Objective: To explore the effect of Sanzi Yangqin Tang drug serum on cysteinyl leukotrienes (CysLTs)-mediated inflammatory pathways in bronchial epithelial cells. Method: Serum pharmacology technique was adopted to treat interleukin-4 (IL-4) and CysLTs-induced bronchial epithelial cells with 1.25%

2.5% and 5% Sanzi Yangqin Tang drug serum as well as blank serum. The concentrations of eotaxin-1 (Eot-1) and Eot-3 in the culture supernatant were detected by enzyme linked immunosorbent assay (ELISA);the expression levels of cysteinyl leukotrienes receptor 1 (CysLTR1) and CysLTR2 in bronchial epithelial cells were detected by Western blot assay;the mRNA expression levels of CysLTR1 and CysLTR2 in bronchial epithelial cells were detected by reverse transcription-polymerase chain reaction (RT-PCR). Result: The concentrations of Eot-1 and Eot-3 in the culture supernatant in 2.50% and 5.00% Sanzi Yangqin Tang drug serum were significantly lower than those in the same serum levels of blank group (P < 0.05);there were no significant differences in protein expression level of CysLTR2 and mRNA expression levels of CysLTR1 between the culture supernatant of 1.25%

2.50% and 5.00% Sanzi Yangqin Tang drug serum and the blank group;the protein expression level of CysLTR1 and mRNA expression level of CysLTR2 in the culture supernatant of 2.50% and 5.00% Sanzi Yangqin Tang drug serum were significantly lower than those in same serum levels of blank group (P < 0.05). Conclusion: Sanzi Yangqin Tang drug serum could block CysLTs-mediated inflammatory pathways and thus treat bronchial asthma by down-regulating the expression levels of CysLTR

as well as the expression and secretion of Eot-1 and Eot-3.