Magnoliae Cortex inhibits intimal thickening of carotid artery through modulation of proliferation and migration of vascular smooth muscle cells

Endovascular injury leads to proliferation and migration of vascular smooth muscle cells from the media to the intima leading to the intimal thickening. The objective of this study was to examine the effect of Magnoliae Cortex extract (MOE) on intimal thickening of rat carotid artery injured by balloon endothelial denudation. MOE was administered orally using gastric sonde at three different doses MOE200 (200 mg/kg), MOE400 (400 mg/kg), and MOE800 (800 mg/kg) for 14 days from the day of balloon injury. Also, in vitro assays of proliferation, migration and expression of matrix metalloproteinase-2 (MMP-2) in human aortic smooth muscle cells (HASMCs) were carried out using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell boyden chamber method and gelatin zymography, respectively. Oral administration of MOE400 and MOE800 for 14 days significantly inhibited intimal area, intimal/medial ratio (I/M), stenosis rate, expression of proliferating cell nuclear antigen (PCNA), MMP-2, and -9 in denudated rat carotid artery. Our in vitro assays revealed that MOE dose dependently inhibited proliferation, migration and expression of MMP-2 in HASMCs. Thus, the results suggest that MOE can be considered as a therapeutic value in the prevention of atherosclerosis because restenosis after percutaneous transluminal coronary angioplasty (PTCA) is supposed to be ‘accelerated atherosclerosis’.