Abstract: Objective NVP (1) was one pure protein that isolated from Nidus Vespae. We found that NVP (1) can inhibit proliferation of bronchial smooth muscle cell. At the same time, we investigated the mechanism of NVP (1) in inhibiting proliferation of bronchial smooth muscle cell. Method Primary cell culture. The effects of NVP (1) on bronchial smooth muscle cells proliferation by MTT assay. The cell cycle was detected by flow cytometry. Western-blotting was used to reveal p21, cdk2 protein expression. Results NVP(1) (6.4×10-3g/L) can arrest bronchial smooth muscle cell in cycle G1 and increase the expression level of p21. On the contrary, NVP (1) can inhibit proliferation of bronchial smooth muscle cell by down-regulating cdk2 protein expression. Conclusion NVP (1) inhibits proliferation of bronchial smooth muscle cells and induces G1 cell cycle arrest.

Key words: The mechanism of Nidus Vespae protein 1（NVP 1）inhibits proliferation of bronchial smooth muscle cell