OBJECTIVETo investigate the effect of the active components from Red Paeonia and Rhizoma chuanxiong (in Xiongshao Capsule, XSC) on matrix metalloproteinases (MMPs) in rabbit model of atherosclerosis.

METHODSFifty New Zealand rabbits were randomly divided into the normal control group (A), the model control group (B), the Simvastatin treated group (C), the low-dose XSC treated group (D) and the high-dose XSC treated group (E), 10 in each group. Rabbits in the normal control group were fed with normal diet, while those in the other four groups were fed with high fat diet and duplicated after two weeks feeding into model of abdominal aortic atherosclerosis by balloon angioplasty. In the 6 successive weeks feeding of high fat diet, Simvastatin 2.5 mg/kg, XSC 0.24 g/kg and 0.48 g/kg per day was given respectively to the rabbits in the three treated groups. Blood sample was collected for determining the level of blood lipids; serum MMP-3 and MMP-9, and tissue inhibitor of metalloproteinase-1 (TIMP-1) with enzyme-linked immunoassay; and the protein expression of MMP-3 and cluster of differentiation antigen 40 ligand (CD40L) in plaque were detected with immunohistochemical method.

RESULTSCompared with Group B, the serum levels of MMP-3 and MMP-9; the expression of MMP-3 and CD40L in plaque; and the blood content of total cholesterol in the three treated groups were significantly lower (P < 0.05 or P < 0.01). Besides, the content of triglyceride and low-density lipoprotein cholesterol were significantly reduced in Group C, while the TIMP-1 showed no statistical difference among different groups (P > 0.05).

CONCLUSIONThe active components of Red Paeonia and Rhizoma chuanxiong play a definite role in stabilizing the atherosclerotic plaque in rabbits, one of their possible mechanisms may be by way of inhibiting the expressions of MMP-3, MMP-9 in vascular walls and blood serum.