OBJECTIVETo observe the effect of oxymatrine (OMT) on calcification of humans umbilical vein smooth muscle cells and its underlying mechanism.

METHODHuman umbilical vein smooth muscle cells (HUSMCs) were calcified by beta-giycerophos-phosphate (beta-GP) and then divided into 6 groups: the control group, the calcification group, the pure OMT group, and lower, middle and higher-dosage OMT groups. Cell calcification were observed by Von Kossa staining, calcium content in HUSMCs were determined by the colorimetric method, the alkaline phosphatase (ALP) activity in HUSMCs were determined by phenyl diphosphate-2-sodium, the osteocalcin (OC) level in HUSMCs were determined by radioimmunossay, the transforming growth factor-beta1 (TGF-beta1) level in HUSMC culture medium and the content changes in psmad2/3 and smad2/3 were determined by the ELISA method, and the expression of Core binding factor alpha1 (Cbfalpha1) protein in HUSMCs were determined by western blot method.

RESULTCompared with the control group, the calcification group showed a great number of black granules among the smooth muscle cells and significant increase in the content of calcium and OC and the activity of ALP; OMT intervention can decrease the content of calcium, OC, TGF-beta1, psmad2/3 and Cbfalpha1 and the activity of ALP. And high-dosage OMT group had better effect than middle and low-dosage groups.

CONCLUSIONOMT can effectively inhibit beta-GP-induced HUSMC calcification and its effect on reducing TGF-beta1, psmad2/3 and Cbfalpha1 may be one of its mechanisms in inhibiting HVSMC calcification.