Immunologic Pathophysiology and Airway Remodeling Mechanism in Severe Asthma: Focused on IgE-Mediated Pathways

Immunomodulatory effect of glabridin in ovalbumin induced allergic asthma and its comparison with methylprednisolone in a preclinical rodent model

Glabridin, a polyphenolic flavonoid derived from Glycyrrhiza glabra (licorice) roots, has shown anti-inflammatory and antioxidant properties. The current study sought to investigate glabridin's immunomodulatory effect in ovalbumin induced allergic asthma. Healthy male Wistar rats were divided into five groups. Group I served as a control group. Asthma was induced in groups II- IV. Groups III and IV were treated with glabridin (40 mg/kg) and methylprednisolone (15 mg/kg), respectively. Inflammatory cells counts were determined in blood and bronchoalveolar lavage fluid (BALF). Serum IgE levels and levels of catalase, superoxide dismutase and glutathione peroxidase in lung homogenate were measured. The levels of mRNA expression of pro-inflammatory, anti-inflammatory and oxidative stress markers were analysed. Delayed type hypersensitivity (DTH) and acute toxicity of glabridin were also checked. Glabridin significantly decreased inflammatory cells in the blood and BALF. It increased the concentration of antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. Glabridin markedly decreased serum IgE levels and DTH when compared to asthmatic rats. It significantly alleviated the expression of TNF-α, IL-4, IL-5, CXCL1, iNOS, and NF-κB. Administering 10 times the therapeutic dose of glabridin did not show any signs of acute toxicity. Findings suggest that glabridin has the potential to ameliorate allergic asthma and its effects are comparable to those of methylprednisolone. The immunomodulatory effect of glabridin might be contributed by the suppression of pro-inflammatory cytokines, oxidative stress markers, IgE antibodies, and elevation of antioxidant enzymes, suggesting future study and clinical trials to propose it as a candidate to treat allergic asthma.

Recent Advancement and Novel Application of Natural Polyphenols for the Treatment of Allergy Asthma: From Phytochemistry to Biological Implications

Allergic diseases, primarily IgE-mediated, exert a substantial global health burden. A pivotal role in allergic reactions is played by mast cells, with histamine serving as a central mediator. Within this context, plant-based polyphenols, abundantly present in vegetables and fruits, show promising potential for allergy prevention. These natural compounds, particularly flavonoids, possess anti-inflammatory and anti-allergic properties, influencing dendritic cells, modulating macrophages, and fostering the proliferation of B cells and T cells. The potent anti-allergic effects of flavonoids are attributed to their ability to reduce the production of signaling factors, suppress cytokine production, and regulate signal transduction and gene expression in mast cells, basophils, and T cells. Notably, their benefits extend beyond allergy prevention, as they hold promise in the prevention and treatment of autoimmune illnesses such as diabetes, rheumatoid arthritis, and multiple sclerosis. In the context of allergic reactions and autoimmune diseases, polyphenols exhibit immunomodulatory effects by inhibiting autoimmune T cell proliferation and downregulating pro-inflammatory cytokines. In recent times, flavonoids, being the most prevalent polyphenols in food, have garnered significant attention from researchers due to their potential health advantages. This review compiles the latest scientific research to highlight the impact of flavonoids on allergic illnesses and their potential as a beneficial dietary component.

The effect of fasting on spirometry indices and respiratory symptoms in asthmatic patients

Introduction: Ramadan can alter the course of diseases by changing nutrition patterns, sleep habits, and medication-taking schedules. There are some concerns that patients with asthma may be affected by these alterations during Ramadan and experience deterioration of their symptoms. This study aimed to investigate the effect of fasting in Ramadan on the severity of the disease and spirometric parameters in patients with asthma.

Methods: An overall 120 patients with moderate to severe asthma were investigated during Ramadan and categorized into two groups of fasting (60 cases) and non-fasting (60 cases) groups. Patients underwent spirometry before and after Ramadan and asthma control status was also assessed. The parameters measured in spirometry were compared in each group before and after Ramadan and also between the two groups.

Results: Spirometric measurements including forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), and FEV1/FVC were not significantly different before and after Ramadan in both groups of fasting and non-fasting patients. Furthermore, there was no significant difference between the two groups in terms of these spirometric parameters changes from baseline. Nevertheless, FEV1 change in the fasting group was significantly higher than that in the non-fasting group (1.46±5.37 vs. -0.13±3.08, respectively; P=0.040).

Conclusion: The results of this study demonstrated that fasting has no significant effect on the severity of asthma and spirometric findings in patients with moderate to severe asthma. Therefore, fasting during Ramadan can be considered safe for patients with asthma.