Effect of hibiscus sabdariffa on experimentally induced renal hypertension in albino rats

the present work was designed to study the effect of Hibiscus Sabdariffa (HS) extract on some cardiovascular and renal parameters in rats subjected to experimentally-induced renal hypertension by left renal artery ligation. HS extract was prepared by both, infusion and decoction and was given orally by gavage in doses extracted from 125, 250, and 500 mg/kg HS for 5-6 weeks started 28 days after renal artery ligation. The selected parameters used are the mean arterial blood pressure (MABP), heart rate (HR), heart weight (HW), serum urea and serum creatinine. The present work demonstrated that HS extract prepared by infusion from 125 mg/kg HS, produced no significant change in the MABP or the HR. Increasing the dose to 250, and 500 mg/kg HS produced significant reduction of both the MABP and HR in renal hypertensive rats. However, discontinuation of the extract 2 days before measurement of the MABP and HR, produced loss of the blood pressure lowering effect, and persistence of the HR slowing effect. The HW was significantly increased in renal hypertensive rats, and surprisingly, there was more significant increase in HW by the all given regimens of HS extract. These results suggest that HS extracted by infusion is an antihypertensive; however, its effect is short-lived, and it isn’t protective against the development of hypertension caused by renal ischemia.