Chinese herbal medicine formula Gu-Ben-Fang-Xiao-Tang attenuates airway inflammation by modulating Th17/Treg balance in an ovalbumin-induced murine asthma model.

Gu-Ben-Fang-Xiao-Tang (GBFXT) is a traditional Chinese medicine formula consisting of 11 medicinal plants, which has been used in the treatment of asthma. The present study aimed to determine the protective effects and the underlying mechanisms of GBFXT on ovalbumin (OVA)-induced allergic inflammation in a mouse model of allergic asthma. A total of 50 mice were randomly assigned to the following five experimental groups: Normal, model, montelukast (2.6 mg/kg), 12 g/kg GBFXT and 36 g/kg GBFXT groups. Airway responsiveness was measured using the forced oscillation technique, while differential cell count in the bronchoalveolar lavage fluid (BALF) was measured by Wright-Giemsa staining. Histological assessment was performed by hematoxylin and eosin staining, while BALF levels of Th17/Treg cytokines were measured by enzyme-linked immunosorbent assay, and the proportions of Th17 and Treg cells were evaluated by flow cytometry. The results showed that GBFXT suppressed airway hyperresponsiveness during methacholine-induced constriction, reduced the percentage of leukocytes and eosinophils, and resulted in decreased absolute neutrophil infiltration in lung tissue. In addition, GBFXT treatment significantly decreased the IL-17A cytokine level and increased the IL-10 cytokine level in the BALF. Furthermore, GBFXT significantly suppressed Th17 cells and increased Treg cells in asthmatic mice. In conclusion, the current results demonstrated that GBFXT may effectively inhibit the progression of airway inflammation in allergic asthma, partially by modulating the Th17/Treg cell balance.

Imbalance of Peripheral Th17 and Regulatory T Cells in Children with Allergic Rhinitis and Bronchial Asthma.

The purpose of the present study is to investigate the prevalence of Th17 and regulatory T (Treg) cells in children with allergic rhinitis (AR) accompanying with bronchial asthma (BA). 24 children with AR, 22 children with BA, 18 children with AR accompanying with BA, and 20 healthy controls were recruited. The prevalence of peripheral blood Th17 and Treg cells were determined by flow cytometry. mRNA expression of retinoid-acid receptor-related orphan receptor (ROR)-γt and forkhead box P3 (Foxp3) were determined by realtime polymerase chain reaction. Cytokine expressions in plasma were determined by enzyme linked immunosorbent assay. The frequency of Th17 cells, ROR-γt mRNA expression, and the plasma levels of IL-17 were significantly higher, while Treg cells and Transforming growth factor (TGF)-ß1 were significantly lower in children with AR accompanying with BA compared with those in children with AR or BA alone or control subjects. In children with allergic airway disease, total IgE levels were positively correlated to the frequency of Th17 cells (r=0.607, p<0.01), plasma IL-17 levels, and negatively correlated to the frequency of Treg cells (r=-0.429, p<0.01) and TGF-ß1 levels (r=-0.224, p<0.01). While Forced expiratory volume in one second (FEV1) (% predicted) was negatively correlated to the frequency of Th17 cells (r=-0.602, p<0.01), plasma IL-17 levels (r=-0.577, p<0.01), and positively correlated to the frequency of Treg cells r=0.504, p<0.01) and TGF-ß1 levels (r=0.231, p<0.05). Our results demonstrate that the imbalance of peripheral Th17/Treg cells plays an important role in the pathogenesis of AR accompanying with BA.