Medicinal & Aromatic Plants
Open Access

Abstract

Therapeutic Effectiveness of an Herbal Medicinal Product of Hibiscus sabdariffa in Hypertensive Patients: A 16 Week Controlled and Randomized Clinical Study

Herrera-Arellano A, Zamilpa A, Jiménez-Ferrer JE, Cruz-Hernández AM, Clemente-Catonga A, Herrera-Alvarez S and Tortoriello J

Background: The antihypertensive effectiveness of extracts from Hibiscus sabdariffa, has been reported in clinical studies of short term. This paper reports the therapeutic effectiveness, safety, and tolerability of an Herbal medicinal Product of Hibiscus sabdariffa administered during 16 weeks to hypertensive patients.

Study design: Randomized, double-blind, controlled clinical trial. Patients: Adults with mild-to-moderate hypertension. Interventions: Experimental, capsules with H. sabdariffa extract (standardized in 100 mg of total anthocyanins); Control, capsules with Lisinopril (5 mg). Dosage: One capsule every 12 h for 16 weeks. Primary outcome: Therapeutic effectiveness (reduction ≥ 10 mmHg of baseline diastolic blood pressure); Tolerability (absence of intense adverse reactions); Safety (absence of pathological changes in liver and kidney biochemical tests).

Statistical analyses: χ², Student t, log-rank tests and ANOVA for repeated measurements.

Results: One hundred fifteen subjects were included; 57 comprised the experimental group. The therapeutic effectiveness observed in the control group was greater than that in the experimental group (p=0.0001); however, the experimental group showed a significant reduction of the blood pressure at the end of 16 weeks of treatment (24/14 mmHg; p=0.0001). Fourteen patients did not tolerate the nocturnal dosage of experimental treatment (24.5%), reporting increase in nocturnal urinary frequency, and a sole control patient did not tolerate the treatment (1.7%; p=0.0003). Safety was 100% with both treatments.

Conclusions: In hypertensive subjects, the therapeutic effectiveness of herbal medicinal product of H. sabdariffa (200 mg of anthocyanins/daily), administered during 16 weeks, was less than that of Lisinopril; however, the experimental treatment significantly reduced systolic and diastolic blood pressure and shows 100% safety. Because H. sabdariffa extract acts as diuretic, the night administration is contraindicated. More clinical studies are necessary to better evaluate the effectiveness and tolerability of the chronic administration of H. sabdariffa standardized extracts in hypertensive patients.