Effect of Src tyrosine kinase on a rat model of asthma

Anti-inflammatory effect of Anadenanthera colubrina var. cebil (Griseb.) Altschul in experimental elastase-induced pulmonary emphysema in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have shown promise in the search for new treatments of pulmonary emphysema. Anadenanthera colubrina, a species native to the Caatinga biome in northeastern Brazil, is widely recognized and traditionally employed in the treatment of pulmonary diseases. Many studies corroborate popular knowledge about the medicinal applications of A. colubrina, which has demonstrated a remarkable variety of pharmacological properties, however, its anti-inflammatory and antioxidant properties are highlighted.

AIM OF THE STUDY

The objective of this study was to investigate the anti-inflammatory potential of the crude hydroethanolic extract of A. colubrina var. cebil (Griseb.) Altschul on pulmonary emphysema in rats as well as to determine its potential genotoxic and cytotoxic effects using the micronucleus assay.

MATERIALS AND METHODS

The stem bark of the plant was collected in Pimenteiras-PI and sample was extracted by maceration using 70% ethanol. A portion of the extract underwent phytochemical analyses using TLC and HPLC. In this study, 8-week-old, male Wistar rats weighing approximately ±200 g was utilized following approval by local ethics committee for animal experimentation (No. 718/2022). Pulmonary emphysema was induced through orotracheal instillation of elastase, and treatment with A. colubrina extract or dexamethasone (positive control) concomitantly during induction. Twenty-eight days after the initiation of the protocol, plasma was used for cytokine measurement. Bronchoalveolar lavage (BAL) was used for leukocyte count. After euthanasia, lung samples were processed for histological analysis and quantification of oxidative stress markers. The micronucleus test was performed by evaluating the number of polychromatic erythrocytes (PCE) with micronuclei (MNPCE) to verify potential genotoxic effects of A. colubrina. A differential count of PCE and normochromatic erythrocytes (NCE) was performed to verify the potential cytotoxicity of the extract. Parametric data were subjected to normality analysis and subsequently to analysis of variance and Tukey or Dunnett post-test, non-parametric data were treated using the Kruskal-Wallis test with Dunn's post-test for unpaired samples. P value < 0.05 were considered significant.

RESULTS

The A. colubrina extract did not show a significant increase in the number of MNPCE (p > 0.05), demonstrating low genotoxicity. No changes were observed in the PCE/NCE ratio of treated animals, compared with the vehicle, suggesting low cytotoxic potential of the extract. A significant reduction (p < 0.05) in neutrophilic inflammation was observed in the lungs of rats treated with the extract, evidenced by presence of these cells in both the tissue and BAL. The extract also demonstrated pulmonary antioxidant activity, with a significant decrease (p < 0.05) in myeloperoxidase, malondialdehyde, and nitrite levels. TNFα, IL-1β, and IL-6 levels, as well as alveolar damage, were significantly reduced in animals treated with A. colubrina extract. Phytochemical analyses identified the presence of phenolic compounds and hydrolysable tannins in the A. colubrina extract.

CONCLUSIONS

The findings of this study highlights the safety of the hydroethanolic extract of Anadenanthera colubrina, and demonstrates its potential as a therapeutic approach in the treatment of emphysema. The observed properties of this medicinal plant provide an optimistic outlook in the development of therapies for the treatment of pulmonary emphysema.

Lonicerin attenuates house dust mite-induced eosinophilic asthma through targeting Src/EGFR signaling

Eosinophilic asthma is the predominant phenotype of asthma, and although these patients are sensitive to glucocorticoid therapy, they also experience many side effects. Lonicerin is a kind of bioflavonoid isolated from the Chinese herb Lonicera japonica Thunb, which has anti-inflammatory and immunomodulatory effects. The aim of this study was to elucidate the effects of lonicerin on eosinophilic asthma and its potential mechanisms. Here, we established a house dust mite (house dust mite)-induced eosinophilic asthma model in BALB/c mouse, and evaluated the effects of lonicerin on it. Our results showed that lonicerin significantly reduced airway hyperresponsiveness the number of inflammatory cells (especially eosinophils) and the elevation of interleukin (IL)-4, IL-5, IL-13 and eotaxin in bronchoalveolar lavage fluid (BALF) supernatants of mice. Additionally, lonicerin also eminently blunted inflammatory infiltration and mucus secretion, as well as mRNA levels of Mucin 5AC (MUC5AC) in lung tissue. Furthermore, results of network pharmacology and molecular docking revealed that Src kinase and epidermal growth factor receptor may be the potential targets responsible for the effects of lonicerin. Finally, in vivo experiments confirmed that lonicerin inhibited activation of the Src/EGFR pathway by decreasing their phosphorylation. Taken together, the present study demonstrated that lonicerin could suppress HDM-induced eosinophilic asthma in mice through inhibiting the activation of Src/EGFR pathway, which also provides a basis for further research as a new potentially therapeutic agent for eosinophilic asthma and its underlying mechanisms in the future.

Nanoparticle Delivery Platforms for RNAi Therapeutics Targeting COVID-19 Disease in the Respiratory Tract

Since December 2019, a pandemic of COVID-19 disease, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread across the globe. At present, the Food and Drug Administration (FDA) has issued emergency approval for the use of some antiviral drugs. However, these drugs still have limitations in the specific treatment of COVID-19, and as such, new treatment strategies urgently need to be developed. RNA-interference-based gene therapy provides a tractable target for antiviral treatment. Ensuring cell-specific targeted delivery is important to the success of gene therapy. The use of nanoparticles (NPs) as carriers for the delivery of small interfering RNA (siRNAs) to specific tissues or organs of the human body could play a crucial role in the specific therapy of severe respiratory infections, such as COVID-19. In this review, we describe a variety of novel nanocarriers, such as lipid NPs, star polymer NPs, and glycogen NPs, and summarize the pre-clinical/clinical progress of these nanoparticle platforms in siRNA delivery. We also discuss the application of various NP-capsulated siRNA as therapeutics for SARS-CoV-2 infection, the challenges with targeting these therapeutics to local delivery in the lung, and various inhalation devices used for therapeutic administration. We also discuss currently available animal models that are used for preclinical assessment of RNA-interference-based gene therapy. Advances in this field have the potential for antiviral treatments of COVID-19 disease and could be adapted to treat a range of respiratory diseases.