Study of the Possible Prophylactic Effect of Hibiscus Sabdariffa Extract on Experimental Hypertension in Rats

Background: Hypertension is a common global health problem with significant mortality and morbidity. Hibiscus sabdariffa (HS) is a plant known in many countries and is consumed as hot and cold drinks. Aim of the work: The present study was designed to assess the possible prophylactic effect of aqueous extract of HS on experimental hypertension in rats. Methods: Renovascular hypertension was induced in rats by left renal artery ligation with 4-0 sterile surgical silk. Sham-operated rats served as control. The animals were divided into: control group, sham group, hypertensive group, hypertensive group pretreated with HS (250mg/kg/day) given orally 30 days before ligation of left renal artery and 30 days after ligation. Results: Pretreatment of hypertensive group with HS extract prevented the development of hypertension and significantly reduced heart rate with significant decrease in serum levels of cholesterol, triglyceride and low density lipoprotein cholesterol while it increased significantly serum high density lipoprotein cholesterol and nitric oxide levels as compared to non-treated hypertensive group. Hibiscus sabdariffa also prevented the decrease in aortic reduced glutathione content and superoxide dismutase enzyme activity while it did not cause any significant change in serum levels of sodium or potassium as compared to non-treated hypertensive group. Conclusion: The present study showed that HS prevented the development of hypertension in an experimental model of hypertension which may be attributed to its negative chronotropic, nitric oxide preserving and antioxidant effects and is not related to serum electrolytes