Hypotensive effect of aqueous saffron extract (Crocus sativus L.) and its constituents, safranal and crocin, in normotensive and hypertensive rats

In this study, the effects of saffron (Crocus sativus) stigma aqueous extract and two active constituents, crocin and safranal, were investigated on blood pressure of normotensive and desoxycorticosterone acetate-induced hypertensive rats. Three doses of crocin (50, 100 and 200 mg/kg), safranal (0.25, 0.5 and 1 mg/kg) and the aqueous extract (2.5, 5 and 10 mg/kg) were administered intravenously in different groups of normotensive and hypertensive animals and their effects on mean arterial blood pressure (MABP) and heart rate (HR) were evaluated. The aqueous extract of saffron stigma, safranal and crocin reduced the MABP in normotensive and hypertensive anaesthetized rats in a dose-dependent manner. For example, administrations of 10 mg/kg of aqueous extract, 1 mg/kg of safranal and 200 mg/kg of crocin caused 60 +/- 8.7, 50 +/- 5.2 and 51 +/- 3.8 mmHg reductions in MABP, respectively. It can be concluded that the aqueous extract of saffron stigma has hypotensive properties which appear to be attributable, in part, to the actions of two major constitutes of this plant, crocin and safranal. It seems that safranal is more important than crocin for lowering down blood pressure of rats.