OBJECTIVETo observe the preventive and therapeutic effect of tanshinone (TA) on artery restenosis in mice and primarily explore the mechanism.

METHODFemale KM mice were randomly divided into model control, low dose and high dose TA groups. Each group had 12 mice. The low and high dose drug groups were respectively given TA 3 and 6 g x kg(-1) x d(-1) by ig; the model control group was given the same volume solvent. The controlateral carotid of ligated artery of model control group was regarded as normal control. 2 days later, the mice' s left common carotid artery was dissected and ligated near the carotid bifurcation, leading to intima hyperplasia and then establishing restenosis model. 4 weeks later, the artery was harvested and stained by hematoxylin-elsin (HE) and immunohistochemistry of PCNA. The morphological changes were checked under microscope; the area of the intimal and medial layer of the vessels, and their ratios were analyzed with image analysis software. The expression level of PCNA was expressed as the positive index.

RESULTCompared with those of normal artery, the intimal area, media area and intima-to-media ratio of ligated artery increased obviously (P < 0.01). But TA could significantly decrease all of these parameters (P < 0.01), and also decrease the positive index of PCNA (P < 0.01).

CONCLUSIONTA effectively inhibits intima hyperplasia, which is mainly characterized with the proliferation and migration of smooth muscle cell induced by abnormal hemodynamic changes. This result suggestes that TA may play a positive role in the prevention of restenosis after PTCA.