Cardiovascular Effect of Capparis spinosa Aqueous Extract. Part III: Antihypertensive Effect in Spontaneously Hypertensive Rats

This study aims to evaluate the hypotensive activity of Capparis spinosa aqueous extract (CSAE) in spontaneously hypertensive (SH) rats. CSAE was lyophilised and administrated daily at a dose of 150 mg kg^-1 for 20 days. CSAE administration produced a significant reduction in systolic blood pressure after eight days of oral administration (p<0.01), a sustained reduction was observed at the end of the end treatment (p<0.01). Heart rate remained unchanged during 20 days of CSAE oral administration. In addition, CSAE administration produced a significant increase in urinary output (p<0.01) and glomerular filtration rate (GFR) (p<0.01) at the eighth day of treatment. Urinary electrolytes excretion was also modified during 20 days of CSAE administration, a significant increase in urinary sodium and potassium excretion was observed from the fourth day (p<0.01) to twentieth day (p<0.001). However, urinary chloride excretion was increased from the eighth day (p<0.01) to the end of treatment (p<0.001). The observed hypotensive effect seems to be independent of renin angiotensin system since the CSAE did not modify the plasma angiotensin converting enzyme and renin activities (p>0.05) after 20 days of oral administration. We conclude that CSAE possess antihypertensive activity in SH rats and the underlying mechanism seems to be mediated via at least an increase in urinary and electrolytes output.