Guizhi-jia-houpu-xingzi decoction attenuates ovalbumin-induced allergic asthma via regulation of Toll-like receptor signal pathway

Purpose: To study the effect of Guizhi-jia-houpu-xingzi (GHX) on ovalbumin-induced allergic asthma in rats.Methods: An animal model of allergic asthma (AA) in rats was established by intraperitoneal injection (ip) of ovalbumin (OVA). Thereafter, GHX (375 mg/kg) was administered orally for 7 days. Pulmonary function, inflammatory cells, immunoglobulin E (Ig) E, interleukin-4 (IL)-4 and interferon-γ (IFN)-γ in serum and bronchoalveolar lavage fluids (BALF) were determined. Furthermore, mRNA expressions of Toll-like receptors (TLRs) signal pathway was determined using real time polymerase chain reaction PCR (q-RT-PCR).Results: GHX (375 mg/kg) significantly decreased respiratory rate (p < 0.01) and Penh value (p < 0.05) when compared with AA rats. The inflammatory cells (p < 0.01) and levels of IL-4 (p < 0.01) and IgE (p < 0.01) were significantly decreased by GHX treatment when compared with AA rats; whereas IFN-γ (p < 0.05) was significantly increased. Furthermore, GHX significantly decreased the mRNA expressions of GATA binding protein (GATA)-3 (p < 0.01), TRL-2 (p < 0.01), TRL-4 (p < 0.01), myeloid differentiation factor 88 (MyD88) (p < 0.01), TNF receptor associated factor 6 (TRAF6) (p < 0.01) and β-arrestin (p < 0.01) in lung tissues, relative to AA rats. However, GHX treatment led to significant up-regulation of mRNA expression of T-bet (p < 0.01).Conclusion: These results demonstrate that GHX possesses a potential for treating allergic asthma via regulation of Toll-like receptor (TLR) signal pathway. They also provide a scientific basis for the probable use of GHX in clinical treatment of allergic diseases in future.Keywords: Guizhi-jia-houpu-xingzi decoction, Ovalbumin, Allergic asthma, Toll-like receptor