Abstract: AIM: To observe the effects of puerarin on the proliferation of vascular smooth muscle cells (VSMC) induced by thrombin and the effects of puerarin on the c-fos protein expression and thrombin receptor (TR) mRNA expression.METHODS: DNA contents were detected by cell number and cell cycle analysis and effects of puerarin on proliferation of VSMC were detected by flow cytometry. The changes of c-fos protein was indi-cated by Western blot, and TR mRNA expression was e-valuated by Reverse Transcription Polymerase Chain Re-action (RT-PCR) which was treated with T and puerarin after 24 hours. RESULTS: T increased the cell numbers of VSMC, the peak of proliferation curve was at 24 h, and the effects of T was in a dose-dependent manner (0.1 -1.0 U°L^-1). 1.5 ×10^-5 -1. 5 ×10^-3mol°L^-1 puerarin significantly suppressed this stimulation of VSMC proliferation and DNA synthesis induced by T. Western blot demonstrated that T increased c-fos protein which treated with T and puerarin after 24 hour. 1.5 ×10^-5 -1.5 ×10^-3mol·L^-1 puerarin suppressed thisincrease. RT-PCR demonstrated that T can significantly increase TR mRNA expression and 1.5×10^-3mol°L^-1 puerarin sup-pressed this increase. CONCLUSION: Puerarin can suppress the proliferation and DNA synthesis of VSMC promoted by T. The inhibitory effects of puerarin are closely related with the suppression of c-fos protein, and partly related with the suppression on TRmRNA.

Key words: puerarin, vascular smooth muscle cell, proliferation, thrombin receptor