Comparison of the acute effects of Tulbaghia violacea William Henry Harvey (Alliaceae) on blood pressure and heart rate of ageing male normotensive Wistar kyoto rats and adult male spontaneously hypertensive rats

Abstract

Purpose: To assess the effect of the crude methanol leaf extracts of Tulbaghia violacea William Henry Harvey (Alliaceae) on blood pressure (BP) and heart rate in ageing normotensive Wistar Kyoto rats (WKY), and compare the results obtained with those for adult spontaneously hypertensive rats (SHR).

Methods: T. violacea (5 – 150 mg/kg) and/or vehicle (dimethylsulfoxide and normal saline) were respectively and randomly administered intravenously to groups of ageing (15 months) WKY and adult (< 5 months) SHR, weighing 380 - 470 and 280 - 320 g, respectively. BP and heart rate (HR) were measured via a pressure transducer connecting the femoral artery and Powerlab equipment.

Results: T. violacea significantly and dose-dependently reduced systolic BP, diastolic BP, mean arterial pressure (MAP) and HR in both strains of rats. No statistically significant differences were however observed when the changes in BP and HR in the two rats strains were compared.

Conclusion: T. violacea was effective in reducing BP and HR in both age-induced and spontaneously hypertensive rats.

Keywords: Age, Wistar Kyoto rats, blood pressure, heart rate, Tulbaghia violacea