The effect of total extract of Securigera securidaca L. seed on thoracic aorta function in high-fat fed rats

Hyperlipidemia is one of the most common diseases in the world which can lead to disorders such as atherosclerosis and therefore coronary heart disease. In Iranian traditional medicine Securigera securidaca L. seed is being used in the treatment of hyperlipidemia. The purpose of this study was to investigate the effect of total extract of S. securidaca seed on function of isolated thoracic aorta in high-fat fed rats. Wistar rats were fed with high fat diet for 36 days. Treatment groups were given orally different doses of the extract in the last two weeks of the procedure. After this period inferior vena cava vein blood was collected and then thoracic aorta was excised. A section of aorta was used for histological study. Vascular contraction in isolated vessels was assessed by using KCl and Phenylephrine. Evaluatation of endothelial function was done by investigating carbachol- and sodium nitrioprusside-induced relaxation of pre-contracted aorta. Contraction responses of aorta to phenylephrine and Kcl were significantly lower in hypercholesterolemic rats compared with control group (P<0.001). In hypercholestrolemic group carbachol-induced endothelial-dependant vasodilatation was also decreased significantly (p<0.001). The extract (100mg/kg) improved endothelial-dependant vasodilatation in hyperlipidemic animals (P<0.05). Sodium nitrioprusside-induced relaxation did not yield significant difference between groups. In histological study there was a little lipid formation around aorta in hypercholesterolemic groups but no atherosclerotic lesion was observed. The results of this study indicate that the extract of S. securidaca’s seeds in addition to having a considerable anti-hyperlipidemic effects, is able to improve vascular endothelium dependent function in high fat fed rats.