Effect of Olea europea L. leaf extract on haemodynamic status and lipid peroxidation in spontaneously hypertensive rats

Abstract

Hypertension is one of the main causes of cardiovascular disorders and since ancient times olive tree leaves have been used in its therapy. However the mechanisms of their atihypertensive effect have not been sufficiently explained yet. The main objective of our study was to investigate acute effect of olive tree leaves extract on haemodynamics and lipid peroxidation in rats with congenital hypertension under normal and blocked synthesis of nitric oxide. For the purpose of our research, there were used olive tree leaf extract EFLA? 943 as well as inhibitor of nitric oxide synthase enzyme L-NAME. Nitric oxide synthesis inhibition led to statistically significant increase of mean arterial pressure, reducing heart rate and cardiac output, increase of total vascular resistance and lipid peroxidation in plasma. Treatment by olive leaf extract led to decrease of mean arterial pressure, reducing the frequency and cardiac output, without change in lipid peroxidation. Olive leaf extract under blockade of nitric oxide led to decrease of mean arterial pressure, total peripheral resistance remained high, cardiac output low, and lipid peroxidation significantly increased. General conclusion is that olive leaf extract has a strong antihypertensive effect, decreases cardiac pre and after load and does not influence lipid peroxidation. Under blockade of nitric oxide synthesis, this extract keeps antihypertensive properties, but due to strong endothelial dysfunction, it is unable to regulate increased total peripheral resistance and marked lipid peroxidation.