OBJECTIVETo observe the clinical effect of Xuefu Zhuyu Capsule (XFZYC) in treating unstable angina pectoris (UAP) and to investigate its mechanism of protection on vascular endothelia.

METHODSSixty UAP patients were randomly assigned to two groups, the 30 in the treated group were treated by conventional therapy plus XFZYC, and the 30 in the control group treated by conventional therapy alone. The frequency and persistent time of angina pectois, dosage of nitroglycerin used, changes of electrocardiogram (ECG) were observed, and the plasma levels of endothelin (ET), nitric oxide (NO), von Willebrand factor (vWF), soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) were tested before and after the two-month therapeutic course.

RESULTS(1) The clinical symptoms as frequency and persistent time of angina pectoris in the treated group were bettered significantly after treatment and the dosage of nitroglycerin used decreased (all P < 0.01), showing significant difference when compared with those in the control group (P < 0.05). (2) The effective rates on UAP symptoms and ECG in the treated group were 86.7% and 76.7% respectively, which were significantly higher than those in the control group (70.0% and 63.3%, P < 0.05). (3) Laboratory examination showed in the control group, changes only displayed in the decrease of vWF and ET and increase of NO (all P < 0.05), while in the treated group, plasma levels of vWF, ET, sVCAM-1 and sICAM-1 after treatment significantly decreased and were lower than those in the control group (P < 0.01), but NO elevated significantly and was higher than that in the control group (P < 0.01).

CONCLUSIONSXFZYC is an effective Chinese patent medicine for treatment of UAP. It displays its effect on protecting vascular endothelia and anti-angina pectoris partially by decreasing the plasma levels of ET, vWF, sVCAM-1 and sICAM-1 and elevating the level of NO.