Objective      To determine the effects of phytoestrogen on the expression of formyl peptide receptor (FPR) and Annexin A1 (AnxA1) in human alveolar epithelial cells under hypoxia exposure.       Methods       Human alveolar type Ⅱ epithelial cells (A549) were cultured and divided into nor

moxia (5％CO

2

and 95％O

2

) and hypoxia (1％O

2

5％CO

2

and 94％N

2

for 24 h) groups. Each group was further divided into the control

genistein treatment group (15 μmol/L before hypoxia) and daidzein treatment group (15 μmol/L before hypoxia). Chemotaxis assay was used to detect the activity of FPR agonists in the supernatants of culture media and lysates of the treated cells in presence or absence of FPR specific inhibitor tBoc2. The protein levels of AnxA1

hypoxia inducible factor 1α (HIF-1α) and nuclear factor κB (NF-κB) were detected by Western blotting. The mRNA level of AnxA1 was assayed by RT

2

-PCR.       Results      Hypoxia induced both cultural supernatants and lysate supernatants had significantly higher chemotactic activity than normoxia (

P

＜0.05). Phytoestrogen treatment also induced higher chemotactic activity than the control groups (

P

＜0.05). Western blotting and RT

2

-PCR indicated that hypoxia up-regulated the expression of AnxA1 significantly at the levels of protein and mRNA (

P

＜0.05). The elevation was inhibited in the presence of phytoestrogen so as well NF-κB and HIF-1α.       Conclusion       Phytoestrogen attenuates hypoxia-induced up-regulated expression of AnxA1 through NF-κB and HIF-1α signal pathways.