUSION

Our findings demonstrate that ketamine sedation may have an advantage of both maintained passive upper-airway collapsibility and a compensatory respiratory response, due to both increase in neuromuscular activity and the increased duty cycle, to acute partial upper-airway obstruction.

Ammonia regulates chicken tracheal cell necroptosis via the LncRNA-107053293/MiR-148a-3p/FAF1 axis

Ammonia (NH₃) is a known harmful gas that causes injury to the respiratory system. Ammonia also exists in haze, forming secondary organic aerosols. However, the specific damage caused by NH₃ in chicken trachea has not been determined. The regulatory mechanism of ceRNA and its multiple roles have been proposed in many pathomechanisms; therefore, we investigated the functional role of ceRNA in chicken trachea after NH₃ inhalation. Broiler chicken trachea exposed to NH₃ was selected as the research object. The pathological ultrastructure was observed by transmission electron microscopy. Transcriptome analyses were applied and referenced, and lncRNA-107053293 and miR-148a-3p and FAF1 were selected. A dual-luciferase reporter assay verified the target relationship. Real-time quantitative PCR (RT-PCR) and western blotting were performed to examine the expression levels of necroptosis genes, such as RIPK1, RIPK3, MLKL, caspase 8, and FADD. Our results indicated that lncRNA-107053293 regulated necroptosis by acting as a competing endogenous RNA of miR-148a-3p. FAF1, as a gene target of miR-148a-3p, also affects necroptosis.

Pharmacological studies pertaining to spasmolytic, bronchodilator and vasodilating effect of Typha domingensis: An evidence-based approach

This study was designed to analyze the pharmacological effects of Typha domingenesis crude 70% aqueous-ethanol extract of Typha domingensis (Td. Cr) in gastrointestinal, respiratory and vascular diseases. Rabbits (2.0-3.0 kg) and BALB/c mice (20-40 g) of local breed have been used as experimental animals using the established methodologies from literature with slight modification. The findings suggested that Typha domingensis caused complete relaxation of spontaneous and K⁺ (80mM)-induced contractions in isolated rabbit jejunum. Rightward parallel shift of calcium concentration response curves was observed. Typha domingensis exhibited relaxant effect on Carbachol (Cch)-induced contractions in isolated rabbit tracheal preparations. Furthermore, Typha domingensis caused relaxation of phenylephrine (1μM)- induced contractions in isolated rabbit aorta preparations. These effects were similar to verapamil, a standard calcium channel blocker. These findings could be the basis for explaining the spasmolytic, bronchodilator and vasodilator activities of the extract, through a possible calcium channel blocking activity.

Biodegradable electrospun patch containing cell adhesion or antimicrobial compounds for trachea repair in vivo

Difficulty breathing due to tracheal stenosis (i.e. narrowed airway) diminishes the quality of life and can potentially be life-threatening. Tracheal stenosis can be caused by congenital anomalies, external trauma, infection, intubation-related injury, and tumors. Common treatment methods for tracheal stenosis requiring surgical intervention include end-to-end anastomosis, slide tracheoplasty and/or laryngotracheal reconstruction. Although the current methods have demonstrated promise for treatment of tracheal stenosis, a clear need exists for the development of new biomaterials that can hold the trachea open after the stenosed region has been surgically opened, and that can support healing without the need to harvest autologous tissue from the patient. The current study therefore evaluated the use of electrospun nanofiber scaffolds encapsulating 3D-printed PCL rings to patch induced defects in rabbit tracheas. The nanofibers were a blend of polycaprolactone (PCL) and polylactide-co-caprolactone (PLCL), and encapsulated either the cell adhesion peptide, RGD, or antimicrobial compound, ceragenin-131 (CSA). Blank PCL/PLCL and PCL were employed as control groups. Electrospun patches were evaluated in a rabbit tracheal defect model for 12 weeks, which demonstrated re-epithelialization of the luminal side of the defect. No significant difference in lumen volume was observed for the PCL/PLCL patches compared to the uninjured positive control. Only the RGD group did not lead to a significant decrease in the minimum cross-sectional area compared to the uninjured positive control. CSA reduced bacteria growth in vitro, but did not add clear value in vivo. Adequate tissue in-growth into the patches and minimal tissue overgrowth was observed inside the patch material. Areas of future investigation include tuning the material degradation time to balance cell adhesion and structural integrity.

Components of Volatile Fractions from Eucalyptus camaldulensis Leaves from Iraqi-Kurdistan and Their Potent Spasmolytic Effects

Inhalation of vapors from a hot tea of Eucalyptus camaldulensis Dehnh. leaves is considered by Iraqi-Kurdistan people an effective spasmolytic and antipyretic remedy for the treatment of respiratory diseases. The constituents of volatile fractions isolated by hydrodistillation from dried leaves of the plant collected in Kurdistan were determined by GC-FID and GC-MS analyses. More than 90% components were identified. The most abundant constituents were 1,8-cineole, p-cymene, α-pinene, terpinen-4-ol, aromadendrene, and α-terpineol. The different volatile fractions induced relaxation on rat isolated aortic and tracheal rings in concentration-dependent manner. These effects appeared to be due to a complex interaction between various terpenoid components rather than being only due to the main oil constituent, 1,8-cineole. The KCa channel and the NO pathway were not significantly involved in the relaxation mechanism, while Ca2+ channels played a major role in the spasmolytic effects.

Phlorofucofuroeckol A from Ecklonia cava ameliorates TGF-β1-induced fibrotic response of human tracheal fibroblasts via the downregulation of MAPKs and SMAD 2/3 pathways inactivated TGF-β receptor

The objective of this study was to investigate inhibitory effects of a bioactive compound isolated from Ecklonia cava on fibrotic responses to transforming growth factor-β1 (TGF-β1)-stimulated Hs680. Tr human tracheal fibroblasts and the associated mechanisms of action. Post consecutive purification, a potent bioactive compound was identified phlorofucofuroeckol A. Phlorofucofuroeckol A significantly suppressed protein expression levels of collagen type I and α-smooth muscle actin (α-SMA) on TGF-β1-stimulated Hs680. Tr human tracheal fibroblasts. Further mechanistic studies determined that phlorofucofuroeckol A suppressed the phosphorylation of p38, extracellular regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) and SMAD 2/3 in TGF-β1-stimulated Hs680. Tr human tracheal fibroblasts. Moreover, we could show that phlorofucofuroeckol A inhibits binding of TGF-β1 to its TGF-β receptor by molecular docking. Based on the results, we propose that phlorofucofuroeckol A suppresses the MAPKs and SMAD 2/3 pathways and relieves cellular fibrotic activities, thus preventing tracheal fibrosis.

Lippia alnifolia essential oil induces relaxation on Guinea-pig trachea by multiple pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Lippia alnifolia Mart. & Schauer, known as "alecrim-do-mato", "alecrim-de-vaqueiro" and "pedrécio", is used in folk medicine as antiseptic and to treat diseases that affect respiratory system, like bronchitis and asthma.

AIM OF THE STUDY

The aim of this work was to investigate the spasmolytic activity and relaxant mechanism of the Lippia alnifolia essential oil (EOLA) on isolated guinea-pig trachea and to correlate with its use in folk medicine.

MATERIALS AND METHODS

Leaves from L. alnifolia were collected in Pico das Almas, Chapada Diamantina, situated in the city of Rio de Contas, Bahia, Brazil. EOLA was extracted by hydrodistillation, analyzed by GC/FID and GC/MS and the volatile constituents were identified. Spasmolytic activity was assayed in isolated guinea-pig trachea pre-contracted with carbachol 1 μM or histamine 10 μM. Relaxant mechanism of EOLA was determined comparing concentration-response curves in the presence or absence of different blockers.

RESULTS

Chemical analysis revealed the presence of carvone (60 ± 0.8%) as major constituent. EOLA (1-243 μg/mL) relaxed isolated guinea-pig trachea pre-contracted with carbachol 1 μM [EC₅₀ = 53.36 (44.75-63.51) μg/mL] or histamine 10 μM [EC₅₀ = 5.42 (4.42-6.65) μg/mL]. The pre-incubation of 4-aminopyridine in histamine-induced contractions did not alter significantly the relaxant effect of EOLA. However, the presence of cesium chloride, glibenclamide, tetraethylammonium, propranolol, indomethacin, dexamethasone, hexamethonium, atropine, L-NAME, methylene blue or ODQ reduced EOLA relaxant effect. EOLA 18 μg/mL pre-incubation in calcium-free medium reduced histamine-evoked contractions, but did not alter histamine contractions in the presence of nifedipine.

CONCLUSIONS

Lippia alnifolia essential oil has spasmolytic activity on isolated guinea-pig trachea and its mechanism of action possibly involves the activation of multiple signal transduction pathways, which culminate in potassium channels activation and cytosolic calcium reduction.

Eucalyptol reduces airway hyperresponsiveness in rats following cigarette smoke-exposed

BACKGROUND

Cigarette smoke is the major cause of airway inflammatory disease, including airway hyperresponsiveness. Eucalyptol (EUC), also named 1.8-cineole, is a monoterpenoid found in essential oil of medicinal plants, showing several biological effects.

HYPOTHESIS/PURPOSE

Based in the eucalyptol protective activity in respiratory diseases as asthma, our hypothesis is that eucalyptol is able to reduce the airway hyperresponsiveness and the respiratory mechanic parameters in rats exposed to cigarette smoke.

STUDY DESIGN

Wistar rats were divided into control and cigarettes smoke (CS) groups. CS group was daily subjected to cigarette smoke and treated by inhalation for 15 min/day with EUC (1 mg/mL) or vehicle during 30 days. After treatment, bronchoalveolar lavage (BAL) was collected to analyze the inflammatory profile, and tracheal rings were isolated for evaluation of the airway smooth muscle hyperresponsiveness. Lung function was analyzed in vivo.

METHODS

The inflammatory profile was evaluated by optical microscopy performing total (Neubauer chamber) and differential leukocyte count (smear slides stained in H&E). The hyperresponsiveness was evaluated in tracheal rings contracted with potassium chloride (KCl) carbamoylcholine (CCh), or Barium chloride (BaCl₂) in presence or absence of nifedipine. The lung function (Newtonian resistance-R_N) was evaluated by bronco stimulation with methacholine (MCh).

RESULTS

BAL from CS group increased the influx of leukocyte, mainly neutrophils and macrophages compared to control group. EUC reduced by 71% this influx. The tracheal contractions induced by KCl, CCh or BaCl₂ were reduced by EUC in 59%, 42% and 26%, respectively. The last one was not different of nifedipine activity. Newtonian resistance (R_N) was also reduced in 37% by EUC compared to CS group. 
 CONCLUSION: EUC reduces the hyperresponsiveness and the airway inflammatory profile, recovering the lung function.

Soluble Guanylate Cyclase Agonists Induce Bronchodilation in Human Small Airways

The soluble guanylyl cyclase (sGC)-cyclic guanosine monophosphate signaling pathway evokes vascular smooth muscle relaxation; whether this pathway mediates airway smooth muscle relaxation remains controversial. We posit that sGC activators are equi-effective as β-agonists in reversing contractile agonist-induced airway smooth muscle shortening. To provide clarity, we tested the efficacy of sGC stimulator and activator drugs, BAY 41-2272 and BAY 60-2270, respectively, in reversing bronchoconstriction of human small airways using human precision-cut lung slices (hPCLS). Both BAY drugs reversed carbachol-induced bronchoconstriction to a maximal degree comparable to that of formoterol. Moreover, the sGC drugs remained effective bronchodilators despite formoterol-induced desensitization of the airways. Analysis of the hPCLS after their activation by sGC or β2-adrenergic receptor agonist showed distinct cyclic nucleotide accumulation in the hPCLS. Collectively, these data suggest that cAMP and cyclic guanosine monophosphate pathways are equi-effective for reversing carbachol-induced bronchoconstriction in the human airway via separate and distinct second messenger pathways. This should open the door for future studies to test whether sGC-targeted drugs alone or in combination can serve as effective bronchodilators in asthma and chronic obstructive pulmonary disease.

Synthesis, Purification, and Selective β2-AR Agonist and Bronchodilatory Effects of Catecholic Tetrahydroisoquinolines from Portulaca oleracea

A green, biomimetic, phosphate-mediated Pictet-Spengler reaction was used in the synthesis of three catecholic tetrahydroisoquinolines, 1, 2, and 12, present in the medicinal plant Portulaca oleracea, as well as their analogues 3-11, 13, and 14, with dopamine hydrochloride and aldehydes as the substrates. AB-8 macroporous resin column chromatography was applied for purification of the products from the one-step high-efficacy synthesis. It eliminated the difficulties in the isolation of catecholic tetrahydroisoquinolines from the aqueous reaction system and unreacted dopamine hydrochloride. Activity screening in CHO-K1/Gα15 cell models consistently expressing α_1B-, β₁-, or β₂-adrenergic receptors indicated that 12 and 2, compounds that are present in P. oleracea, possessed the most potent β₂-adrenergic receptor agonist activity and 2 was a selective β₂-adrenergic receptor agonist at the concentration of 100 μM. Both 12 and 2 exhibited dose-dependent bronchodilator effects on the histamine-induced contraction of isolated guinea-pig tracheal smooth muscle, with EC₅₀ values of 0.8 and 2.8 μM, respectively. These findings explain the scientific rationale of P. oleracea use as an antiasthmatic herb in folk medicine and provide the basis for the discovery of novel antiasthma drugs.

Nebulized Ipratropium bromide protects against tracheal and bronchial secretion during bronchoscopy: A randomized controlled trial

BACKGROUND

Anticholinergic administration prior to flexible bronchoscopy has been investigated, but studies have not yielded consistent results.

METHODS

Patients were randomized 1:1 to receive nebulized 4 ml ipratropium bromide (1 mg, n = 125) or placebo (n = 125) for 15 minutes as premedication, 20 to 40 minutes before bronchoscopy. Airway secretions, bleeding, patient discomfort, procedure time, and procedure-related adverse events were compared between the groups.

RESULTS

Nebulized ipratropium bromide prior to bronchoscopy could reduce airway secretions and patient discomfort (P = .02; P < .001, respectively), but not tracheobronchial bleeding or procedure time (P = .51, P = .36, respectively). Chest nodule or mass was the most common indication for performing bronchoscopy. The adverse events were higher in ipratropium bromide group, and hypertension was the most common complication.

CONCLUSION

Nebulized ipratropium bromide prior to bronchoscopy is a more effective regimen that shows a practical benefit on the airway secretions and patient comfort, though these effects may not translate into any marked reduction in bleeding or of procedure time under general anesthesia. We suggest that routine nebulized ipratropium bromide premedication for bronchoscopy could be useful and beneficial.

TRIAL REGISTRATION

chictr.org.cn: ChiCTR1800016881.

Establishment of rapid risk assessment model for cigarette smoke extract exposure in chronic obstructive pulmonary disease

Rapid risk assessment models for different types of cigarette smoke extract (CSE) exposure are critical to understanding the etiology of chronic obstructive pulmonary disease. The present study investigated inflammation of cultured tracheal tissues with CSE exposure. Rat trachea rings were isolated, cultured, then exposed to various concentrations of CSE from 3R4 F reference cigarettes for 4 h. Tissue/cellular morphology, ultrastructure, viability and damage, inflammatory cell infiltration, and inflammatory protein levels were measured and compared to untreated controls. Human bronchial epithelial cells (BEAS-2B) exposed to 0 or 300 μg/mL CSE were cocultured with macrophages to assess extent of mobilization and phagocytosis. Endotracheal epithelium cilia densities were significantly reduced with increasing CSE concentrations, while mucous membranes became increasingly disordered; both eventually disappeared. Macrophages became larger as the CSE concentration increased, with microvilli and extended pseudopodium covering their surface, and many primary and secondary lysosomes present in the cytoplasm. Inflammatory cell infiltration also increased with increasing CSE dose, as did intracellular adhesion molecule-1(ICAM-1), interleukin-6(IL-6). The method described here may be useful to qualitatively characterized the effects of the compound under study. Then, we use BEAS-2B cell line system to strength the observation made in the cultured tissues. Probably, an approach to integrate results from both experiments will facilitate its application. These results demonstrate that cultured rat tracheal rings have a whole-tissue structure that undergoes inflammatory processes similar to in vivo tissues upon CSE exposure.

In vivo clearance of nanoparticles by transcytosis across alveolar epithelial cells

Nanoparticles in polluted air or aerosolized drug nanoparticles predominantly settle in the alveolar lung. Here, we describe a novel, highly effective pathway for the particles to cross the alveolar epithelium and reach the lymph and bloodstream. Amorphous silica nanoparticles, suspended in perfluorocarbon, were instilled into the lungs of mice for intravital microscopy. Particles formed agglomerates that settled on the alveolar wall, half of which were removed from the lung within 30 minutes. TEM histology showed agglomerates in stages of crossing the alveolar epithelium, in large compartments inside the epithelial cells and crossing the basal membrane into the interstitium. This pathway is consistent with published kinetic studies in rats and mice, using a host of (negatively) charged and polar nanoparticles.

The contribution of beta-2 adrenergic, muscarinic and histamine (H1) receptors, calcium and potassium channels and cyclooxygenase pathway in the relaxant effect of Allium cepa L. on the tracheal smooth muscle

ETHNOPHARMACOLOGICAL RELEVANCE

There are report regarding therapeutic effects for Allium cepa L. (A. cepa) in Iranian traditional medicine and the plant has showed anti-inflammatory, anti-allergic, anti-hyperglycemic, antioxidant, anti-cancer, anti-hypertension, anti-hypercholesterolemia and anti-asthmatic activities in previous studies.

AIM OF THE STUDY

In this study, the contribution of β2 adrenergic, muscarinic and histamine (H1) receptors, calcium and potassium channels, and cyclooxygenase pathway in the relaxant effect of A. cepa extract on tracheal smooth muscle (TSM) was assessed.

MATERIALS AND METHODS

TSM was contracted by KCl (60 mM) or methacholine (10 μM) for 5 min and cumulative concentrations of A. cepa extract (2, 4, 8, 16, 32 and 64 mg/ml) were added to organ bath every 5 min. Theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control, and saline (1 ml) as negative control were also examined in non-incubated tissues. The relaxant effect of A. cepa extract was examined on non-incubated and incubated TSM with propranolol, chlorpheniramine, diltiazem, atropine, glibenclamide and indomethacin.

RESULTS

A. cepa showed concentration-dependent relaxant effects on non-incubated TSM contracted by KCl (60 mM) or methacholine (10 μM), (P < 0.01 to p < 0.001). There was no significant difference in the relaxant effects of A. cepa between non-incubated and incubated tissues with glibenclamide, atropine, chlorpheniramine and indomethacin. The plant extract showed significant lower relaxant effects in incubated TSM with propranolol and diltiazem compared to non-incubated tissues. EC50 values of A. cepa extract in incubated TSM with propranolol and diltiazem were significantly lower than non-incubated tissues (p < 0.001 and p < 0.05, respectively). The relaxant effects of different concentrations of the extract of A. cepa were not significantly different with those of theophylline. The concentrations of A. cepa extract and theophylline were significant correlated with their relaxant effects (p < 0.05 to p < 0.001). In incubated TSM with propranolol and diltiazem, concentration ratio minus one (CR-1) values was positive (2.65 ± 0.63 and 1.28 ± 0.43 respectively).

CONCLUSION

The A. cepa extract showed relatively potent relaxant effect on TSM which was comparable to the effect of theophylline. The results showed that β2-adrenergic stimulatory and/or calcium channel blockade are the possible mechanisms for the relaxant effects of the plant.

Ciprofibrate attenuates airway remodeling in cigarette smoke-exposed rats

Airway remodeling is a key pathological lesion in chronic obstructive pulmonary disease (COPD), and it leads to poorly reversible airway obstruction. Current pharmacological interventions are ineffective at controlling airway remodeling. To address this issue, we queried the Connectivity Map (cMap) database to screen for drug candidates that had the potential to dilate the bronchus and inhibit airway smooth muscle (ASM) proliferation. We identified ciprofibrate as a drug candidate. Ciprofibrate inhibited cigarette smoke extract-induced rat ASM cell contraction and proliferation in vitro. We exposed Sprague-Dawley (SD) rats to clean air or cigarette smoke (CS) and treated the rats with ciprofibrate. Ciprofibrate improved pulmonary function, inhibited airway hypercontraction, and ameliorated morphological small airway remodeling, including airway smooth muscle proliferation, in CS-exposed rats. Ciprofibrate also significantly reduced IL-1β, IL-12p70, IL-17A and IL-18 expression, which are related to airway remodeling, in the sera of CS-exposed rats. These findings indicate that ciprofibrate could attenuate airway remodeling in CS-exposed rats.

Pharmacological basis for the medicinal use of Alcea rosea in airways disorders and chemical characterization of its fixed oils through GC-MS

Alcea rosea L. also known as Althea rosea belongs to the Malvaceae family. This medicinal herb, traditionally used to treat several conditions including airway disorders like asthma and chronic bronchitis. This study evaluated the bronchodilatory effects and possible mechanism of A. rosea on guinea-pig tracheal tissues. Moreover lipophilic profiling of A. rosea has been carried out by using Gas-Chromatography-Mass-Spectrometry. A total of 19 compounds have been identified from the plant, n-hexane fraction. These compounds have been further confirmed from their Van den Dool and Kratz (I) Indices. Major class of metabolite identified from the plant includes fatty acid, saturated and unsaturated fatty acid esters. Hydrocarbons have also been detected from the n-hexane fraction. These fatty acid esters have not been reported previously by GC-MS and were identified first time from the flowers of Alcea rosea. In-vitro experiments were performed on guinea-pig tracheal tissues, mounted in Kreb's solution at 37°C and bubbled with carbogen. In isolated guinea-pig trachea, A. rosea inhibited carbamylcholine and K+ (80 mM)-induced contractions, potentiated isoprenaline concentration-response curves (CRCs) and suppressed Ca²⁺ CRCs. These results suggest that A. rosea cause bronchodilation through dual inhibition of phosphodiesterase enzyme and Ca²⁺ influx, which substantiate its potential in airways disorders.

Antitussive, expectorant, and anti-inflammatory effects of Adenophorae Radix powder in ICR mice

ETHNOPHARMACOLOGICAL RELEVANCE

Adenophora triphylla var. japonica is frequently used as an oriental medicinal plant in Korea, China, and Japan for its anti-inflammatory, antitussive, and hepatoprotective effects.

AIM OF THE STUDY

In the present study, the antitussive, expectorant, and anti-inflammatory effects of AR powder were investigated using animal models to evaluate their potential to treat respiratory disorders.

MATERIALS AND METHODS

AR powder was administered orally to mice once daily for 11 days, at dose levels of 400, 200, and 100 mg/kg. Theobromine (TB), ambroxol (AM) and dexamethasone (DEXA) were used as standard drugs for antitussive effects, expectorant effects and anti-inflammatory effects, respectively. Evaluations of antitussive effects were based on changes in body weight, the number of cough responses and the histopathology of the lung and trachea. Expectorant effects were based on changes in the body weight, macroscopic observations of body surface redness, the mucous secretion of the trachea and histopathology of lung (secondary bronchus). Anti-inflammatory effects were based on changes in the body weight, macroscopic observations involving redness and edema of the treated ear, absolute and relative ear weights and histopathology of the treated ears.

RESULTS

Allergic acute inflammation and coughing induced by exposure to NH₄OH and symptoms of xylene-induced contact dermatitis were significantly inhibited by treatment with AR powder in a dose-dependent manner. Histological analyses revealed that AR powder decreased the OD values in trachea lavage fluid, reduced body surface redness, thicknesses of intrapulmonary secondary bronchus mucosa, and the number of PAS-positive mucous producing cells. Overall, AR powder administered at 200 mg/kg displayed superior antitussive and expectorant effects as compared to TB (50 mg/kg), and AM (250 mg/kg). At the highest concentration (400 mg/kg) AR powder displayed only moderately improved anti-inflammatory activities as compared to DEXA (1 mg/kg).

CONCLUSION

The results obtained in this study suggest that AR powder exerts dose-dependent, favorable antitussive, expectorant, and anti-inflammatory activities achieved through modulation of the activity of mast cells and respiratory mucous production. Therefore, AR powder may serve as a therapeutic agent in various respiratory disorders, especially those that occur as a result of environmental toxicants.

A valve powered by earthworm muscle with both electrical and 100% chemical control

Development of bio-microactuators combining microdevices and cellular mechanical functions has been an active research field owing to their desirable properties including high mechanical integrity and biocompatibility. Although various types of devices were reported, the use of as-is natural muscle tissue should be more effective. An earthworm muscle-driven valve has been created. Long-time (more than 2 min) and repeatable displacement was observed by chemical (acetylcholine) stimulation. The generated force of the muscle (1 cm × 3 cm) was 1.57 mN on average for 2 min by the acetylcholine solution (100 mM) stimulation. We demonstrated an on-chip valve that stopped the constant pressure flow by the muscle contraction. For electrical control, short pulse stimulation was used for the continuous and repeatable muscle contraction. The response time was 3 s, and the pressure resistance was 3.0 kPa. Chemical stimulation was then used for continuous muscle contraction. The response time was 42 s, and the pressure resistance was 1.5 kPa. The ON (closed) state was kept for at least 2 min. An on-chip valve was demonstrated that stopped the constant pressure flow by the muscle contraction. This is the first demonstration of the muscle-based valve that is 100% chemically actuated and controlled.

Fine particulate matter (PM2.5) enhances airway hyperresponsiveness (AHR) by inducing necroptosis in BALB/c mice

OBJECTIVE

To observe the effects of prolonged exposure to high concentrations of PM_2.5 on the trachea and lungs of mice and to determine whether the damages to the trachea and lung are induced by necroptosis.

METHODS

Six- to eight-week-old female Balb/C mice of PM group were restrained in an animal restraining device using a nose-only "PM_2.5 online enrichment system" for 8 weeks, in Shijiazhuang, Hebei, China. Anti -Fas group was exposed to PM_2.5 inhalation and anti-Fas treatment via intranasal instillation. The mice in the control group inhaled filtered clean air. PM_2.5 sample was collected and analyzed. Airway Hyperresponsiveness (AHR) was tested. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for Hematoxylin and eosin (HE) staining, electron microscopy, cellular inflammation, cytokines, Tunel, Fas, RIPK3 and MLKL expression.

RESULTS

Compared to the other two groups, PM group displayed significantly increased AHR, neutrophils in BALF, significant bronchitis and alveolar epithelial hyperplasia and inflammation and necroptosis which were indicated by increased TUNEL, Fas, RIPK3 and MLKL measure.

CONCLUSION

Our findings suggest that PM_2.5 can enhance AHR and these changes are induced by necroptosis-related inflammation.