Yan-Hou-Qing formula attenuates allergic airway inflammation via up-regulation of Treg and suppressing Th2 responses in Ovalbumin-induced asthmatic mice.

ETHNOPHARMACOLOGICAL RELEVANCE

Yan-Hou-Qing (YHQ), a Chinese medicine formula containing fourteen kinds of materials, has been designed for pharyngitis and cough treatment in Oriental medicine. In the present study, the anti-allergic effects and underlying mechanisms of YHQ in inhibition of airway hyper responsiveness (AHR) was explored in an ovalbumin (OVA)-induced allergic asthma mouse model.

MATERIALS AND METHODS

BALB/c mice were sensitized by OVA and cholera toxin (CT) and challenged with OVA intranasally to induce allergic asthma mouse model. YHQ (200 mg/kg) was orally administered for 3 weeks from week-2 after OVA sensitization. The AHR and histological changes of lung tissues were evaluated by whole-body barometric plethysmography analysis and hematoxylin and eosin (H&E) staining, respectively. The serum concentration of OVA-specific IgE and T helper 2 (Th2) cytokines (IL-4 and IL-13) were determined by enzyme-linked immune sorbent assay (ELISA). Flow cytometry was performed to evaluate the percentage of CD4CD25Foxp3 regulatory T cells (Treg) in the spleen.

RESULTS

The elevated AHR responses, heavier inflammatory cell infiltration and Th2 cytokines in allergic asthma group indicated Ovalbumin-induced asthmatic mouse models were built successfully. Compared to allergic asthma group, OVA-induced AHR responses and eosinophil infiltration in lung were improved significantly, and the productions of OVA-specific IgE and Th2 cytokines, IL-4 and IL-13, in the serum were also reduced dramatically after the treatment of YHQ. Moreover, YHQ treatment significantly increased the percentage of CD4CD25Foxp3 Treg in OVA-induced allergic asthma mouse model.

CONCLUSIONS

YHQ improves the allergic asthma related symptoms via promotion of CD4CD25Foxp3 Treg and suppression of Th2 responses in mouse model, suggesting YHQ can be used as a potent agent to alleviate allergic asthma related symptoms.