A comprehensive in vivo study of the antihypertensive properties and toxicity of roselle (Hibiscus sabdariffa L.)

Abstract

Background: Roselle (Hibiscus sabdariffa L.) calyces have been used in traditional medicine as diuretics, mild laxatives, and antihypertensive agents but to date, a comprehensive study of its pharmacological activity and safety has not been conducted. Aims of the study: The current study aims to provide a comprehensive evaluation of the antihypertensive efficacy and toxicity profile of Roselle (H. sabdariffa L.) calyces extract. Utilizing animal models, the investigation assessed the dose-dependent pharmacological effects and safety of H. sabdariffa L. Results: The findings indicate that the extract exerts a significant antihypertensive effect at a dose of 250 mg/kg body weight (BW), lowering systolic and diastolic blood pressures by 10.12% and 11.63%, respectively. Ethyl acetate fractions administered at 112.5 mg/kg BW demonstrated greater efficacy than n-hexane and aqueous fractions, suggesting that the active compounds likely possess semi-polar properties. Acute toxicity testing yielded an LD50 of 8.75 g/kg BW for male rats and 7.5 g/kg BW for female rats, classifying the extract as slightly toxic. The sub-chronic toxicity study shows that H. sabdariffa L. demonstrates an effect on bodyweight and urea levels in male and female rats, while the change in the blood parameters, creatinine level, and the liver index was only observed in female rats. Conclusions: These data suggest that H. sabdariffa L. extract exhibits therapeutic promise but should be administered cautiously, preferably at doses lower than 250 mg/kg BW, due to potential toxicity.