Objective    To observe the effects of indole-3-carbinol on neointimal  hyperplasia and restenosis of rat artery after balloon injury and the possible mechanisms.     Methods    Balloon dilation was used to establish the neointimal injury model of left carotid artery in rats. Twenty Sprague-Dawley rats were randomly divided into single balloon dilation group (control group) and balloon dilation followed by indole-3-carbinol therapy group (therapeutic group). After balloon dilation

indole-3-carbinol (12.5

25

50 mg/d) was applied to the rats for 7 days respectively. The rats were killed two weeks after balloon dilation and the injured vascular specimens were harvested for pathologic examination and immunohistochemical staining.     Results    ①The neointimal thickness

neointimal area in the therapeutic groups were significantly less than that of the control group (P0.05). The stenosis ratio of vessels in the therapeutic groups decreased by 25.2%

29.9% and 48.5% respectively

as compared with the control group. ②The percentages of PCNA positive cells were obviously decreased in the therapeutic groups as compared with the control group. ③The apoptosis of vascular smooth muscle cells was significantly higher in the therapeutic groups than the control group (P0.01).      Conclusion    Taking indole-3-carbinol orally can inhibit neointimal hyperplasia in vivo

which mechanism may be related to inhibiting the proliferation and promoting the apoptosis of vascular smooth muscle cells.