OBJECTIVETo observe the therapeutic effect of qingxin capsule (QXC) in treating patients with hypertension of mild or moderate degree, and to explore its mechanism in lowering blood pressure.

METHODSAdopting randomized double-blind double-simulated positive controlled clinical trial design, 98 patients were randomly divided into three groups, they were treated by QXC (n = 34), captopril (n = 32) and QXC plus captopril (n = 32), respectively for 12 weeks. Changes of blood pressure, clinical symptoms, quality of life (QOF), plasma levels of calcitonin gene-related peptide (CGRP), angiotensin II (Ang II) and endothelin (ET) in patients before and after treatment were observed, and the adverse reactions to the treatment were recorded.

RESULTSThe markedly effective rate in lowering blood pressure of QXC, captopril and QXC plus captopril was 44.1%, 53.1% and 75.0% respectively, the markedly effective rate in ameliorating symptoms was 56.0%, 47.0% and 50.0% respectively. In respect of reducing symptomatic scores, QXC > captopril > QXC + captopril, in respect of ameliorating QOF, QXC was superior to captopril (P < 0.05). Single or combined use of QXC and captopril could increase the plasma CGRP level. QXC could also reduce the plasma levels of Ang II and ET, showing statistical significance in comparing the levels before and after treatment (P < 0.05).

CONCLUSIONQXC can safely and effectively lower blood pressure of patients with mild or moderate degree of hypertension. QXC alone or combined with captopril could improve clinical symptoms and raise QOF in patients more potently than that of captopril alone. The mechanism of QXC might be related with its inhibition on the activity of circulatory renin-angiotensin system and adjustment on ET/CGRP imbalance.