The aqueous calyx extract of Hibiscus sabdariffa may lower blood pressure and pulse rate by sympathetic nervous system‐dependent mechanism(s) (1170.11)

Abstract

This study tested the hypothesis that the hypotensive effect of the aqueous calyx extract of Hibiscus sabdariffa (HS) may be sympathetically mediated. Following ethical approval and informed consent, the cold pressor test (CPT) was performed in 20 healthy subjects before and after the oral administration of 15mg/Kg HS. The blood pressure (BP) and pulse rate (PR) responses were measured digitally. Mean arterial pressure (MAP; taken as representative BP) was calculated. Experiments were performed in accordance with the Principles of the Declaration of Helsinki. Results are expressed as mean ±SEM. P<0.05 was considered significant. CPT done in the absence of HS resulted in a significant rise in BP and PR (111.1 ± 2.1mmHg and 100.8 ± 2.0/min) from the basal values (97.9±1.9mmHg and 87.8±2.1/min; P<0.0001 respectively). In the presence of HS however, these fell significantly (101.5±1.8mmHg and 92.4±2.0/min; P<0.0001 respectively). These results suggest that the hypotensive effect of HS may be due to an attenuation of the discharge of the sympathetic nervous system.Grant Funding Source: Personal Funds