Hypertension is one of the most important modifiable risk factors for cardiovascular and
cerebrovascular diseases. We investigated the potential antihypertensive effect of the purple passion
fruit peel (PFP) extract, a mixture of bioflavonoids, phenolic acids, and anthocyanins, in spontaneously
hypertensive rats and human. A high-performance liquid chromatography analysis was performed to
identify the active ingredients of the PFP extract. In a rat liver toxicity assay, no hepatotoxicity was
observed after 9 hours incubation in the presence of PFP extract (20 μg/mL). The PFP extract also
revealed hepatoprotection against chloroform (1 mmol/L)-induced liver injury. In the experimental
model, 24 spontaneously hypertensive rats were divided into 3 treatment groups for a period of
8 weeks: control group and groups fed diet supplemented with either 10 or 50 mg/kg PFP extract. The
diet supplemented with PFP extract at 50 mg/kg significantly lowered systolic blood pressure by
12.3mmHg (P b.01) and markedly decreased serum nitric oxide level by 65% (P b.05) compared with
the control group. The effect of the treatment on immune parameters was also evaluated, which showed
no statistical changes. Studies were then extended to hypertensive human subjects who were
administered PFP extract (400 mg/d) or placebo pills within a 4-week randomized, placebo-controlled,
double-blind trial. The effects of the PFP extract were evaluated by blood pressure measurement. The
systolic and diastolic blood pressure of the PFP extract–treated group decreased significantly by 30.9 ±
6.3 and 24.6 ± 3.3mmHg, respectively, compared with the placebo group (P b.001). No adverse effect
was reported by the patients. The results suggest that the antihypertensive effect of the PFP extract may,
in part, be mediated through nitric oxide modulation. It is suggested that the PFP extract may be offered
as a safe alternative treatment to hypertensive patients.
© 2007 Elsevier Inc. All rights reserved.