The inhibition of quercetin and isorhamnetin on the proliferation of cultured human vascular smooth muscle cells

Objective To observe the role of quercetin (QUE) and isorhamnetin(ISOR) on the proliferation of human vascular smooth muscle cell (VSMC). Methods The effects of quercetin (QUE), isorhamnetin(ISOR) and norepinephrine (NE) on these VSMC growth and DNA synthesis was investigated by cell counting, 3H-thymidine incorporation. Results ①QUE could inhibit proliferation and DNA synthesis of VSMC but these effects of ISOR was weaker than that of QUE. When VSMC were treated by 1-200 μmol/L of QUE or ISOR, the best inhibitory effects occured at 200 μmol/L. There were dose-dependent inhibitory effects in different concentration of QUE ISOR. ② NE 10 μmol/L could stimulate proliferation and DNA synthesis of VSMC. The effects can be inhibited by phentolamine(Ph). ③ QUE and ISOR markedly inhibit proliferation and DNA synthesis of VSMC induced by NE, and also are in a dose dependent manner. At the some time QUE and ISOR had cooperative effects on inhibition of the stimulation of NE. ④QUE and ISOR also had more powerful inhibitory effect on proliferation and DNA synthesis of VSMCs co-incubation with NE than Ph. ⑤There were no cyto-toxic effects on VSMC treated with QUE and ISOR. Conclusion These results indicated that QUE and ISOR had no cyto-toxic effect on VSMCs cultured in vitro and could effectively inhibit the proliferation and DNA synthesis of VSMCs, especially inhibit the proliferation and DNA synthesis of VSMC stimulated by NE.