Hydroxysafflor yellow A attenuates left ventricular remodeling after pressure overload-induced cardiac hypertrophy in rats

Context: Hydroxysafflor yellow A (HSYA), the main chemical component of the safflower yellow pigments, is used extensively in traditional Chinese medicine for the treatment of cerebrovascular and cardiovascular diseases. Objective: The present study determined the effects of HSYA on left ventricular hypertrophy after pressure overload and investigated the underlying mechanisms. Materials and methods: Cardiac hypertrophy was induced by the ligation of abdominal aorta in male Wistar rats. The rats were then divided into five groups and treated with captopril (100 mg/kg) or HSYA at different doses (0, 10, 20 and 40 mg/kg). Six weeks after treatment, the weight of left ventricle, LVMI (left ventricular mass index) and pathological changes were measured. MMP-2 (metalloproteinase 2) and MMP-9 (metalloproteinase 9) levels were determined by ELISA. Protein expressions of Bcl-2 and Bax were evaluated by immunohistochemistry. Results: HSYA (20, 40 mg/kg) significantly attenuated the increase of LVMI (ventricular weight/body weight) by 13.04 and 30.43% respectively, when compared with the model group. This was associated with the amelioration of pathological lesion, such as cardiac muscle fibers were smaller and the nuclei of cardiomyocytes were lightly stained in animals treated with HSYA (20, 40 mg/kg). In addition, the administration of HSYA at doses of 20 and 40 mg/kg increased the Bcl-2/Bax ratio (1.17 +/- 0.08 and 1.39 +/- 0.07 versus 0.71 +/- 0.06). In addition, the serum MMP-2 and MMP-9 levels were blocked by the treatment at doses of 20 and 40 mg/kg HSYA (MMP-2, 76.1 +/- 9.2 and 65.6 +/- 6.8 versus 82.9 +/- 6.2, ng/ml; MMP-9, 66.6 +/- 4.8 and 57.5 +/- 5.0 versus 83.5 +/- 6.0, ng/ml). Conclusion: These findings indicated that HSYA has beneficial effects on hypertensive ventricular remodeling, which may involve mechanisms of inhibiting cell apoptosis and suppressing metalloproteinases expression.